FR2562451A1 - Composite cutting insert for machining high-resistance workpieces and process for manufacturing this insert - Google Patents

Abstract

The composite cutting insert comprises three layers: a cutting layer, made of an extra hard constituent, a substrate, made of metal suitable for brazing, and an intermediate layer which is located between the cutting layer and the substrate and consists of a mixture containing 5 to 40% by weight of the constituent of the cutting layer and 10 to 80% by weight of the constituent of the substrate, the remainder being products from the reaction between the constituents indicated. The insert is manufactured by a process comprising the preparation of the charge for the cutting layer, the charge for the substrate and the charge for the intermediate layer consisting of a mixture of 10 to 60% by weight of the charge for the cutting layer and of 40 to 90% by weight of the charge for the substrate. These charges are placed in a matrix, the charge for the intermediate layer being located between the charge for the substrate and the charge for the cutting layer. Then the layers are compressed under low pressure, after which the blank obtained is pressed at 40 to 150 x 10<8> Pa at a temperature of 1200 to 3500 DEG K. Application to the manufacture of cutting tools for machining very high-resistance workpieces.

Description

The present invention relates to composite cutting inserts for machining high strength parts, and to methods of manufacturing such inserts. The composite cutting insert is the active element in tools for machining high resistance parts and working with hard materials. By way of example of such tools, there may be mentioned the various kinds of single-cut tools, drill bits, cutters, bits, etc.

At present, great development has been given to various kinds of composite wafers, comprising an extra hard component cutting layer and a substrate suitable for soldering. Thus, for example, French patent NO 2089415 describes a cutting insert comprising a metal carbide substrate, suitable for brazing, and a cutting layer consisting of diamond particles. Such a cutting insert is obtained by placing the intended load. to the production of carbide in
A protective sheath, by placing diamond particles on this load and sintering at a temperature of 1400 to 1600 C under a pressure of about 40 kbar (40 x 108 pa). One of the drawbacks of such a cutting insert is the large difference in the expansion coefficients of the diamond cutting layer and of the carbide layer constituting the substrate, which causes, during the use of the cutting insert , the appearance at the interface of the layers of critical stresses leading to the separation of the layers and the putting out of use of the wafer.

French patent NO 2144426 describes a cutting insert which consists of a metal carbide substrate and a cutting layer containing crystals of cubic boron nitride and aluminum in the form of a composition with nickel, cobalt , manganese, iron, vanadium or chromium Such a plate is obtained by placing crystals of cubic boron nitride, aluminum in composition with nickel, manganese, iron, vanadium or chromium on the carbide substrate (that is to say on the starting mixture for the production of the metal carbide) then by sintering at a temperature
8 from 1300 to 16000 C, under a pressure greater than 40 x 108
Pa. In this case, the stresses appearing at the interface of the substrate layer and the cutting layer are smaller than those appearing in the wafer of patent No. 2089415, but, on the other hand, the cutting properties of the active cutting layer are greatly altered, hence the lowering of the quality of this kind of cutting inserts. A similar drawback is presented by the cutting insert described in French patent NO 2143954; consisting of a metal carbide substrate and a cubic boron nitride cutting layer, in which aluminum alloyed with cobalt, nickel or manganese is present. The cutting insert, described in French patent NO 2143954, is obtained by placing a hexagonal boron nitride powder, with the addition of aluminum alloyed with cobalt, nickel or manganese, on the charge intended for the production of the carbide, then by sintering at a temperature of about 14000C under a pressure of approximately So x 108 Pa.
- Similar composite cutting inserts (cutting pads3, in which one of the layers is made of an extra-hard material (diamond, cubic boron nitride) or a mixture of such a material with a metal, - the second, the substrate, is metal or metal carbide, are described in the patents NO 3745623 and 3850053 of the United States, ~ NO 2213827 of France, NO 2324155 of RFA and NO 43-30409 of Japan. However, due to the large difference between the coefficients of expansion of the layer of extra-hard material and of the layer of metal or metal carbide, the two-layer platelets frequently break at the interface of said layers during their manufacture, during their brazing during the manufacture of the cutting tool, or during their use.

