Abstract
Sintering behavior of Fe-Cu-Ni compacts prepared by electroless plating on iron powder was studied by means of the dilatometric method and electron probe micro analysis. The copper growth in the compacts of plated powder was markedly reduced during heating in the temperature range of gamma iron, compared with the case of mixed powder. The following mechanism was proposed for the decrease in copper growth in the compacts of plated powder. The nickel-copper alloy layer formed on the surface of iron particles retards the diffusion of copper to the surface of iron during heating. This alloy layer also prevents liquid copper from contacting with the surface of iron particles directly, and finally absorbs liquid copper to form a solid solution in the temperature range above the melting point of copper. Therefore, the decrease in grain boundary diffusion of copper in the iron particles brings about the reduced copper growth, compared with the case without making the alloy layer.
