DE2534777C2 - Method for soldering a polycrystalline body made of extremely hard material based on boron nitride and / or diamond with a metal part and solder for carrying out this method - Google Patents

Description

consists.

5. solder containing copper, tin and titanium for the method according to any one of claims 1 to 4, characterized in that it is made of

13 to 60% copper,
5 to 15% tin,
5 to 25% titanium,

2 to 15% lead and

03 to 20% of a metal from the group

Molybdenum, tungsten, tantalum

consists

6. Lot according to claim 5, characterized in that it contains 0.5 to 20% of a non-metallic filler contains

7. Lot according to claim 6, characterized in that the non-metallic filler is a powder with 1 to 50 μΐη grain size is

The invention relates to a method for soldering a polycrystalline body made of extremely hard material based on boron nitride and / or diamond with a metal part in which on the body one Metal coating made of at least one metal which causes high adhesion to the material and at least a metal exhibiting reduced oxidizability is present and the soldering process is carried out at atmospheric pressure takes place in air. The invention also relates to a solder containing copper, tin and titanium for these Procedure.

In DE-PS 2010 183 there is a coated diamond for cutting, grinding and the like. Diamond particles or diamond splinters are called diamond used completely with a layer of titanium and / or zircon and on top of another one Layer of copper or nickel are provided. These two layers are applied galvanically, electroless or by vacuum methods. The diamond particles or diamond splinters prepared in this way are then adhered to the surface of a support individually or in a plurality or individually or in multiple layers or in another conglomerated structure partly or entirely in Matrices made of metal, ceramic or organic material are embedded on the diamond particles applied layers take up about 10 to 30 percent by volume of the total particles. The first Layer on the diamond particles serves for good adhesion, while the second layer protects the first layer before oxidation is used.

The cutting elements for cutting and grinding tools are novel, super-hard synthetic materials based on diamond and boron nitride.

Since the new super-hard materials z. B. Compared to natural diamonds, low temperature when changing to a hexagonal modification, increased brittleness and reduced strength, have increased chemical resistance and coefficients of thermal expansion that differ from the metals, With which they can be soldered, strongly differ, is the development of new soldering processes and new solders which are most suitable for these purposes. As practice shows, the known ones correspond Processes and solders for soldering and metallizing are not completely the same as for new ones for the production of cutting and grinding tools for certain materials.

There is known a method for pouring a

liquid solder in the gap between natural diamond and metal under vacuum at a temperature of 900 to 1100 ⁰ C. Gold-tantalum, gold-niobium, silver-copper-titanium, silver-titanium alloys as well as aluminum and silicon-containing alloys use (FR-PS 13 32 423, US-PS 3192 620, GB-PS 9 32 729.11 51 666.20 31 913).

The process ensures adhesive strength of the soldering

A method for pressing the diamond crystals into a copper-tin-titanium metal powder is also known (JP-PS 47-44 134) or in an alloy based on copper-tin-chromium-tungsten (GB-PS 1114 353) with subsequent liquid phase sintering. Because of this The process also ensures adhesive strength of the soldering

The soldering processes listed are only used to a limited extent because they lead to thermal formation Tensions lead to the soldering points, which when soldering particularly brittle materials such as polycrystalline, Superhard materials based on diamond boron nitride, the formation of cracks in the body of the superhard material In addition, the processes are expensive because of the use of a high vacuum apparatus.

Also known is a method for soldering metal and diamond in which a metal coating is made Titanium and zirconium is applied in a vacuum at a temperature sufficient for adhesion of the metal coating on the diamond is sufficient and in which the metal is soldered to the metallized diamond, by applying silver-copper solder to the soldering surface of the diamond at the melting temperature of the solder will.

By using the plastic solder, this process provides the solder seam strength and elimination the thermal stresses in the solder joint. However, the method is insufficiently reliable because of the quick oxidizability of the titanium and zirconium fiber coating, which often affects the quality of the soldering (Decrease in adhesion) Decreased Because of the use of vacuum apparatus, the process is also expensive.

When soldering and metallizing diamond and boron nitride, solder is based on copper-tin-titanium alloys (JP-PS 47-44 134), the opposite of the materials based on diamond and boron nitride has high adhesion is most commonly used.

