Abstract
The effects of both presintering and sintering times and temperatures on the volume change and tensile property were investigated with iron-l%carbon powder compacts. The presintering was carried out under the condition where carbon hardly diffused into iron, and the sintering was done under the easy-to-diffuse condition.
The two-stage sintering decreased the volume change (expansion) of the powder compacts during the sintering and improved both the tensile strength and the elongation compared with the conventional process. The improvement is considered to be caused not only by the bonding of iron particles, but the activation of the iron particle surface by hydrogen gas during the presintering.
