DE2226586C3

DE2226586C3 - Process for the production of polycrystalline cubic boron nitride

Info

Publication number: DE2226586C3
Application number: DE19722226586
Authority: DE
Original assignee: Wsesojusnyj nautschno-issledowatelskij Institut abrasiwow i schlifowanija, Leningrad (Sowjetunion)
Filing date: 1972-05-31
Publication date: 1976-08-26

Description

findungsgemäßen Verfahrens verwendet man 2 bis Die genannte Mischung setzt man einem Druck vonThe process according to the invention is used from 2 to The mixture mentioned is put under a pressure of

20 ⁰Zo der genannten Silizium- oder Germaniumver- 80 kbar und einer Erhitzung auf 1800⁰C während20 ⁰ Zo of said silicon or germanium ver- 80 kbar and heating to 1800 ⁰ C during

bindungen. 2 Minuten aus. Durch eine solche Einwirkung bildetties. 2 minutes off. Forms through such exposure

Der Vorteil des erfindungsgemäßen Verfahrens sich kubisches Bornitrid mit einer Größe der Kri-The advantage of the method according to the invention is cubic boron nitride with a size of the Kri-

besteht darin, daß bei der Verwendung der genann- 5 stallite von 10~³ cm.consists in the fact that when using the mentioned 5 stallite of 10 ~ ³ cm.

ten Initiatoren das kubische Bornitrid unmittelbar .ten initiators the cubic boron nitride directly.

während der Herstellung polykristaliine Struktur an- B e ι s ρ ι e 1 4polycrystalline structure during production. B e ι s ρ ι e 1 4

nimmt. Man wiederholt die im Beispiel 3 beschriebenetakes. The procedure described in Example 3 is repeated

Nachstehend wird die Erfindung durch die Be- Methodik, man verwendet jedoch statt des Siliziumschreibung von Beispielen für die Durchführung des io nitrids Germaniumnitrid. Die Mischung setzt man Verfahrens näher erläutert, die das Wesen des erfin- einem Druck von 75 kbar und einer Erhitzung auf dungsgemäßen Verfahrens kennzeichnen. 1800° C während 3 Minuten aus. Die Kristallite desThe invention is described below using the Be methodology, but instead of using silicon writing of examples of the implementation of the io nitride germanium nitride. The mixture is set Process explained in more detail, which is the essence of the inven- a pressure of 75 kbar and a heating on mark in accordance with the procedure. 1800 ° C for 3 minutes. The crystallites of

gebildeten kubischen Bornitrids weisen eine Größeformed cubic boron nitride have a size

Beispiel 1 bis 10"⁴ cm auf.Example 1 to 10 " ⁴ cm on.

Man bereitet eine Mischung, die 80 % hexagonales Beispiel 5Prepare a mixture that is 80% hexagonal Example 5

Bornitrid und 20% Siliziumnitrid enthält. Die erhal- Man bereitet eine Mischung, welche 93% hexago-Contains boron nitride and 20% silicon nitride. The result is a mixture containing 93% hexagon

tene Mischung, das Reaktionsgemisch, bringt man in nales Bornitrid und 7% Siliziumnitrid enthält. Dietene mixture, the reaction mixture, is brought into nales boron nitride and contains 7% silicon nitride. the

die Kammer einer Anlage beliebiger Konstruktion erhaltene Mischung führt man in die Kammer einer ein, die die Erzeugung eines hohen Druckes und 20 Anlage beliebiger Konstruktion ein, die die Erzeu-the chamber of a system of any construction is fed into the chamber of a mixture one that generates high pressure and 20 systems of any construction that generate

einer hohen Temperatur ermöglicht. Als Medium, gung eines hohen Druckes und einer hohen Tempe-allows a high temperature. As a medium, a high pressure and a high temperature

welches den Druck überträgt, verwendet man Litho- ratur gewährleistet. Als Medium, welches den Druckwhich transmits the pressure, one uses lithography guaranteed. As a medium, which is the pressure