This solder is not very plastic and brittle. Its coefficient of thermal expansion differs from the Thermal expansion coefficients for the new, super-hard materials based on diamond and boron nitride. This inevitably leads to thermal stresses in the soldering zone, which causes a large number of cracks on the cutting element and rapid tool wear during the Require work.

The invention is based on the object of providing a method for soldering metals and materials on diamond and / or to develop a boron nitride base and a solder for this process, which means that the go Metal coatings with high strength and freedom from tension in the soldered connections the production of a reliable soldered connection by reducing the oxidisability of the metal coating and increasing performance during the soldering process, which can be carried out in air, are guaranteed.

This object is achieved by a method of the type specified at the outset, which is implemented according to the invention by the Features of claim 1 is characterized

This object is also achieved by a method of the type specified at the outset, according to the invention is characterized by the features of claim 2

Preferred embodiments of these methods are defined according to the invention by the features of the subclaims 3 and 4 marked

The solder containing copper, tin and titanium is for the method according to the invention by the claim 5 indicated composition

According to the invention, preferred embodiments of this solder are defined by dependent claims 6 and 7 marked

The metals chromium, molybdenum, tantalum, tungsten alone (claim 1) or these metals together with Titanium (claim 2) result in a high adhesive activity (adhesion) due to their chemical interaction with diamond and / or boron nitride during deposition at temperatures suitable for chemical Reaction is sufficient (800 to 1000 ° C).

The metals silver, lead, tin, Cobalt, copper and nickel are not adhesive with regard to diamond and / or boron nitride and take over essentially the function of the oxidation protection of the highly adhesive metals.

The specified amounts to be applied result in high adhesion of the metal coating to the Materials based on diamond and / or boron nitride and thus represent an optimal concentration range of adhesive metals and metals that have a reduced oxidizability.

The soldering process is carried out in air at atmospheric pressure, which increases the performance of the process is increased. So that the high adhesion of the metal coating to the materials on diamond and / or boron nitride base is retained, the soldering process is carried out under a layer of liquid flux performed for soldering metals with metallic hard solders because of its low melting point (500 to 700 ° C) is determined.

The metals used to reduce the oxidizability of the first metal coating are high Plasticity, thereby advantageously an additional indispensable requirement for the soldering process is fulfilled; Furthermore, these metals result in good wettability with the solder.

The one that ensures firm adhesion to materials based on boron nitride and / or diamond and a metal coating having a low oxidizability is applied in two stages, and Although a layer of a hard metal is first produced at 800 to 1000 ° C in a vacuum, this metal enters into a chemical reaction with the material on which it is based, resulting in a high degree of adhesion Metal coating is achieved. This first layer is applied in a thickness of 0.0005 to 0.001 mm. Then a layer of a metal that is not very oxidizable is also applied so that the The function of oxidation protection of the first layer takes over and good wettability with the solder possesses, in a thickness of 0.001 to 0.01 mm.

But it is also possible to use the metal coating on the materials of the basis with high adhesion and low oxidizability by applying a melt of the coating metal, which is opposite to the metallizing materials have a high adhesive strength

owns, is applied. The adhesion takes place on The reason for the chemical adsorption of the adhesive component of the melt on the material of the Basis for its interaction in a vacuum (or in a protective atmosphere) at a temperature that is sufficient for a chemical reaction to take place, while the outer layer of the alloy provides protection against oxidation of the metal coating takes over. The optimal thickness of the metal coating is 0.01 to 0.5 mm.

The method for metallizing the surface of the material based on diamond and / or boron nitride can be any. There are, for example, the evaporation of metal when heated by means of an electron beam and the deposition of metal vapors on a relatively cold sample (T = 200 to 500 ⁰ C), electrolytic deposition of metals on the material and subsequent annealing to achieve adhesion, immersion of the material in the adhesive Melt, application of powder-shaped pastes of the adhesive alloy mixed with an easily burn-out organic adhesive and subsequent stoving to achieve firm adhesion of the metal layer to the surface, among other things.

The required high degree of adhesion of the metal coating to the surface of the material is achieved by annealing in a vacuum (or under protective gas argon, helium) at temperatures at which chemical Reactions take place at the boundary between diamond or boron nitride and the adhesive metal.

