RU2829867C1 - Method of producing superhard composite material for cutting tools - Google Patents

Abstract

FIELD: various technological processes.

SUBSTANCE: invention relates to production of a sintered superhard composite material based on cubic boron nitride, intended for making cutting tools. Method of producing the composite material involves preparing a mixture by mixing powders of cubic boron nitride in amount of 55-65 wt.% of the weight of the charge, titanium metal and iodine with a weight ratio of titanium to iodine of 5:1. A titanium layer is deposited on the surface of particles of cubic boron nitride by chemical deposition from a gas phase. When temperature rises at rate of 7.00±0.50 deg/min and holding at final temperature for 120 minutes, a layer of titanium nitrides and borides is formed. Cutting tool workpieces are formed from the obtained powder. Sintering of workpieces is carried out at 1,450±50 °C under pressure 3.8±0.2 GPa for 10 s with simultaneous formation of a binder of titanium nitride and titanium diboride. For the preparation of the mixture and further processing, cubic boron nitride powder of fraction (mcm) 10/5 is used and the process of forming a layer of titanium nitrides and borides on the surface of cubic boron nitride particles is carried out to a final temperature of 725±5 °C, or cubic boron nitride powder of fraction (mcm) 8/4 is used and said process is carried out to final temperature of 710±5 °C, or cubic boron nitride powder of fraction (mcm) 3/1 is used and said process is carried out to a final temperature of 675±5 °C.

EFFECT: invention enables to obtain a superhard composite material intended for processing hardened steels with hardness of up to 65 HRC, grey and chilled cast irons, hard-to-machine materials and for making wear-resistant structural parts.

1 cl, 6 dwg, 1 tbl, 14 ex

Description

The invention relates to powder metallurgy, in particular to sintered superhard composite materials based on cubic boron nitride, intended for use in cutting tools used for processing hardened steels with a hardness of up to 65 HRC, gray and chilled cast irons, difficult-to-machine materials, as well as for the manufacture of wear-resistant structural parts.

Superhard materials based on cubic boron nitride are characterized by increased heat resistance, hardness, resistance to cyclic exposure to high temperatures, low friction coefficient, chemical resistance to iron, which is the main component of most steels subjected to mechanical cutting [1]. When manufacturing cutting tools based on cubic boron nitride powder, coatings are used in the "superhard material grain - coating - bond" system to activate the processes of wetting, adhesion and chemical interaction, which allows increasing the degree of fixation of grains in the bond and thereby the performance of the tool.

Typically, cutting inserts with a cubic boron nitride content of up to 95 vol. % are used for cutting difficult-to-machine materials [2]. For wider use of cutting tools made of composite materials based on cubic boron nitride, it is necessary to strive to minimize the content of this expensive component in the material and reduce the parameters of material synthesis without significant loss of cutting properties.

Composite materials based on cubic boron nitride with TiN-TiB ₂ binders are promising for the creation of thermally stable, high-hardness cutting tools resistant to impact and corrosion [3]. The presence of refractory compounds in the matrix, which have increased hardness and crack resistance, makes it possible to slow down the processes of recrystallization and phase transformation of cubic boron nitride into hexagonal, as well as to reduce the crushing of cubic boron nitride grains by squeezing them with a binder [4].

A method for producing a superhard composite material based on cubic boron nitride for cutting tools and the composite material obtained in this way is known in accordance with invention RU 2147972 (C1) [5], in which cubic boron nitride powder and/or boron nitride powder coated with a boride or titanium nitride are first wetted in ethyl alcohol, granulated and pressed at a pressure of 1⋅10 ⁴ -2⋅10 ⁴ kgf/cm ² , then the resulting briquette is placed in a heater with a washer pressed from a mixture of natural graphite and hexagonal boron nitride placed at the end of the briquette, an aluminum gasket is placed on the inside of the washer, the container is subjected to vacuuming for 1-2 hours, after which an aluminum gasket and washer are placed at the other end of the container, the container is placed in a matrix and under a pressure corresponding to the thermodynamic stability of cubic nitride boron, heat the briquette by passing an electric current at a constant power for 10-180 s, then reduce the pressure to atmospheric and remove the composite material blank. The resulting composite material contains cubic boron nitride powder and/or a 5/1 μm fraction of cubic boron nitride powder with a coating of boride and titanium nitride with a titanium content of up to 25 wt. %. The number of aluminum spacers is determined based on 2 mm of the height of the composite material briquette per one spacer with a thickness of 0.2 mm. The original powder is placed on a hard alloy substrate, which is pre-ground and degreased in ethyl alcohol.

