Discontinuous precipitation initiated at interphase boundaries in a Zn-rich Zn-6.3 at.% Ag alloy

Abstract

Discontinuous precipitation in a two-phase Zn-rich Zn-6.3 at.% Ag alloy has been studied. It has been shown that the η′/ε interphase boundaries have the ability to initiate discontinuous precipitation as do the η′/η′ grain boundaries. The back-polishing method is used to show the interconnection between a discontinuous precipitate colony and the η′/ε interphase boundary. The reaction front velocity of discontinuous precipitation initiated at the η′/η′ grain boundary is 12-90% higher than that of discontinuous precipitation initiated at the η′/ε interphase boundary under various ageing temperatures.