JPS589890A - Metallization of silicon carbide formed 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 The present invention relates to a method of metallizing a silicon carbide molded body, and more particularly to a metallizing method that provides excellent adhesive strength to a silicon carbide molded body.

Conventionally, there are methods for metallizing oxide ceramics such as alumina, such as a high melting point metal method and a metal oxidation method. Recently, sintering technology has advanced, and the application of high-density silicon carbide molded bodies to turbine blades as a heat-resistant material and module substrates as a highly thermally conductive material has been reconsidered.

However, the metallization method for silicon carbide molded bodies has not been established, which has been a bottleneck in the application of silicon carbide molded bodies.

An object of the present invention is to provide a method for metallizing a silicon carbide molded body with excellent adhesive strength.

The present invention provides a metallizing method in which a silicon carbide molded body is coated with metal powder and baked, and the hydrocarbon molded body is coated with MO80.
It is characterized by applying a paste in which metal powder containing ~99.5% by weight and 0.5% by weight of W2O is dispersed in an organic vehicle and baking it in an inert atmosphere.

In the present invention, it is essential to use a mixed powder of Mo powder and W powder or a Mo-W alloy powder, and the content of W in these metal powders is less than 0.15% by weight or less than 20% by weight. If the temperature exceeds 20 to 0.5% by weight, the adhesive strength will be poor and the baking temperature will increase.
It is necessary that the content be in the range of 90.5% by weight.

Note that this metal powder is not limited to pure metal, and metal powders of MO alloy and W alloy can be used.

Depending on the use of the silicon carbide molded product, a metal plating surface may be required on the metallized surface. layers can be plated. If the thickness of the plating layer is less than 0.5 μm, the effect will be small;
If the thickness exceeds .mu.m, it is uneconomical and the adhesive strength also decreases, so the plating thickness is preferably in the range of 0.5 to 300 .mu.m.

Metallization can be processed into any shape, and there are no restrictions on the shape for processing.

If the baking temperature is less than 1200''C, the metallized layer will become porous and the adhesive strength will be low, and if it exceeds 1400''C, the adhesive strength will decrease, so a range of 1250 to 1400''C is preferred. In particular, when it exceeds 1700'c, the amount of evaporation of the metallizing material becomes large, the metallizing layer becomes thin, and the adhesive strength decreases.

The adhesion mechanism of metallized metallization is thought to be the formation of an intermediate layer, similar to that of oxide-based ceramics, and when a cross section of an actual metallized material is analyzed with an X-ray microanalyzer, the formation of silicides and carbides is observed.

Example 1 Silicon carbide powder was mixed with 2 parts by weight of HeO as a sintering aid, and vacuum hot press molded at 2050'c for 30 minutes. Mo powder and W powder were added to a silicon carbide molded body with the composition shown in Table 1. A paste with a viscosity of approximately 100,000 centipoise dispersed in thiethyl cell a/calpitol acetate was applied and baked at a temperature range of 1200'C to 1700'C, and then the metallized layer was electroplated with Ni to a thickness of 5 μm, The adhesive strengths are shown in Tables 1 and 2. As is clear from Tables 1 and 2, the adhesive strength of the metallized layer of the present invention is strong and excellent.

Table 1 Table 1 Table 2 Table 2 Example 2 Silicon carbide molded by mixing silicon carbide powder and 2 parts by weight of BeO as a sintering aid and vacuum pot press molding at 2o5o'C for 30 minutes. A paste (viscosity, approximately 100,000 centipoise) of the mixed powder shown in Table 3 dispersed in 7% ethyl cellulose/carpitol acetate was applied to the body.
Bake for 30 minutes at 'c. Next, the metallized layer was plated with drowsy Ni (film thickness: 5 μm) L, and the adhesive strength was
It is shown in the table.

Example 3 Silicon carbide powder was mixed with 2 parts by weight of BeO as a sintering aid, and 90 parts by weight of Mo powder and 10 parts by weight of W powder were added to a silicon carbide molded body which was vacuum hot press molded at 2050'c for 30 minutes. A paste of mixed powder dispersed in 7% ethyl acetate/carpitol acetate was applied and baked at 1300'c. Next, the metallized layer was plated with the metal shown in Table 4, and the adhesive strength was measured.

Table 4

Claims (1)

[Claims] 1. In a metallizing method in which a silicon carbide molded body is coated with metal powder and baked, the silicon carbide molded body is coated with MO80-9.
A method for metallizing a silicon carbide molded body, characterized by applying a paste in which metal powder containing 9.5% by weight and 20 to 0.5% by weight of W is dispersed in an organic vehicle and baking it in an inert atmosphere. . 2. The method for metallizing a silicon carbide molded body according to claim 1, wherein the baking in the inert atmosphere is performed at a temperature of 1250° C. to 1400° C. 3. A method for metallizing a silicon carbide molded body as described in claim 1 or 2, characterized in that a metal layer is further provided on the metallized layer of the silicon carbide molded body.