Laser beam as a drill. Equipment for laser processing in the production of printed circuit boards

Drilling holes in watch stones - this is where the laser began its work. We are talking about ruby stones, which are used in watches as sliding bearings. When making such bearings, it is necessary to drill holes with a diameter of only 0.1-0.05 mm in ruby - a very hard and at the same time fragile material. For many years, this jewelry operation was performed in the usual mechanical way using drills made from thin piano wire with a diameter of 40-50 microns. Such a drill made up to 30 thousand revolutions per minute and simultaneously made about a hundred reciprocating movements. Drilling one stone required up to 10-15 minutes. How to remove ear plugs - wax plug nmedik.org/sernaya-probka.html.

Since 1964, low-productivity mechanical drilling of watch stones has been widely replaced by laser drilling. Of course, the term “laser drilling” should not be taken literally; the laser beam does not drill a hole - it pierces it, causing intense evaporation of the material. Nowadays, laser drilling of watch stones is common practice. For this purpose, in particular, neodymium glass lasers are used. A hole in the stone (with a workpiece thickness of 0.5-1 mm) is made by a series of several laser pulses with an energy of 0.5-1 J. The productivity of the laser installation in automatic mode is a stone per second. This is a thousand times higher than the productivity of mechanical drilling!

Soon after its birth, the laser received the next task, which it coped with just as successfully - drilling (punching) holes in diamond dies. To obtain very thin wire from copper, bronze, tungsten, the technology of pulling metal through a hole of the appropriate diameter is used. Such holes are drilled in materials that have particularly high hardness, because during the process of drawing the wire, the diameter of the hole must remain unchanged. Diamond is known to be the hardest. Therefore, it is best to pull a thin wire through a hole in the diamond - through the so-called diamond dies. Only with the help of diamond dies is it possible to obtain ultra-thin wire with a diameter of only 10 microns. But how do you drill a thin hole in a super-hard material like diamond? It is very difficult to do this mechanically - it takes up to ten hours to mechanically drill one hole in a diamond die. But, as it turned out, it is not at all difficult to punch through this hole with a series of several powerful laser pulses.

Today, laser drilling is widely used not only for particularly hard materials, but also for materials that are characterized by increased fragility. The laser drill turned out to be not only a powerful, but also a very delicate “tool.” Example: the use of a laser when drilling holes in chip substrates made of alumina ceramics. Ceramics are unusually fragile. For this reason, mechanical drilling of holes in the chip substrate was carried out, as a rule, on “raw” material. The ceramics were fired after drilling. In this case, some deformation of the product occurred, and the relative position of the drilled holes was distorted. The problem was solved with the advent of laser drills. Using them, you can work with ceramic substrates that have already been fired. Using lasers, very thin holes are punched in ceramics - only 10 microns in diameter. Such holes cannot be obtained by mechanical drilling.

4. Laser cutting and welding.

A laser beam can cut absolutely anything: fabric, paper, wood, plywood, rubber; plastic, ceramics, asbestos sheets, glass, metal sheets. At the same time, it is possible to obtain neat cuts along complex profiles. When cutting flammable materials, the cut site is blown with a stream of inert gas; the result is a smooth, unburnt cut edge. Continuously emitting lasers are usually used for cutting. The required radiation power depends on the material and thickness of the workpiece. For example, a 200 W CO2 laser was used to cut boards 5 cm thick. The incision width was only 0.7 mm; Naturally, there was no sawdust.

To cut metals, lasers with a power of several kilowatts are needed. The required power can be reduced by using the gas-laser cutting method - when, simultaneously with the laser beam, a strong stream of oxygen is directed onto the surface to be cut. When a metal burns in an oxygen stream (due to the metal oxidation reactions occurring in this stream), significant energy is released; As a result, laser radiation with a power of only 100-500 W can be used. In addition, a stream of oxygen blows away the melt and combustion products of the metal from the cutting zone.

The first example of this type of cutting is laser cutting of fabrics in a weaving factory. The installation includes a 100 W CO2 laser, a system for focusing and moving the laser beam, a computer, and a device for tensioning and moving tissue. During the cutting process, the beam moves along the surface of the fabric at a speed of 1 m/s. The diameter of the focused light spot is 0.2 mm. The movements of the beam and the tissue itself are controlled by a computer. The installation allows, for example, cutting out material for 50 suits within an hour. The cutting is performed not only quickly, but also very accurately; in this case, the edges of the cut are smooth and hardened. The second example is the automated cutting of aluminum, steel, and titanium sheets in the aviation industry. Thus, a 3 kW CO2 laser cuts a 5 mm thick titanium sheet at a speed of 5 cm/s. Using an oxygen jet, approximately the same result is obtained with a radiation power of 100-300 W.

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Ministry of Education and Science of the Russian Federation. Federal State Budgetary Educational Institution of Higher Education. Vladimir State University named after A.G. and N.G. Stoletov.

Department of Physics and Mathematics.

Abstract on the topic

“Laser hole drilling”

Completed:

Student of LT group - 115

Gordeeva Ekaterina

Vladimir, 2016

Introduction

Laser beam as a drill

Laser drilling of holes in metals

Drilling in non-metallic materials

Laser drilling of holes in hard surfaces

Laser drilling features with increased fragility

Conclusion

Bibliography

Introduction

Currently, the laser successfully performs a number of technological operations and, above all, such as cutting, welding, drilling holes, heat treatment of the surface, scribing, marking, engraving, etc., and in some cases provides advantages over other types processing. Thus, drilling holes in the material can be completed faster, and scribing of dissimilar materials is more advanced. In addition, some types of operations that were previously impossible to perform due to difficult accessibility are being performed with great success. For example, welding of materials and drilling of holes can be done through glass in a vacuum or atmosphere of various gases.

The word “laser” is made up of the initial letters in the English phrase Light Amplification by Stimulated Emission of Radiation, which translated into Russian means: amplification of light through stimulated emission. Classically, it so happened that when describing laser technologies for processing materials, the main attention is paid only to the lasers themselves, the principles of their operation and technical parameters. However, in order to implement any process of laser dimensional processing of materials, in addition to the laser, a beam focusing system, a device for controlling the movement of the beam along the surface of the workpiece or a device for moving the product relative to the beam, a gas injection system, optical guidance and positioning systems, and process control software are also required laser cutting, engraving, etc. In most cases, the choice of parameters of devices and systems that directly service the laser is no less important than the parameters of the laser itself. For example, for marking bearings with a diameter of less than 10 mm, or precision laser spot welding, the time spent on product positioning and focusing exceeds the time of engraving or welding by one to two orders of magnitude (the time required to mark a bearing is approximately 0.5 s). Therefore, without the use of automatic positioning and focusing systems, the use of laser complexes in many cases becomes economically impractical. The analogy of laser systems with cars shows that the laser performs the functions of an engine. No matter how good the engine is, the car will not move without wheels and everything else.

