RU2428521C2 - Procedure for treatment of cutting tool in stationary combined discharge of low temperature plasma of low pressure - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: tool is positioned in chamber which is vacuumised and is supplied with process gas to working pressure (P). At this pressure there is possible gas break down at minimal strength of electro-magnetic field. Further, positive voltage of bias (U) is supplied on the tool forming electrostatic field around the tool sufficient for maintaining stable generation of plasma and there is generated micro-wave energy to a level of super-high frequency - SHF of power (W) 10-90 Wt. Cutting edges of the tool are subjected to plasma during 1.5-17 minutes (t_pr), further, the tool is cooled. Also, during treatment process there is performed control over bias current (I) occurring in a measuring circuit at plasma generation chosen from the range 2÷17 mcA and final lag temperature (T) chosen from the range 10÷230°C. At deviation from the allowed value of bias current (I) the mode of treatment is normalised by changing anode current of a magnetron (Ian). At exceeding the allowed value of final lag temperature (T) treatment of the tool is terminated earlier.

EFFECT: raised wear resistance of cutting tool.

4 cl, 10 dwg, 3 tbl

Description

The invention relates to the technology of surface hardening processing of tool materials by flows of charged particles and is intended for use in mechanical engineering and tool production, namely for processing complex cutting tools and tool materials.

A known method of hardening a carbide cutting tool of the TC and VK groups (RF patent No. 2167216, IPC: C23C 14/48, C23C 14/58), including applying a wear-resistant coating followed by irradiation with an ion beam, stabilizes the alloy structure by heat treatment before coating, and Irradiation is carried out by a powerful pulsed ion beam of the composition C ⁺ and H ⁺ , with a duration of 40-70 ns, an energy of 200-400 keV, an ion current density in the range of 50-200 A / cm ² , and a dose of 10 ¹² -10 ¹⁴ ion / cm ² . In this case, a wear-resistant coating is applied by the method of condensation of a substance from the plasma phase under conditions of ion bombardment (CIB). Heat treatment of the tool is carried out in a vacuum chamber for 1 hour at a temperature of 600 ° C.

As a result of a comprehensive modification, including preliminary heat treatment, application of a wear-resistant coating and subsequent exposure to an ion beam, an increase in the wear resistance of a carbide cutting tool during turning of structural steels is provided.

The disadvantage of this method is that for the implementation of this method of hardening, it is necessary to use at least three types of technological equipment: a vacuum thermal furnace, a NNV-6 installation, and a Temp technological accelerator, which makes this processing method quite energy-intensive, highly costly, and inaccessible . In addition, in the known method for surface hardening, flows of C ⁺ and H ⁺ ions are used, formed by extraction from an appropriate ion source, followed by passage of the charged charged particles through a system of devices for focusing, accelerating and delivering charged particles to the treated surface and subsequent scanning of the generated beam ions on the surface. When processing complex surfaces, this method of forming a flow of charged particles is ineffective due to the inability to process shaded surface elements when scanning a beam.

A known method for producing a stationary combined discharge of a low-temperature plasma of low pressure and a device for its implementation (RF patent No. 2277763, IPC: H05H 1/18), in which a positive potential is applied to the electrically conductive object, which forms an electrostatic field around which an microwave field is superimposed at the microwave power level, lower than that necessary to excite and maintain at the protruding parts or pointed edges of the object an electrodeless microwave discharge of a low temperature LASMA stationary combined discharge, which has an impact on the protruding parts or sharp edges, surface microroughness treated surface.

This method is aimed only at obtaining a stationary combined discharge of low-temperature plasma and does not contain process data for processing tools, including complex ones, in order to increase their wear resistance.

The objective of the invention is to provide a method of hardening a cutting tool, including a complex one, which allows to increase the wear resistance of the tool.

