Dislocation Analysis in Mg₂Ca Lamella of Crept α -Mg/C14–Mg₂Ca Eutectic Alloy

Abstract

The dislocations introduced during creep in the hard C14–Mg₂Ca lamellae for the α-Mg/C14–Mg₂Ca eutectic alloy were analyzed using high-resolution transmission electron microscopy. The isolated dislocations are introduced into C14 lamellae from the stress-concentrated α/C14 interface during creep and identified as α dislocation with the Burgers vector of 1/3[1120], supposing that all dislocations in the Mg₂Ca phase split into partial dislocations. The introduced perfect dislocation is an α dislocation on the basal plane, which can dissociate into partial dislocations by the following reaction during creep; 1/3[1120]→1/3[1010]＋SF₍₀₀₀₁₎＋1/3[0110].