When carrying out the method according to claim 3, the access of oxygen to the metallized surface of the materials based on diamond and / or boron nitride, starting with one Temperature of 500 "C, i.e. at the beginning of the intensive Oxidation of the coating and the impairment of adhesion formation are prevented.

The use of a flux according to patent claim 4 ensures a melting point of 500 ⁰ C and unchanged properties during the entire soldering process.

The solder according to patent claim 5 has a melting point of up to 1000 ^° C., ie an initial temperature when the modifications from diamond and cubic boron nitride (wurtzite) transition into the hexagonal shape. It also has high adhesive activity with respect to the base materials.

The combination of the components of the solder with lead increases the fluidity and plasticity of the solder; the The presence of tungsten, molybdenum and tantalum reduces the coefficient of thermal expansion and approximates it to the basis for the materials. The ratio between tin and copper is for Adjustment of the strength properties and the melting point of the solder selected.

A titanium content of less than 5% leads to a severe decrease in the adhesion and of more than 25% leads to a severe drop in adhesion unwanted embrittlement of the solder.

A lead content of more than 15% in the solder can lead to a lead to a significant reduction in strength properties.

A content of metals of the group molybdenum, tungsten and tantalum of more than 40% leads to a Increase in the melting point of the solder, which is due to the possible transition from diamond to cubic Boron nitride (wurtzite) in the hexagonal modification is undesirable.

The use of a non-metallic filler in the form of a powder with 1 to 50 μm grain size is used Increasing the plasticity of the solder. This grain size of the powder creates a permanent one Microporosity in the solder, which increases the plasticity.

The invention is explained in more detail below on the basis of specific exemplary embodiments

One of the possible compositions of Flux No. 1 can be as follows. Flux No. 1 (Composition in% by weight):

35% boric anhydride

42% dehydrated potassium fluoride

23% potassium fluoroborate

ts The other, similar in properties to the first Flux No. 2 has the following composition (in% by weight):

70% boric acid
9% calcium fluoride
21% borax

It is possible to use the flux no. 3, consisting of

20% boric acid
80% borax

or No. 4 flux consisting of

10% sodium fluoride

8% zinc chloride

32% lithium chloride

50% potassium chloride

example 1

A polycrystal with a height of 3.9 mm by 4 mm and made of cubic boron nitride modification is used for soldering (Elbor) and a steel holder with a height of 5 mm 0 χ 20 mm.

This polycrystal is pre-metallized with a chromium layer by electron beam sputtering of metal and its deposition up to a layer thickness of 0.001 mm; the process is carried out under a reduced pressure of 1 to 5 x 10 ^-5 mm Hg Further, the polycrystal is coated with a copper protective layer to a thickness of 0.005 mm chemically deposited.

The weight ratio of the components was: chromium 20% and copper 80%. Further, the annealing is carried out under a reduced pressure of 2 to 5 x 10- ⁵ mmHg at a temperature of 950 ⁰ C in the course of 20 minutes. The metallized polycrystal is inserted into a prepared cylindrical hole in the steel holder, which is drilled through the front side along its axis, with a soldering gap of 0.15 mm on each side. tin and 80% copper, with a heating and Abkühlnngsgeschwindigkeit of 20 ° C / s performed in the course of 1.5 minutes, the soldering temperature was 900 ⁰ C. Under the influence of capillary forces flowing the solder when melted into the solder gap

The solder joint. showed uniform inflow of solder, no voids and no cracks on the cutting element as well as no other soldering defects, the adhesion of the solder to the polycrystal was good

Example 2

An Elbor polycrystal of 4.2 mm diameter is used for soldering and 4.6 mm high and a steel holder of 5.5 mm 0 and 20 mm high.

The polycrystal is pre-metallized with a chrome layer in the chemical precipitation process up to a thickness of 0.0008 mm. Furthermore, the polycrystal is coated with a cobalt protective layer in the process of vacuum metallization up to a thickness of 0.005 mm. The weight ratio of the components in this case was 15% chromium and 85% cobalt. The annealing of the metal coating is carried out under a reduced pressure of 1 to 5 x 10 ^-5 mm Hg at a temperature of 95 ⁰ C in the course of 30 minutes. The metallized polycrystalline is inserted into a prepared cylindrical hole in the steel holder, which is drilled through on the front side along its axis, with a soldering gap of 0.10 mm on each side. Contains tin and 80% copper, carried out at a heating and cooling rate of 30 ° C / s for 1 min. The soldering temperature is 900 ° C.

