Abstract
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.
