Abstract
Effect of agitation-grinding on the resistance-sintering characteristics of atomized aluminium powder was experimentally studied. The powder pretreated by agitation-grinding in a juice-mixer for 6 min was able to be resistance-sintered. The resistance-sintering behavior of this powder with power input less than 150 kVAC/g was similar to the powder pretreated by drying in low vacuum. But in the powder compacts resistance-sintered with power input higher than 150 kVAC/g, the end region of the specimen was melted down, while the drying-pretreated powder was able to be resistance-sintered as a sound compact with same power input. This difference was considered to be related to the difference of the distribution of oxide film in the powder compacts. Influence of agitation-grinding on the isothermal-sintering behavior of the powder compacts was also studied. Low density compacts of the agitation-ground powder showed larger shrinkage than those of the non-treated powder, while high density compacts of the former showed slower shrinkage than those of the latter. This phenomenon was discussed in connection with the formation of metallic contacts between particles in compressed compacts.