A method for producing superhard composite materials is known in accordance with development RU 92007535 (A) [6], which provides for mixing micropowders of cubic boron nitride with micropowder of a refractory metal, their joint processing in halogen vapors of this metal at a temperature of 950-1150 °C until the refractory metal is completely converted into borides and nitrides that form diffusion coatings on the grains of cubic boron nitride micropowders, and hot pressing to obtain cutting plate blanks. An embodiment of the method is proposed in which the obtained micropowder of cubic boron nitride with a diffusion coating on grains consisting of borides and nitrides of a refractory metal is mixed with micropowder of pure cubic boron nitride in the following ratio of components: micropowder of cubic boron nitride with a diffusion coating of grains of 20-80 mass. %, pure cubic boron nitride micropowder - the rest. Then cold pressing of the powder mixture is carried out, the obtained blanks are placed in a shell of aluminum or aluminum alloys with additives of alkali, alkaline earth and/or transition metals or coated on both sides with plates of the said materials. In addition, it is possible to mix cubic boron nitride micropowders with a diffusion coating on grains and pure cubic boron nitride with aluminum or aluminum alloy powder in the following ratio of components: cubic boron nitride micropowder with a diffusion coating on grains 15-65 wt. %, aluminum or aluminum alloy powder - 2.5-10 wt. %, pure cubic boron nitride micropowder - the rest.

The disadvantage of the above-considered methods for manufacturing superhard composite materials for cutting tools is the use of aluminum during sintering. Due to the impregnation of the workpiece with aluminum melt and subsequent phase formation during sintering, a bond is formed. Due to the use of cubic boron nitride with a large spread of grain sizes in these technical solutions, the impregnation of the workpiece may occur unevenly, which in turn contributes to the appearance of defects and reduces the physical and mechanical properties of the material. When using fine-grained powders, impregnation with aluminum is difficult and leads to incomplete sintering of the material and the formation of increased porosity of the cutting tool workpieces.

Invention EP 0 570 635 (A1) [7] proposes polycrystalline abrasive compacts and methods for producing them from diamond or cubic boron nitride granules bonded by a sintered matrix obtained from a coating on the granules. The coating comprises one or more layers of active material which chemically bonds to the surface underneath. The compacts are produced by coating fine cubic boron nitride or diamond granules with a coating of active material and sintering the coated particles with or without metal or alloy powder. The compacts are produced using a short sintering step at relatively low pressures and temperatures. These compacts have improved fracture properties due to the nature of the coated particles included therein. The method for producing a polycrystalline abrasive compact with controlled fracture characteristics includes selecting fine granules of cubic boron nitride or diamond with a diameter in the range from 0.1 to 200 μm, applying at least two layers of a coating of an active material selected from titanium, zirconium, hafnium, tungsten, vanadium, niobium, tantalum, chromium, molybdenum, silicon or their carbide, bromide, nitride or oxide, with a total thickness in the range from 0.1 to 1.0 μm. In this case, the outer layer is a sintered material selected from nickel, copper, cobalt or carbide, nitride or boride of titanium, tantalum, molybdenum, zirconium, hafnium, vanadium, chromium, tungsten, silicon or niobium. The coated granules are sintered at approximately 1000°C and approximately 2000 psi for a holding time of less than 5 minutes to produce a polycrystalline abrasive compact.

The disadvantage of this method is the use of cubic boron nitride powders with a wide range of particle sizes in the composition of the charge for the production of material for the cutting tool. The interaction surface of polyfractional powders is different, which adversely affects the uniformity of the coating application and which, in turn, can lead to unevenness of the microstructure of the sintered material and a decrease in its performance properties.

