压下量及时效对搅拌摩擦加工6061铝合金组织和力学性能的影响

Effect of reduction and aging on microstructure and mechanical properties of 6061 aluminum alloy processed by friction-stir

对6061-T6铝合金板材进行搅拌摩擦加工,研究搅拌摩擦加工压下量和时效热处理对合金的宏观形貌、显微组织、显微硬度和拉伸强度的影响。结果表明：当搅拌头转速为1200 r/min,进给速度为90 mm/min,压下量为1 mm时,搅拌区由细小等轴晶组成,硬度约74 HV,抗拉强度达346 MPa,伸长率为24.7%;经过180℃时效处理后,搅拌区硬度达到107 HV,抗拉强度为397 MPa,伸长率为13.2%。断口形貌分析表明搅拌区拉伸断裂为韧性断裂。

The effect of friction-stir process reduction and aging heat treatment on macroscopic morphology,microstructure,microhardness and tensile strength of 6061-T6 aluminum alloy sheets machined by friction-stir process was investigated. The results show that when the rotation rate is 1200 r/min,processing speed is 90 mm/min and reduction is 1 mm,the friction stir zone of the alloy consists of fine equiaxed grains,the hardness is about 74 HV,the tensile strength is 346 MPa and the elongation is 24. 7%. After aging at 180 ℃,the hardness of friction stir zone reaches 107 HV,the tensile strength is 397 MPa,and the elongation is 13. 2%. The fracture surface analysis shows that the tensile fracture in the friction stir zone is ductile fracture.