Support member for high-temperature heat-treated metal molding object and process for production thereof
A carbonaceous support member for a high-temperature heat-treated metal molding object, particularly a setter for heat-treatment in powder metallurgy, is formed as a carbon-ceramic composite shaped product having a bulk density of 1.2-1.6 g/ml and including a carbonaceous matrix and 3-20 wt. % of ceramic particles which are uniformly dispersed in the carbonaceous matrix and partly exposed to the surface of the composite. The support member can effectively prevent carburization of a metal molding object supported thereby during the heat-treatment without causing a problem of peeling of coating layer as encountered in a ceramic-coated support member. The support member may be prepared by compression molding of a powdery mixture of a fine carbon precursor and ceramic particles, followed by heating at 1000-2000° C. to carbonize the fine carbon precursor.
1. A support member for a high-temperature heat-treated metal molding object, comprising: a carbon-ceramic composite shaped product comprising a carbonaceous matrix and 3-20 wt % of ceramic particles uniformly dispersed in the carbonaceous matrix and partly exposed to a surface of the carbon-ceramic composite shaped product, said carbon-ceramic composite shaped product having a bulk density of 1.2-1.6 g/ml, wherein the carbonaceous matrix comprises a non-graphitic carbon material having a 002-plane layer spacing (d 002 ) of at least 0.34 nm.
2. A support member according to claim 1 , wherein the ceramic particles have a particle size giving cumulatively 50% by volume of 50-500 μm.
3. A support member according to claim 1 , wherein the ceramic particles comprise fused alumina having an alumina purity of at least 90 wt. %.
4. A support member according to claim 1 , wherein the carbon-ceramic composite shaped product is a carbonized product of a compression molded compact of a dispersive mixture of carbon precursor particles and ceramic particles.