Study On Aging Treatment Of Rapidly Solidified A356

The copper mould suction casting process can get good microstructure with high cooling rate,and the material properties can be greatly improved with the aging treatment.The solidification condition has important influence on the size and morphology of microstructure and The greate degree of subcooling can greatly improve the cooling rate and reduce segregation.Under the condition of non-equilibrium solidification,A356 was used as the experimental material in this paper to explore the law of solidification structure change of alloy and the ageing strengthening behavior of non-equilibrium solidification structure during aging treatment;and the microstructure evolution of the alloy and its influence on the mechanical properties were analyzed during the copper mold suction molding process and aging treatment process;and the aging treatment process with good effect was explored.Firstly,the effects of rapid solidification on the grain size and mechanical properties of the alloy were studied.The grain shape factor and equivalent diameter were 0.71 and 12.65 um,and the tensile strength reached 203.4MPa.The analysis of DSC curve revealed that the material after the copper mold suction molding process has no solid solution endothermic peak,It means that,the material does not need to be solution treated,because the copper mold absorption casting process itself obtains the supersaturated melt.Then,the effects of aging treatment temperature and time on the microstructure and mechanical properties of the materials were analyzed,and the effects of optimal aging treatment process and processing parameters on the microstructure were obtained.When the aging temperature is low,the mechanical properties increase with the increase of aging treatment time.When the aging temperature is high,the aging treatment time is optimal,and the mechanical properties decrease rapidly with the aging treatment time.