第二相对Mg-Ca-Sn镁合金铸态组织和力学性能的影响  

Effect of Second Phases on Microstructure and Mechanical Properties of As-Cast Mg-Ca-Sn Magnesium Alloy

作　　者：蒋斌[1,2] 周冠瑜[1] 戴甲洪 夏祥生[3] 万元元[3] 潘复生[1,2] 

机构地区：[1]重庆大学,重庆400030 [2]重庆市科学技术研究院,重庆401123 [3]中国兵器工业第59研究所,重庆400039

出　　处：《稀有金属材料与工程》2014年第10期2445-2449,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51171212);国家科技支撑计划"十二五"项目(2011BAE22B03-3;2013DFA71070);重庆市科委资助项目(CSTC2010AA4048;CSTC2012JJJQ50001;CSTC2012GGB50003)

摘　　要：研究了含有不同第二相的金属型铸造Mg-Ca-Sn镁合金的显微组织和力学性能。结果表明:在合金中Ca和Sn单独存在可以在一定程度抑制铸态基体晶粒长大,Mg2Ca在晶界或枝晶界处连续分布,Mg2Sn呈颗粒状在晶界和晶内分布。Ca和Sn同时存在时,有CaMgSn在基体上呈半连续的点状或针状,在凝固过程中可作为α-Mg的异质形核核心,与单独添加相比,镁基体的铸态晶粒尺寸显著细化。运用边-边匹配模型分析了CaMgSn化合物与α-Mg之间的异质形核晶体学关系。晶粒细化后的Mg-Ca-Sn镁合金的显微硬度得到明显提高。The effects of second phases on microstructure and mechanical properties of as-cast Mg-Ca-Sn permanent moulding magnesium alloy were investigated.The results indicate that sole addition of Ca and Sn refined grain size of as-cast magnesium alloy in a certain degree.Mg2 Ca phase precipitated at grain boundaries continuously and granular Mg2 Sn phase existed at grain boundaries and inside the grains.Point and needle-like CaMgSn phase can be formed after Ca and Sn combined addition.Because CaMgSn particles acted as heterogeneous nucleus of α-Mg during solidification,the grain of α-Mg was significantly refiner than sole addition one.The edge-to-edge matching model was used to analyze the crystallography mismatch relationship between CaMgSn and α-Mg.Microhardness of Mg-Ca-Sn magnesium alloy was improved remarkably with finer grain size.

关 键 词：Mg-Ca-Sn镁合金 晶粒细化 边-边匹配 

分 类 号：TG146.22[一般工业技术—材料科学与工程]