Morphological and Crystallographic Characterizations of the Ca-Mg-Zn Intermetallics Appearing in Ternary Diffusion Couples

In the present research, seven multi-phase diffusion couples, with terminal alloys having different microstructural features, were prepared and annealed for 4 weeks at 335°C. The phase relations and change of morphological characteristics of each phase were studied along the diffusion zone by means of scanning electron microscopy/energy dispersive X-ray spectroscopy and quantitative electron probe microanalysis. Depending on the different terminal compositions of the diffusion couples, the morphological evolution in the diffusion zone can be: tooth-like, matrix phase with isolated and/or dendritic precipitates. Electron back-scattered diffraction analysis was carried out to investigate the crystal orientation of the ternary compounds and the crystal orientation relations at the interface of the diffusion zones.