The solder joint showed a uniform flow of the solder, no voids and no cracks or anything else Soldering defect in the cutting element from Elbor, the adhesion of the solder was good

Example 3

For soldering, a polycrystal 3.5 mm 0 4.6 mm high on the basis of black Diamonds, d. H. based on Karbonado, and a steel holder with a height of 5 mm and 20 mm was chosen

The Karbonado polycrystal is first made with a Tantalum layer in the process of vacuum metallization up to a thickness of 0.0005 mm and also in the same Process metallized with a silver layer up to a thickness of 0.01 mm

The weight ratio of the components was 3% tantalum and 97% silver. The annealing of the metal coating is carried out under a reduced pressure of 1 to 5 ■ 10- ⁵ mmHg at a temperature of 900 ⁰ C in the course of 15 minutes. The metallized polycrystal is inserted into a prepared cylindrical hole in the steel holder, which is drilled through the front side along its axis, with a soldering gap of 0.10 mm per side and containing 72% silver, was carried out at a heating and cooling rate of 30 ° C / s for 0.7 minutes. The soldering temperature is 800 ° C

The solder joint showed uniform flow of the solder, no voids, cracks and other soldering defects Cutting element; the adhesion of the solder to the Karbonado polycrystal was good

Example 4

An Erbor polycrystal with a diameter of 4.1 mm is used for soldering and 44 mm height and a steel holder with 5.5 mm 0 and 20 mm height selected

The polycrystal is first coated with a tantalum layer in the process for vacuum metallization up to a thickness of 0.001 mm and furthermore in the same process metallized with a nickel layer up to a thickness of 0.005 mm.

The weight ratio of the ingredients was 20%

Tantalum and 80% nickel. Annealing the Metallisierüberzuges is carried out under a reduced pressure of 1 to 5 x 10 ^-5 mm Hg at a temperature of 1000 ⁰ C in the course of 30 minutes. The metallized Polycrystal is prepared in a cylindrical Hole in the steel holder, which is drilled through on the face along its axis, with a solder gap of 0.20 mm per side placed. The high-frequency soldering is carried out in air under molten flux No. 4 with a solder of 20% tin and 80% copper with a heating and cooling rate of 30 ° C / s for 1 min. The soldering temperature is 900 ° C.

The solder joint showed uniform inflow of the

Solder, no voids, cracks and other soldering defects in the cutting element, the adhesion of the solder to the polycrystalline! was good.

Example 5

For soldering, an Elbor polycrystal with 4.0 mm 0 and 4.4 mm height and a steel holder with 5.0 mm 0 and 20 mm height selected

The polycrystal is first coated with a molybdenum layer in the process for vacuum metallization up to a thickness of 0.001 mm and furthermore in the same process with a lead layer up to a thickness of 0.005 mm metallized. The weight ratio of the components was 10% molybdenum and in this case 90% lead. The glow of the metal coating is under made a sub-pressure of 1 to 5 x 10 ^-5 mm Hg at a temperature of 700 ⁰ C in the course of 10 minutes. The metallized polycrystal is in a prepared cylindrical hole in the steel holder, which is drilled through along its axis at the front with A soldering gap of 0.10 mm per side is used. The high-frequency soldering is carried out in air under molten Flux No. 2 with a solder containing 15% tin and 85% copper at a heating and cooling rate of 20 ° C / s for 1.5 min. The soldering temperature is 920 ° C

The solder joint showed uniform flow of the solder, no voids, cracks and other soldering defects Cutting element from Elbor, the solder adhered well to the polycrystal

Example 6

A Karbonado polycrystal with a height of 3.7 mm and a height of 4.7 mm and a steel holder are required for soldering 5.0 mm 0 and 20 mm height selected