The closest to the claimed invention is development SU 1583457 (A1) [8], according to which a sintered superhard tool material was obtained from a charge of a certain composition using the high pressure and high temperature method.

The charge for producing sintered superhard tool material contains activating metals or their alloys and cubic boron nitride grains with a two-layer coating, the inner layer of which consists of a eutectic alloy nitride (TiN) - titanium diboride (TiB ₂ ), and the outer layer consists of a compound, the composition of which monotonically changes towards the outer surface from titanium nitride to titanium oxynitride of the composition TiN _x O _y , where x = 0.6-0.9, y = 0.5-0.9, and x + y = 1.1-1.8, with the following ratio of the charge components: activating metals or their alloys 1-10 wt. %, eutectic alloy nitride - titanium diboride 3-25 wt. %, a compound, the composition of which monotonically changes from titanium nitride to titanium oxynitride of the composition TiN _x O _y 1-15 wt. %, cubic boron nitride the rest.

Powders of cubic boron nitride of the LM/10/3 brand are mixed in the required proportion with powders of titanium of the PTOM brand and placed in a quartz reactor, heated in vacuum to a temperature of 1000°C and maintained for 20-60 minutes. As a result of the action of volatile iodides and the greater diffusion mobility of nitrogen compared to boron, a coating is formed in which the layer adjacent to the surface of cubic boron nitride is a eutectic alloy TiN-TiB ₂ , and the outer layer consists of TiN. The obtained powders of cubic boron nitride are annealed in vacuum at 500°C for 5-20 minutes, as a result of which the outer layer of titanium nitride is diffusionally saturated with oxygen with the formation of titanium oxynitride grains TiN _x O _y of the required formula composition on the surface. The resulting powders are mixed with the powder of the adhesively active metal or its alloy, a plasticizer is added and they are briquetted in the form of cylindrical tablets with a diameter of 5 mm and a height of 11 mm. After drying, the tablets are placed inside a graphite heater inserted into a container made of lithographic stone and subjected to hot pressing in a high-pressure chamber at a pressure of 5 GPa (50 kbar), a temperature of 1600 ° C for 10 seconds. From the sintered blanks, tool material of a cylindrical shape with a diameter of 4 mm and a height of 6 mm is manufactured.

The disadvantage of this technical solution is the use of cubic boron nitride powder with nominal particle sizes in the range from 3 to 10 μm in the charge for producing the material. In this case, the application of a layer of titanium nitrides and borides to cubic boron nitride particles of different sizes occurs at the same temperature, which leads to unevenness in the thickness of the applied coating and the microstructure of the sintered material.

In addition, annealing in a vacuum leads to the formation of a surface layer of an oxynitride phase of variable composition, changing over a wide range, which does not guarantee the stability of the material properties from batch to batch.

Another disadvantage of the method is the need to subject the workpiece to a pressure of 5 GPa (50 kbar) and a temperature of 1600°C during the sintering process, which requires the use of expensive carbide tooling and the operation of large-capacity hydraulic presses.

The objective of the present invention is to obtain a superhard composite material for a cutting tool intended for processing hardened steels with a hardness of up to 65 HRC, gray and chilled cast irons, difficult-to-machine materials, as well as for manufacturing wear-resistant structural parts. The said objective is solved by using the proposed production method, which uses narrow fractions of cubic boron nitride powders. According to this method, a titanium layer is applied to the cubic boron nitride particles by chemical vapor deposition, followed by the formation of a layer of titanium nitrides and borides on the surface of the cubic boron nitride particles, and blanks of the cutting tool are formed and sintered from the obtained powder with the applied coating, with the simultaneous formation of a bond of titanium nitride and titanium diboride.

