A new orientation relationship OR13 and irrational interfaces between Mg2Sn phase and magnesium matrix in an aged Mg alloy

Abstract

A new orientation relationship OR13 is identified in Mg/Mg2Sn phase transformation system, which can be described as <011> // <01-10>, and {100} about -17° from (0001), with Mg indexed by four indices. The major facet of OR13 type precipitate is F1 // (1.14, 1, -1) // (2, -1, -1, 4.85), inclined about 33° from (0001). Its preference can be well explained by good lattice matching between the two phases. Although OR13 deviates only about 1.6° from OR9, precipitate shape changes considerably, indicating that lattice matching pattern is sensitive to OR. This helps to better understanding otherwise easily omitted features of alloy microstructure.