grafiestein. Die genannte Mischung unterwirft man überträgt, verwendet man Lithografiestein. Die ge-graphic stone. The said mixture is subjected to transfers using lithographic stone. The GE-

einem Druck von 65 kbar und einer Erhitzung auf nannte Mischung setzt man einem Druck von 70 kbar eine Temperatur von 1700⁰C während 2 Minuten. 25 und einer Erhitzung auf 1750° C während 1 Minutea pressure of 65 kbar and heating to the said mixture, a pressure of 70 kbar, a temperature of 1700 ^° C. for 2 minutes. 25 and heating to 1750 ° C for 1 minute

Durch eine solche Einwirkung bildet sich in der aus. Durch eine solche Einwirkung bildet sich in derSuch an action forms in the. Such an action forms in the

Kammer kubisches Bornitrid mit einer Größe von Kammer kubisches Bornitrid, dessen Kristallite eineChamber of cubic boron nitride with a size of chamber cubic boron nitride, the crystallites of which are a

Kristalliten (Polykristallen) von 10~³ cm. Größe von 10~* cm aufweisen.Crystallites (polycrystals) of 10 ~ ³ cm. Size of 10 ~ * cm.

Beispiel 2 3« Beispiel 6Example 2 3 «Example 6

Es wird die im Beispiel 1 beschriebene Methodik Man bereitet eine Mischung, welche 95 % hexagowiederholt, man verwendet aber statt des Silizium- nales Bornitrid, 2 % Siliziumnitrid und 3 % Siliziumnitrids Siliziumborid. borid enthält. Die erhaltene Mischung führt man inThe methodology described in Example 1 is used. A mixture is prepared which repeats 95% hexagos, Instead of silicon, however, boron nitride, 2% silicon nitride and 3% silicon nitride are used Silicon boride. contains boride. The mixture obtained is carried out in

35 die Kammer einer Anlage beliebiger Konstruktion35 the chamber of a system of any construction

Beispiel 3 ^em> die die Erzeugung eines hohen Druckes undExample 3 ^em > the generation of high pressure and

einer hohen Temperatur gewährleistet. Als Medium,a high temperature guaranteed. As a medium,

Man bereitet eine Mischung, welche 98% hexago- welches den Druck überträgt, verwendet man Litho-A mixture is prepared, which is 98% hexagonal, which transfers the pressure, if litho-

nales Bornitrid und 2% Germaniumborid enthält. grafiestem. Die genannte Mischung setzt man einemContains nal boron nitride and 2% germanium boride. graphiest. The said mixture is what you put into one

Die erhaltene Mischung führt man in die Kammer 40 Druck von 75 kbar und einer Erhitzung auf 1800° CThe mixture obtained is fed into the chamber 40 with a pressure of 75 kbar and heating to 1800.degree

einer Anlage beliebiger Konstruktion ein, die die während 1 Minute aus. Durch eine solche Einwir-a system of any construction, which the during 1 minute. Such an impact

Erzeugung eines hohen Druckes und einer hohen kung bildet sich in der Kammer kubisches Bornitrid,Generating a high pressure and a high voltage, cubic boron nitride is formed in the chamber,

Temperatur gewährleistet. Als Medium, welches den dessen Kristallite eine Größe von ΙΟ"³ cm auf-Temperature guaranteed. As a medium, which has a size of ΙΟ " ³ cm in its crystallites

Druck überträgt, verwendet man Lithografiestein. weisen.To transfer pressure, lithographic stone is used. point.

Claims

Therefore, in the further description of the claims: Substances that favor the formation of cubic boron nitride, referred to as initiators.

