Influence of Solutionizing and Aging Treatment on the Microstructure and Mechanical Properties of AA7075 Friction Stir Welded Joints in Different Conditions
For heat-treatable strengthened aluminum alloys,post-weld heat treatment stands out as a prevalent meth-od to mitigate the softening of friction stir-welded joints and augment their mechanical characteristics.This investiga-tion applies the T6 treatment(solution treatment and artificial aging)to joints formed from AA7075-T6 and AA7075-O,examining the impact of T6 treatment on the microstructure and mechanical properties of the joints.The findings reveal that both joints display varying degrees of abnormal grain growth(AGG)in the weld nugget zone,with the AGG area percentage notably higher in the T6-T6 joint as compared to the O-T6 joint.Concerning mechan-ical performance,the T6 treatment not only effectively resolves the softening issue in the welded state but also height-ens the overall hardness of the joint.The average hardness consistently exceeds 180 HV,displaying a linear trend in hardness distribution.AGG significantly influences the tensile properties of the joints,wherein the O-T6 joint exhib-its substantially greater strength and plasticity than the T6-T6 joint,achieving a strength of 575.5 MPa and an elon-gation of 7.1％.
solutionizing and aging treatmentfriction stir weldingAA7075microstructuremechanical properties
NETL
NSTL
万方数据