The aim of the invention is to create a composite cutting insert for machining high-strength parts, which would give the cutting tool mechanical strength and increased resistance and which would allow the machining of discontinuous surfaces on parts. .

Another object of the invention is to develop a method of manufacturing the composite cutting insert which would make possible a reliable junction between. the substrate and the cutting layer of the wafer chemically, giving good resistance to the cutting tool, as well as obtaining a wafer whose attachment to the tool holder would be easy.

The objective of the invention was to manufacture a composite cutting wafer, consisting of a substrate and a cutting layer, in which the cutting layer would not peel off from the substrate, that is to say would be bonded to it in a manner. reliable.

The solution consists of a composite cutting insert for machining high resistance parts, comprising a cutting layer made of an extra-hard component and a metal substrate suitable for brazing, in which, according to the invention, between the cutting layer and -the substrate, there is an intermediate layer consisting of a mixture of the following constituents
- extra-hard component of the cutting layer, at a weight rate of 5 to 40%
substrate metal, at a weight ratio of 10 to 80%
- products of the reaction between the constituents indicated, at a weight rate equal to the balance.

In such a wafer, the cutting layer and the substrate are chemically bonded together with the aid of the intermediate layer, so they do not come off during use of the cutting tool. The mechanical resistance and the resistance of the cutting tool armed with such an insert are greater.

Another important advantage of the composite insert is that it allows the machining of discontinuous surfaces on parts, while the known inserts, made of two layers, do not allow the machining of discontinuous surfaces (i.e. (say surfaces with grooves, notches, recesses and abrupt transitions).

The composite cutting insert according to the invention is manufactured by a process comprising the preparation of fillers for the cutting layer and the substrate, the placing of these fillers in a die, their compression under the pressure necessary for the preparation (the shaping) of a compact blank, the action of high pressures and high temperatures on the blank obtained, a process in which, according to the invention, between the charge for the cutting layer and the charge for the substrate, interposing an intermediate filler layer obtained by mixing 10 to 60 X by weight of filler for the cutting layer and 40 to 90 X by weight of filler for the substrate,
In what follows, a detailed description is given of the composite cutting insert and of the method of manufacturing this insert.

The cutting layer of the wafer can be produced with the following constituents: cubic boron nitride, doped cubic boron nitride, wurtzitic boron nitride, diamond, as well as their mixtures.

The substrate of the wafer can be made of metals suitable for brazing or of -alloys of these metals, of steel, as well as of metal carbides.

Various variations in the composition of the composite cutting insert are possible, depending on the material adopted for its cutting layer and depending on the material adopted for the substrate.

According to the invention, the composite site cutting plate may consist of a cutting layer of cubic boron nitride, a titanium substrate and an intermediate layer which contains 5 to 10% by weight of cubic boron nitride and 35 to 70%. X by weight of titanium, the balance being titanium borides and nitrides.
The cutting tool armed with such an insert is recommended for machining high strength steels and other difficult to machine materials. Note that this tool machines not only continuous surfaces, but also discontinuous surfaces. Such a tool has shown in use high mechanical strength and high wear resistance.

According to the invention in a second variant, the composite cutting plate consists of a diamond cutting layer, a titanium substrate and an intermediate layer containing 20 to 30 X by weight of diamond and 30 to 40 X by weight of titanium , the balance being titanium carbide. The cutting tool armed with such an insert is recommended for machining non-ferrous metals and their alloys. It is also endowed with high mechanical strength and high wear resistance and is suitable for machining both continuous and discontinuous surfaces on parts.

According to the invention, in a third variant, the composite cutting insert consists of a diamond cutting layer, a metal carbide substrate, for example cobalt tungsten carbide, and an intermediate layer containing from 10 to 30-% in weight of diamond t from 60 to 90% by weight of said carbide, the balance being the products of the reaction between the diamond and the carbide. The cutting tool armed with such an insert is recommended for machining non-ferrous metals and their alloys.

