微量稀土钇对Al-7Si-0.3Mg铸造合金的强化及共晶转变温度的影响  

Effect of Trace Yttrium on Strengthening and Eutectic Transformation Temperature of Casting Al-7Si-0.3Mg Alloy

作　　者：胡心平 李瑞鑫[1,2] 王青 Hu Xinping;Li Ruixin;Wang Qing(School of Mechanical and Automotive Engineering,Qilu University of Technology,Jinan 250353,China;Shandong Machinery Design and Research Institute,Qilu University of Technology,Jinan 250353,China)

机构地区：[1]齐鲁工业大学机械与汽车工程学院,山东济南250353 [2]齐鲁工业大学山东省机械设计研究院,山东济南250353

出　　处：《稀有金属材料与工程》2022年第8期2947-2954,共8页Rare Metal Materials and Engineering

基　　金：山东省科技发展计划(2018GGX103012)。

摘　　要：采用拉伸实验,硬度测试,微观组织OM及SEM(+EDS)分析,XRD,DSC等方法,研究了微量钇(质量分数分别为0.025%、0.05%、0.075%、0.1%)以及T6处理对铸造Al-7Si-0.3Mg合金的组织性能及其共晶转变温度的影响。结果表明,钇微合金化后的Al-7Si-0.3Mg合金的屈服强度(YS)、抗拉强度(UTS)和延伸率(El)均有所提高,以0.05%Y含量的综合性能最佳。结合微观组织分析表明,强化相主要为Si相和Mg_(2)Si相,且Mg_(2)Si往往伴随着Si相存在。微含量的钇使α_(Al)+β_(Si)→Liquid反应温度下降(分别下降1.1、2.0、1.4、2.2℃),且使α_(Al)→Liquid反应温度有所提高;适量的钇促进α-Al异质形核基底的形成,且与β_(Si)和Mg_(2)Si等形成多元相,提高凝固时的过冷度。The effects of trace yttrium(yttrium content 0.025wt%,0.05wt%,0.075wt%)and T6 treatment on the microstructure,properties,and eutectic transformation temperature of Al-7Si-0.3Mg alloy were studied by tensile test,hardness test,microstructure analysis of OM,SEM(+EDS),XRD and DSC.The results show that the YS,UTS and E1 of the aluminum alloy after yttrium microalloying are improved,and the comprehensive performance of alloy with 0.05%Y is the best among the designed aluminum alloys.The strengthening phases are mainly Si and Mg_(2)Si phase,and Mg_(2)Si phase usually appears with Si phase.The added yttrium decreases the transformation temperature of α_(Al)+β_(Si)→Liquid,which decreases by 1.1,2.0,1.4 and 2.2℃when 0.025%,0.05%,0.075%and 0.1%Y is added,respectively.In addition,the transformation temperature of α_(Al)→Liquid is increased somewhat after yttrium microalloying.An appropriate amount of yttrium that forms multiple phases with β_(Si),Mg_(2)Si and so on,which promotes the formation of heterogeneous nucleation substrate,and improves the supercooling in solidification.

关 键 词：Al-7Si-0.3Mg合金 钇微合金化 共晶转变温度 断口分析 DSC分析 

分 类 号：TG146.21[一般工业技术—材料科学与工程]