SiCp分散性对AlSi_7Mg/SiCp复合材料性能及组织的影响  

Influence of SiCp dispersion on mechanical property and microstructure of AlSi_7Mg/SiCp composites

作　　者：童慧[1] 胡正飞[1] 张振[1] 祁昌亚 单既万 何大海[1] 莫凡[1] 

机构地区：[1]同济大学材料科学与工程学院上海市金属功能材料开发应用重点实验室,上海201804

出　　处：《材料热处理学报》2016年第12期1-6,共6页Transactions of Materials and Heat Treatment

基　　金：国家科技支撑计划"高速磁浮交通工程化集成系统研究"(2013BAG19B01)

摘　　要：研究AlSi_7Mg/SiCp复合材料中Si C颗粒（SiCp）分散性以及Ca含量对复合材料力学性能的影响,并利用光学显微镜（OM）、扫描电镜（SEM）、X射线衍射（XRD）等微观分析方法研究了不同Ca含量对SiCp分散性的影响。结果表明：SiCp含量在10%~15%时复合材料抗拉强度明显得到提高,当SiCp含量达到20%时复合材料抗拉强度低于母材。不同SiCp含量的拉伸试样断口均为脆性断裂,这和材料中的SiCp簇团、气孔及夹杂有关。Ca的加入会明显影响复合材料的拉伸性能及SiCp在基体中的分散性。Ca含量在0.5%~1.5%时,AlSi_7Mg/SiCp复合材料拉伸性能较好。当Ca含量达到1.5%时,基体中生成一种富含Al、Ca、Si的金属间化合物Ca_2Al4Si_3,并且金属间化合物的数量及尺度大小随着Ca含量的增加而增大,引起SiCp聚集在这些金属间化合物区域内及其边界上,这可能是因为SiCp与金属间化合物间的润湿性好于与基体的润湿性。Effect of SiCp dispersion and Ca content on mechanical properties of AlSi_7Mg/SiCp composites were evaluated. Optical microscope（OM）,scanning electron microscopy（SEM） and X-ray diffraction（XRD） were used to investigate the effect of Ca content on the SiCp dispersion. The results show that the tensile strength of the AlSi_7Mg/SiCp composites is obviously improved compared to the matrix when SiCp content is in the range of 10%-15%,while the tensile strength decreases and lower than that of the matrix when SiCp content up to 20%. All these tensile fractures show brittle fracture which are concerned with the SiCp cluster,holes and inclusions. The addition of Ca can obviously affect the tensile properties of the AlSi_7Mg/SiCp composites and the SiCp distribution in the matrix. The tensile strength of the AlSi_7Mg/SiCp composites is better when the Ca content is in the range of 0. 5%-1. 5%. When the Ca content is up to 1. 5%,intermetallic compounds Ca2Al4Si3 are formed,and the amount and the dimensions of intermetallic compounds increase with Ca addition,which lead to the aggregation of SiCp in these intermetallic compounds and their boundaries. It is probably because SiCp have good wettability to the intermetallic compounds than that of the aluminum alloy matrix.

关 键 词：铝基复合材料 SICP 分散性 CA 力学性能 断口分析 

分 类 号：TB333[一般工业技术—材料科学与工程]