In the following variant, the composite cutting plate is constituted, according to the invention, by a cutting layer containing from 40 to 60 X by weight of cubic boron nitride and from 40 to 60 X by weight of wurtzitic boron nitride, a substrate carbon steel and an intermediate layer containing 20 to 25% by weight of the component of the cutting layer and 45 to 60% by weight of steel, the balance being the products of the reactions between the indicated components. The cutting tool armed with such an insert is used for machining hardened steels and other materials that are difficult to machine.

I1 is particularly suitable for machining discontinuous surfaces.

In yet another variant, the composite cutting wafer consists of a cutting layer of cubic boron nitride doped with aluminum, a titanium substrate and an intermediate layer containing 5 to 10% peas of cubic boron nitride and from 70 to 85% by weight of titanium, the balance being the products of the reaction between boron nitride and titanium.

Another subject of the invention is a process for manufacturing the composite cutting insert, which comprises:
the preparation of the filler for the cutting layer, with an extra-hard constituent or a constituent which can be transformed into an extra-hard material during the carrying out of the process;
preparing the filler for the substrate, with a metal having a melting point near 12000K or higher, suitable for brazing
preparing the filler for the intermediate layer, with constituents of the filler for the cutting layer and the filler for the substrate.

The prepared charges are placed in a matrix1 in a strictly determined order: first the charge intended for the substrate, then the charge intended for the intermediate layer, then the charge intended for the cutting layer, or in the reverse order: charge for the cutting layer, filler for the intermediate layer and filler for the substrate. The layers thus arranged are compressed under a pressure of 3 to 8 x 108 Pa so as to obtain a compacted blank (preformed block, compressed, briquette). Then, the blank obtained is placed in the chamber of a high pressure device, in which it is subjected to the action of a pressure of 40 to 150 x 108 Pa and a temperature of 12000 to 35000K.

Practically, the process is carried out as follows.

First, fillers of three kinds are prepared: a filler for the substrate, a filler for the intermediate layer and a filler for the cutting layer. For this, the starting components for each batch are ground to a grain size of 0.5 to 20-40 µm.

For the filler for forming the cutting layer, the preferable grain size is 0.5-10vm.

The filler for the substrate can have a grain size of 3-5 µm at 40 µm and even up to 100 µm, although it is preferable that the grain sizes are similar in all fillers.

In the case where the starting constituents are diamond, cubic boron nitride, wurtzitic boron nitride, the separated granular class is impregnated with an aqueous solution of starchy materials (dextrin) to improve its compressibility.

The filler for the intermediate layer is prepared by mixing the constituents of the cutting layer and the constituents of the substrate in the desired proportion, i.e. 10 to 60 by weight of the constituent of the cutting layer and 40 to 90 % by weight of substrate component.

The charges thus prepared are placed in a matrix, so that the intermediate layer is located between the charge layer of the substrate and the charge layer for the cutting layer. This done, the indicated layers are compressed (in the majority of cases, the compression pressure is 3 to 8 x 108 Pa) until a compact blank is obtained. In the case where the component of the filler for the cutting layer is an extruded material, the compression pressure of the blank may also be higher. The blank obtained is extracted from the die and introduced into the chamber of a high pressure device, where it is subjected to the action of a high pressure, from 40 to 150 x 108 Pa, at a temperature of 12000 to 35000K.

The pressure and the temperature are chosen within the ranges indicated according to the starting constituents, entering into the composition of the filler of each of the layers: of the substrate, of the intermediate layer and of the cutting layer.

In summary, the invention is characterized in that, between the filler for the substrate and the filler for the cutting layer, an intermediate filler layer is interposed, obtained by mixing from 10 to 60-X x by weight of constituent for the layer. cutting and 40 to 90% by weight of component for the substrate.

