抄録
Vickers hardness distributions in disk shaped and hollow-disk shaped compacts with SiC granules, which showed typical elasto-plastic behavior, and their sintering shrinkage were measured to investigate the influence of the CIP Compaction method on the density distribution. The reduction of raw density toward the center in the radial direction was indicated indirectly from Vickers hardness measurements for the disk shaped compact. For the hollow-disk shaped compact prepared with mandrel, however, the density near the interface to mandrel increased extremely, while little or no density gradient was observed in other part. In the hollow-disk shaped compact, the result that the shrinkage of inner diameter was smaller than that of outer diameter was qualitatively compatible with the density distribution provided by hardness measurements. The density distribution in the disk shaped compact from hardness measurements qualitatively agreed with the density distribution predicted by finite element method (FEM) analysis with assumption of nonlinearity for the powder material, but the density distribution in the hollow-disk shaped compact did not completely agree with that predicted by FEM. For the hollow-disk shaped compact, it was thought that the differences in results between measurements and FEM analysis were influenced by the reduction of applied pressure near the center and the stress concentration near the interface to mandrel.