The Karbonado polycrystal is first made with a Molybdenum layer in the process of vacuum metallization up to a thickness of 0.0010 mm and then with a copper layer in the process of electrolytic deposition up to a thickness of 0.01 mm metallized The weight ratio of the constituents was 30% molybdenum and 70% copper. The annealing of the metal coating is carried out under a vacuum of 1 to 5-10 mm Hg at a temperature of 700 ^° C. in the course of 30 minutes. The metallized

Polycrystal is prepared in a cylindrical

• Hole in the steel holder along its axis is drilled through at the front, with a soldering gap of 0.15 mm used per eye. The high-frequency soldering is in air under molten flux No. 3 with a solder containing 28% copper and 72% silver at a heating and cooling rate of 30 ° C / s for 07 minutes. The soldering temperature is 800 ° C

The solder joint showed uniform flow of the solder, no voids, cracks and other soldering defects Cutting element, the adhesion of the solder to the polycrystal was good.

Example 7

An Elbor polycrystal with a diameter of 4.1 mm is used for soldering and 4.5 mm high and a steel holder with 5.5 mm 0 and 20 mm high.

The polycrystal is first metallized with a tungsten layer in the process of vacuum metallization up to a thickness of 0.0001 mm and then with a copper layer in the same process. The weight ratio of the components was 20% tungsten and 80% copper. The glow of the metal coating is carried out under a reduced pressure of 1 to 5 ■ 10 ~ ⁵ mm Hg at a Temperstur of! 000 ⁰ C over the course of 30 minutes.

The metallized polycrystal is inserted into a prepared cylindrical hole in the steel holder, which runs along it Axis is drilled through on the face side, inserted with a soldering gap of 0.20 mm on each side. The high frequency soldering is carried out in air under molten flux No. 4 with a solder containing 20% tin and 80% copper, at a heating and cooling rate of 30 ° C / s for 1 minute. The soldering temperature is 900 ° C.

The solder joint showed uniform flow of the solder, no voids, cracks and other soldering defects Cutting element, the adhesion of the solder to the polycrystal was good.

Example 8

For soldering, an Elbor polycrystal with a height of 4.1 mm and 4.5 mm and a steel holder with a height of 5.5 mm and 20 mm height selected

The polycrystal is first metallized with a tungsten layer in the process for vacuum metallization up to a thickness of 0.0001 mm and then in the same process with a tin layer. The weight ratio of the components was 20% tungsten and 80% tin. The annealing of the metal coating is carried out under a reduced pressure of 1 to 5 x 10 ^-5 mm Hg at a temperature of 1000 ° C in the course of 30 minutes. The metallized polycrystal is inserted into a prepared cylindrical hole in the steel holder, which is drilled through the front side along its axis with a soldering gap of 0.20 mm per side Contains 80% copper with a heating and cooling rate of 3Q ° C / S 1 ΓΏΪΩ IaR "dür ^ h ^^ f ¹ ** ^ * ^ ΓΙ · Λ Ι nHemiurahir is 900 ° C

The solder joint showed uniform flow of the solder, no voids, cracks and other soldering defects Cutting element, the adhesion of the solder to the polycrystal was good

Example 9

An Elbor polycrystal with a diameter of 4.1 mm is used for soldering and 4.5 mm high and a steel holder with 6 mm 0 and 20 mm high.

First of all, the Elbor polycrystal is coated with one layer an alloy with the following composition in terms of weight

6Ti + 10 Pb + 11.5 Sn + 724Cu + 1 Mo

by spreading a paste of the powdery alloy, mixed with an organic adhesive that can easily be burned out in a vacuum, up to a thickness of 0.1 mm. Subsequently, the polycrystal is annealed under a reduced pressure of 1 to 5 ■ 10 ^-5 mm Hg at a temperature of 900 ° C during 5 minutes.

The metallized polycrystal is inserted into a prepared cylindrical hole in the steel holder, which runs along it

ίο Axis is drilled through at the front, with a soldering gap 0.2 mm on each side. The high frequency soldering is done in air under molten flux # 1 with a solder containing 19% tin, 78% copper and 3% nickel with a heating and cooling amount speed of 20 ° C / s carried out. The soldering tempe temperature is 900 ° C.

