AZ80镁合金的深冷处理

研究了深冷处理对AZ80镁合金组织及力学性能的影响,并用扫描电镜分析了挤压态、T4态和T4+深冷处理态试样的室温拉伸断口。试验结果表明,深冷处理能改善合金的显微组织,从而提高其力学性能。在本试验条件下,AZ80镁合金最佳深冷处理工艺为-180℃×2 h。挤压态试样室温拉伸断口为准解理断裂;T4处理后,断口形貌为具有一定塑性变形的准解理断裂;T4+深冷处理后,断口又呈现出以准解理为主的脆性断裂特征。

Deep Cryogenic Treatment of AZ80 Magnesium Alloy

The effect of deep cryogenic treatment was investigated on microstructure and mechanical properties of AZ80 magnesium alloy. The fractures of specimens after extruding, T4 treating and T4 treating plus deep cryogenic treating were analyzed by SEM. The results show that the deep cryogenic treatment can permit microstructure and properties to be improved on. The optimal deep cryogenic treatment process consists in holding at -180 ℃ for 2 h. The fracture of tensile specimen under extruded or T4 condition is of quasi-cleavage or of quasi-cleavage with a certain amount of plastic deformation, respectively. However, the fracture of specimen under T4 plus deep eryo-treated condition will be essentially characterized by brittle quasi-cleavage fracture.