高压下TiAl金属间化合物的结构和弹性性质(英文)  

Structural and elastic properties of TiAl intermetallics under high pressure

作　　者：李旭升[1] 霍晓阳[1] 高洁[1] 杨印[1] 王海燕[1] 

机构地区：[1]河南理工大学材料科学与工程学院,焦作454000

出　　处：《四川大学学报（自然科学版）》2012年第2期367-372,共6页Journal of Sichuan University(Natural Science Edition)

基　　金：国家自然科学基金(40572025);support of the high-performance grid computing platform of Henan Polytechic University and the support from Ph.D.Program Foundation (B2009-59);Introduction of Talents of Henan Polytechnic University Foundation(No.Y2009- 1);the National Science Foundations of China (Grant No.50802024)

摘　　要：利用从头算平面波赝势密度泛函理论方法研究了高压下L10-TiAl金属间化合物的结构和弹性性质.研究发现当压力在0～20 GPa范围内时,c/a的值基本上保持一常数1.02,与实验结果吻合.当压力在20～45 GPa范围内时,c/a的值随压力的增加从1.02线性减小到0.99.这表明在低压下沿c轴和沿a轴的压缩性是一样的,但是高压下沿c轴比沿a轴更容易压缩.计算了从0到20 GPa压力下L10-TiAl的弹性常数.同时我们还计算了剪切各向异性比率A和Voigt剪切模量,与实验结果和别人的计算结果相吻合.The structural and elastic properties of L10-TiA1 intermetallics under high pressure are inves- tigated by ab initio plane-wave pseudopotential density functional theory method. It is found that under the pressure from 0 to 20 GPa the values of c/a ratio keep almost constant 1.02, which is in full agree- ment with the experiment. With the pressure increasing from 20 to 45 GPa the values of c/a ratio decrease almost linearly from 1.02 to 0.99. This indicates under low pressure the compression along caxis and aaxis is the same, but the compression along caxis is easier than along a-axis under higher pressure. The elastic constants of L10-TiA1 have been calculated under different pressures from 0 to 20 GPa. At the same time we have also calculated the shear anisotropy ratio A and Voigt shear modulus G_v, which agree well with the experimental results and other calculated results.

关 键 词：密度泛函理论 弹性性质 TIAL 

分 类 号：O521.2[理学—高压高温物理] O522.2[理学—物理]