The invention makes it possible to obtain a composite cutting wafer in which the cutting layer and the substrate are secured in a reliable manner by an intermediate layer in which, under the action of pressures and high temperatures, reaction products are formed. constituents of the cutting layer and the substrate. This has a favorable influence on the mechanical resistance of the wafer during its use. We have also succeeded in preventing the detachment (loosening) of the layers (cutting layer and substrate) during the use of the insert on a cutting tool, detachment which occurs in known inserts made up of two layers: the cutting layer and the substrate.

The filler for the cutting layer may contain at least one of the following powder constituents: cubic boron nitride, doped cubic boron nitride, wurtzitic boron nitride, hexagonal boron nitride, diamond, graphite, as well as any extra constituent. suitable hard component or component - capable of being transformed into an extruded component under the action of high pressure and temperature. The filler for the cutting layer can be doped with 0.5 to 5% by weight of additions such as aluminum, boron, aluminum borides and nitrides.

The starting constituents used for the filler for the substrate can be metals with a melting point near 12000K or higher, suitable for brazing, their alloys, steel, fillers for metal carbides and other suitable constituents. in powder form. The term “filler for a metal carbide” is understood to mean a starting mixture used to produce a metal carbide. In the flush of a cobalt tungsten carbide, this filler is a mixture of tungsten carbide and cobalt, or else a mixture of tungsten, carbon and cobalt.

The composition of the charge of the intermediate layer depends in each specific case on the constituent taken for the charge of the cutting layer and on the constituent taken for the charge of the substrate. It follows the following possible embodiments of the method.

According to the invention, the composite cutting insert is manufactured by successively placing in a matrix a filler for the cutting layer, consisting of cubic boron nitride, a filler for the intermediate layer, consisting of 5 to 10 X by weight of nitride cubic boron and 90 to 95% by weight titanium, and a filler for the substrate, consisting of titanium. The listed layers are compressed in the die and the resulting blank is subjected to the action of a pressure of 40 to 90 x 108 Pa, at a temperature of 18000 to 24000K.

The composite insert obtained by the process just described is used on a cutting tool, mainly intended for machining ferrous metals. During its use, no detachment of the cutting layer and the substrate is observed.

In a second variant, the method comprises the successive placement in the matrix of three layers:
a diamond filler for the cutting layer;
a filler for the intermediate layer, consisting of 30 to 40% by weight of diamond and 60 to 70% by weight of titanium;
and a filler for the substrate, consisting of titanium.

The three loads are compressed under a pressure of approximately 8 x 108 Pa and the blank obtained is subjected to the action of a pressure of 40 to 70 x 108 Pa, at a temperature of 120 in at 18000K. The composite wafer thus obtained can be used for the manufacture of a cutting tool, preferably intended for the machining of non-ferrous metals, as well as ceramics or plastics reinforced with glass fibers.

In a third variant embodiment of the invention, the constituent used in the process for the filler intended for the cutting layer is graphite.

The graphite filler is placed in a die, followed by the filler for the intermediate layer, consisting of 10 to 30% by weight of graphite and 70 to 90% by weight of cobalt tungsten carbide, and the filler for the substrate. , consisting of a charge for the production of a cobalt tungsten carbide.

The three layers are compressed in the die under a pressure of about 8 x 108 pa and the blank obtained is subjected to the action of a pressure of 90 to 150 x 108 Pa at a temperature of 24000 to 36000K.

This variant illustrates the possibility of using, for the production of the cutting layer, a non-hard component, which then passes to the extra-hard state. Under the action of high pressure, the reaction products of the constituents, ie tungsten and cobalt carbides, are formed in the intermediate layer.

