Discontinous precipitation in a Cu-12 at.% in alloy

Abstract

The feasibility of discontinuous precipitation from phase boundaries vis-a-vis grain boundaries has been investigated for the first time. Suitable heat treatments with a Cu-12 at.% In alloy produce measurable amounts of peritectic and eutectoid areas in the microstructure prior to discontinous precipitation. It has been demonstrated that the boundary between a supersaturated matrix and a eutectoid colony, under favourable conditions, can initiate discontinuous precipitation in the former. A suitable initiation mechanism from such phase boundaries has been proposed. Detailed kinetic analysis of the precipitation reaction and exhausted comparison with the published data reveal that the matrix/precipitate type phase boundaries are equally capable of undertaking discontinuous precipitation as the grain boundaries.