间接挤压铸造Al-11Si-3Cu-Mg合金的组织、性能和偏析行为  

Microstructure,Mechanical Properties and Element Segregation of Al-11Si-3Cu-Mg Alloy by Indirect Squeeze Casting

作　　者：江艳星 石洪伟 郑继廷 饶宇 屈铜贵 陈民锭 高伟全 王东涛 Jiang Yanxing;Shi Hongwei;Zheng Jiting;Rao Yu;Qu Tonggui;Chen Minding;Gao Weiquan;Wang Dongtao(Guangzhou Hede Lightweight Forming Technology Co..Ltd.;Huajin New Material Research Institute(GuangZhou)Co.,Ltd.;School of Materials Science and Engineering,Suzhou University.)

机构地区：[1]广州和德轻量化成型技术有限公司 [2]华劲新材料研究院(广州)有限公司 [3]苏州大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2023年第2期272-276,共5页Special Casting & Nonferrous Alloys

摘　　要：研究了Al-11Si-3Cu-Mg合金在间接挤压铸造工艺下的微观组织、力学性能和Si、Cu元素偏析行为。结果表明,在110 MPa压力下,间接挤压铸造成形的试样截面处的微观组织呈现出明显的不均匀性,表现为外层细小α-Al固溶体枝晶,内层为粗大枝晶,Al-Si共晶组织分布在α-Al固溶体枝晶间隙,在局部形成较大的偏聚块,内外层中间形成一圈Al-Si共晶组织和富Cu相的偏聚环;经T6热处理后,其抗拉强度为443 MPa,屈服强度为312 MPa,伸长率为2.85%。在试样截面处从中心到边缘进行能谱分析,发现外层Si和Cu元素在重力作用下呈正偏析,内层在压力作用下呈现负偏析;元素偏析越严重,越容易形成裂纹,对力学性能产生不利影响。The microstructure,mechanical properties and segregation behavior of Si and Cu elements of high strength and toughness cast aluminum alloy by indirect squeeze casting process were investigated.The results reveal that the microstructure of the specimen at the cross section of indirect extrusion casting shows obvious inhomogeneity with fine dendrites in the outer layer and coarse dendrites in the inner layer,and a ring of eutectic silicon and copper-rich phase is formed in the middle of the inner and outer layers.After T6 heat treatment,its mechanical properties can reach 443 MPa in tensile strength,312 MPa in yield strength and 2.85%in elongation.Energy spectrum analysis from center to edge at the cross section of the sample reveals positive segregation of Si and Cu elements in the outer layer and negative segregation in the inner layer,and their segregation behavior was analyzed.Generation of cracks is more relative with more serious element segregation,which has an adverse impact on the mechanical properties.

关 键 词：铝硅合金 高强韧铸造Al-11Si-3Cu-Mg铝合金 元素偏析 挤压铸造 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG249.2[金属学及工艺—金属材料]