Another important factor in choosing laser technology systems is their ease of maintenance. As practice has shown, operators have low qualifications for servicing such equipment. One of the reasons for this is that laser systems are installed in most cases to replace outdated technological processes (impact and chemical marking of products, mechanical engraving, manual welding, manual marking, etc.). Managers of enterprises who modernize their production, as a rule, for ethical reasons, replacing old equipment with new ones, leave behind the old (literally and figuratively) service personnel. Therefore, to introduce laser technological systems into production under the given initial conditions of its development (in the post-Soviet republics), it is necessary to provide for the highest possible level of automation and ease of training. We should not ignore the fact that the salary of unskilled personnel is lower than that of a trained specialist. Therefore, it is more economically profitable to buy complex equipment with the possibility of ease of maintenance than to invite highly qualified personnel.

Thus, the task of using laser technologies in modern production should be considered not only from the point of view of the technical parameters of the laser itself, but also taking into account the characteristics of equipment and software that make it possible to use the specific properties of the laser to solve a particular technological problem.

Any laser system designed for dimensional processing of materials is characterized by the following parameters:

Processing speed (cutting, engraving, etc.);

Resolution;

Processing accuracy;

The size of the working field;

Range of processing materials (ferrous metals, non-ferrous metals, wood, plastic, etc.);

Range of sizes and weights of products intended for processing;

Product configuration (for example, engraving on flat, cylindrical, wavy surfaces);

The required time to change the tasks performed (change of engraving pattern, configuration - cutting line, change of processing material, etc.);

Time for installation and positioning of the product;

Parameters of environmental conditions (temperature range, humidity, dust) in which the system can be operated;

Requirements for the qualifications of service personnel.

Based on these parameters, the type of laser and beam scanning device are selected, the design of the product fastener is developed, the level of automation of the system as a whole is developed, the issue of the need to write specialized programs for preparing drawing files, cutting lines, etc. is decided.

The main technical characteristics that determine the nature of the treatment are the energy parameters of the laser - energy, power, energy density, pulse duration, spatial and temporal structure of radiation, spatial distribution of radiation power density in the focusing spot, focusing conditions, physical properties of the material.

Laser beam as a drill

Drilling holes in watch stones - this is where the laser began its work. We are talking about ruby stones, which are used in watches as sliding bearings. In the manufacture of such bearings, it is necessary to drill holes with a diameter of only 1-0.05 mm in ruby - a very hard and at the same time fragile material. For many years, this jewelry operation was performed in the usual mechanical way using drills made from thin piano wire with a diameter of 40-50 microns. Such a drill made up to 30 thousand revolutions per minute and simultaneously performed about a hundred reciprocating movements. Drilling one stone required up to 10-15 minutes.

Since 1964, low-productivity mechanical drilling of watch stones has been widely replaced by laser drilling. Of course, the term “laser drilling” should not be taken literally; The laser beam does not drill a hole - it pierces it, causing intense evaporation of the material. Nowadays, laser drilling of watch stones is common practice. For this purpose, in particular, neodymium glass lasers are used. A hole in the stone (with a workpiece thickness of 0.5-1 mm) is made by a series of several laser pulses with an energy of 0.5-1 J. The productivity of the laser installation in automatic mode is a stone per second. This is a thousand times higher than the productivity of mechanical drilling!

Soon after its birth, the laser received the next task, which it coped with just as successfully: drilling (punching) holes in diamond dies. Perhaps not everyone knows that to produce very thin wire from copper, bronze, tungsten, the technology of pulling metal through a hole of the appropriate diameter is used. Such holes are drilled in materials that have particularly high hardness, because during the process of drawing the wire, the diameter of the hole must remain unchanged. Diamond is known to be the hardest. Therefore, it is best to pull a thin wire through a hole in the diamond - through the so-called diamond dies. Only with the help of diamond dies is it possible to obtain ultra-thin wire with a diameter of only 10 microns. But how do you drill a thin hole in a super-hard material like diamond? It is very difficult to do this mechanically; it takes up to ten hours to mechanically drill one hole in a diamond die.

This is what a hole in a diamond die looks like in cross-section. Laser pulses punch out a rough channel in a diamond workpiece. Then, by treating the canal with ultrasound, grinding and polishing, they give it the required profile. The wire obtained by pulling through a die has a diameter d

These neat 0.3mm diameter holes are punched into a 0.7mm thick alumina ceramic slab using a CO2 laser

Using lasers, very thin holes are punched in ceramics, with a diameter of only 10 microns. Note that such holes cannot be obtained by mechanical drilling.

There was no doubt in anyone’s mind that drilling was the calling of a laser. Here the laser actually had no worthy competitors, especially when it came to drilling particularly thin and particularly deep holes, when holes need to be drilled in very fragile or very hard materials. Relatively little time passed and it became clear that the laser beam can be successfully used not only for drilling, but also for many other material processing operations. So today we can talk about the emergence and development of a new technology - laser.

Laser drilling of holes in metals

There are benefits to using a laser as a drilling tool.

There is no mechanical contact between the drilling tool and the material, as well as breakage and wear of drills.

The accuracy of hole placement increases, since the optics used to focus the laser beam are also used to aim it at the required point. The holes can be oriented in any direction.

A greater ratio of depth to drilling diameter is achieved than is the case with other drilling methods.

When drilling, as well as when cutting, the properties of the material being processed significantly influence the laser parameters required to perform the operation. Drilling is carried out with pulsed lasers operating both in the free-running mode with a pulse duration of about 1 μs, and in the Q-switched mode with a duration of several tens of nanoseconds. In both cases, there is a thermal effect on the material, its melting and evaporation. The hole grows in depth mainly due to evaporation, and in diameter due to the melting of the walls and the flow of liquid under the created excess vapor pressure.

Typically, deep holes of the desired diameter are obtained by using repeated low-energy laser pulses. In this case, holes are formed with a smaller taper and of better quality than holes obtained with a higher single pulse energy. The exception is for materials containing elements capable of creating high vapor pressure. Thus, brass is very difficult to weld with pulsed laser radiation due to the high zinc content, however, when drilling, brass has some advantages, since zinc atoms significantly improve the evaporation mechanism.

Since the multi-pulse mode makes it possible to obtain holes of better quality with the required geometry and with a slight deviation from the specified dimensions, in practice this mode has become widespread when drilling holes in thin metals and non-metallic materials. However, when drilling holes in thick materials, single high-energy pulses are preferred. Diaphragming the laser beam makes it possible to obtain shaped holes, but this method is more often used when processing thin films and non-metallic materials. In the case where laser drilling is carried out in thin sheets with a thickness of less than 0.5 mm, there is some unification of the process, consisting in the fact that holes with a diameter of 0.001 to 0.2 mm can be made in all metals at relatively low powers.

