AN X-RAY INVESTIGATION OF AGE-HARDENING PROCESS OF A Mg-5wt%Zn ALLOY
Xu Shunsheng (Hsu Shun-sheng);Su Qianwu Shanghai Institute of Metallurgy; Academia Sinica
Cite this article:
Xu Shunsheng (Hsu Shun-sheng);Su Qianwu Shanghai Institute of Metallurgy; Academia Sinica. AN X-RAY INVESTIGATION OF AGE-HARDENING PROCESS OF A Mg-5wt%Zn ALLOY. Acta Metall Sin, 1980, 16(1): 73-136.
Abstract The age-hardening processes of a Mg-5wt%Zn alloy have been studied bymeans of hardness measurement and X-ray diffraction analysis. On aging of thisalloy at 165℃, two hardness peaks with corresponding structural changes in thealloy were noticed. X-ray investigation of this alloy in quenched state revealedthat plate-like zinc clusters parallel to (0001) and {1010} planes of the magne-sium matrix were formed. At the initial stage of 165℃ aging, two-and three-dimensional metastable transition phase β'_1 particles and one-dimensional transitionphase β'_2 rods were precipitated out from the super-saturated solid solution. β'_1 existedonly for very short periods, while B'_2 still grew after aging for a total period of100h. when an equilibrium phase β began to precipitate out. During aging at190℃, only one hardness peak appeared, corresponding to the concurrent pre-cipitation of β'_2 and β phases. The structural parameters of β'_1 and β'_2 and theirorientational relationships with the matrix have en determined. The thermal stability of β'_2 was found to be rather high at 250℃, implyingthe probable applicability of the aged Mg-Zn alloys at higher temperatures.