The problem is solved in that the method of processing the cutting tool in a stationary combined discharge of low-temperature low-pressure plasma, excited at its protruding parts or pointed edges, includes placing the cutting tool in the chamber, evacuating the chamber, supplying to the chamber process gas that does not oxidize the surface of the cutting tool, up to working pressure (P) at which breakdown of the process gas is possible with a minimum electromagnetic field strength in the continuous mode generating microwave energy, applying a constant positive bias voltage (U) to the instrument, forming an electrostatic field around it, sufficient to maintain stable plasma generation, generating microwave energy into the chamber to a microwave power level (W) of 10-90 W by adjusting the magnetron anode current (I _en) combined to form a stationary low-temperature plasma discharge, plasma exposure to the machining tool cutting edges for 1,5-17 minutes (t _v) and then cooled e of the instrument in the process gas environment at a working pressure of at least 5 min, and the process is monitored for the bias current (I) that occurs in the measuring circuit during plasma formation and is selected from the range 2–17 μA and the final lag temperature of the instrument ( T), selected from the range of 10 ÷ 230 ° C, corresponding to the size and material of the tool being processed, when deviating from the permissible value of the control parameter - bias current (I), the normalization of the processing mode is carried out by changing the anode of the current magnetron (I _AN ), when the permissible value of the control parameter is exceeded - the final lag temperature (T), the tool is stopped ahead of schedule.

Processing is carried out in nitrogen at a pressure of 300 Pa or in argon at a pressure of 250 Pa.

The tool is placed on the processed part directly in the zone of formation of the stationary combined discharge of low-temperature low-pressure plasma; when the area of the processed surface of the tool is exceeded, the plasma formation zone is processed, the segments of the processed surface of the tool are placed alternately in the plasma formation zone.

When processing a tool with a polished surface of the cutting edges, the quality and degree of sufficiency of processing are controlled by changing the color of the polished surface, which is allowed ranging from golden to dark bronze, with a shade lighter than golden, the tool is repeated and judged by the shade darker than dark bronze unsuitability.

The invention is illustrated by the following drawings in figures 1-10.

Figure 1 shows a schematic illustration of a device for hardening a cutting tool in a stationary combined discharge of a low-temperature low-pressure plasma.

Figure 2 shows graphs of the correspondence of the diameters of the drills technological parameters of processing.

Figure 3 shows the graphs of the correspondence of the nominal values of the taps technological processing parameters.

Figure 4 presents the electron microscopic image of the surface of the cutting edge of the drill before and after plasma processing.

Figure 5 presents the electron microscopic image of the amorphized microstructure of the surface of the thin section of the cutting edge of the drill after plasma treatment (a), the matrix base of the tool material of the drill ⌀ 2.65 mm (core) (b).

Figure 6 shows the electron microscopic image of the microstructure of the surface of the cut of the drill with a formed layer of crushed carbide phase.

7 shows the distribution of microhardness in depth for a drill ⌀ 2.65 mm

On Fig shows the relationship of changes in the distribution of microhardness in depth with a change in the shade of the treated surface after plasma treatment for taps M5 (a) and M8 (b).

Figure 9 presents a comparison of the distributions of microhardness in depth for the initial (a) and plasma-treated (b) replaceable multi-faceted carbide inserts coated with TiN and the results of resistance tests under production conditions are presented.

Figure 10 presents a comparison of the distributions of microhardness in depth for the original (a) and plasma-treated (b) replaceable polyhedral carbide inserts with a ground TiN coating and the results of resistance tests under production conditions are presented.

The proposed process includes plasma processing of a cutting tool and its subsequent cooling in a process gas medium at a working pressure in a device in which a stationary combined discharge of low-temperature low-pressure plasma is excited.

This tool processing method is characterized by the following process parameters:

- the working pressure used in the processing of gas (P), selected from a range of 250 ÷ 300 Pa depending on the minimum breakdown intensity of the electromagnetic field;

- constant positive bias voltage (U) supplied to the tool being processed, selected from a range of 20 ÷ 270 V to form an electrostatic field around the tool that supports stable plasma generation;

- the level of microwave power (W), installed in the processing zone, selected from the range of 10 ÷ 90 W to ensure the occurrence of a discharge of low-temperature plasma of low pressure at the processed surface of the tool;

- the anode current of the magnetron (I _en ), set within 12.5 ÷ 85 mA to regulate a given level of microwave power;

- the processing time of the instrument in plasma (t _about ) from 1.5 to 17 min;

- cooling time treated tool (t _OHL) of at least 5 minutes;

- bias current (I) arising in the measuring circuit during plasma formation - a control parameter selected from the range of 2 ÷ 17 μA;

- final lag temperature (7) - control parameter selected from the range of 10 ÷ 230 ° C.

The indicated parameters of the plasma processing of tools for each particular case are determined by the graphs of correspondence of the optimal parameters of the processing modes of the tools to their standard sizes, based on the data of preliminary processing of the tools.

