PRODUCTION OF SUPERPLASTIC SILICON NITRIDE WHISKER REINFORCED 2124 ALUMINUM COMPOSITE MATERIAL

摘要

PURPOSE:To produce a superplastic Si3N4 whisker reinforced 2124Al composite material by uniformly mixing Si3N4 and 2124Al alloy powder, pressure-sintering the mixture in vacuum applying recompression and hot extrusion to the sintered compact, and further applying are hardening to the sintered compact. CONSTITUTION:A mixture is prepared by uniformly mixing Si3N4 (alpha-type, beta-type) and 2124Al alloy powder (less than 44mum) in an organic solvent, such a alcohol, while applying ultrasonic waves. Subsequently, the solvent is removed from the mixture by means of evaporation. The obtained powder mixture is pressure- sintered in vacuum by means of hot pressing. At this time, the above-mentioned pressure sintering is preferably carried out, e.g. at about 600 deg.C and about 200MPa. The sintered compact is recompressed in the air at 600 deg.C and about 400MPa, subjected to hot extrusion at about 500 deg.C, and further age-hardened by means of T6 heat treatment. By this method, the superplastic Si3N4 whisker reinforced 2124Al composite material increased in overall elongation can be obtained.