In the previous paper we confirmed that the abonormal exothermic reaction of Cu-Al (10wt%) compact during sintering could be eliminated by using the mother alloy powder of γ
2 composition containing about 20wt% Al in Cu. However, the trouble is that the denscification of the above described compact after sintering at 900°C was far poorer than that of the usual compact of the same composition prepared from pure Cu and Al powders.
In this point of view we studied the effects of Mn or Fe on the exothermic reaction of the Cu-Al compacts during sintering mainly by dilatometry. Results obtained are as follows :
(1) Even if the pure Mn or Fe powder was added, the abnormal exothermic reaction always appeared in the Cu-Al compacts at about 550°C during sintering, in the presence of free Al.
(2) When the alloying element of Mn or Fe was mixed in the pure Cu powder by using the mother alloy powder of Al-Mn or Al-Fe, the abnormal exothermic reaction disappeared in the mixed compacts of the ternary Cu-Al-Mn or Cu-Al-Fe system. However, appreciable expansion was found in each of them from 500°C during sintering, probably due to the appearance of the ternary β phase.
(3) From the view point of denscification, the Al-Fe mother alloy powder was more favorable than Al-Mn powder, moreover, a small amount of pure Ni powder promoted the denscification of the former.
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