The influence of melt superheating treatment on the microstructures of Mg-3.5Si-1Al alloys unmodified and modified with 0.2%Sr-Sb(mass fraction) was investigated.The results show that when the melt superheating temper...The influence of melt superheating treatment on the microstructures of Mg-3.5Si-1Al alloys unmodified and modified with 0.2%Sr-Sb(mass fraction) was investigated.The results show that when the melt superheating temperature increases from 750 to 900℃,the average size of primary Mg2Si in the unmodified alloys decreases progressively from about 27 to about 19μm,while that in Sr-Sb-modified alloys is refined considerably from about 14 to about 7μm when the temperature increases from 750 to 850℃,and then slightly increases to about 9μm with temperature further increasing to 900 C,which might be attributed to the burning loss of Sr and Sb in melts.However,the superheating temperature only has a slight effect on the morphologies of both primary and eutectic Mg_2Si phases in unmodified and Sr-Sb-modified alloys.展开更多
基金Project(50501010)supported by the National Natural Science Foundation of Chinaproject supported by the 985-AutomotiveEngineering of Jilin University,China
文摘The influence of melt superheating treatment on the microstructures of Mg-3.5Si-1Al alloys unmodified and modified with 0.2%Sr-Sb(mass fraction) was investigated.The results show that when the melt superheating temperature increases from 750 to 900℃,the average size of primary Mg2Si in the unmodified alloys decreases progressively from about 27 to about 19μm,while that in Sr-Sb-modified alloys is refined considerably from about 14 to about 7μm when the temperature increases from 750 to 850℃,and then slightly increases to about 9μm with temperature further increasing to 900 C,which might be attributed to the burning loss of Sr and Sb in melts.However,the superheating temperature only has a slight effect on the morphologies of both primary and eutectic Mg_2Si phases in unmodified and Sr-Sb-modified alloys.