钇添加量对低硅铸造铝合金组织与拉伸性能的影响  

Effect of Y Addition on Structure and Tensile Properties of Low-Silicon Cast Aluminum Alloy

作　　者：蓝凯 杨弋涛[1] LAN Kai;YANG Yitao(School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学材料科学与工程学院,上海200444

出　　处：《机械工程材料》2025年第1期44-50,共7页Materials For Mechanical Engineering

摘　　要：向低硅铸造铝合金中添加了不同质量分数(0,0.03%,0.06%,0.09%,0.12%,0.15%)的钇元素,并对其进行了T6热处理,研究了钇添加量对合金显微组织和拉伸性能的影响,并分析了影响机理。结果表明:随着钇添加量增加,合金的α-Al形核温度和共晶硅转变温度先升高后降低,合金中α-Al和共晶硅先细化后粗化,铸态共晶硅形貌向纤维状变化,热处理态共晶硅形貌向球粒状变化,屈服强度和抗拉强度先增大后减小,断后伸长率基本降低;当钇添加质量分数为0.09%时,α-Al形核温度以及共晶硅转变温度最高,热处理后的显微组织为细小的α-Al枝晶与球粒状共晶硅,屈服强度、抗拉强度和断后伸长率较大,综合力学性能最佳;当钇添加质量分数增至0.15%时,合金中析出粗针状Al2Si2Y相,拉伸断裂模式由韧脆混合断裂转变为脆性断裂。The low-silicon cast aluminum alloys containing different mass fractions(0,0.03%,0.06%,0.09%,0.12%,0.15%)of Y were prepared and treated by T6 heat treatment.The effect of Y addition amount on the microstructure and tensile properties of the alloy were studied,and the mechanism was analyzed.The results show that with the increase of Y addition,theα-Al nucleation temperature and eutectic silicon transformation temperature of the alloy first increased and then decreased,theα-Al and eutectic silicon in the alloy were first refined and then coarsened,the as-cast morphology of eutectic silicon changed to threadiness,and the heat treated state morphology of eutectic silicon changed to spherutic,the yield strength and tensile strength first increased and then decreased,and the percentage elongation after fracture basically decreased.When Y mass fraction was 0.09%,theα-Al nucleation temperature and eutectic silicon transformation temperature were the highest.After heat treatment,the microstructure was fineα-Al dendrite and spherutic eutectic silicon,the yield strength,tensile strength and percentage elongation after fracture were relatively large,namely the comprehensive mechanical properties were the best.When excessive Y was added(0.15%),the coarse acicular Al2Si2Y phase was precipitated in the alloy,and the tensile fracture mode changed from the toughbrittle mixed fracture to the brittle fracture.

关 键 词：铸造铝硅合金 显微组织 过冷度 析出相 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]