To implement the proposed method, you can use the device to obtain a stationary combined discharge of low-temperature plasma of low pressure (RF patent No. 2277763, IPC: H05H 1/18) (see figure 1). This device contains a processing chamber 1, the inner space of which is limited by a pipe 2 made of radiolucent material embedded in a cylindrical resonator 3, and its ends, which are hermetically connected to each other. A slot emitting antenna 4 is installed on the cylindrical resonator 3. The chamber 1 is connected to the pump of the vacuum system 5. A gas inlet system 6 is used to supply the process gas to the chamber 1. In the chamber 1 there is a holder 7 with a replaceable collet 8 for installation of the processed tool 9 in the chamber 1. The holder 7 is connected through a cable to the protection elements 10 and through a sealed connector 11 to the potential supply unit 12. The chamber 1 on the opposite side of the connection to the vacuum system 5 is closed by a door 13 with a window 14 for visual observation. The device comprises a microwave energy generator 15, from which microwave waves are excited through a waveguide slot antenna 4, rolled into a ring, in a cylindrical resonator 3. When applying electrostatic and microwave electromagnetic fields at the end of the processed object 9, a stationary combined discharge of low-temperature low-pressure plasma 16 occurs.

The proposed method is as follows.

The processed tool 9 is fixed in a replaceable collet 8 of the holder 7 located in the processing chamber 1. Part of the surface of the tool and the collet 8 are isolated by a transparent material 17, and the surface to be plasma processed remains open. Then, the instrument prepared for plasma treatment is located in the processing chamber 1 so that the non-insulated end part of the tool is located at a fixed point in the space of the processing chamber, the coordinate of which relative to the emitting slots of the waveguide-slot antenna depends on the geometry of the tool. Then the door 13 of the processing chamber is tightly closed, the fore-vacuum pump 5 is turned on, the chamber is pumped out to the maximum pressure (~ 10 Pa), after which the process gas is supplied to the processing chamber through the gas inlet system 6 to the working pressure (P) corresponding to the minimum breakdown electromagnetic field strength in used gas in the continuous generation of microwave energy (the value of the working pressure for the applied process gas is determined by literature).

Then, a constant positive bias voltage is applied to the tool to be processed from a range of 20-270 V from the potential supply unit 12 through a sealed connector 11, a cable with multilayer protection elements 10 and a holder 7. In this case, the tool is at a positive potential and an electrostatic field is formed around it. The value of the constant positive bias voltage is determined by the schedule (figa).

After that, by adjusting the anode current of the magnetron (I _en ) in the chamber 1 set the level of the input microwave power from the range of 10-90 watts. In this case, microwave electromagnetic waves come in continuous generation from a microwave energy generator 15 through a waveguide slot antenna 4 into a cylindrical resonator 3.

When superhigh-frequency electromagnetic oscillations are applied to the electrostatic field around the part of the tool to be processed, a stationary stationary combined discharge of low-temperature low-pressure plasma appears in the processing chamber 16.

When a compensated stream of charged plasma particles acts on the surface of the processed tool, a bias current I is recorded in the measuring circuit, which controls the processing process. Depending on the geometry of the tool, a bias current change of 2 ÷ 17 μA is allowed, the nominal value of which is determined according to the schedule (Fig.2c). During monitoring of the processing process when the permissible bias current value (I) deviates, the processing mode is normalized by changing the magnetron anode current (I _an ) until the bias current value (I) is set.

The effect of the compensated flow of charged plasma particles on the treated surface causes the tool to heat up, the lag temperature of which is recorded by a thermocouple located in the holder 7 (not shown in Fig. 1). The maximum effect of the compensated flow of charged plasma particles occurs on the protruding elements or the pointed edges of the tool, the treated surface of which is intensively heated, the melting of small surface defects, the melting of the micron surface layer, accompanied by intensive dissolution of the carbide phase in it, which causes a change in the chemical composition of the tool material in this layer. At the same time, the value of the final lag temperature of the instrument (T) should be within 20 ÷ 230 ° С depending on its type and size.

After the time (t _r ) of the plasma treatment or when the permissible value of the final lag temperature (T) is exceeded, determined from the graphs (Fig. 2d, d), the plasma effect on the treated surface is stopped by switching off the microwave energy generator. The tool is cooled in a process gas environment at operating pressure for at least 5 minutes or to a safe level (below 80 ° C).