In order to create a material with the required characteristics, a method of production is proposed, which includes preparing a batch by mixing cubic boron nitride powders in an amount of 55-65 mass % of the batch mass, metallic titanium and iodine at a mass ratio of titanium to iodine of 5:1, applying titanium to the cubic boron nitride particles by chemical vapor deposition, forming a layer of titanium nitrides and borides with a temperature increase at a rate of 7.00±0.50 deg/min and holding at the final temperature for 120 minutes, molding cutting tool blanks and sintering the blanks at a temperature of 1450±50°C under a pressure of 3.8±0.2 GPa for 10 seconds with the simultaneous formation of a bond of titanium nitride and titanium diboride.

In the proposed invention, the technical effect is achieved by using cubic boron nitride powders of fractions (μm) 10/5, 8/4 and 3/1 in the initial batches and selecting the optimum final temperature for each fraction of cubic boron nitride powder for the formation of a layer of titanium nitrides and borides on the surface of cubic boron nitride particles.

The selected sintering temperature of the blanks is due to the fact that sintering temperatures below 1400°C are insufficient to form a matrix of the required structure, and, consequently, to firmly retain the grains of cubic boron nitride. Under such temperature conditions, the material does not sinter. Using a sintering temperature above 1500°C requires the use of large-tonnage hydraulic presses, which will lead to an increase in electricity costs and, as a consequence, an increase in the cost of the material.

The proposed invention is new, has an inventive level and is feasible on an industrial scale. The invention can be implemented using equipment currently used to produce superhard cutting tools.

Below are examples of the implementation of the claimed invention.

Example 1.

Powders of cubic boron nitride (cBN-M990, fraction 10/5 μm, Funik, China), titanium (PTN-8, fraction 10/0 μm, Normin, Russia) and iodine (iodine mass fraction 99.5%, Reakhim, Russia) were mixed in a ratio of 60 wt. %, 33.4 wt. % and 6.6 wt. %, respectively, in a planetary mill with steel grinding media in a M:Sh ratio of 1:1 for 12 h. The resulting mixtures were separated from the grinding media, subjected to magnetic separation, loaded into a quartz reactor, after which air was evacuated from the reactor and the reactor was filled with high-purity argon (≥99.998 vol. %). Titanium was applied to cubic boron nitride particles by chemical vapor deposition in an argon flow with the temperature raised to 725±5°C at a rate of 7.00±0.50 deg/min and held at the final temperature for 120 minutes. After the reaction mixture cooled, the remaining iodine was removed from it by washing with distilled water through FM filter paper.

As a result, a continuous coating of titanium nitrides and borides with a thickness of 390-530 nm was formed on the surface of cubic boron nitride grains (Fig. 1).

The powder with the applied layer was molded into blanks of the required geometry by uniaxial cold pressing on a hydraulic press under a pressure of 100 MPa. Before the pressing process, the batch was plasticized with a 10% solution of polyvinyl alcohol in water in an amount of 10% of the mixture weight.

Sintering was carried out in a high-pressure apparatus of the "anvil with a dimple" type, installed on a DO138B hydraulic press. During sintering, the pressed material was simultaneously exposed to a pressure of 3.8±0.2 GPa and a temperature of 1450±50°C for 10 sec. Under the influence of high pressures and temperatures, a single structure was formed from the shells of cubic boron nitride grains, formed by the TiN-TiB ₂ binder, uniformly distributed between the cBN grains and firmly bonding them to each other (Fig. 2). The parameters of the synthesis of the cutting material prevent the transformation of the cubic phase of boron nitride into the hexagonal phase.

The cutting properties of cBN-TiN-TiB ₂ plates were assessed based on the results of machining tool steel grade KhVG GOST 5950-2000 with a hardness of 59-60 units by HRC without the use of cutting fluids on a MAZAK QTN250IIM CNC lathe using turning cutters. The tests were carried out according to the following mode: speed - 110 m/min, feed - 0.1 mm/rev, cutting depth - 0.5 mm, cutting time during tests was 5 minutes. The wear criterion during tests of the cutting plate was the size of the plate wear area along the rear face formed during 5 minutes of turning, in the absence of chips on the front or rear surfaces.

The test results are shown in Table 1.

Example 2.

