The effect of heat treatment on Mg2Si coarsening in aluminum 6105 alloy

Abstract

The coarsening behavior of Mg2Si intermetallic particles was studied during homogenization of aluminum 6105 alloy. An industrially homogenized 6105 aluminum alloy contained large globular undissolved Mg2Si. With subsequent heat treatment at 590 degreesC over 1 week, it was found that the large Mg2Si precipitates coarsened with time. The coarsening of the large Mg2Si precipitates was quantified by statistical analysis of micrographs. A linear relationship between (R) over bar (3.8) - (R) over bar (3.8)(i) and time fits the experimental measurements quite well, indicating that the coarsening is diffusion controlled, with grain-boundary diffusion dominating volume diffusion.