压力下Mg-Al-Ca合金中Al_2Ca相结构、弹性及电子性能的第一原理研究  

First-principles Study of Structural, Elastic and Electronic Properties of Al_2Ca Phase in Mg-Al-Ca Under Pressure

作　　者：杨晓敏[1] 侯华[1] 赵宇宏[1] 韩培德[2] 

机构地区：[1]中北大学材料科学与工程学院,山西太原030051 [2]太原理工大学材料科学与工程学院,山西太原030024

出　　处：《热加工工艺》2014年第22期50-52,56,共4页Hot Working Technology

基　　金：国家自然科学基金项目(51204147;51274175);科技部国际科技合作项目(2011DFA50520);山西省研究生优秀创新项目(20133105)

摘　　要：采用基于密度泛函理论的CASTEP程序包,计算了不同压力下Al2Ca相的结构、弹性与电子性能。计算所得0 GPa下Al2Ca的晶格参数与实验和其他理论值相吻合。结果表明：随压力增大,Al2Ca相的体模量B、剪切模量G、杨氏模量E增大,材料的硬度增大;且压力低于30 GPa时,Al2Ca为脆性相,之后随压力的增大,材料呈延性,增大压力提高了材料的塑性和延展性。态密度计算结果表明：在压力0~50 GPa下,随压力增加,结构稳定性变差,但其结构仍然是稳定的,没有发生相转变。The structural, elastic and electronic properties of Al2 Ca phase under pressure were determined by using CASTEP program based on the density functional theory. The calculated structural parameters at 0GPa agree well with experimental and other theoretical data. The calculated elastic properties show that the bulk modulus B, shear modulus G and Young＇s modulus E increase with increasing pressure, and the hardness increases. The pressure of Al2 Ca phase is below 30 GPa and the ductility and plasticity can be improved as the pressure increasing. The calculations of the density of states（DOS）show that the structural stability of Al2 Ca becomes weaker with pressure increasing from 0 to 50 GPa, but the structure remains stable and there is no induced structural phase transformation.

关 键 词：Al2Ca相 弹性性能 电子结构 第一性原理 

分 类 号：TG146.2[一般工业技术—材料科学与工程]