The morphology and orientation of Mn 5Si 3 precipitates in an Mg–Sn–Mn–Si alloy

Abstract

This paper reports a preliminary study of Mn 5Si 3 precipitates in an Mg–Sn–Mn–Si alloy. The transmission electron microscopy investigation reveals that the Mn 5Si 3 precipitates have a plate shape, approximately 50 nm in thickness and 200 nm in width. The orientation relationship (OR) between the precipitates and matrix is not unique, but all measured ORs obey the following relationship: g (1 0 − 1 0)Mn5Si3 // Δ g 1 // Δ g 2, where Δ g 1 = g (2 − 1 − 1 0) Mn5Si3 − g (0 0 0 2)Mg, Δ g 2 = g (3 − 1 − 2 0) Mn5Si3 − g (0 0 0 2)Mg. The precipitate morphology and their OR with the matrix are explained with a Δ g parallelism rule, showing good agreement.