The solid solubilities of 15 common alloying elements in the L12-type intermetallic compound Ni3Si have been determined at 900°C, and their substitution mode has been deduced from the direction of solubility lobe of the compound. It is shown that the alloying behavior in Ni3Si is determined by both size and electronic factors, i.e, the substitution mode is governed by electronic configuration and solubility by the both. The solubilities of alloying elements can be explained on the two dimensional map proposed by Alonso and Simozar.
Four isotherms of Ni-Si-X (X = Fe,Cr, Co,Cu) have been obtained. They are very similar in structure.