Drilling holes in metals can be used in a number of cases. Thus, with the help of pulsed lasers, dynamic balancing of parts rotating at high speed can be performed. The imbalance is selected by locally melting a certain volume of material. The laser can also be used to fit electronic elements either by local evaporation of the material or by general heating. High power density, small spot size and short pulse duration make the laser an ideal tool for these purposes.

Lasers used for drilling holes in metal must provide a power density of the order of 107 - 108 W/cm2 in the focused beam. Drilling holes with metal drills with a diameter of less than 0.25 mm is a difficult practical task, while laser drilling makes it possible to obtain holes with a diameter commensurate with the radiation wavelength with a fairly high placement accuracy. Specialists from General Electric (USA) have calculated that laser drilling of holes is highly economically competitive compared to electron beam processing. Currently, solid-state lasers are mainly used for drilling holes. They provide pulse repetition rates of up to 1000 Hz and power in continuous mode from 1 to 103 W, in pulsed mode up to hundreds of kilowatts, and in Q-switched mode up to several megawatts. Some results of processing with such lasers are given in the table

	Thickness, mm	Hole diameter, mm	Duration drilling	Laser energy,
		input	day off
Stainless steel				10 pulses
Nickel steel
Tungsten

Molybdenum

Drilling in non-metallic materials

Hole drilling is one of the first areas of laser technology. First, by burning holes in various materials, experimenters used them to estimate the radiation energy of laser pulses. Currently, the process of laser drilling is becoming an independent direction of laser technology. Materials that can be drilled using a laser beam include non-metals such as diamonds, ruby stones, ferrites, ceramics, etc., in which drilling holes using conventional methods is difficult or ineffective. Using a laser beam, you can drill holes of different diameters. The following two methods are used for this operation. In the first method, the laser beam moves along a given contour, and the shape of the hole is determined by the trajectory of its relative movement. Here, a cutting process takes place, in which the heat source moves at a certain speed in a given direction: in this case, as a rule, continuous-wave lasers are used, as well as pulsed ones, operating at an increased pulse repetition rate.

In the second method, called projection, the processed hole follows the shape of a laser beam, which can be given any cross-section using an optical system. The projection method of drilling holes has some advantages over the first one. So, if you place a diaphragm (mask) in the path of the beam, then in this way you can cut off its peripheral part and obtain a relatively uniform intensity distribution over the cross section of the beam. Thanks to this, the boundary of the irradiated zone becomes sharper, the taper of the hole decreases, and the quality improves.

There are a number of techniques that allow you to additionally select part of the molten material from the hole being processed. One of them is the creation of excess pressure with compressed air or other gases, which are supplied to the drilling zone using a nozzle coaxial with laser radiation. This method was used to drill holes with a diameter of 0.05-0.5 mm in ceramic plates up to 2.5 mm thick using a CO2 laser operating in continuous mode.

Drilling holes in hard ceramics is a difficult task: the conventional method requires a diamond tool, while other existing methods have difficulties associated with the size of the hole in diameter, equal to tenths of a millimeter. These difficulties are especially noticeable when the thickness of the plate being processed is greater than the diameter of the hole. The ratio of hole depth (material thickness) to its diameter is a measure of the quality of producing thin holes; it is 2:1 for conventional drilling and about 4:1 for the ultrasonic method used when drilling ceramics and other refractory materials.

The laser method of drilling this class of materials allows one to obtain a better ratio with a very high accuracy of hole placement and relatively less time. Thus, when laser drilling high-density polycrystalline alumina ceramics, a ruby laser with a pulse energy of 1.4 J, a focused lens with a focal length of 25 mm on the surface of the disk, and providing a power density of about 4-106 W/cm2 was used. On average, 40 pulses at a repetition rate of 1 Hz were needed to drill a 3.2 mm thick ceramic disk. The laser pulse duration was 0.5 ms. The resulting holes were tapered with a diameter of about 0.5 mm at the inlet and 0.1 mm at the outlet. It can be seen that the ratio of the depth to the average diameter of the hole is about 11:1, which is significantly greater than the similar ratio for other methods of drilling holes. For simple materials, this ratio during laser drilling can be 50:1.

To remove combustion products and the liquid phase from the drilling zone, blowing with air or other gases is used. More efficient blowing of products occurs when a combination of blowing from the front side and vacuum from the back side of the sample. A similar scheme was used to drill holes in ceramics up to 5 mm thick. However, effective removal of the liquid phase in this case occurs only after the formation of a through hole.

In table Figure 7 shows the parameters of holes in some non-metallic materials and their processing modes.

Material	Hole parameters	Processing mode
	Diameter, mm	Depth, mm	Depth to diameter ratio	Energy, J	Pulse duration	Flux density, W/cm2	Number of pulses per hole



Ceramics

Laser drilling of holes in hard surfaces

Laser drilling of holes is characterized by physical processes such as heating, evaporation and melting of the material. It is assumed that the hole increases in depth as a result of evaporation, and in diameter as a result of melting of the walls and displacement of liquid by excess vapor pressure.

To produce precision holes with a tolerance of about 2 µm, lasers with very short pulses in the ns and ps range are used. Allowing you to control the diameter of the hole at a given level, i.e. not leading to heating and melting of the walls, which are responsible for the growth of the hole diameter, but leading to the evaporation of material from the solid phase. Also, the use of lasers with ns and ps pulse ranges can significantly reduce the presence of solidified liquid phasic on the side surfaces of the hole.

At the moment, there are several methods for implementing laser drilling of holes: single pulse drilling uses a single pulse as a result of which a hole is drilled. The advantages of this method are speed. Disadvantages: high pulse energy, low thickness and canonical shape of the hole due to a decrease in the transfer of thermal energy with increasing hole depth.

In impact drilling, a hole is created under the influence of several laser pulses of insignificant duration and energy.

Advantages: the ability to create deeper holes (about 100 mm), obtaining holes of small diameter. The disadvantage of this method is the longer drilling process.

Ring drilling occurs under the influence of several laser pulses. First, the laser hammer drills the initial hole. He then enlarges the starting hole by moving in an increasing circular path on the workpiece several times. Most of the molten material is forced out of the hole in a downward direction. Spiral drilling, unlike circular drilling, does not involve making an initial hole. From the very first pulses, the laser moves along a circular path across the material. With this movement, a large amount of material comes up. Moving like a spiral staircase, the laser deepens the hole. After the laser passes through the material, several more circles can be performed. They are designed to widen the underside of the hole and smooth out the edges. Twist drilling produces very large and deep holes of high quality. Advantages: obtaining large and deep holes of high quality.