After lowering the temperature of the instrument, the inlet of the process gas into the chamber 1 and its pumping are stopped. The atmosphere is let into the chamber through the corresponding inlet valve (not shown in FIG. 1), after which the door 13 is opened and the processed tool 9 is removed.

In a stationary combined discharge of a low-temperature low-pressure plasma, it is allowed to process an instrument whose dimensions exceed the zone of plasma formation. If the area of the tool surface to be treated is exceeded, the treatment is carried out by placing segments of the surface to be machined alternately in the plasma formation zone.

Such an effect of the stationary combined discharge of low-temperature low-pressure plasma on all types and sizes of the processed tool made of tool steels is accompanied by a change in the color of the polished surface from a golden hue to dark bronze, which corresponds to the maximum change in microhardness in depth in the surface layers on the protruding sections and cutting edges. Moreover, for such tools, the intensity of surface painting is a criterion for assessing the quality of plasma processing and its adequacy. When the surface shade is lighter than golden, the treatment is repeated, and the suitability of the instrument is darker than the dark bronze.

For carbide tools, the criterion for assessing the quality of plasma treatment is the change in microhardness in depth in the surface layers in the protruding sections.

The wear resistance of a tool subjected to a stationary combined discharge of a low-temperature low-pressure plasma increases by 3-4 times as a result of the formation of a modified layer on the surface in which shear deformations arising from friction under cutting conditions are localized.

This method of plasma treatment, in which the end part of the tool is completely covered by plasma, allows you to process a cutting tool, including a complex one, from various grades of tool steels and hard alloys, with and without wear-resistant coatings applied to them.

The method of processing a cutting tool in a stationary combined discharge of low-temperature low-pressure plasma can be illustrated by the following examples.

Example 1

A preliminary low-fat complex-profile cutting tool, for example, a 2.65 mm polished drill made of P6M5 tool steel, is installed in a replaceable collet in a setup in which a stationary combined discharge of low-temperature low-pressure plasma can be excited. Part of the surface of the instrument, not subject to plasma treatment, is isolated by several layers of radiolucent material, for example, a thin fluoroplastic tape. Then the tool is placed in chamber 1. The door of the processing chamber is tightly closed, after which chamber 1 is pumped out to a pressure limit of ~ 10 Pa and the process gas is injected with nitrogen through the gas inlet system and the operating pressure is maintained at P = 300 Pa, at which breakdown in nitrogen is possible at minimum electromagnetic field strength in the continuous generation of microwave energy. The value of the working pressure for nitrogen is determined according to Fig. A.4. “Breakdown fields during continuous operation in clean air, oxygen, nitrogen at a frequency of 2.8 GHz at Λ = 0.202 cm” in the appendix to the book by McDonald A. Microwave gas breakdown. / A.Mac-Donald; trans. from English M.M.Savchenko, A.G. Frank. - M.: Mir, 1969 .-- 212 p.

Then, a constant positive bias voltage is applied to the processed drill from the potential supply unit 12, the value of which is determined according to the schedule in Fig. 2a in accordance with the drill diameter ⌀ 2.65 mm and equal to U = + 85 V. In the processing chamber, the level of the supplied microwave power (W) by adjusting the anode current of the M-105 magnetron to 25 mA, which corresponds to a drill diameter of ⌀ 2.65 mm (fig.2b). As a result of this, conditions are created for the excitation and stable generation of a stationary combined discharge of low-temperature low-pressure plasma, and an orange-pink glow of plasma 16 appears at the terminal uninsulated part of the drill ⌀ 2.65 mm 16. In this case, the bias current I, which in this the case is 2.7 μA, which corresponds to a drill diameter of ⌀ 2.65 mm (pigv). The drill processing time t _r was 8 minutes. The heating of the treated surface is recorded with a thermocouple installed in the holder 7. When the drill ⌀ 2.65 mm is finished, the final lag temperature T is 35 ° C, the permissible final lag temperature for this drill is 40 ° C according to the schedule (fig.2d). In this case, the bias current I, the final lag temperature T, and the processing time (t _r ) are controlled parameters. At the end of the technological plasma exposure time, the magnetron anode current I _en is switched off, a constant positive bias voltage U, while the surface of the instrument is subjected to sharp cooling at the working pressure of the process gas.

After cooling the treated drill for 5 minutes, the supply of process gas through the gas inlet system 6 is stopped, the vacuum pump 5 is turned off, the atmosphere is let into chamber 1 through the atmosphere inlet valve, the door 14 of chamber 1 is opened and the treated drill ⌀ 2.65 mm is removed. In this case, the color of the processed polished surface of the drill changed to a saturated golden hue.