Powders of cubic boron nitride (cBN-M990, fraction 8/4 μm, Funik, China), titanium (PTN-8, fraction 10/0 μm, Normin, Russia) and iodine (iodine mass fraction 99.5%, Reakhim, Russia) were mixed in a ratio of 60 wt. %, 33.4 wt. % and 6.6 wt. %, respectively, similar to Example 1. Titanium was applied to particles of cubic boron nitride by raising the temperature to 710±5°C according to Example 1.

As a result, a continuous coating of titanium nitrides and borides with a thickness of 270-390 nm was formed on the surface of cubic boron nitride grains (Fig. 3).

The forming and sintering of the blanks was carried out according to example 1. The unified structure formed by the TiN-TiB ₂ binder, uniformly distributed between the grains of cubic boron nitride, is shown in Fig. 4.

The cutting properties of the obtained material were assessed similarly to example 1.

The test results are shown in Table 1.

Example 3.

Powders of cubic boron nitride (cBN-M990, fraction 3/1 μm, Funik, China), titanium (PTN-8, fraction 10/0 μm, Normin, Russia) and iodine (iodine mass fraction 99.5%, Reakhim, Russia) were mixed in a ratio of 60 wt. %, 33.4 wt. % and 6.6 wt. %, respectively, similar to Example 1. Titanium was applied to cubic boron nitride particles by raising the temperature to 675±5°C according to Example 1.

As a result, a continuous coating of titanium nitrides and borides with a thickness of 110-180 nm was formed on the surface of cubic boron nitride grains (Fig. 5).

The forming and sintering of the blanks was carried out according to example 1. The unified structure formed by the TiN-TiB ₂ binder, uniformly distributed between the grains of cubic boron nitride, is shown in Fig. 6.

The cutting properties of the obtained material were assessed similarly to example 1.

The test results are shown in Table 1.

Example 4.

Powders of cubic boron nitride (cBN-M990, fraction 10/5 μm, Funik, China), titanium (PTN-8, fraction 10/0 μm, Normin, Russia) and iodine (iodine mass fraction 99.5%, Reakhim, Russia) were mixed in a ratio of 55 wt. %, 38.3 wt. % and 6.7 wt. %, respectively, similar to Example 1. Titanium was applied to the particles of cubic boron nitride by raising the temperature to 725±5°C according to Example 1.

The molding and sintering of the blanks was carried out according to example 1.

The cutting properties of the obtained material were assessed similarly to example 1. The test results are presented in Table 1.

Example 5.

Powders of cubic boron nitride (cBN-M990, fraction 8/4 μm, Funik, China), titanium (PTN-8, fraction 10/0 μm, Normin, Russia) and iodine (iodine mass fraction 99.5%, Reakhim, Russia) were mixed in a ratio of 65 wt. %, 29.2 wt. % and 5.8 wt. %, respectively, similar to Example 1. Titanium was applied to cubic boron nitride particles by raising the temperature to 710±5°C according to Example 1.

The molding and sintering of the blanks was carried out according to example 1.

The cutting properties of the obtained material were assessed similarly to example 1.

The test results are shown in Table 1.

Example 6.

Powders of cubic boron nitride (cBN-M990, fraction 3/1 μm, Funik, China), titanium (PTN-8, fraction 10/0 μm, Normin, Russia) and iodine (iodine mass fraction 99.5%, Reakhim, Russia) were mixed in a ratio of 60 wt. %, 33.4 wt. % and 6.6 wt. %, respectively, similar to Example 1. Titanium was applied to cubic boron nitride particles by raising the temperature to 725±5°C according to Example 1.

The molding and sintering of the blanks was carried out according to example 1.

The cutting properties of the obtained material were assessed similarly to example 1.

The test results are shown in Table 1.

Example 7.

Powders of cubic boron nitride (cBN-M990, 8/4 μm fraction, Funik, China), titanium (PTN-8, 10/0 μm fraction, Normin, Russia) and iodine (iodine mass fraction 99.5%, Reakhim, Russia) were mixed in a ratio of 60 wt. %, 33.4 wt. % and 6.6 wt. %, respectively, similar to Example 1. Titanium was applied to cubic boron nitride particles by raising the temperature to 925±5°C according to Example 1.

