Abstract
The sintering process and spheroidization of the pores of iron and ferrophosphorus (27 wt%P) mixed powder compacts were investigated by means of photomicroscopic examination, DTA and EPMA. The results obtained were as follows:
On sintering at higher temperatures than the eutectic temperature (1050°C), the liquid of iron-phosphorus was formed and penetrated into inherent pores in the compact. As a consequence, new large rounded pores were formed at the original location of the ferrophosphorus particles, and the size and shape of the pores became small and spherical with an increase of compacting pressure even in short-time sintering. Therefore, it was considered that the appearance of spherical pores was mainly attributed to the occurrence of a liquid phase. The α-phase sintering due to the result of the diffusion of P arround 1100°C did not show any remarkable effect on the spheroidization of the pore. A model of sintering process of iron and ferrophosphorus mixed powder compacts was proposed, using the diffusion data obtained from the model experiment. And the size of spherical pore was successfully explained by the model.
