Interpretation of the orientation relationship and habit plane orientation of the equilibrium β-phase in an Mg–Y–Nd alloy

The habit plane of the equilibrium β(Mg14Nd2Y) phase in Mg–Y–Nd alloys was found to deviate from (1 −1 2)β/(1 0 −1 0)α by about 3°. The present work analyzed the interface structure and orientation relationship (OR) by CSL/DSC model and Δg parallelism rule. For a better matching degree in the habit plane, the stepped interface containing a quasi-invariant line with a terrace of (1 −1 2)β/(1 0 −1 0)α is preferred, which requires a small rotation of 0.24° from Burgers OR. The simulation results are consistent with experimental observations.