The solder joint showed uniform flow of the solder, no voids, cracks and other soldering defects Cutting element from Elbor, the adhesion of the solder to the

Polycrystal was good. Example 10

A Karbonado-Poly crystal is required for soldering 3.5 mm 0 and 4.2 mm high and a steel holder with 5.5 mm 0 and 20 mm high were selected

First, the Karbonado polycrystal is coated with a layer of an alloy with the following composition

10Ti + 12Pb + 7Sn + 68Cu + 3W

provided mm by dipping into the melt at a reduced pressure of 1 to 5 x 10 ^-5 mm Hg at a temperature of 900 ° C during 5 minutes to a thickness of 0.05.

The metallized polycrystal is inserted into a prepared cylindrical hole in the steel holder, which runs along it The axle is drilled through on the face side and inserted with a soldering gap of 0.15 mm on each side

with a solder with the following composition in% by weight

Copper 70, iron 0.1, lead 0.03, bismuth 0.002, antimony 0.05, zinc remainder

carried out

The heating and cooling rate is 30 ° C / s. The soldering temperature is 850 ° C.

The solder joint showed uniform flow of the solder, no voids, cracks and other soldering defects so cutting element the adhesion of the solder to the polycrystal was good

Example 11

A hexanite polycrystal with a diameter of 5.0 mm and a height of 5.1 mm and a steel holder are required for soldering 8 now 0 and 20 mm height selected

The hexanite polycrystal is first coated with a layer of an alloy with the following composition in% by weight

8Ti + 12Pb +11 Sn + 49Cu + 20Ta

by spreading a paste of the powdery alloy, mixed with an organic adhesive that can be easily burned out in a vacuum, up to a thickness of O ^ mm. Subsequently, the polycrystal is under a reduced pressure of 1 to 5 - annealed 10 ^-5 mm Hg at a temperature of 900 ° C in the course of 10 minutes,

IO

15th

20th

25th

The metallized polycrystal is inserted into a prepared cylindrical hole in the steel holder, which is drilled through along its axis on the front side, with a soldering gap of 0.2 mm on each side. The high frequency soldering is carried out in air under molten flux No. 3 with a solder containing 20% tin and 80% copper at a heating and cooling rate of 20 ° C / sec. The soldering temperature is 900 ⁰ C.

The solder joint showed uniform flow of the solder, no voids, cracks and other soldering defects Cutting element, the adhesion of the solder to the polycrystal was good

Example 12

An Elbor polycrystal with a diameter of 4.0 mm is used for soldering and 4.5 mm high and a steel holder with 5.5 mm 0 and 20 mm high. (The diameter information were corrected from 40 or 55 mm to 4.0 or 5.5 mm after the filing date.)

First, the Elbor polycrystal is coated with a layer of an alloy with the following composition in Parts by weight

6Ti + IOPb -I- 10.5Sn + 73.5Cu + 03Mo
+ 0.7Al ₂ O ₃

by spreading a paste of the powdery alloy mixed with an organic adhesive that can easily be burned out in vacuo up to a thickness of 0.2 mm (the dispersity of the aluminum oxide powder was 1 μm). Subsequently, the polycrystal is annealed under a vacuum of 1 to .5 ■ 10- ⁵ ITiIn Hg at a temperature of 900 ° C during 5 minutes

The metallized polycrystal is inserted into a prepared cylindrical hole in the steel holder, which is drilled through the front side along its axis, with a soldering gap of 0.2 mm on each side. copper containing solder with a heating and cooling rate of 20 ° C / s performed, the soldering temperature is 900 ⁰ C

The solder joint showed uniform flow of the solder, no voids, cracks and other soldering defects Cutting element from Elbor, the solder adhered well to the polycrystal

Example 13

50

A Karbonado polycrystal is used for soldering 3.6 mm 0 and 4.0 mm high and a steel holder with 5.5 inns 0 and 20 min high were selected

First, the Karbonado polycrystal is coated with a layer of an alloy with the following composition in% by weight

5Ti + 10 Pb + 7 Sn + 58 Cu + 0.5 W + 19.5

SiC

by spreading a paste of the powdery alloy mixed with an organic adhesive that can be easily burned out in vacuo up to a thickness of 0.3 mm (the dispersity of the silicon carbide powder was 7 μm). Subsequently, the polycrystal is annealed mm under a reduced pressure of 1 to 5 x 10- ⁵ mmHg at a temperature of 900 ° C during 5 minutes to a thickness of 0.05.