Advantages of laser drilling: the ability to produce small holes (less than 100 microns), the need to drill holes at an angle, drill holes in very hard materials, the ability to produce non-round holes, high process productivity, low thermal effect on the material (with a decrease in pulse duration, heating decreases material), non-contact method allowing drilling of fragile materials (diamond, porcelain, ferrite, sapphire crystal, glass), high process automation, long service life and process stability.

This work is devoted to the search for optimal modes of laser drilling of holes on various hard surfaces.

An infrared pulsed Nd:YAG laser with a wavelength of 1064 nm was used to carry out the experiments. With a maximum laser power of 110 W, a pulse repetition rate of 10 kHz, and a pulse duration of 84 ns, the holes in this work were produced by impact drilling. During laser drilling, the laser radiation power varied from 3.7 W to 61.4 W, and the diameter of the laser spot on the sample surface varied from 2 mm to 4 mm.

Laser drilling of holes was carried out on the following hard surfaces: plastic (yellow), carbon fiber, aluminum, thickness 1, 22, 3 mm, respectively. laser drilling hole metal

The quality of laser surface drilling is significantly influenced by the following parameters: average laser radiation power, laser spot diameter on the surface of the sample, physical properties of the material (coefficient of absorption of laser radiation by the surface, melting temperature), laser radiation wavelength, pulse duration and laser drilling method (single pulse, impact drilling, etc.).

Table 1 shows laser drilling modes on various hard surfaces.

Modes for laser drilling holes on various surfaces

Laser drilling of highly fragile materials

Laser drilling are widely used to produce holes not only in hard and superhard materials, but also in materials characterized by increased fragility.

For laser hole drilling Currently they use the Kvant-11 installation, created on the basis of a pulsed YAG-Nd laser. Laser welding is also based on the welding action of focused radiation from a pulsed laser. Moreover, both seam and spot welding are used

The main processes during laser When drilling non-metallic materials, as well as when cutting, heating, melting and evaporation from the laser irradiation zone occur. In order to ensure these processes, it is necessary to have a power density of 106 - 107 W/cm2 created by the optical system in the focal spot. In this case, the hole grows in depth due to the evaporation of materials; there is also melting of the walls and ejection of the liquid fraction due to the excess vapor pressure created. Domestic industry is currently widely using laser drilling of holes in diamonds, providing high precision and control over the formation of holes during the drilling process.

Drilling holes with metal drills with a diameter of less than 0 25 mm is a difficult practical task, while laser drilling allows you to obtain holes with a diameter commensurate with the radiation wavelength, with a fairly high placement accuracy.

It is known from experiments that the technical characteristics and features of precision laser cutting of thin metal plates are determined in general by the same conditions and factors as the technical characteristics of the processes multi-pulse laser drilling . The average width of a through cut in thin metal plates is usually 30 - 50 microns along the entire length of the sample, their walls are almost parallel, and the surface does not contain large defects or foreign inclusions. One of the features of pulsed radiation cutting is the possibility of the so-called canalization effect. This effect is expressed in the entrainment of a high-quality (diffraction) beam into the channel formed by previous pulses through re-reflection from its wall. The formation of a new channel begins after the entire diffraction beam is displaced beyond the contours of the previous one. This process determines the ultimate cut wall roughness and can stabilize cutting accuracy by compensating for pattern instability during multi-pass machining. In this case, the roughness of the cut edges usually did not exceed 4 - 5 microns, which can be considered quite satisfactory.

Lasers also perform such an operation as rough finishing of spent dies to the next larger diameter according to the standard. If with mechanical drilling this operation took about 20 hours, then with In laser drilling, it requires only a few dozen pulses. The total time interval is about 15 minutes for roughing one die.

Drilling holes is perhaps one of the first areas of laser technology. Currently the process Laser drilling is becoming an independent area of laser technology and occupies a significant share in domestic and foreign industry. Materials that can be drilled using a laser beam include non-metals such as diamonds, ruby stones, ferrites, ceramics, etc., in which drilling holes using conventional methods is difficult or ineffective.

However, when drilling holes in thick materials, single high-energy pulses are preferred. Diaphragming the laser beam makes it possible to obtain shaped holes, but this method is more often used when processing thin films and non-metallic materials. In that case, To when l laser drilling is produced in thin sheets with a thickness of less than 0.5 mm, there is some unification of the process, consisting in the fact that holes with a diameter of 0.001 to 0.2 mm can be produced in all metals at relatively low powers. For large thicknesses, according to Fig. 83, nonlinearity appears due to the screening effect.

Even earlier, it was noted that the use of flexible PCBs increases their reliability, reduces device assembly time by hundreds of hours, and provides a gain in volume and weight by 2–4 times compared to the use of rigid PCBs in MEA. Now the previously existing obstacle in the development of flexible PCBs, namely the well-known conservatism of designers accustomed to working with conventional PCBs, can be considered a passed stage. At the same time, the task of reducing mechanical stresses between the PCB and the LSIs installed on it in the crystal holder is simplified, and it also becomes possible to obtain laser drilling of subminiature holes with a diameter of 125 microns (instead of 800 microns in conventional PCBs) for interlayer switching by continuously filling them with copper. Finally, flexible polyimide PCB is transparent, allowing you to visually inspect all solder joints in each layer under carefully selected lighting conditions.

Conclusion

In conclusion, I would like to dwell on some general issues of introducing laser technologies into modern production.

The first stage of creating a laser technological installation is the development of technical specifications. In many cases, customers try to play it safe and include characteristics that far exceed the actual production needs. As a result, the cost of equipment increases by 30-50%. Paradoxically, the reason for this is, as a rule, the relative high cost of laser systems. Many business leaders argue as follows:

“...if I buy new expensive equipment, then its characteristics should exceed the norms that are necessary at the moment, “maybe” someday I will need it...”. As a result, the potential capabilities of the equipment are never used, and its payback time increases.

An example of this approach is the transition from mechanical marking of parts to laser marking. The main criteria for marking are the contrast of the inscription and resistance to abrasion. Contrast is determined by the ratio of the width and depth of the engraving line. The minimum line width for mechanical engraving is approximately 0.3 mm. To obtain a contrasting inscription, its depth should be about 0.5 mm. Therefore, in many cases, when drawing up technical specifications for a laser installation, these parameters are taken into account. But the line width for laser engraving is 0.01-0.03 mm, respectively, the depth of the inscription can be made 0.05 mm, i.e. an order of magnitude less than with mechanical. Therefore, the relationship between laser power and marking time can be optimized relative to the cost of the system. As a result, the price of the laser system is reduced, and as a result, its payback time.