The effect of the compensated flow of charged plasma particles on the surface of the drill causes it to heat up, to melt small burrs and surface defects, which as a result causes a decrease in surface roughness. The melting of micron surface layers is accompanied by the mutual dissolution of the phases that make up the P6M5 tool steel located in this layer (Fig. 4a, Fig. 4b), which causes their alloying and a change in the chemical composition of the surface layer. Figure 4 clearly shows a decrease in the number per surface unit and size of carbide grains, as well as the clarification of the treated surface, which indicates an increase in the concentration of metals with a high atomic mass in the surface layer.

Abrupt cooling of molten near-surface layers in a vacuum causes its amorphization to a depth of 4.5 μm (Fig. 5a, Fig. 5b) and structural changes with the formation of a crushed carbide phase to a depth of ~ 40 μm (Fig. 6).

Such changes in the surface layers are accompanied by a change in microhardness (Fig. 7) and an increase in wear resistance by 4.5 times (Table 3).

Example 2

Drills of nominal values ⌀ 0.8, 4.1, 7.0, 10.5 mm from tool steel P6M5 were processed in a stationary combined discharge of low-temperature low-pressure plasma according to a procedure similar to example 1. The values of the input and control technological parameters were determined from the graphs (figure 2) and amounted to:

U = 35 V; 113 V; 127 V; 137 V;

I _en = 17.5 mA; 25 mA; 27 mA; 55 mA

I = 2 μA; 4 μA; 5.6 μA; 10 μA;

t _rev = 2 min; 12 min; 15 minutes; 16.5 min;

T = 18 ° C; 50 ° C; 68 ° C; 93 ° C, which corresponds to the standard sizes of these drills.

As a result of plasma treatment, the microhardness of the polished surface of the cutting edges increased from 6.0-8.0 GPa to 10.0-18.0 GPa (Table 1), the color of the surface of the drills after processing changed from a golden tint to a shade of dark bronze, and wear resistance increased from 2.5 to 4.5 times (table 3).

Example 3

In example 3, plasma taps of nominal values M5, M6, M8 of tool steels P6M5, P18, HSSE with various coatings are subjected to plasma processing and the processing is carried out analogously to example 1, with input technological parameters determined from the graphs (Fig. 3) in accordance with the standard sizes of taps analogously to example 2. As a result of plasma treatment, the microhardness of the surface of the calibrating cutting elements of the tap increased, which is confirmed by the data given in table 2, the wear resistance increased from 3.6 to 4.1 times (table 3), while vet taps the surface changed from golden brown to dark bronze color.

On Fig shows the relationship of changes in the distribution of microhardness in depth with a change in the shade of the treated surface.

The surface of the tap, having a light golden hue or darker than dark bronze, has a lower microhardness after plasma treatment. In this case, a change in the surface hue from golden to dark bronze is a criterion for assessing the quality of the plasma processing of the tool and its adequacy. This approach allows visual express control of plasma treatment without resorting to lengthy measurements of microhardness. In addition, it was experimentally established that for a tool with a surface tint lighter than a golden tint, it is advisable to repeat the treatment until the surface tint is obtained within the required limits, and if the tint of the treated surface is darker than dark bronze, if necessary, decide on the unsuitability of the tool.

Example 4

In example 4, a slotted cutter 2900-7381 (material - VK6OM carbide) ⌀ 40 mm with a cutter thickness of 0.225 mm, having a dark gray surface tint, the dimensions of which exceed the limits of the zone of formation of the stationary combined discharge of low-temperature low-pressure plasma, is subjected to plasma treatment . The processing of a groove mill according to the procedure is similar to that of a drill in Example 1, except that the plasma is formed on a part (half the diameter) of the machined surface of the mill. Moreover, the technological parameters for this type of tool are selected experimentally from the ranges: U = 125 V; I _en = 25 mA; I = 5 μA; t _rev = 8 min; T = 50 ° C. In this case, the processing of the cutter is carried out twice. During the next treatment, an unprocessed cutter segment is installed in the plasma formation zone while maintaining the conditions for the excitation of a stationary combined discharge of low-temperature low-pressure plasma, i.e. the location of the cutter in the working chamber and the input technological processing parameters. After plasma treatment, the surface of the cutter is lightened to gray. The wear resistance of the cutter increased 4 times (table 3).

