Abstract
The influence of alpha-gamma transformation on the sintering behaviour of powder compacts and wire couples of pure iron, Fe-Ni alloys (1-21 wt% Ni) and Fe-Co alloy (5 wt% Co), which were sintered in cyclic fashion over the temperature range containing alpha-gamma transformation temperature or not, was studied. Results obtained are summarized as follows.
(1) In the cyclic sintering of pure iron, sintering rate of the powder compact was suppressed by alpha-gamma transformation, but sintering of wire couples was impossible due to the transformation strain.
(2) In the cyclic sintering of Fe-Ni and Fe-Co alloys, the sintering rate was markedly promoted by alpha-gamma transformation due to the superplasticity caused by phase transformation.
(3) The difference in the sintering behaviours between pure iron and other ferrous alloys originated from the difference of extent of transformation stress and creep resistance of the materials.
