| Understanding the thermal deformation law of aluminum alloy and its subsequent aging process is of great significance for maximizing the performance of aluminum alloy.In this paper,the high temperature hot deformation compression test of 6061 forged aluminum alloy was firstly carried out by Gleeble-3500 thermal simulation test,and the true stress-strain curve at different deformation rates between 0.001-10s-1 and different deformation temperatures of 375-500℃ was obtained.Based on the analysis of the influence of deformation rate and deformation temperature on the mechanical behavior of 6061 aluminum alloy during hot deformation,the flow constitutive equation of high temperature deformation is established.Secondly,after the solution treatment of 6061 aluminum alloy at 540 ℃,the aging treatment was carried out with different holding time and different temperature.The hardness measurement,metallographic microstructure analysis and TEM micromorphology analysis of the alloy under different aging conditions were studied in depth.The mechanical properties of 6061 aluminum alloy and the regularity of the microstructure conditions were determined to determine the optimum heat treatment aging process for 6061 aluminum alloy.Research indicates:(1)The results of thermal simulation test show that the flow stress of 6061 aluminum alloy increases with the increase of strain rate,but decreases with the increase of heat distortion temperature.The Zener-Hollomon parameter is suitable for describing the rheological behavior of the alloy;(2)The best aging process of 6061 aluminum alloy is 200℃×6h.At this time,the 6061 aluminum alloy has the highest hardness of 114.26HV,Maximum conductivity 14.7Ms/m.(3)The shape of the precipitated phase of 6061 aluminum alloy changes with the aging time.At 200℃,the precipitated phase was acicular for 3 h,and after 6 h of aging,the precipitated phase was granular.(4)The main precipitation phase of the 6061 aluminum alloy during the aging process was Mg2Si.When the time of aging is increased,the size of the precipitation phase of the grain boundary and the spacing between the precipitation phases are gradually increased. |
PDF Full Text Request