Y对原位Mg_2Si/Al基复合材料初生相Mg_2Si的细化机制  

Refining mechanism of rare earth Y on primary phase Mg_2Si in-situ Mg_2Si/Al composites

作　　者：刘政[1] 白光珠 罗浩林[2] 

机构地区：[1]江西理工大学机电工程学院,江西赣州341000 [2]江西理工大学材料科学与工程学院,江西赣州341000

出　　处：《有色金属科学与工程》2016年第1期28-33,共6页Nonferrous Metals Science and Engineering

基　　金：国家自然科学基金资助项目(51361012);江西省自然科学基金资助项目(20114bab206014);江西省教育厅重点科技项目(GJJ11021)

摘　　要：选用稀土Y和采用普通重力铸造法制备原位自生Mg_2Si/Al基复合材料,研究不同含量的稀土Y对初生相Mg_2Si形貌、尺寸和力学性能的改变.结果表明:稀土Y对Mg_2Si/Al复合材料的凝固组织有影响;添加Y处理的Mg_2Si/Al基复合材料的Mg_2Si颗粒变得更加细小;通过计算二维错配度,发现Y可以作为初生相Mg_2Si的异质形核质点从而细化颗粒,同时Y与Al相互作用形成Al3Y相可阻止Mg_2Si相长大;此时铸态Mg_2Si/Al合金复合材料的力学性能得到改善,其最大抗拉强度和延伸率分别为144 MPa和4.19%.In-situ Mg2Si/Al composites were prepared by common weight casting technique and rare earth Y was selected. The change of the morphology of primary phase Mg2Si, the size and mechanical properties because of rare earth Y content was investigated. The results indicate that there are some effects of Y on the microstructure of Mg2Si/Al alloy composites, and the MgESi particles treated by Y in the composites become finer. By calculating the planar disregistry, it is found that the Y can be used as the heterogene-nuclei of the primary Mg2Si phase to refine grain size, in which Al3Y phase formed by interaction between Y and Al could hold back Mg2Si phase growth. The mechanical properties of the composites with addition of Y are improved, in which the maximum tensile strength and elongation of the composites reach to 144 MPa and 4.19 %, respectively.

关 键 词：MG2SI 复合材料 稀土Y 二维错配度 形核基底 

分 类 号：TG146.2[一般工业技术—材料科学与工程] TF125.24[金属学及工艺—金属材料]