Example 5

In Example 5, replaceable multi-faceted T15K6 carbide inserts with a TiN coating and a ground TiN coating (WNUM-080404 GOST 19048-80) are subjected to plasma treatment.

In plasma treatment, a multifaceted plate was mounted in chamber 1 in the holder so that the working faces of the plate were completely located in the zone of formation of the stationary combined discharge of low-temperature low-pressure plasma. The processing procedure is similar to the processing of the drill in example 1 according to the technological parameters selected experimentally for this type of tool from the ranges: U = 150 V; I _en = 25 mA; I = 10 μA; t _rev = 15 min; T = 230 ° C.

After plasma treatment, a change in the color of the surface of the instrument was not visually identified, and the measurement of microhardness in depth revealed the formation of a dense layered structure of the surface layers of interchangeable polyhedral plates different from the original structure. The distribution of microhardness in depth is shown in Fig.9-10. This structure of the surface layers has an increased wear resistance of 4.4 and 3.8 times for T15K6 carbide inserts with a TiN coating and a ground TiN coating compared to the original untreated plates (Table 3).

Example 6

In example 6, a drill ⌀ 7.0 mm of tool steel P6M5 is subjected to plasma treatment in a stationary combined discharge of low-temperature low-pressure plasma. Processing is carried out according to a procedure similar to example 1, with the values of the input technological parameters shown in the nomogram (figure 2), argon was used as the process gas at a pressure of 250 Pa. As a result of the change in the process gas, a bright lilac-pink glow of plasma 16 appears at the terminal uninsulated part of the drill ⌀ 7.0 mm.

The optimal value of the working pressure of argon, corresponding to the minimum breakdown intensity of the electromagnetic field, is determined experimentally taking into account the data given in well-known literature (Fig. 5.3.11. "The probability of ionization of N ₂ , CO, O ₂ , NO, CO"; Fig.5.3 .12. "Probability of argon ionization"; table 10.10.1. "The magnitude of the product of pressure on the ambipolar diffusion coefficient for various ions in different gases", given in the book by I.Mac-Daniel. Collisions in ionized gases / I.Mac- Daniel. - M.: Mir, 1967. - 832 p.).

As a result of plasma processing, there was a change in the microhardness of the surface layers, the color of the polished surface of the cutting edges of the drills and wear resistance, similarly to example 2.

Thus, processing a tool in a stationary combined discharge of low-temperature low-pressure plasma at low microwave power levels is a promising, very effective and economical way to improve the operational characteristics of cutting tools for various purposes by 3-4.5 times.

Depending on the energy of plasma particles on the treated surface, various processes can be carried out: smoothing the surface (electro polishing), polymerization with the formation of a close-packed polymer film, diffusion processes and alloying, i.e. to structural changes in the surface and bulk properties of the processing object.

METHOD OF PROCESSING THE TOOL IN THE STATIONARY COMBINED DISCHARGE OF LOW-TEMPERATURE PLASMA OF LOW PRESSURE

Table 1 Comparison table of properties of drills from tool steel P6M5 of various denominations No. p / p Drill diameter mm Microhardness, GPa / Depth, microns Shades of the polished surface of the tool after processing source after plasma treatment one 0.8 5.79-8.43 / 2.06 15.08-17.82 / 1.52 Golden bronze 2 2.65 5.96-7.6 / 2.16 16.21-16.99 / 1.48 Golden 3 4.1 5.81-8.17 / 2.08 14.98-5.86 / 0.87 Dark bronze four 7.0 5.88-8.26 / 2.1 16.08-16.85 / 1.51 Golden 5 10.5 5.78-7.76 / 2.14 9.66-13.68 / 0.61 Dark golden

METHOD OF PROCESSING THE TOOL IN THE STATIONARY COMBINED DISCHARGE OF LOW-TEMPERATURE PLASMA OF LOW PRESSURE

table 2 Comparative table of properties of taps from tool materials of various denominations No. p / p Tap size Tool material / coating Microhardness, GPa / Depth, microns Shades of the polished surface of the tool after processing source after plasma treatment one M5 P6M5 5.73-6.56 / 2.35 12.82-14.48 / 1.5 golden 2 M6 P6M5 5.67-7.82 / 2.17 10.57-13.57 / 1.62 dark bronze 3 M8 P18 7.52-9.88 / 1.9 13.91-19.91 / 1.56 rich golden four M10 (Titex Plus) Hsse 9.02-10.25 / 1.35 23.35-24.53 / 0.87 dark golden 5 M8 P6M5 / TiN 8.81-9.91 / 1.96 14.74-17.59 / 1.44 rich golden 6 M10 (Pokolm company) Hard alloy 6.99-12.05 / 1.72 13.99-15.99 / 1.5 not identified coating 11.38-15.41 / 1.54 28.05-33.5 / 1.03 not identified

