Initiation sites for discontinuous precipitation in some Cu-base alloys

Abstract

A systematic effort has been made to investigate the suitability of various interfaces, natural as well as artificial, to initiate discontinuous precipitation. The interfaces studied in the present investigation include sample surface (external), and grain and interphase boundaries. It has been demonstrated that in addition to grain boundaries, non-conventional initiation sites like coherent faces of a twin or eutectic/eutectoid boundaries under favourable conditions may also nucleate discontinuous precipitation. In general, the ability of an interface to undergo thermally activated migration appears to be the most important criterion for the initiation of discontinuous precipitation.