超声处理对AS31镁合金组织及性能的影响

Effects of Ultrasonic Treatment on Solidification Structure and Mechanical Properties of AS31 Magnesium Alloy

研究了超声处理对AS31镁合金凝固组织和力学性能的影响,并对其作用机理进行了探讨。结果表明,随着超声功率增加,AS31镁合金的晶粒尺寸显著细化,组织中共晶Mg2Si相形貌、尺寸和分布明显得到改善。当施加超声功率为750 W时,共晶Mg2Si相由粗大汉字状转变为短棒状,其平均尺寸由未施加超声时的160μm减少到50μm。另外其抗拉强度和伸长率分别为203 MPa和3.4%,比未超声合金分别提高了25%和100%,分析其断口发现,未经超声处理的AS31镁合金表现为解理断裂,经过超声处理的AS31镁合金表现为韧窝断裂。

Effects of ultrasonic treatment on the solidification and mechanical properties of AS31 magnesium alloy were investigated,and its mechanism was described.The results reveal that with the increase of ultrasonic power,the grain size of AS31 magnesium alloy is refined obviously,and the morphology,size and distribution of eutectic Mg2Si in the microstructure of the alloy are improved greatly.With the ultrasonic power of 750 W,the eutectic Mg2Si phase in the alloy is changed from coarse Chinese script to short rod ones.The average size is reduced from 160μm to 50μm.Meanwhile,the strength and elongation of the alloy reach up to 203 MPa and 3.4%,compared with those of the non-ultrasonic treatment alloy,increased by 25% and 100%,respectively.The fracture analysis of AS31 magnesium alloy without ultrasonic treatment presents cleavage fracture,while the ultrasonic treatment AS31 magnesium alloy presents dimple fracture.