鉄系圧粉体の焼結時の寸法変化におよぼす脱ろう条件の影響

Abstract

The influence of delubricating conditions on dimensional change of the compacts of the system Fe-2wt%.Cu-0.8wty.C-0.75wt%.Zn-st was examined under an atmosphere of endothermic gas. An abnormal expansion, which increases under slower heat pattern and atmosphere of lower dew point, occurred above about 500°C. As this expansion becomes larger, copper growth decreases, the shrinkage becomes larger and carbon content after sintering becomes higher.The diffusion of carbon is greatly influenced by delubricating conditions but that of copper is little. The delubrication in Ar, N2, H2 and dissociated ammonia atmosphere makes the sintering behaviors and sintered properties stable. In the case of endothermic gas, the similar tendency is observed at the rapid delubrication under the high dew point atmosphere.