METHOD OF PROCESSING THE TOOL IN THE STATIONARY COMBINED DISCHARGE OF LOW-TEMPERATURE PLASMA OF LOW PRESSURE

Table 3 Generalized results of comparative resistance tests of a cutting tool that has been processed in a plasma of a combined low-pressure discharge No. p / p Tool view Size Processed material Processing machine The increase in wear resistance, times one 2 3 four 5 6 one Cutter with a solder plate T15K6 - Art. 10864-VI CNC Lathe 16K20F3 4,5 2 Replaceable carbide multi-faceted plates T15K6 with TiN coating WNUM-080404 GOST 19048-80 Art. SHX15 Lathe 16K20F3S5 3.8-4.4 3 Cutter 53558 P6M5 ⌀ 15.9 mm SHX15 Lathe for processing pins mod. 116 1,5 four Grooving mill 2900-7381 VK6OM The thickness of the working part of the cutter - 0.225 mm Abrasive filled plastic Semi-automatic milling of collectors of a microelectric motor DP-22-01 four 5 Drill P6M5 ⌀ 0.8 mm Fiberglass foil with double-sided metallization 1.7 mm thick Bench drilling machine, mod. NSP-2 3.6 6 Drill P6M5 ⌀ 2.65 mm Art. CVH with HRC 55 ... 60 units Bench drilling machine, mod. EM-102 4,5 7 Drill P6M5 ⌀ 4.1 mm Copper MOB Lathe 16K20F3.192.001.000 2.5 8 Tap P6M5 M3 Article 3 Reversible Drilling Machine 3.6 9 Tap P6M5 M5 Article 3 Vertical drilling machine mod. 2N125L 3.62 10 Tap P6M5 M8 Article 3 Vertical drilling machine mod. 2N125L 4.01

Claims (4)

1. A method of processing a cutting tool in a stationary combined discharge of low-temperature low-pressure plasma excited at its protruding parts or pointed edges, including placing the tool in the chamber, evacuating the chamber, supplying the process gas non-oxidizing surface of the tool to the chamber to the working pressure (P), in which breakdown of the process gas is possible at a minimum electromagnetic field strength in the continuous generation of microwave energy, supply to the instrument nt constant positive bias voltage (U), forming around the electrostatic field sufficient to maintain a stable plasma generation, the generation of microwave energy in the chamber to the level of microwave power (W) 10-90 W by controlling the anode current (I _en) combined to form a stationary low-temperature plasma discharge, exposure to plasma cutting edges on the machining tool during 1,5-17 min (t _v) and subsequent cooling of the tool in a process gas environment at working Pressure at least 5 min, while monitoring the process by the bias current (I) that occurs in the measuring circuit during plasma formation and is selected from the range of 2-17 μA, and the final lag temperature (T) is selected from the range of 10 ÷ 230 ° C, corresponding to the size and material of the processed tool, when deviating from the permissible value of the control parameter - bias current (I), the normalization of the processing mode is carried out by changing the anode current of the magnetron (I _an ), when the permissible value of the control is exceeded parameter - the final lag temperature (T) the processing of the tool is stopped ahead of schedule. 2. The method according to claim 1, characterized in that the treatment is carried out in nitrogen at a pressure of 300 Pa or in argon at a pressure of 250 Pa. 3. The method according to claim 1, characterized in that the tool is placed on the processed part directly in the zone of formation of the stationary combined discharge of low-temperature low-pressure plasma, when the area of the processed surface of the tool exceeds the plasma formation zone, the processing is carried out by placing segments of the processed surface of the tool alternately in the plasma formation zone . 4. The method according to claim 1, characterized in that when processing a tool with a polished surface of the cutting edges, the quality and degree of sufficiency of processing are controlled by changing the color of the surface of the cutting edges, which is allowed in the range from golden to dark bronze, with a shade lighter than golden the processing of the instrument is repeated, and by its shade darker than dark bronze, its unsuitability is judged.

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