The introduction of laser technologies in many cases makes it possible to solve “old” problems using fundamentally new methods. A classic example of this is the application of protective inscriptions, stamps, etc. on products to ensure protection against counterfeiting. The capabilities of laser technology make it possible to identify a security inscription by a single line in the inscription. The ability to use cryptographic methods makes it possible to implement “dynamic” protection against counterfeiting, i.e. while maintaining the overall pattern, after a certain time some elements change, recognizable only by experts or special equipment. Inaccessible to mechanical counterfeiting methods is the ability to create a small edge (3-10 microns) with a laser from metal emissions at the edges of the engraving line. The integrated use of such techniques minimizes the likelihood of counterfeiting and makes it economically unprofitable.

The introduction of laser technologies at this stage of technological development (the transition from “wild” capitalism to normal production) is just one of the options for the beginning of the formation of what is called high-tech production. Those small enterprises that use several laser systems of this kind have confirmed the law of the dialectic of the transition from quantity to quality. New equipment requires fundamentally new methods of servicing it, which usually requires increased attention from staff and maintaining “cleanliness” in the room where it is located. Those. There is a transition to a qualitatively new level of production culture. In this case, usually, the number of employees decreases, and enterprise managers begin to solve issues of organizing the work not of the “work collective”, but of optimizing the work of the enterprise, in which employees are only an integral part of the technological process. Regardless of whether laser technology will be used in this production in the future or not, the experience gained and the formed culture will not disappear anywhere. This is what outside observers usually call a technological or scientific-technical revolution, although in fact it is a normal evolutionary process. The development history of many large technology firms shows that at some point in time during the initial stages of development, they all went through a similar transition phase. It may turn out that we are currently at a stage of technological development where relatively small investments in new technologies now will lead to large returns in the future. In synergetics, the science of self-organizing systems, such a situation is subject to the “butterfly” law (R. Bradbury “And the thunder struck...”), which describes the process when small changes in the past or present lead to global consequences in the future.

List of used literature

1. Rykalin N.N. Laser processing of materials. M., Mechanical Engineering, 1975, 296 p.

2. Grigoryants A.G., Shiganov I.N., Misyurov A.I. Technological processes of laser processing: Textbook. manual for universities / Ed. A.G. Grigoryants. - M.: Publishing house of MSTU im. N.E. Bauman, 2006. -664 p.

3. Krylov K.I., Prokopenko V.T., Mitrofanov A.S. Application of lasers in mechanical engineering and instrument making. - L., Mechanical Engineering. Leningr. department, 1978, 336 p.

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Laser drilling of holes in metals

There are benefits to using a laser as a drilling tool.

There is no mechanical contact between the drilling tool and the material, as well as breakage and wear of drills.

The accuracy of hole placement increases, since the optics used to focus the laser beam are also used to aim it at the required point. The holes can be oriented in any direction.

A greater ratio of depth to drilling diameter is achieved than is the case with other drilling methods.

When drilling, as well as when cutting, the properties of the material being processed significantly influence the laser parameters required to perform the operation. Drilling is carried out with pulsed lasers operating both in the free-running mode with a pulse duration of about 1 μs, and in the Q-switched mode with a duration of several tens of nanoseconds. In both cases, there is a thermal effect on the material, its melting and evaporation. The hole grows in depth mainly due to evaporation, and in diameter - due to the melting of the walls and the flow of liquid under the created excess vapor pressure.

Lasers used for drilling holes in metal must provide a power density of the order of 10 7 -10 8 W/cm 2 in the focused beam. Drilling holes with metal drills with a diameter of less than 0.25 mm is a difficult practical task, while laser drilling makes it possible to obtain holes with a diameter commensurate with the radiation wavelength with a fairly high placement accuracy. Specialists from General Electric (USA) have calculated that laser drilling of holes is highly economically competitive compared to electron beam processing (Table 1). Currently, solid-state lasers are mainly used for drilling holes. They provide pulse repetition rates up to 1000 Hz and power in continuous mode from 1 to 10 3 W, in pulsed mode - up to hundreds of kilowatts, and in Q-switched mode - up to several megawatts. Some results of processing with such lasers are given in Table. 2.

Laser metal welding

Laser welding had two stages in its development. Initially, spot welding was developed. This was explained by the availability at that time of powerful pulsed solid-state lasers. Currently, with the availability of powerful gas CO 2 and solid-state Nd:YAG lasers that provide continuous and pulsed-continuous radiation, seam welding with a penetration depth of up to several millimeters is possible. Laser welding has a number of advantages compared to other types of welding. In the presence of a high light flux density and an optical system, local penetration is possible at a given point with great accuracy. This circumstance makes it possible to weld materials in hard-to-reach areas, in a vacuum or gas-filled chamber if it has windows transparent to laser radiation. Welding, for example, microelectronic elements in a chamber with an inert gas atmosphere is of particular practical interest, since in this case there are no oxidation reactions.

Welding parts occurs at significantly lower power densities than cutting. This is explained by the fact that welding requires only heating and melting of the material, i.e., power densities are required that are still insufficient for intense evaporation (10 5 -10 6 W/cm 2), with a pulse duration of about 10 -3 -10 -4 With. Since laser radiation focused on the material being processed is a surface heat source, heat is transferred into the depth of the parts being welded due to thermal conductivity, and the penetration zone changes over time with a properly selected welding mode. In the case of insufficient power densities, there is a lack of penetration of the welded zone, and in the presence of high power densities, metal evaporation and the formation of holes are observed.

Welding can be done on a gas laser cutting machine at lower powers and using a weak injection of inert gas into the welding zone. With a CO 2 laser power of about 200 W, it is possible to weld steel up to 0.8 mm thick at a speed of 0.12 m/min; The quality of the seam is no worse than with electron beam processing. Electron beam welding has slightly higher welding speeds, but is carried out in a vacuum chamber, which creates great inconvenience and requires significant overall time costs.

In table Figure 3 shows data on butt welding with a CO 2 laser, power 250 W, of various materials.

At other CO 2 laser radiation powers, the seam welding data given in Table 1 was obtained. 4. When welding overlapping, end and corner, velocities were obtained close to those indicated in the table, with complete penetration of the material being welded in the area affected by the beam.

Laser welding systems are capable of welding dissimilar metals, producing minimal thermal effects due to the small laser spot size, and welding thin wires with a diameter of less than 20 microns in a wire-to-wire or wire-to-sheet configuration.

Literature

1. Krylov K.I., Prokopenko V.T., Mitrofanov A.S. Application of lasers in mechanical engineering and instrument making. — L.: Mechanical engineering. Leningr. department, 1978. - 336 p.

2. Rykalin N.N. Laser processing of materials. - M., Mechanical Engineering, 1975. - 296 p.

The composition of concrete mixtures used in construction includes coarse materials such as crushed stone and gravel. In addition, concrete structures are reinforced. Therefore, when drilling, the tool must overcome metal and stone obstacles. The quality of a hole drilled in concrete directly depends on the correct choice of tool and drilling method.

