Some Experiments on the Sintering of Powder Metal Compacts (II)

In the previous report, the present authors studied the Thermal change of binary compact constituenents of which form a simple binary eutectic alloy. the resulT showed that even in a mechanical mixture of powderly metals, the similar phase change would take place as in the case of an alloy made by melting. In the present works, the object is to confirm whether the similar change will occur in the case of binary alloys which form an intermetallic compound.The following alloy systems were experimented : Te-I, Mg-Pb, Mg-Sb, Mg-Zn, Te-Pb, Mg-Bi, Mg-Sn and Te-Bi. From thermal behaviours of compacts composed of these metals in heating, four types of the formation of intermetallic compound were recognized as follows :(a) The formation of intermetallic compound takes place at a lower temperature than any of the eutectic temperatures in the alloy system.(b) The formation of intermetallic compound takes place following one of the eutectic reactions.(c) The formation of intermetallic compound takes place at a temeperature between the two eutectic reactions.(d) The formation of intermetallic compound takes place at a higher temperature than those of any eutectic reactions.In the cases of (a), (b) and (c), a metal compact of eutectic composition melts at the eutectic temperature, but in the case of (d), it hardly melts at the eutectic temperature.