An analysis of the critical conditions for diffusion-induced void formation in Ni-Cu laminate composites

Abstract

An analysis that predicts, based on Kirkendall porosity formation, the critical composition difference that can exist without diffusion-induced porosity formation in laminate composites between solid-solution alloys is presented. Predictions based on laminate composites fabricated from pure nickel to nickel-copper solid-solution alloys indicate that porosity formation should be suppressed if the copper content in the solid-solution layer is below 40 at.%. The predictions are verified with metallographic observations on a series of annealed laminate composites. The implications of this study on the stability and mechanical properties of composites at high temperatures are discussed.