Fe-Si焼結体の諸性質に及ぼすCu添加の影響について

抄録

In order to investigate the effects of Cu addition on various properties of sintered Fe-Si compacts, the microscopic and mechanical examination of Fe-Si-Cu compacts, sintered and then aged at various temperatures, were carried out. The dilatometric curves of these compacts were also measured to study the sintering process. The results were summarized as follows:
1) The density of Fe-Si-Cu compacts little decreased up to 3% Cu content when the compacts were sintered at the temperature above 1220°C.
2) The controll of copper growth was due to the following reason. Cu and Si powders yielded the eutectic liquid at 802°C which succesively produced Fe₃Si phase containing a small quantity of Cu with neighboring Fe powders, and then a considerable amount of Cu was surrounded with the Fe₃Si phase. It seemed therefore that the liquid of Cu could not flow into the Fe particles at the melting point of Cu.
3) Fe-Si-Cu compacts particularly showed a higher strength than Fe-Cu compacts because the former was more densified and strengthened the Fe matrix by the addition of Si than the latter.
4) In the case of Fe-3%Si-3%Cu compacts sintered at 1220°C for 1 hr, we obtained a tensile strength of 78 kg/mm² and an elongation of 3% under the condition of aging at 500°C for 2 hrs.
5) In the sintered and aged Fe-Si-Cu compacts, Si was uniformly diffused and the Cu(ε) phase was precipitated in the aFe phase.