From the following variant embodiment of the method, a charge for the cutting layer, consisting of hexagonal boron nitride, doped with 0.5 to 5% by weight of aluminum, is poured into the matrix, then one places in place the intermediate layer of a filler consisting of 10-20 wt% filler employed for the cutting layer and 80-90 wt% titanium, and finally a titanium filler. The three charges are compressed under a pressure of 3 to 8 × 108 Pa. After which, the blank obtained is subjected to the action of a pressure of 60 to 90 × 108 Pa, at a temperature of 21000 to 29000K. Under the action of high pressure and temperature, reaction products of boron nitride and titanium are formed in the intermediate layer.

According to a further variant of the method, the filler for the cutting layer, consisting of 1 to 12% by weight of hexagonal boron nitride and 88 to 99% by weight of wurtzitic boron nitride, is poured into the matrix. , then the intermediate filler layer, consisting of 30 to 36% by weight filler of the cutting layer and 64 to 70% by weight of carbon steel, is placed in the die, and, finally, the layer load for the substrate, consisting of carbon steel.

The compressed blank is placed in the chamber of a high pressure device, in which it is subjected to the action of a pressure of 60 to 90 x 108 Pa at a temperature of 20,000 to 25,000K. Under the action of high pressure and temperature, reaction products of constituents, i.e. borides and nitrides of iron are formed in the intermediate layer.

For a better understanding of the invention, examples of the composite cutting insert and examples of implementation of the manufacturing process of this insert are given.

Example 1.

First, fillers of three kinds are prepared: a filler for the substrate, a filler for the intermediate layer and a filler for the cutting layer. For this, the starting constituents are ground and the granular class is separated from 0.1 to 15 µm. In the case where the starting constituents used are powders of extra-hard materials, the separated granular class is impregnated with an aqueous solution of starchy materials (dextrin).

The filler for the intermediate layer is prepared by mixing the constituents of the cutting layer and the constituents of the substrate in the desired proportion.

- In the example considered, the fillers thus obtained are placed in the matrix: the filler for the substrate, consisting of a titanium powder, the filler for the intermediate layer, consisting of carefully mixed constituents - titanium and nitride cubic boron, the weight ratio of titanium being 90 X and the weight ratio of cubic boron nitride, 10 X - and the load for the cutting layer, consisting of a powder of cubic boron nitride, then compressed under a pressure of 5 x-108 Pa. The obtained blank is placed in the chamber of a high pressure device where it is subjected to a pressure of 70 x 108 Pa, at a temperature of 20000K, pen in 30 seconds. Under these conditions, titanium borides and nitrides are formed in the intermediate layer.

After removing the pressure and cooling, a three-layer wafer is obtained.

By X-ray analysis, the constituent phases of the intermediate layer were determined, which contained about 5% by weight of cubic boron nitride and about 70% by weight of titanium, the balance being borides and nitrides of titanium.

Such an insert was used on a cutting tool (single-cut), the attachment to the tool holder having been carried out by brazing. The brazing did not destroy the wafer. When cutting hardened alloy steel, the tool strength was 1.5 times greater than that of tools armed with known inserts.

Exemole 2.

The wafer manufacturing process is carried out in the same way as in Example 1, but the filler used for the cutting layer consists of 95% by weight of hexagonal boron nitride powder and 5% by weight of aluminum, and the intermediate layer consists of 20% by weight of a mixture of hexagonal boron nitride and aluminum and 80% by weight of titanium. The substrate is made of titanium and the compression is carried out as described in example i. The blank obtained is subjected to the action of a pressure of 60 x 108 Pa at a temperature of 21000K for 45 seconds. In the prepared wafer, the X-ray analysis revealed an intermediate layer containing about 10 X by weight of cubic boron nitride doped with aluminum and about 60% by weight of titanium, the balance being borides and nitrides of titanium.

The properties of the wafer obtained are similar to those of the wafer of Example 1.

Example 3.

The draft is developed in the same way as
Example 1, but the filler used for the cutting layer consists of a diamond powder. Layer
intermediate is carried out with a load consisting of
30% by weight of diamond powder and 70% by weight of titanium powder, and the filler for the substrate consists of titanium. The resulting blank is subjected to the action
a pressure of 65 x 108 Pa at a temperature of 16000K, for 50 seconds. In the elaborate wafer, X-ray analysis revealed an intermediate layer
containing about 20 X by weight of diamond and about 35 X
by weight of titanium, the balance being titanium carbide.

