High-resolution electron microscopy observations of the microstructure of a rapidly solidified Mg–9.0 wt% Al–1.0 wt% Zn–4.0 wt% Sn alloy

Abstract

The present study examines the microstructure of rapidly solidified ribbons of an Mg–9.0 wt% Al–1.0 wt% Zn–4.0 wt% Sn alloy. XRD and transmission electron microscopy (TEM), including high-resolution transmission electron microscopy (HRTEM), confirmed that the rapidly solidified ribbons consist of α-Mg, γ-Mg₁₇Al₁₂ and β-Mg₂Sn phases. The predominant fraction of the γ-Mg₁₇Al₁₂ phase reveals intergranular texture morphologies with the Burgers OR. The minor fraction of the γ phase exists in short-lath morphology with a typical grain size of 30 nm, and its orientation relationship with the matrix is also the Burgers orientation relationship. The β-Mg₂Sn particle reveals spherical morphology with the typical grain size of 40 nm, and its orientation relationship with the matrix is in the form of , .

Keywords:

• rapid solidification
• high-resolution electron microscopy
• magnesium alloy

Acknowledgements

This research was supported by National Natural Science Foundation of China (Grant Nos. 50771074 and 50571075) and by New Century Excellent Talents in University (Grant No. NCET-07-0640).