1. Process for the production of polycrystalline From DT-AS 11 69 902 is a process for nem cubic boron nitride from hexagonal boron 5 production of electroconductive cubic boron nitride in the presence of a silicon or germanitride from a Geraisch of hexagonal boron nitride containing compound at a pressure and the catalyst, namely the lithium nitride, of over 55 kbar and a temperature of over and additions of silicon and / or germanium in 1700 ⁰ C, characterized in that pure form or as compounds, which are called silicon or Germanium compounds decompose under the action of temperature to form silicon and borides and / or nitrides of silicon and / or germanium. The germanium obtained is used. cubic semiconductor boron nitride has conductivity

2. The method according to claim 1, characterized by the p-type, due to the inclusion of silicon, that 2 to 20% of the mentioned and / or germanium atoms are in the boron nitride lattice, silicon or germanium compounds, thus an impurity conductivity, what on it turns. indicates that an education from the masses is not

is possible, which are described in the DT-AS, namely from silicon and germanium borides and

nitrides. ao The initiators proposed according to the invention

for the conversion of λ-ΒΝ - / i-BN, namely the

The present invention relates to the silicon and germanium borides and / or nitrides, It is known that improvements in manufacturing processes do not decompose at high temperatures polycrystalline cubic boron nitride, from the doors (~ 2000 ° C) with the formation of silicon and Abrasive material of high hardness is made of 25 germanium in its pure form.

can. For this reason alone, the inventive

Various methods of manufacturing, according to methods of manufacturing polycrystalline cubic boron nitride, are known. They consist nem cubic boron nitride from large dimensions that hexagonal boron nitride at a temperature exposes a surge of technical Entwickvon than 1000 ⁰ C and a pressure of about 30 illustrates lung and differs in principle from the 40 kbar in the presence of a catalyst. State of the art, the method of production The catalyst used is generally cubic semiconductor boron nitride, where individual alkali and alkaline earth metals and their nitrides. The small crystals of /? - BN in the order of magnitude of about 0.3 to 0.4 mm obtained using such a catalyst, the cubic boron nitride does not always have a high 35 According to DT-OS 21 10 218 is a method of strength, especially during operation and the Aufbe- known, in which as initiators for the conversion of currency in moist media as a result of the * -BN- ♦ - / J-BN borides, nitrides, suicides and Ger grains of the Cubic boron nitride can be used in significant manide of transition metals. Amount of forming by-substances. It should be pointed out, however, that among those that can flow through the moisture are, among other things, 40 germanium and the metal nitrides which are formed during synthesis and are used as catalytic silicon nitrides and / or borides germanium and sator. It is also known that silicon is not one of the transition metals that it counts during the manufacture of grinding the periodic table. The polycrystalline cubic boron nitride obtained according to the invention from the known cubic boron nitride in a partial destruction of the grains of the 45 a size of 4 mm differ in their cubic boron nitride and the abrasive product physically mechanical properties as the itself due to the tendency of the thermal conductivity as a catalyst , the extent of their pressure-resistant metal nitrides comes to oxidation. ability and the like of the known products.

According to the known methods, one object of the present invention is the developing crystals of the cubic boron nitride, which in the 50 development of a process for the production of cubic Manufacture of grinding tools are used. Boron nitride, which makes it possible, a material However, their use as cutting tools is of polycrystalline structure for cutting tools obtained because of the small dimensions of the obtained, which has high mechanical strength Crystals extremely difficult. and has resistance in moist media.

For the production of material that is necessary for the 55 To achieve this goal, the task Turn in cutting tools is suitable, need to put such an initiator to choose which one individual small crystals are bound to each other. the formation directly in the reaction process of a This is effected by the action of a high compact polycrystalline material. Pressure and a high temperature to smaller The problem set is achieved in that

Crystals of cubic boron nitride, which make the 60 one in the manufacture of polycrystalline Cutting tool technology - cubic boron nitride from hexagonal boron nitride in material is made much more difficult. Presence of a silicon or germanium containing

In the terminology used to this day, compounds at a pressure of over are used as catalysts which favor ^{the formation of the cubic 55 kbar and a temperature of over 1700 ° C. boron nitride.} However, according to the invention, the substances serving as catalysts in the bond borides and / or nitrides of silicon and / end product, the cubic boron nitride, are used in pure or germanium as silicon or germanium compounds. Shape not included. According to a preferred embodiment of the