热处理对高真空压铸AlSi10MnMg合金拉伸性能的影响  

Influence of Heat Treatment on Tensile Properties of High Vacuum Die Casted AlSi10MnMg Alloy

作　　者：罗国健 孙有平[1,2,3] 何江美[1] 刘华燊 罗章 LUO Guojian;SUN Youping;HE Jiangmei;LIU Huashen;LUO Zhang(School of Mechanical and Automotive Engineering,Guangxi University of Science and Technology,Liuzhou 545006,China;Guangxi Earthmoving Machinery Collaborative Innovation Center,Guangxi University of Science and Technology,Liuzhou 545006,China;Guangxi Key Laboratory of Automobile Components and Vehicle Technology,Guangxi University of Science and Technology,Liuzhou 545006,China)

机构地区：[1]广西科技大学机械与汽车工程学院,柳州545006 [2]广西科技大学、广西土方机械协同创新中心,柳州545006 [3]广西科技大学广西汽车零部件与整车技术重点实验室,柳州545006

出　　处：《机械工程材料》2024年第4期44-50,共7页Materials For Mechanical Engineering

基　　金：广西重点研发计划项目(桂科AB23026104);广西科技基地和人才专项项目(桂科AD22080042)。

摘　　要：分别对高真空压铸AlSi10MnMg合金进行T5(180℃×2 h)、T6(515℃×1 h空冷+175℃×2 h)和T7(460℃×1 h水冷+175℃×2.5 h)热处理,研究了不同热处理条件下该合金的显微组织和拉伸性能。结果表明:经过T5热处理后的铸态试验合金铝基体相长大,圆整度较高,晶粒尺寸主要集中在20~80μm,硅相仍呈细长状,与铸态试验合金相比,试验合金的抗拉强度提高了8.9%,断后伸长率降低了9.1%;经过T6和T7热处理后,铝基体相形状不规则程度降低,晶粒尺寸分别为2~50,2~30μm,组织更均匀致密,硅相由铸态时的细长状演变为规则的圆形,试验合金的抗拉强度分别降低了26.0%和23.9%,断后伸长率分别提高了54.5%和72.7%;铸态和T5态试验合金的拉伸断裂方式均为韧脆混合断裂,T6和T7态试验合金的断裂方式则以韧性断裂为主,其中T7态试验合金拉伸断口中的韧窝细密且深,塑性更好。High vacuum die casted AlSi10MnMg alloy was treated by T5(180℃×2 h),T6(515℃×1 h air cooling+175℃×2 h)and T7(460℃×1 h water cooling+175℃×2.5 h)heat treatment,respectively.The microstructure and tensile properties of the alloy under different heat treatment conditions were studied.The results show that the aluminum matrix phase of the as-cast alloy grew after T5 heat treatment,the roundness was high,and the grain size was mainly concentrated in the range of 20-80μm.The Si phase after T5 heat treatment was still a slender shap.Compared with those of the as-cast test alloy,the tensile strength of the test alloy increased by 8.9%and the percentage elongation after fracture was reduced by 9.1%after T5 heat treatment.After the heat treatment of T6 and T7,the irregular degree of aluminum matrix phase shape decreased,the grain size was 2-50,2-30μm,respectively,and the microstructure was relatively uniform and dense.The Si phase changed from a slender shape in the cast state to a regular round shape.Compared with those of the as-cast test alloy,the tensile strength of the test alloy after T6 and T7 heat treatment was reduced by 26.0%and 23.9%,and the percentage elongation after fracture increased by 54.5%and 72.7%,respectively.The tensile fracture modes of the as-cast and T5 heat-treated test alloys were both tough-brittle mixed fracture.The fracture mode of the test alloys in T6 and T7 states were mainly ductile fracture,while the tough dimple in the tensile fracture of the T7 heat-treated test alloy was fine and deep,indicating better plasticity.

关 键 词：高真空压铸 AlSi10MnMg合金 热处理 显微组织 拉伸性能 

分 类 号：TG166.3[金属学及工艺—热处理]