Use of EBSD to identify phases in interdendrite region of a cast Zn-Al-based alloy (ZA27)

Abstract

Electron backscattered Kikuchi diffraction methodology was used to identify phases in the interdendrite region of an alloy ZA27. Two Zn-rich hexagonal close-packed structure phases eta and epsilon phases were distinguished using predetermined lattice parameters of the phases. In relation to studies of scanning electron microscopy and X-ray diffraction, electron backscattered diffraction results revealed that the Al-rich precipitates of the alpha phase were from decomposition of the eta'(T), and the four-phase transformation: alpha+epsilon--> T'+eta, had occurred in the epsilon phase after ageing at 150 degrees C for 8 h.