DIMENSIONAL CHANGE OF IRON POWDER COMPACTS IN LATERAL DIRECTION DURING COMPACTING, DE-WAXING AND SINTERING.

Cylindrical compacts, phi 10 multiplied by h10 mm, for the size measurement and cubic compacts, 10 mm in size, for the dilatometry were formed of an electrolytic iron powder by die-wall lubricating alone, or by admixing 0. 3-1. 5 wt% of zinc-stearate. On the dilatometer, the compacts were heated slowly at 10 degree C/min in hydrogen. Some of the compacts containing zinc-stearate, expanded in the lateral direction and shrank in the pressing direction simultaneously during the early stage of de-waxing.