摘要
在热力学计算分析的基础上,用SiO2粉末和纯镁制备Mg-3%Si(质量分数)中间合金,并用光电直读光谱仪测定制备的中间合金Si的含量,表明其含量稳定且可控。用普通重力铸造法制备了Mg-2Y-1Si合金和Mg-3Y-1Si合金,该合金的铸态组织由α-Mg相、(α-Mg+Mg2Si)共晶组织以及在晶内、枝晶间少量分布的点状Mg24Y5相组成。通过对α-Mg晶格常数的计算及通过原子尺寸、电负性、晶体结构的对比,证明Y固溶在基体中形成固溶体。研究表明,Y通过依附在生长界面前沿,有效抑制基体的生长速度,细化基体组织,且随着Y添加量的增加,细化效果更加明显。
Based on thermodynamic calculation and analysis,the Mg-3%Si（mass fraction） intermediate alloy was prepared with SiO2 powders and Mg.The Si content of the prepared intermediate alloy was determined with Photoelectricity Direct-Reading Spectrometer.The results show that the Si content of the prepared intermediate alloy is stable and controllable.Mg-2Y-1Si and Mg-3Y-2Si alloy were prepared by general gravity casting.The microstructure of as-cast Mg-2Y-1Si and Mg-3Y-1Si alloy consists of α-Mg phase,α-Mg＋Mg2Si eutectic structure and few globular shape Mg24Y5 phases within grain and dendrites.The results indicate that Y is formed into solid solution,which is proved by calculating lattice constants and comparing atomic size factor,electronegativity difference,and the crystal structure.The study shows that Y effectively inhibits growth rate of matrix and refines matrix structures.And with the increasing of Y addition,the refined results become more obviously.
出处
《兵器材料科学与工程》
CAS
CSCD
2011年第2期23-27,共5页
Ordnance Material Science and Engineering
基金
国家自然科学基金(50271054)
教育部博士点基金(20070700003)
河南省科技攻关资助项目(102102210031)
河南省教育厅自然科学基金资助项目(2010A430008)
关键词
Mg-Y-Si合金
热力学
稀土
晶格常数
镁合金
固溶体
Mg-Y-Si alloy
thermodynamics
rare earth
lattice constant
magnesium alloy
solid solution
