| 摘要 |
<p>The invention concerns a process for manufacturing a part made of high temperature-resistant, ceramic material based on aluminum nitride and reaction sintering. The process comprises the steps of preparing a homogeneous mixture of boron nitride powder, aluminum powder and a paste-like binder, capable of solidifying by chemical reaction and by solvent loss through drying. The mixture is formed by mold casting and then pressed and heated, to a temperature not exceeding approximately 70° C., to harden the binder and to obtain a solid and manipulable unfired part. The binder is eliminated by heating to a temperature of approximately 300° C. Pores of the unfired part are impregnated by immersing the part in a bath of molten aluminum or aluminum alloy to form an impregnated preform. Thereafter, the impregnated preform is removed from the bath, cooled, and machined to the final dimensions of the part. A ceramic is obtained by reaction sintering the machined part at a temperature of 900 to 1000° C. Residual aluminum is removed from the pores of the ceramic part by heat treating it, at a temperature of 1100 to 1250° C., cooling it, and mechanically eliminating the aluminum that has collected on the surface of the part.</p> |
