Masanori Kiyoshige1, Kuniyasu Sakai1 and Kiyoshi Kita1
1Technical Research Laboratory, Kawasaki Heavy Industries, Ltd., Akashi
In most industrial metals and alloys, a small amount of minor elements are contained as additional elements or impurity. However, it is impossible for the present to predict how these elements behave against the segregation behavior of major elements. The authors have investigated the segregation tendency of third elements, Mn, Si, Fe, Cr and Al, in Ni-30%Cu alloy.
The results obtained are as follows:
(1) The dendrite arm spacings of unidirectionally solidified Ni-30%Cu alloys were hardly affected by a small addition of third element, while the morphological aspects of the dendrite were varied.
(2) Among the minor elements studied, Mn and Si segregated with solute Cu, but Fe, Cr and Al segregated with solvent Ni.
(3) It is considered that the tendency of segregation of minor elements related with the relative valency effect, since it is possible to explain this tendency by the difference in solubility between solvent and solute.
(4) It is found that the segregation ratio of Cu was increased by the addition of a minor element which had a tendency to segregate with solvent Ni.
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