材料期刊网

X射线衍射、电子显微镜和硬度的研究结果表明。淬火态合金析出平行(0001)_(Mg)和{1010)Mg面的溶质原子聚集区.150和220℃的时效过程分别为:过饱和固溶体→β’_1→重溶→β’_2→β’_2→+β,和过饱和固溶体→β’_2→β’_2→+β.β’_1显二维和三维形态,而β’_2以垂直(0001)Mg面的一维细杆物析出.150℃时效初期析出β’_1,存在时间极短,后期β’_2和β长期共存.初步测定了β’_1和β’_2的结构参数及取向关系. 添加Al促进时效析出,并提高β’_2的热稳定性.

Plate-like solute atom clusters parallal to (0001)_(Mg) and {1010}_(Mg) planes have been observed in the as-quenched alloy. The age-hardening process of the alloy at 150℃ is: super-saturated solid solution→β_1'→redissolved→β_2'→β_2'+β; and that at 220℃ is: super-saturated solid solution→β_2'→β_2'+β. The results show that β_1' pocesses two-and three-dimensinal morphologies and β_2' is one-dimensional rod precipitates perpendicular to (0001)_(Mg) plane. β_1' particles precipitated out from the matrix at the initial stage of 150℃ aging, which exist only for a very short period. However, β_2' and β coexisted for a long time at the later stage. The structural parameters of β_1' and β_2' as well as their orientational relationships with the matrix have also been determined. The addition of Al promotes the age-hardening process and enchances the thermal stability of β_2'.