Study On Multi-pass Hot Deformation And Microstructure Evolution Of Aluminum Alloy

In modern industrial applications,aluminum alloy has become the most suitable material for replacing steel materials in the automotive industry due to its low density,corrosion resistance and high specific strength.The 6000 series aluminum alloy with relatively comprehensive performance has wider application prospects in the automotive field.The forming of aluminum alloy sheet is mainly hot rolling,and its mechanical properties and microstructure are closely related to the process parameters of the rolling process.The evolution of microstructure is extremely complicated,including dynamic recovery,dynamic recrystallization,static recovery,static recrystallization,etc.It is of great significance to master the law of change and use mathematical methods to describe this law:controlling the aluminum alloy simulation rolling process The parameter variable is used to study microstructure change of the sample,and then the ideal microstructure can be obtained to obtain a material with good mechanical properties.In this paper,6063 aluminum alloy was used to conduct multi-pass hot compression process experiments and microstructure evolution research.The parameters of reversed parameters were used to modify the flow stress parameters.Finally,the mathematical method was used to describe the grain size evolution during multiple simulated hot rolling.law.The main contents of this paper include:(1)Using semi-continuously cast aluminum alloy ingots,refer to the heat treatment process and thermal deformation experimental parameters of 6063 aluminum alloy in a large number of literatures,set the homogenization experimental temperature 520??580?,the holding time is 0.5 h?10 h,pass the time and temperature The control seeks the optimal homogenization treatment scheme and guides the preparation of the hot deformation specimen.(2)The homogenization experiment results were used as a reference for the homogenization system before hot compression experiment,and then the double pass thermal deformation experiment was performed The temperature is set from 300? to 500?,the strain rate is 0.001-0.1s-1,and the heat preservation time is 10s?90s.The flow stress curve is obtained by controlling the temperature,strain rate and residence time between the passes.Microstructure with hot deformation specimens.(3)During the thermal compression process,the DIC device was used to record the deformation process to explore the relationship between temperature and deformation mode.The deformation mode and mechanical properties were fitted by LS-DYNA software.The parameters of the thermal compression data were modified by the simulated annealing method of LS-OPT software to optimize the rheology.Stress curve.(4)Based on the results of the compression experiment,the micro-crystals with different temperature and strain rate are included in the statistics of size and morphology.Based on the classical grain deformation formula,the linear regression method is used to establish the grain under multi-pass hot compression conditions.The equation for the evolution of grain size along the direction of compression is used to determine the effect of the residence time of the pass on the grain size.