稀土钇对A356铝合金凝固组织和力学性能的影响  

Effect of Rare Earth Yttrium on Solidification Structure and Mechanical Properties of A356 Aluminum Alloy

作　　者：周文华 周细应[1] 彭以辉 答建成 尹恒虎 顾文秀 ZHOU Wenhua;ZHOU Xiying;PENG Yihui;DA Jiancheng;YIN Henghu;GU Wenxiu(School of Materials Engineering,Shanghai University of Engineering Science,Shanghai 201620,China;Shanghai Aruis Auto Parts Co.,Ltd.,Shanghai 201600,China)

机构地区：[1]上海工程技术大学材料工程学院,上海201620 [2]上海阿瑞氏汽车配件有限公司,上海201600

出　　处：《热处理》2022年第3期27-30,36,共5页Heat Treatment

摘　　要：制备了不含稀土钇和含0.1%、0.3%、0.5%和0.9%Y(质量分数)的A356铸造铝合金。采用金相显微镜、扫描电子显微镜、拉伸试验等检测了这些合金的显微组织、拉伸性能和拉伸断口特征。结果表明:与不含钇的合金相比,在添加0.1%Y的A356合金中,α-Al相的二次枝晶臂间距明显减小,共晶硅呈细小的颗粒状;随着钇含量的增加,α-Al相的二次枝晶臂间距增大,但小于未添加稀土钇的A356合金;过多稀土钇的加入导致合金中形成块状稀土化合物,从而大大减小了稀土钇细化A356铝合金组织的作用;添加不同量钇的A356铝合金的抗拉强度和断后伸长率均有不同程度的提高,未添加钇的合金的抗拉强度为164.05 MPa,断后伸长率为4.20%,添加0.1%Y的合金的抗拉强度和断后伸长率为175.55 MPa和6.71%;不含稀土钇的A356合金以解理断裂为主,而含0.1%Y的A356合金拉伸断口有大量韧窝,为韧性断裂。A356 aluminum casting alloys without rare earth yttrium and with 0.1,0.3,0.5,and 0.9%Y by mass were fabricated.The microstructure,tensile properties and tensile fracture characteristic of such alloys were detected by means of metallographic microscope,scanning electron microscope and tensile testing.The results showed that(a)in the A356 alloy with 0.1%Y,the secondary dendrite arm spacing ofα-Al phase decreased obviously relative to the alloy without yttrium,and the eutectic silicon was in fine granular form;(b)with the increase in yttrium content,the secondary dendrite arm spacing ofα-Al phase increased,but was less than that of the A356 alloy without rare earth yttrium;(c)the addition of excessive rare earth yttrium led to the formation of massive rare earth compounds in the ally,thereby significantly reduced the action of rare earth yttrium on refinement of microstructure in the A356 aluminum alloy;(d)the addition of different amounts of rare earth yttrium increased both tensile strength and elongation of A356 aluminum alloy to a certain extent,with the tensile strength and elongation being 164.05 MPa and 4.20%for the A356 alloy without yttrium,and 175.55 MPa and 6.71%for the A356 alloy with 0.1%Y;and(e)the A356 alloy was predominantly cleavage fracture,whereas the A356 alloy with 0.1%Y exhibited a large amount of dimples in tensile fracture,being a ductile failure.

关 键 词：稀土钇 A356铝合金 变质处理 拉伸性能 

分 类 号：TG113[金属学及工艺—物理冶金]