The molding and sintering of the blanks was carried out according to example 1.

The cutting properties of the obtained material were assessed similarly to example 1.

The test results are shown in Table 1.

Example 8.

Powders of cubic boron nitride (cBN-M990, fraction 10/5 μm, Funik, China), titanium (PTN-8, fraction 10/0 μm, Normin, Russia) and iodine (iodine mass fraction 99.5%, Reakhim, Russia) were mixed in a ratio of 60 wt. %, 33.4 wt. % and 6.6 wt. %, respectively, similar to Example 1. Titanium was applied to particles of cubic boron nitride by raising the temperature to 925±5°C according to Example 1.

The molding and sintering of the blanks was carried out according to example 1.

The cutting properties of the obtained material were assessed similarly to example 1.

The test results are shown in Table 1.

Example 9.

Powders of cubic boron nitride (cBN-M990, fraction 10/5 μm, Funik, China), titanium (PTN-8, fraction 10/0 μm, Normin, Russia) and iodine (iodine mass fraction 99.5%, Reakhim, Russia) were mixed in a ratio of 70 wt. %, 25 wt. % and 5 wt. %, respectively, similar to Example 1. Titanium was applied to particles of cubic boron nitride by raising the temperature to 755±5°C according to Example 1.

The molding and sintering of the blanks was carried out according to example 1.

The cutting properties of the obtained material were assessed similarly to example 1.

The test results are shown in Table 1.

Example 10.

Powders of cubic boron nitride (cBN-M990, fraction 10/5 μm, Funik, China), titanium (PTN-8, fraction 10/0 μm, Normin, Russia) and iodine (iodine mass fraction 99.5%, Reakhim, Russia) were mixed in a ratio of 70 wt. %, 25 wt. % and 5 wt. %, respectively, similar to Example 1. Titanium was applied to cubic boron nitride particles by raising the temperature to 925±5°C according to Example 1.

The molding and sintering of the blanks was carried out according to example 1.

The cutting properties of the obtained material were assessed similarly to example 1.

The test results are shown in Table 1.

Example 11.

Powders of cubic boron nitride (cBN-M990, fraction 10/5 μm, Funik, China), titanium (PTN-8, fraction 10/0 μm, Normin, Russia) and iodine (iodine mass fraction 99.5%, Reakhim, Russia) were mixed in a ratio of 70 wt. %, 25 wt. % and 5 wt. %, respectively, similar to Example 1. Titanium was applied to particles of cubic boron nitride by raising the temperature to 800±5°C according to Example 1.

The molding and sintering of the blanks was carried out according to example 1.

The cutting properties of the obtained material were assessed similarly to example 1.

The test results are shown in Table 1.

Example 12.

Powders of cubic boron nitride (cBN-M990, fraction 10/5 μm, Funik, China), titanium (PTN-8, fraction 10/0 μm, Normin, Russia) and iodine (iodine mass fraction 99.5%, Reakhim, Russia) were mixed in a ratio of 80 wt. %, 17 wt. % and 3 wt. %, respectively, similar to Example 1. Titanium was applied to particles of cubic boron nitride by raising the temperature to 800±5°C according to Example 1.

The molding and sintering of the blanks was carried out according to example 1.

The cutting properties of the obtained material were assessed similarly to example 1.

The test results are shown in Table 1.

Example 13.

Powders of cubic boron nitride (cBN-M990, fraction 10/5 μm, Funik, China), titanium (PTN-8, fraction 10/0 μm, Normin, Russia) and iodine (iodine mass fraction 99.5%, Reakhim, Russia) were mixed in a ratio of 80 wt. %, 17 wt. % and 3 wt. %, respectively, similar to Example 1. Titanium was applied to cubic boron nitride particles by raising the temperature to 925±5°C according to Example 1.

The molding and sintering of the blanks was carried out according to example 1.

The cutting properties of the obtained material were assessed similarly to example 1.

The test results are shown in Table 1.

Example 14.

