Y与Sr协同作用对Al-Mg-Si合金微观组织和力学性能的影响  

Synergistic Effect of Sr and Y on Microstructure and Mechanical Properties of Al-Mg-Si Alloys

作　　者：陈志强 贾锦玉 胡文鑫 王小青[1,2] CHEN Zhi-qiang;JIA Jin-yu;HU Wen-xin;WANG Xiao-qing(State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization,Baotou 014030,Inner Mongolia,China;Baotou Research Institute of Rare Earths,Baotou 014030,Inner Mongolia,China)

机构地区：[1]白云鄂博稀土资源研究与综合利用国家重点实验室,内蒙古包头014030 [2]包头稀土研究院,内蒙古包头014030

出　　处：《铸造》2020年第4期367-373,共7页Foundry

基　　金：国家重点研发计划项目(2016YFB0101205)。

摘　　要：利用金相显微镜和扫描电子显微镜等设备研究了稀土Y和Sr共同添加对Al-Mg-Si铝合金α-Al枝晶和共晶Si相显微组织的影响及作用机理。研究表明,Al-Y中间合金对Al-Mg-Si铝合金α-Al晶粒有明显细化作用,而且对共晶硅也具有变质效果。Y与Sr协同作用对Al-Mg-Si合金细化和变质的效果更佳。Al-Mg-Si铝合金经Y和Sr协同作用后,α-Al晶粒尺寸从62.1μm减小到48.48μm,共晶硅颗粒平均尺寸减小到4μm,宽径比减小到1.7,铸态抗拉强度提高了27.2%,达到213.3 MPa。稀土Y和Sr共同添加到Al-Mg-Si合金后,稀土Y主要以化合物AlSiYMg存在,并未与Sr生成化合物而降低Sr对Si的变质作用。文中还对稀土Y和Sr协同作用机理进行了分析和讨论。The effect and action mechanism of the combination addition of Y and Sr on the microstructures of the α-Al phases and eutectic silicon phases of the Al-Mg-Si alloys was investigated by optical microscopy and scanning electron microscopy. The results indicate that the Al-Y master alloys could not only refine the grain size of the α-Al phase, but also improve the morphology of the eutectic silicon. The synergistic effect of Y and Sr on the modification and refinement of the Al-Mg-Si alloys was better. Due to the synergistic effect of Y and Sr, the grain size of α-Al phase decreased from 62.1 μm to 48.48 μm.The size and the aspect ratio of the Si particles were reduced to 4μm and 1.7, respectively. Moreover, the tensile strength was increased by 27.2%,reaching 213.3 MPa. After the addition of Y and Sr into the Al-Mg-Si alloy, the rare earth Y mainly existed in the form of AlSiYMg compounds. Therefore, the modification of Sr on the eutectic silicon phase was not attenuated for the formation of the compound of AlSiYSr. The synergistic effecting mechanism of Y and Sr was analyzed and discussed in this paper.

关 键 词：Al-Mg-Si铝合金 稀土Y-Sr 晶粒细化 变质 显微组织 

分 类 号：TG146.45[一般工业技术—材料科学与工程]