热处理工艺对复合熔体处理A356合金组织和性能的影响  

Effect of Heat Treatment Processes on the Structural and Mechanical Properties of A356 Alloy With Complex Melt Treatment

作　　者：王波[1] 李青 刘让贤[1] 孙甲尧[1] 陈胜迁[1] WANG Bo;LI Qing;LIU Rangxian;SUN Jiayao;CHEN Shengqian(Zhangjiajie Institute of Aeronautical Engineering,Zhangjiajie 427000;Guangzhou College of Technology and Business,Guangzhou 510850)

机构地区：[1]张家界航空工业职业技术学院,张家界427000 [2]广州工商学院,广州510850

出　　处：《宇航材料工艺》2024年第3期55-62,共8页Aerospace Materials & Technology

基　　金：湖南省教育厅科学研究优秀青年项目(23B1102);湖南省自然科学基金项目(2020JJ7074)。

摘　　要：利用熔体超声处理、Sr/Ce复合变质及热处理相结合的方法提高铝合金的强韧性,通过金相组织分析及力学性能测试研究了固溶处理对A356合金组织和性能的影响。研究结果表明,熔体处理有利于改善α-Al枝晶和共晶硅相,铸态合金的抗拉强度和伸长率分别达到215 MPa和9.5%;T6热处理后,共晶硅的形态由纤维状转变成独立分布的颗粒状,而除了伸长率之外,合金的力学性能都显著提高;随着固溶时间的延长,共晶硅的等效直径呈现先减小后增大的趋势,而长径比逐渐减小,合金的拉伸性能和硬度均呈现先增大后减小的趋势;当固溶时间为4 h时,合金的综合力学性能达到最佳,其抗拉强度、屈服强度、伸长率和显微硬度分别达到300、240 MPa、8.0%和110HV。This paper demonstrated that the strength and toughness of Al alloy could be improved when ultrasonic melt treatment,Sr/Ce complex modification and heat treatment worked together.The effect of solid solution treatment on the microstructure and properties of A356 alloy was also studied by metallographic microscope(OM),scanning electron microscope(SEM),tensile machine and hardness instrument.The research results showed that melt treatment contributed to the improvement of theα-Al dendrites,and eutectic silicon phases,and the tensile strength of as-cast alloy reached 215MPa with elongation of 9.5%.After T6 heat treatment,the morphology of eutectic silicon changed from fibrous to spherical particles distributed independently,and mechanical properties were significantly also improved,except for elongation.As the solution time increased,the equivalent diameter of eutectic silicon decreased first and then increased,while the aspect ratio gradually decreased.Meanwhile,the tensile properties and microhardness of the alloys showed a trend of first increasing and then decreasing.When solution time was 4h,the optimized comprehensive mechanical properties of the alloy were obtained and its tensile strength,yield strength,elongation and microhardness reached 300MPa,240MPa,8.0%and 110HV,respectively.

关 键 词：A356 超声处理 共晶硅 Sr/Ce复合变质 

分 类 号：TG292[金属学及工艺—铸造]