热处理对超声挤压态Mg-6Zn-0.5Y-2Sn合金微观组织和拉伸性能的影响（英文）

Effect of Heat Treatment on Microstructure and Tensile Properties of Ultrasonically Treated As-extruded Mg-6Zn-0.5Y-2Sn Alloy

研究了热处理对超声挤压态Mg-6Zn-0.5Y-2Sn合金微观组织和拉伸性能的影响。结果表明,经过时效处理(T5)和固溶+时效处理(T6),合金的晶粒尺寸变得更加均匀,MgSnY相和Mg2Sn相分布的更加弥散,且数量有所增加。而且,T5和T6处理均提高了合金的屈服强度,其中T5处理的提高作用十分明显。经过T5处理之后,合金的屈服强度从165 MPa增加到了269 MPa,增长率达到63.1%。MgSnY相和Mg2Sn相在合金基体中产生的析出强化作用,是提高热处理态合金屈服强度的主要原因。此外,T5处理比T6处理更加有效地提升了合金的综合力学性能。

The effect of heat treatment on the microstructure and tensile properties of an ultrasonically treated as-extruded Mg-6Zn-0.5Y-2Sn alloy was investigated. The results show that after the aging treatment and solid solution+aging treatment, the grain size of the test alloys becomes more uniform. The MgSnY and Mg2Sn phases are much more dispersed and increased in amount. In addition, both the aging and solid solution+aging treatment improve the yield strength of the test alloys, especially, the aging treatment significantly improves the yield strength from 165 MPa to 269 MPa, increased by 63.1%. The precipitation strengthening, which is derived from the MgSnY and Mg2Sn phase, is the major factor for improving the yield strength of the test alloys with heat treatment. Moreover, the aging treatment more effectively improve s the comprehensive tensile properties of test alloy compared with the solid solution+aging treatment. The mechanisms for the experimental observations were also discussed.