JPS5864273A - Silicon nitride sintered body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] This invention is ^i! The present invention relates to a non-plated material, that is, a nitride ceramic sintered body, which contains St and has a storage area.

In recent years, ceramic materials have been actively used as heat-resistant materials, and among them,
Covalent compounds that are stable heat-resistant substances, %
Kfil silicon carbide (5i1N, ), silicon carbide book (S
iC) is known to be a very excellent material.

Ceramics are used by molding and sintering powdered ceramic powder, but in the case of Si@N, SiC, etc., unlike general oxide ceramics, they are S sinterable substances. Therefore, it is difficult to obtain a dense sintered body even if only a single composition, for example, 5ilN4 powder is sintered.

(D * Me) For example, in the case of Si aNa powder, K ＃'i
Sintering is carried out by adding oxide powders such as MtlO-Atto@, Y, O-Ce01, BeO, etc. as a sintering aid.

The commonly used method of press molding using powder to which a sintering aid has been added and then heating and sintering in vacuum or normal pressure has a low sintering cost and can be used industrially.

Further, in the case of St and N4, the pores remain as they are even after sintering, so a sintered body with a relative density of 97s and t- can be obtained by this method.

On the other hand, according to the hot press method in which sintering is performed under pressure at high temperature, a denser sintered body can be obtained.

Further, the mixed side combination of sintering aid is sintered in a high pressure gas atmosphere with a little or no sintering aid,
Methods such as explosive molding that instantly apply high pressure to the powder to crush it and then sintering have been tried, but all methods increase the sintering cost and still cause a decrease in strength at pan temperature. It has its drawbacks and has not been a successful industrial method.

By the way, the conventional method for producing St, N4 powder as the starting material for non-numerical ceramic sintered bodies is to use a mixture of silica powder and vertical wood powder.

A method of heating at 1,800-1,700℃ in a gas stream and electrifying it, or a method of heating a hydrogen compound of 72 ng gas and a phoneme to 800 ℃
There is a method in which a gas phase reaction is carried out once at ~1900°C.

Sl and N4 powders produced by any of the above methods can be used as they are as raw materials for producing sintered carved bodies.

The Si and N4 sintered bodies produced in this way are being considered for application in car engines and turbine engines as Senmix, which has high heat resistance and texture. However, the second use of Kameeha 1 in the trenches has already been carried out.

Another disadvantage of Si, N, sintered bodies is that they have poor reactivity. For this reason, there was a drawback that the bonding distance between the Si@N4 sintered body and the mixed material or metal member was very close.

The above-mentioned drawbacks of the Si@N4 baked sweetfish body [
This invention was developed as a result of extensive research.

Konno's invention is Si, N4 powder K A1. , O, and Y
,0. Powdered sintering aid from 1 to 20% by weight, Tm, W%
Mo.

At least 1 m of gold-boride powder such as Cr and t5~
A mixed powder of 40 and 1 is added to N, gas or N.

It has been discovered that by sintering in a non-oxidizing atmosphere containing gas 1, a 1g sintered body of electrified silicon that can be brazed with other ceramics or metals can be obtained.

It is known that in order to obtain a Si, N4 sintered body using general KSi, N4 powder, sintering is carried out in N gas at 1 atm and above 1700°C. It is also known to add saponified products such as N, N wood KAA*0*s MHO, FegO@ as a sintering aid. but,
Since Fisi and N4 decompose during such sintering, in order to prevent this, sintering is also carried out by backing a mixture of K AtN +BN powder with Si and N4 powders.

However, although the 54sNa flb aggregate obtained by such K treatment has properties of 1iliIi strength and high density, it lacks bonding properties.

To do this, add a powdered sintering aid to the K Si, N, powder, and metal borides such as Ta%W1Mo, Cr, and add this mixed powder to N, gas, or FiN, a non-oxidizing powder containing gas. It is sintered in an atmosphere.