The metallized polycrystal is inserted into a prepared cylindrical hole in the steel holder, which runs along it Axis is drilled through on the face side, inserted with a soldering gap of 0.15 mm on each side. The high frequency soldering is in air under molten flux No. 2 with a solder with the following composition in Wt%

Copper 70, iron 0.1, lead 0.03, bismuth 0.002, antimony 0.05, zinc remainder

carried out at a heating and cooling rate of 30 ° C / s. The soldering temperature is 850 ⁰ C.

The solder joint showed uniform flow of the solder, no voids, cracks and other soldering defects Cutting element, the adhesion of the solder to the polycrystal was good.

Example 14

A hexanite polycrystal with a height of 5.5 mm and a height of 5.3 mm and a metal holder are used for soldering Iron-nickel-copper alloy in the form of an 8 mm high plate with dimensions 15 mm χ 15 mm chosen

First, the hexanite polycrystal is coated with a layer of an alloy with the following composition in% by weight

7 Ti + 12 Pb + 11 Sn + 49 Cu + 20 Ta + 1
BN

by spreading a paste, powdery alloy, mixed with an organic adhesive that can easily be burned out in vacuo, up to a thickness of 0.4 mm (the dispersity of the boron nitride powder was 5 μm). Subsequently, the polycrystal is annealed under a reduced pressure of 1 to 5 x 10 ^-5 mm Hg at a temperature of 900 ⁰ C in the course of 10 minutes,

The metallized polycrystal is inserted into a prepared cylindrical hole in the metal holder, which runs along its length The axis drilled through on its side surface is inserted with a soldering gap of 0.2 mm per side Kcchfrcqucr.zlciur.g is melted in air Flux No. 3 with a solder containing 20% tin and 80% copper at a rate of heating and cooling at 20 ° C / s. The soldering temperature is 900 ° C

The solder joint showed uniform flow of the solder, no voids, cracks and other soldering defects Cutting element, the adhesion of the solder to the polycrystal was good

65

Claims (4)

Patent claims: 1. Method for soldering a polycrystalline body made of extremely hard material on the basis of boron nitride and / or diamond with a metal part that has a metal coating on the body made of at least one metal causing high adhesion to the material and at least a metal exhibiting reduced oxidizability is present and the soldering process takes place Atmospheric pressure takes place in air, characterized in that the polycrystalline body initially with an upper layer of at least 0.0005 to 0.001 mm having a layer thickness a metal selected from the group consisting of chromium, molybdenum, tantalum and tungsten as an adhesion causing Metal is selected and then with another, a layer thickness of 0.001 to 0.01 mm having a top coat of at least one metal selected from the group consisting of silver, lead, tin, cobalt, copper and nickel is selected as a metal with reduced oxidizability, in such amounts that the first layer makes up 3 to 65% of the total weight of the coating, after which the soldering process is carried out in air under a layer of liquid flux for brazing will. 2. Method for soldering a polycrystalline body made of extremely hard material on the basis of boron nitride and / or diamond with a metal part with a metal coating on the body of at least one metal causing high adhesion to the material and at least a metal exhibiting reduced oxidizability is present and the soldering process takes place Atmospheric pressure takes place in air, characterized in that the polycrystalline body initially with a coating of molten metal with a layer thickness of 0.01 to 0.5 mm is provided, which consists of 3 to 65% of at least one metal from the group of chromium, molybdenum, Tantalum, tungsten and titanium, which cause high adhesion, and the remainder of at least one metal the group copper, silver, lead, tin, nickel or cobalt, which have reduced oxidizability, consists, after which the brazing process in air under a layer of liquid flux for brazing is carried out. 3. The method according to any one of claims 1 or 2, characterized in that the soldering process when The melting point of the solder lasts 0.5 to 2 minutes and with a heating or cooling rate of the soldering surfaces from 10 to 30 ° C / s using a liquid flux, the one Has a melting point of 500 to 700 ° C, is carried out. 4. The method according to claim 3, characterized in that the flux from 60 35% boric anhydride, 42% dehydrated potassium fluoride and 23% potassium fluoroborate