Powders of cubic boron nitride (cBN-M990, fraction 10/3 μm, Funik, China), titanium (PTN-8, fraction 10/0 μm, Normin, Russia) and iodine (iodine mass fraction 99.5%, Reakhim, Russia) were mixed in a ratio of 60 wt. %, 33.4 wt. % and 6.6 wt. %, respectively, similar to Example 1. Titanium was applied to particles of cubic boron nitride by raising the temperature to 710±5°C according to Example 1.

The molding and sintering of the blanks was carried out according to example 1.

The cutting properties of the obtained material were assessed similarly to example 1.

The test results are shown in Table 1.

List of sources:

1. Angseryd, J., et al. Detailed microstructure of a cBN based cutting tool material / J. Angseryd, M. Elfwing, E. Olsson, // International Journal of Refractory Metals and Hard Materials. - 2009. - Is. 27. - P. 249-255.

2. Bulatov O.N. et al. Phase composition and physical and mechanical properties of cutting compositions based on cubic boron nitride / O.N. Bulatov, S.S. Ordanyan, V.I. Rumyantsev, N.Yu. Korableva, V.N. Fishchev // Refractories and technical ceramics. No. 1-2. - 2019. - P. 3-9.

3. Synthetic superhard materials: In 3 volumes. Volume 1 Synthesis of superhard materials / edited by V.M. Novikov [et al.]. - Kyiv: Naukova Dumka, 1986. - P. 280.

4. Shipilo V.B., Shishonok N.A., Dutov A.G. Superhard materials: production, properties and application // Actual problems of solid state physics: Collection of articles for the 40th anniversary of the ISPSS NAS of Belarus and the 90th anniversary of its founder, Academician N.N. Sirota / NAS of Belarus, Institute of Solid State Physics and Semiconductors. - Minsk, 2003. - P. 650-698.

5. RU 2147972 (C1) - Method for producing superhard composite material based on cubic boron nitride for cutting tools and composite material / Authors: S.S. Ordanyan, T.M. Svyazkina, S.V. Zhuravlev, S.A. Hotakko, V.A. Yashin; patent holder: Open Joint-Stock Company "Ilyich Abrasive Plant" [Russia]. Published 27.04.2000.

6. RU 92007535 (A) - Method for manufacturing superhard composite materials / Authors: A.N. Kudelsky, V.A. Ponomarenko, N.N. Stepanov, V.T. Vesna [Russia]. Published 10.02.1995.

7. EP 0570635 (A1) - Products and process for making multigrain abrasive compacts / Authors: D.E. Slutz, F.R. Corrigan; patent holder: General Electric Company [USA]. Published 24.11.1993.

8. SU 1583457 (A1) - Charge for producing sintered superhard tool material / Authors: V.T. Vesna, V.P. Maslov, V.A. Ponomarenko, E.Ya. Dovgal, S.V. Chizhov, G.V. Yakovlev [Russia]. Published 07.08.1990.

Claims (1)

A method for producing a superhard composite material for a cutting tool, including preparing a charge by mixing cubic boron nitride powders in an amount of 55-65 mass. % of the charge weight, metallic titanium and iodine at a titanium to iodine weight ratio of 5:1, applying a titanium layer to the surface of cubic boron nitride particles by chemical vapor deposition, forming a layer of titanium nitrides and borides with a temperature increase at a rate of 7.00±0.50 deg/min and holding at a final temperature for 120 min, molding cutting tool blanks from the resulting powder and sintering the blanks at a temperature of 1450±50°C under a pressure of 3.8±0.2 GPa for 10 s with the simultaneous formation of a bond of titanium nitride and titanium diboride, characterized in that cubic boron nitride powder of fraction (μm) 10/5 is used to prepare the charge and further processing and the process of forming a layer of titanium nitrides and borides on the surface of cubic boron nitride particles is carried out to a final temperature 725±5°C, or cubic boron nitride powder of fraction (μm) 8/4 is used and the specified process is carried out to a final temperature of 710±5°C, or cubic boron nitride powder of fraction (μm) 3/1 is used and the specified process is carried out to a final temperature of 675±5°C.