High-resolution electron microscopy observations of continuous precipitates with Pitsch-Schrader orientation relationship in an Mg–Al based alloy and interpretation with the O-lattice theory

High-resolution electron microscopy was applied to analyze the continuous precipitated particles of the γ-Mg17Al12 phase with Pitsch-Schrader OR in the heat-treated AZ91 alloy at 473 K for 8 h. The existence of a continuous precipitated particle with the Pitsch-Schrader OR including the selection of the habit plane and the growth direction in Mg–Al system is rationalized by the constrained coincidence site lattice/constrained complete pattern shift lattice (CCSL/CDSCL) model and the O-lattice theory.