Dry concrete drilling is the process of forming a hole without the use of water or any other coolant. Today it is difficult to imagine a more reliable, safe and accurate method than drilling concrete surfaces with diamond-coated tools. Such drilling is performed with special installations, which in turn require certain handling skills. Therefore, for help, it is better to turn to professionals who know well how to do this quickly and efficiently.

Diamond tools allow you to drill holes with a diameter of 15 to 1000 mm and a depth of up to 5 m

The list of tasks solved using drilling is very wide.

Basically, diamond drilling is used to create holes in ceilings and walls for:

heating pipes, gas supply, electricity supply;
fire safety systems;
ventilation systems and air conditioners;
various communications (Internet, telephone, etc.);
installation of fences and railings on staircase openings;
installation of chemical anchors;
installation of equipment for swimming pools.

Diamond drilling technology can also be used to cut openings in floors and walls. for ventilation ducts, doors, windows and other needs in cases where it is not possible to use special equipment for cutting concrete for this purpose.

The technology of this method is that holes with a diameter of 130-200 mm are drilled along the perimeter of the future opening. Then the edges of the opening are leveled using a hammer drill or a cement-sand mixture. Despite the fact that this method requires a lot of time, the result is practically no different from cutting. This technology is called line diamond drilling.

Drilling concrete without impact

Diamond drilling technology is based on a unique feature of diamond – its unsurpassed hardness. The cutting edge of the drilling tool is coated with a diamond-containing coating, the so-called “matrix”. During the drilling process, the diamond segments of the tool produce shockless local destruction in the cutting zone. Simultaneously with the destruction of concrete, abrasion of the matrix itself occurs, but since it is multi-layered, new diamond grains appear on its surface and the working edge remains sharp for a long time.

Diamond drilling has one very important advantage - the complete absence of harsh impacts on the concrete surface and unbearable noise. Such positive qualities make diamond technology indispensable when carrying out repair work in apartments of multi-storey buildings. Diamond drilling allows you to avoid the formation of cracks on wall surfaces, which sooner or later lead to a complete loss of their load-bearing capacity, a decrease in the level of heat and sound insulation, and a deterioration in strength characteristics.

Since during monolithic construction it is impossible to pre-lay all technological holes for various needs, drilling with a diamond tool becomes the only way to create openings when laying heating, water supply and other communications pipes. Using a jackhammer for such work is not only economically unprofitable, but also extremely unsafe, since dynamic loads on reinforcing belts can cause cracks in concrete surfaces.

Diamond tools are popular due to their ability to drill concrete with any degree of reinforcement

Diamond drilling can be done in two ways: using water, which reduces the heating of the tool, and also “dry”. Technologically, dry drilling is much simpler and therefore more convenient. It is performed using special crowns called “dry cutters”. The body of these crowns has through holes that provide heat dissipation and reduce the risk of deformation.

Unlike wet drilling tools, the diamond segments of which are attached to the work surface using solder, dry drilling bits are made exclusively using laser welding.

Why is laser welding of diamond segments so important in dry drilling? The answer is very simple: the temperature in the drilling zone without the use of coolant very quickly rises to 600 degrees.

This temperature is the melting point of ordinary solder, so the segment soldered with its help simply flies off and remains in the hole. To continue working, the segment must be removed from the hole, since it is impossible to drill it. A tool with segments welded by laser welding is able to withstand fairly high temperatures and does not become “greasy” during operation.

Husqvarna was one of the first to propose the idea of dry drilling holes in concrete surfaces. She developed a special adapter for this method with the ability to connect to a vacuum cleaner.

The vacuum cleaner removes dust generated during drilling and cools the bit at the same time. Since the adapter is connected to the base of the bit, dust collects directly in the drilling area and does not spread throughout the room.

Advantages of dry drilling

The main advantage of dry diamond drilling is the ability to use this method in cases where the use of water cooling is unacceptable. Besides, Dry drilling machine can be used in relatively small spaces. The installation for the wet method occupies a much larger area, since it is equipped, as a rule, with a rather impressive water tank used to cool the tool.

The dry method of drilling holes in concrete is especially relevant when the work is carried out:

in close proximity to electrical wiring;
at sites where there is no water supply;
in premises with a fine finish;
with the risk of flooding the lower rooms with water.

Unfortunately, the dry method has many disadvantages. The main one is the inability to work with maximum productivity and load. This is due to the rapid heating of diamond segments, which leads to a decrease in the resource intensity of the tool and its rapid failure. With the dry method, the drilling process is periodically interrupted to cool the tool by air-vortex flows.

Dry drilling has limitations on the diameter and depth of holes

Thus, wet drilling is a preferable method, despite the fact that its use entails additional efforts to organize the work, namely, it is necessary to take care of the supply and drainage of water. However, when carrying out work of a sufficiently large volume, the additional efforts associated with water supply will not be as burdensome compared to the costs of the dry method. In other words, it is much easier to take care of the supply and drainage of water than to drill with a lot of effort and time.

Processing tool used

For dry drilling, diamond core bits are used that do not require additional cooling. They are cooled due to air flows and high-quality lubrication. The crown looks like a hollow metal cylinder. At one end of this glass there is a cutting edge coated with diamond. The other or back side of the crown is intended for fastening in the equipment used and has a plug.

The crown produces circular cutting movements during drilling. These movements occur at high speed and under pressure, so the tool very accurately destroys the desired area of the concrete surface. The drilling speed and tool wear directly depend on the pressure force. Very high pressure leads to rapid destruction of the tool, and very low pressure significantly reduces the speed of drilling work. Therefore, the correct calculation of the mechanical force is very important. When calculating this force, the total area of the diamond segments and the type of material being processed must be taken into account.

There are a huge number of varieties of diamond crowns. Depending on their size they are divided into:

small-sized;
average;
large-sized;
extra large.

Small crowns include crowns with a diameter of 4-12 mm. They are mainly used for drilling small holes for electrical wiring. Medium bits have a diameter of 35-82 mm and are used for drilling holes for sockets, small pipes, etc.

Large bits with a diameter of 150-400 mm are used for drilling holes in permanent reinforced concrete structures, for example, for entering high-voltage electrical cables or sewers. Nozzles with diameters of 400-1400 mm are used in the development of fairly powerful infrastructure facilities. In fact, 1400 mm is not the limit for crowns.

A larger nozzle can be made upon request. An important parameter is also the length of the drilling tool. The length of the shortest nozzles does not exceed 15 cm. The length of middle class crowns is 400-500 cm.

Depending on the shape of the cutting surface, the following types of core drills for concrete are distinguished:

ring. They look like a solid diamond matrix in the shape of a ring, attached to the body. Typically, such drills have a small diameter, but there are exceptions;
gear are the most common type of core drills. ;
combined. Such crowns are used mainly for special types of concrete work.