The cutting tool armed with such an insert is used for machining non-ferrous metals and alloys.

Example 4.

The manufacturing process of the composite wafer is carried out in the same way as in Example 1, but the filler for the cutting layer consists of
the following powder constituents: 92% by weight of boron nitride; tzitic and 8% by weight of hexagonal boron nitride. The filler for the intermediate layer consists of 30% by weight of boron nitride and 70% by weight of carbon steel powder. - The charge for the
substrate - is carbon steel powder. After the pre
compression, the blank is subjected to the action of a pressure
sion of 75 x 108 Pa at a temperature of 22000K, for
30 seconds The middle layer of the engineered composite wafer contains approximately 20% by weight of nitride
cubic and wurtzitic boron and about 53 X steel,
the balance being borides and iron nitrides. When
the brazing of the plate obtained on a tool holder,
no detachment (rupture) of the wafer was observed
vé. The armed cutting tool of this insert is used
for machining discontinuous surfaces on hardened steels.

Example 5.

The blank is produced in the same way as in Example 1, but the filler used for the cutting layer consists of graphite. For the intermediate layer, the filler consists of 20% by weight of graphite and 80% by weight of filler for the production of a cobalt tungsten carbide. The filler for the substrate is a filler for making a cobalt tungsten carbide. The blank obtained is subjected to the action of a pressure of 120 y 108 Pa at a temperature of 25000K, for 55 seconds. In the composite wafer, the intermediate layer contains about 18% by weight diamond and about 80% by weight carbide, the balance being the reaction products.

When brazing and using the insert on a cutting tool, no breakage of layers was observed.

Example 6.

The blank is prepared in the same way as in Example 1, but the filler used for the cutting layer consists of 8% by weight of hexagonal boron nitride and 92% by weight of wurtzitic boron nitride. The filler for the intermediate layer consists of 20% by weight of boron nitride and 80% by weight of chromium. The filler for the substrate consists of chromium. The blank obtained is subjected to the action of a pressure of 90 x 108
Pa at a temperature of 24000K, for 60 seconds. In the composite wafer, the intermediate layer contains about 50% by weight of cubic boron wurtzitic nitride and about 20% by weight of chromium, the balance being nitrides and borides of chromium.

When brazing and using the insert on a cutting tool, no breakage of layers was observed.

Claims (14)

