Effects of Micropores on Processing and Properties of Porous Irons

Abstract

Porous irons with only micropores were produced through powder metallurgy route. Corn starch of small particle size (5-15μm) was utilized to regulate the densification of green compacts. The structural and mechanical properties of porous irons sintered at different temperatures were evaluated. The porosities increased with increasing the starch content, which reduced compressive strength and increased volumetric shrinkage. The compressive yield stress increased with increasing sintering temperature. It was also found that the effect of sintering temperature on the microstructure and compressive properties was more obvious when green compacts were less densified. Moreover, volumetric shrinkage of porous irons without adding starch remains in a quite low level for different sintering temperatures.