The cutting part of gear bits consists of individual diamond elements, which can be from 3 to 32

The material from which the segments are made and in which the diamonds are fixed is called a binder, and in the language of professionals - a matrix. It gives the diamond segment its shape and strength. During practical use, the matrix must wear out in such a way that the “working” diamonds break off after becoming dull, and new and sharp diamonds act as their “replacement” on the cutting surface.

Depending on the location of diamonds in the matrix of cutting segments, crowns are divided into:

single-layer. The matrix in this case has only one surface layer of diamond cutters. Their density is no more than 60 pcs/carat. Single-layer diamond tips are considered the most short-lived. They are used mainly for drilling concrete without reinforcement;
multilayer. The density of micro-incisors in such matrices can be up to 120 pieces/carat. Multilayer crowns are also called self-sharpening. When the surface layer of diamonds wears out, the next layer is exposed;
impregnated. Such crowns also have a matrix with several layers of diamond grains, but their density is about 40-60 pieces/carat.

Despite the variety of types of diamond tools, their structure is identical. As a rule, it consists of a supporting metal body and a diamond-containing layer, which directly interacts with the material and forms the basis of the tool. This layer is a mixture of diamonds and metal powder.

The more accurately the composition of the binder is selected, the more efficiently and better the diamond tool will work as a whole. There is no standard recipe for making the binder.

Each major manufacturer develops its own diamond-bearing layer formula for each instrument, thereby ensuring its uniqueness.

The most popular consumables from the following manufacturers are now:

Bosch. Products manufactured under this brand ensure high-quality construction work, as they are reliable and have a long service life;
Husqvarna. This manufacturer is famous for using innovative technologies in the manufacture of diamond tools;
Cedima is one of the leading manufacturers of cutting tools for concrete;
Rothenberger. This company is engaged in the production of diamond drilling equipment and components for it;
Hilti specializes in the production of very high quality equipment and constantly improves its production process;
Anchor- domestic company. Initially, it was engaged in the sale of foreign equipment, but since 2007 it began to produce its own instruments.

Husqvarna is a pioneer in diamond drilling for industrial concrete

The rotation of the crown occurs due to the force of the drilling equipment. The bit can be installed either on a conventional drill or on a special installation. The installation rotates the tool at high speed, but there is no impact. The nozzle simply rotates and gradually presses on the concrete surface. Thus, it bites into the thickness of the concrete millimeter by millimeter.

Since the crown is hollow inside, only its walls cut into the concrete. This significantly speeds up and simplifies the work process. The crown will penetrate into the wall surface to the required position in just a few minutes, and then it will simply need to be pulled out along with the cut piece of concrete.

Main stages of the technical process

The work algorithm for drilling concrete structures is as follows:

crown selection;
drilling rig assembly;
preparation of the work site;
marking the working surface with an exact indication of the drilling center;
installation of the unit on a working surface;
installation of a drill bit;
performing drilling;
completion of drilling;
checking the quality of work.

The installation must be assembled very carefully. It is recommended to pay special attention to the fastening of the drilling tool. It is very important that there is nothing unnecessary around during drilling, so the work site must be cleared of debris and other unnecessary objects. Marking the working surface begins by drawing two intersecting perpendicular lines. Then a circle of the required diameter is built from their center. This circle will be the location for installing the crown.

During drilling, it is also necessary to take into account some nuances. To begin with, the crown must be very carefully adjusted, placing it exactly within the drawn circle. First, test drilling is performed for 4-8 seconds. This creates a small channel, which makes it easier to install the crown and perform major drilling.

At the end of the working process, the crown is removed and the degree of wear is checked. The central part of the cut hole is removed along with the crown, but sometimes it is necessary to pry it a little with a crowbar or a hammer drill. Another interesting fact is that a worn nozzle can be repaired in a special workshop. The quality of the work performed directly depends on the quality of the equipment used. Some of the best are considered to be drilling rigs from manufacturers such as Hilti, Husqvarna, Cedima, Tyrolit.

The service life of a diamond tool depends largely on the type of material in which the hole is drilled, on the type of diamond segment and on the correct use of the drilling rig. As a rule, large-diameter crowns also have a longer working life, which is associated with a larger number of diamond segments. The average resource of diamond bits with a diameter of 200 mm with good saturation of the cutting segments when drilling reinforced concrete is about 18-20 linear meters.

Non-rigid fastening of the installation and the tool leads to breaking off of the cutting segments of the tool

In this case, the main consumption of diamond segments is to overcome the reinforcement. Factors such as excessively strong or uneven feed of the bit or its beating when the support post is not rigidly fastened can greatly reduce the life of the bit or even completely destroy it.

Laser drilling of concrete

Industrial laser hole drilling began shortly after its invention. The use of a laser to drill small holes in diamond grains was reported back in 1966. The advantage of laser drilling is most clearly manifested when creating holes with a depth of up to 10 mm and a diameter of tenths to hundredths of a millimeter. It is in this size range, as well as when drilling brittle and hard materials, that the advantage of laser technology is undeniable.

You can drill holes with a laser in any material. For this purpose, as a rule, pulsed lasers with a pulse energy of 0.1-30 J are used. Using a laser, you can drill blind and through holes with different cross-sectional shapes. The quality and accuracy of hole manufacturing is affected by such temporal parameters of the radiation pulse as the steepness of its leading and trailing edges, as well as its spatial characteristics, determined by the angular distribution within the radiation pattern and the distribution of radiation intensity in the plane of the laser aperture.

At the moment, there are special methods for forming the above parameters, which allow you to create holes of various shapes, for example, triangular and exactly corresponding to the given quality characteristics. The spatial shape of the holes in their longitudinal section is significantly influenced by the location of the focal plane of the lens relative to the target surface, as well as the parameters of the focusing system. In this way, cylindrical, conical and even barrel-shaped holes can be created.

Over the past twenty years, there has been a sharp increase in the power of laser radiation. This is due to the advent and further development of compact lasers of a new architecture (fiber and diode lasers). The relative cheapness of emitters with a power of more than 1 kW has ensured their commercial availability for specialists engaged in research in various fields. As a result of these studies, high-power laser radiation began to be used for cutting and drilling hard materials such as concrete and natural stones.

Laser technology, free from noise and vibration, is most effectively used in seismic areas when creating holes in existing concrete buildings. They are used there to strengthen dilapidated houses with steel ties, as well as during the restoration of architectural monuments. In the nuclear industry, high-power laser radiation is widely used to decontaminate concrete nuclear structures that have already been decommissioned. In this case, users are attracted by the low dust emission during processing of concrete structures. Remote control of the process, i.e., the remote location of equipment from the facility, also plays an important role.