1. Composite cutting insert for machining high resistance parts, comprising a cutting layer made of an extra-hard component and a metal substrate suitable for soldering, characterized in that between the cutting layer and the substrate there is a layer intermediate consisting of a mixture of the following constituents extra-hard component of the cutting layer3 at a weight ratio of 5 to 40 X, metal of the substrate, at a weight rate of 10 to 80%, products of the reaction between the constituents indicated at a weight ratio equal to the balance. 2. Composite cutting insert according to claim 1, characterized in that the cutting layer consists of cubic boron nitride, doped cubic boron nitride, diamond or a mixture of these materials. 3. Composite cutting insert according to claim 1, characterized in that. the substrate consists of metals suitable for brazing, alloys of these metals, steels or metal carbides. 4. Composite cutting insert according to any one of claims 1 to 3, characterized in that the cutting layer is constituted by cubic boron nitride, the substrate by titanium3 and the intermediate layer by 5 to 10% by weight of nitride. cubic boron and 35 to 70% by weight of titanium3 the balance being titanium borides and nitrides. 5. Composite cutting insert according to any one of claims 1 to 3, characterized in that the cutting layer consists of diamond, the substrate of titanium, and the intermediate layer of 20 to 30: by weight of diamond and 30 to 40% by weight of titanium, the balance being titanium carbide. 6. Composite cutting insert according to any one of claims 1 to 3, characterized in that the cutting layer is constituted by diamond, the substrate by cobalt tungsten carbide, and the intermediate layer by 60 to 90% by weight. of the mentioned carbide and 10 to 30% by weight of diamond, the balance being products of the reactions between the diamond and the carbide. 7. Composite cutting insert according to any one of claims 1 to 3, characterized in that the cutting layer consists of cubic boron nitride doped with aluminum, the substrate with titanium, and the intermediate layer with 5 to 10% by weight of cubic boron nitride and 70 to 85% by weight of titanium, the balance being products of the reaction between boron nitride and titanium. 8. A method of manufacturing a composite cutting insert according to any one of claims 1 to 7, comprising 1) preparing the filler for the cutting layer1 with an extra-hard component or a component capable of transforming into an extra-hard material when subjected to the action of high pressures and temperatures; 2) preparing the filler for the substrate, with a metal suitable for brazing 3) placing said loads in a die and compressing them under a pressure of 3 to 8 x 108 Pa, so as to obtain a compact blank; and 4) the action on the blank obtained by high pressure and high temperature, characterized in that, between the load for the cutting layer and the load for the substrate, an intermediate load layer is interposed consisting of a mixture consisting of 10 to 60% by weight filler for the cutting layer and 40 to 90% filler for the substrate. 9. Method according to claim 8, characterized in that the starting constituent for the filler intended for the cutting layer is a powder of cubic boron nitride, doped cubic boron nitride, wurtzitic boron nitride, boron nitride. hexagonal, diamond or graphite, or a mixture of these powders. 10. The method of claim 8, characterized in that the starting component for the filler intended for the substrate is a metal powder with a melting point close to 12000K or higher, suitable for brazing, or an alloy of this metal. , of steel, or else a filler intended for the production of a metal carbide. 11. Method according to any one of claims 8 to 10, characterized in that the filler for the cutting layer consisting of cubic boron nitride is successively poured into the matrix, the filler for the intermediate layer consisting of 5 to 10% by weight cubic boron nitride and 90-95% by weight titanium, and the filler for the substrate consisting of titanium, then the filler layers are compressed under a pressure of 3-8 x 108 Pa and the blank obtained is subjected to the action of a pressure of -40 to 9O x 108 Pa and a temperature of 18000 to 24000K. 12. Method according to any one of claims 8 to 10, characterized in that. that the filler for the cutting layer consisting of diamond, the filler for the intermediate layer consisting of 30 to 40 X by weight of diamond and 60 to 70 X by weight of titanium, and the filler for the substrate consisting of titanium, then these charges are compressed under a pressure of 3 to 8 x 108 Pa, and the blank obtained is subjected to the action of a pressure of 40 to 70 x 108 Pa and a temperature of 12000 to 18000K. 13. Process according to any one of claims 8 to 10, characterized in that the filler for the cutting layer consisting of graphite is successively poured into the matrix, the filler for the intermediate layer consisting of 10 to 30% by weight of graphite and 60 to 90% by weight of filler intended for the production of a tungsten carbide with cobalt, and the filler for the substrate constituted by a filler for the production of a tungsten carbide with cobalt, then these layers are compressed under a pressure of 3 to 8 x 108 Pa and the. subjects the blank obtained to the action of a pressure of 90 to 150 x 108 Pa and a temperature of 2400C to 35000K. 14. Method according to any one of claims 8 to 10, characterized in that the filler for the cutting layer consisting of hexagonal boron nitride doped with 0.5 to 5% is successively poured into the matrix. by weight of aluminum, the filler for the intermediate layer consisting of 10 to 20% by weight of hexagonal boron nitride and 80 to 90% by weight of titanium, and the filler for the substrate consisting of titanium, then these are compressed loads under a pressure of 3 to 8 x 108 Pa and the blank obtained is subjected to the action of a pressure of 60 to 90 x 108 Pa and a temperature of 21000 to 29000K.