固溶处理时间对铸造Al-Si-Mg合金低温力学性能的影响  

Effects of Solution Treatment Time on Mechanical Properties of Cast Al-Si-Mg Alloy at Low Temperature

作　　者：马广辉 李广龙[2] 崔勇 刘海 金玉静 MA Guang-hui;LI Guang-long;CUI Yong;LIU Hai;JIN Yu-jing(Precision Manufacturing Engineering Department,Suzhou Institute of Industrial Technology,Suzhou 215104,Jiangsu,China;School of Materials Science and Engineering,Shenyang University of Technology,Shenyang 110870,Liaoning,China)

机构地区：[1]苏州工业职业技术学院精密制造工程系,江苏苏州215104 [2]沈阳工业大学材料科学与工程学院,辽宁沈阳110870

出　　处：《铸造》2024年第8期1103-1108,共6页Foundry

基　　金：江苏省高等学校自然科学研究面上项目(21KJB430006);江苏高校“青蓝工程”项目(202219QL001);苏州工业职业技术学院院级自科与社科培育项目(2022kypy07);苏州工业职业技术学院科研启动项目(2019kyqd004)。

摘　　要：对铸造Al-7Si-0.3Mg合金进行了20℃、-20℃和-60℃的拉伸试验,研究了固溶时间对其力学性能和显微组织的影响,并分析了Si相对断裂行为的影响及其作用机理。结果表明,随着固溶时间的延长,合金在20℃、-20℃和-60℃下屈服强度、抗拉强度和伸长率都呈先增加后降低的趋势,在固溶时间为10 h时取得最大值。随着固溶时间的延长,合金中Si相的尺寸和长宽比有所减小,在固溶时间为10 h时,合金中尺寸较小的Si相主要呈颗粒状,继续延长固溶时间至15 h时,Si相的尺寸和长宽比增加。随着试验温度的降低,Si相附近的滑移带数量呈现逐渐减少的趋势,较低温度下合金断口附近出现了较多的断裂Si相,但是相对而言,固溶时间为10 h的断裂Si相处的裂纹较小,且断口以小解理平面和韧窝为主,韧性相对未固溶时更好。The low temperature tensile test of cast Al-7Si-0.3Mg alloy was carried out.The effect of solid solution time on the mechanical properties and microstructures of Al-7Si-0.3Mg alloy at 20℃,-20℃and-60℃was investigated,and the effect of Si on the fracture behavior and its mechanism were analyzed.The results showed that with prolonging in the solution time,the yield strengths,tensile strengths and elongations of the alloys at 20℃,-20℃and-60℃increased firstly and then decreased,and the maximum value could be obtained with the solution time of 10 h.With prolonging in the solution time,the size of Si phase and the ratio of length to width decreased.When the solid solution time was 10 h,the smaller Si phase in the alloy exhibited mainly granular shape,and with increasing the solution time to 15 h the size and length-width ratio of Si phase were increased.With the decrease of the test temperature,the number of slip bands near the Si phase showed a decreasing trend,and there were more fracture Si phases near the fracture surface at low temperature.Fracture Si exhibited the smaller cracks when the solid solution time was 10 h,the fracture is dominated by small cleavage plan and dimple.The toughness was better than that of ones without solution.

关 键 词：Al-7Si-0.3Mg合金 固溶处理 SI相 低温拉伸 

分 类 号：TG146.2[一般工业技术—材料科学与工程]