A laser electric drill is used to drill holes in concrete walls and other surfaces.. It consists of an electric motor, gearbox, spindle shaft, laser device, and drilling tool. The latter has the form of a screw, which is directly connected to the gearbox housing. A high-temperature crown is attached to one end of this screw, and its other end is connected to a spindle-shaft. The laser device is located in the upper part of the gearbox housing.

Laser beam significantly increases drilling speed in solid concrete walls and granite blocks

Security measures

When drilling holes in concrete structures, personal protective equipment should be used. These include goggles, canvas gloves, and a respirator. The operator must be dressed in thick work clothes and rubber shoes. During work, you must ensure that any items of clothing do not fall into the moving parts of the drilling equipment.

According to statistics, workers on construction sites suffer the greatest number of injuries due to malfunctioning power tools or their improper use. Therefore, the power tool must be in good working order. In addition, before each use it is necessary to check the power cable for damage. During work, the cable must be positioned so that it cannot be damaged in any way.

It is safest to drill concrete while standing on the floor, but, unfortunately, this is not always the case. In this way, you can drill a hole only at the level of human height. If the hole is located higher, an additional base must be used. The main rule in this case is the reliability of the foundation. It should provide the worker with a stable, level position while working. An additional safety measure when working at height is removing any objects from the work area that could cause injury if accidentally dropped.

When drilling holes in concrete walls, there is a high probability of damage to various communications. This could be electrical wiring, central heating pipes, etc. Live electrical wires can be easily detected using a hidden wiring detector.

When drilling holes with a laser, you should avoid getting various parts of the body into its action area to avoid getting burned. You should not look at the laser beam itself or its reflection, so as not to damage the cornea of the eyes. For the same reason, it is necessary to work only in special safety glasses. When working with laser equipment, you should follow the same safety rules as when using any power tool.

Cost of work

The pricing of concrete drilling services is influenced by factors such as:

required hole diameter. As the diameter increases, the cost of drilling also increases;
surface material, in which drilling will be done. In reinforced concrete structures, drilling is more expensive than in brick walls;
drilling depth. Naturally, the longer the future hole is, the more expensive the drilling itself will be.

Additional factors may also influence the cost of drilling work. For example, drilling at height requires the use of additional equipment. Drilling at an angle cannot be performed without the use of a special tool.

The cost of work may also increase if it is carried out outdoors and in adverse weather conditions.

Estimated cost of drilling holes with a diamond tool:

Hole diameter, mm	Cost of 1 cm of drilling, rub.
Hole diameter, mm	Brick	Concrete	Reinforced concrete
16 – 67	20	26	30
72 – 112	22	28	35
122 – 142	24	30	37
152 – 162	28	35	44
172 – 202	39	50	66
250	57	77	94
300	72	88	110
400	110	135	155
500	135	175	195
600	145	195	210

conclusions

Diamond technology is today undoubtedly the safest, fastest and most cost-effective option for drilling holes in the hardest building materials. Using annular drills you can create holes that exactly match a given diameter. The shape of the holes is also ideal and does not require any additional processing, which significantly saves time and, most importantly, money for the service customer.

The advantages of diamond drilling, such as the absence of noise and vibration, make it possible to carry out work not only on large construction sites, but also in residential premises that are both at the stage of repair and in a finished (finished) state. Thanks to diamond tools and professional equipment, wall and floor coverings completely retain their original appearance when working in a clean room.

Practical nuances of dry drilling concrete with a diamond crown are presented in the video:

Orders are fulfilled by laser cutting a wide range of materials, configurations and sizes.

Focused laser radiation makes it possible to cut almost any metals and alloys, regardless of their thermophysical properties. With laser cutting, there is no mechanical impact on the material being processed and minor deformations occur. As a result, it is possible to carry out laser cutting with high precision, including easily deformable and non-rigid parts. Thanks to the high power of laser radiation, high productivity of the cutting process is ensured. In this case, such a high quality of cut is achieved that threads can be cut in the resulting holes.

Widely used in procurement production. Main advantage laser cutting- it allows you to switch from one type of parts of any geometric complexity to another type practically without wasting time. Compared to traditional cutting and machining methods, the speed varies several times. Due to the absence of thermal and force effects on the manufactured part, it does not undergo deformation during the manufacturing process. The quality of the manufactured products allows for butt welding without displacement of the cut edges and pre-treatment of the joined sides.

Solid State Lasers Non-metallic materials cut much worse than gas materials, but they have an advantage when cutting metals - for the reason that a wave with a length of 1 micron is reflected worse than a wave with a length of 10 microns. Copper and aluminum for a wavelength of 10 microns are an almost perfectly reflective medium. But, on the other hand, making a CO2 laser is easier and cheaper than a solid-state one.

Accuracy laser cutting reaches 0.1 mm with a repeatability of +0.05 mm, and the quality of the cut is consistently high, since it depends only on the constancy of the speed of movement of the laser beam, the parameters of which remain unchanged.

Brief characteristics of the cut: scale is usually absent, slight taper (depending on thickness), the resulting holes are round and clean, very small parts can be obtained, cutting width is 0.2-0.375 mm, burns are invisible, thermal impact is very small, it is possible to cut non-metallic materials.

Drilling holes

An important factor for laser cutting is flashing the initial hole to start it. Some laser machines have the ability to produce up to 4 holes per second using the so-called flying piercing process in cold-rolled steel 2 mm thick. The production of one hole in thicker (up to 19.1 mm) sheets of hot-rolled steel during laser cutting is carried out using power piercing in approximately 2 s. Using both of these methods allows you to increase laser cutting productivity to the level achieved with CNC punching presses.

Punching holes

Using this method, it is possible to obtain holes with a diameter of 0.2-1.2 mm with a material thickness of up to 3 mm. With a hole height to diameter ratio of 16:1, laser punching is more economical than almost all other methods. The objects of application of this technology are: sieves, needle ears, nozzles, filters, jewelry (pendants, rosaries, stones). In industry, lasers are used to punch holes in watch stones and in drawing dies, and productivity reaches 700 thousand holes per shift.

Scribing

Often used is the non-through cutting mode, the so-called scribing. It is widely used in industry, in particular in microelectronics, to separate silicon washers into individual elements (fragments) along a given contour. In this process, the mutual orientation of the projection of the electric field vector of the incident radiation and the scanning direction also turns out to be essential to ensure high efficiency and quality of the process.

Scribing widely used in industry (microelectronics, watch industry, etc.) for separating thin polycor and sapphire wafers, less often for separating silicon washers. In this case, to carry out further mechanical separation, scribing to a depth of about a third of the total thickness of the plate being separated is sufficient.

Micromachining processes

The high degree of automation in recent years has made it possible to again use processes such as adjusting resistor values and piezoelectric elements, annealing of implanted coatings on the surface of semiconductors, deposition of thin films, zone cleaning and crystal growth. The capabilities of many processes have not yet been fully explored.