According to such sintering, N! The gas friend is N, and the metal boride decomposes in the gas atmosphere, and Mo is formed on the surface of the sintered body.
1W, etc. metal layers are piled up, and these gold j14 layers are usually soldered or metal f! In order to form an i1 solution, Si, N,
It is possible to connect the sintered body to other ceramics or metals.

Another special feature of the sintered body obtained by this invention is that it is cut out from wood in the form of a plate or rod into a desired shape, and only the rounded part contains tl & tortoise N2 gas or FiN gas. By processing in an atmosphere, new cut surfaces can be easily metallized.

In order to improve the bondability of the sintered body as shown in E, the amount of gold Il and boride used is preferably 5 to 40]. The reason for 7 depends on the required bonding strength, but 5.
If the weight is less than S, the gold boride will decompose and the amount of gold 14 adhering to the surface layer of the sintered body will be insufficient, and if the weight is more than 401L ft.
This is because if it is used, the 0 series imitation will be lost as a 5ilN4 shoyu body.

There are many types of borides with different atomic ratios, among which CrB, s,
Mo, J, Mo, B% MaB,, WB, W,
B etc. are effective for ~. The reason for this failure is that these gold particles deposited on the surface of the sintered body (2) during sintering have poor digging ability with the gold and brazing metal.

Mlo and Y as sintering aids, 0. Matsumoto Rishi Haj
For children, violet chi is appropriate for numbers 1-201.

On the other hand, if it is less than 1ffik%, it will not be possible to obtain a sufficient sintering density during sintering, and if it is more than 201 ts, the 5ilN shield will turn into a glass pigeon and become a tube! i! This is because the degree decreases.

And this M, 0. The convenience ratio of and Y2O, is 4, Os
: Y, 0. = 8: 1 to ! = 8 is suitable; anything else is not preferred because the heat resistance of the obtained sintered body decreases.

In addition, as for the sintering conditions of the present invention, the S+INatR body with improved bondability of the present invention obtained in this way has a 1-hour air evaporation time because the Kinho of Omuki-byo is deeply buried inside the sintered body. Compared to the normal metallizing method, it is slightly heavier and has a cloudy grade of strength.1 The atmosphere during sintering in this invention is N2,
In addition to gases such as NH, which serve as nitrogen supply sources, mixed gases such as Co, H, and the like are not supported.

Next, this invention will be explained in detail by way of examples.

Practical Example: The violet W8 adjuvant and the violet U1 compound powder shown in Table 1 were blended into 5iBN4 powder wood of 5 tarck company, H-1 grade, and the mixture was stirred in a ball mill for 10 hours.

After drying the obtained slurry, 50% of stearin was added to it as a plate binder, and a wire piece was embossed at 2t/d using 1OX7X40Oy. Sintering was performed at 1700°C to -1750°C for 1 hour.

The properties of the obtained sintered body were examined and the results are shown in Table 1.

In addition, for the bonded test, a 44) * 5isb body of the same size of this invention was brazed to the tip of a square rod-shaped SK material 5 x 5, the SK material of this test piece was held, and sintered. A load was applied to the body side and bondability was determined at room temperature.

As a result, it was found that those with good bonding properties were broken with W inside the silver solder, while those with poor bonding properties were peeled off on the surface of Si, N, and sintered bodies.

This FiSisN: It is presumed that this is due to the difference in bonding strength with the metal layer on the surface of the sintered body. Sintering is not something that is often used in modern times, and even with the use of sintered bodies made using hot press, it has been found that the same effect can be achieved.

Claims (4)

[Claims] (1) Powders of At, O, and Y, 0.0. (C) A silicon nitride sintered body whose remainder is sintered using a mixed powder of silicon nitride powder, designated as l#I*. (2) The silicon nitride powder has a particle size of 0.1 to 5.
The nitrided silicon sintered body according to claim 1, wherein the total amount of other metal impurities in the iron powder is 1 or less. (3) The nitrided silicon sintered body according to claim 111, characterized in that the mixed powder is sintered in an N gas atmosphere. (4) The nitrided silicon sintered body according to claim 1, wherein the mixed powder is sintered in an atmosphere containing N and gas.