基于第一性原理计算Rh含量对Ir-Rh合金力学性能的影响

发布时间：2018-03-11 06:23

本文选题：虚晶近似　切入点：力学性能　出处：《物理学报》2016年15期 　论文类型：期刊论文

【摘要】：采用密度泛函理论的第一性原理平面波赝势方法,基于虚拟晶体势函数近似,通过计算Ir-xRh(x=0,5,10,20,30,40,50,60,70,80,90,100)合金的弹性常数、体积模量、剪切模量、杨氏模量、泊松比等力学常数、电荷密度和能态密度,研究Rh含量对Ir-Rh合金力学性能的影响通过实验对计算结果加以验证,证明将虚晶近似法运用在Ir-Rh合金力学性能的计算中是合理的研究结果表明,Ir-Rh合金的强度和硬度随Rh含量的升高迅速增大,在Ir-10 Rh处达到最大值后快速下降到Ir-40 Rh处后先缓慢上升再缓慢下降.Rh的添加会引起材料脆化,其脆性大小随着Rh含量的升高先增大后减小,在Ir-50 Rh处达到最大值.另外,计算了纯Ir,Ir-10 Rh,Ir-50 Rh,纯Rh的电荷密度、Ir和Rh的差分电荷密度以及能态密度,结果表明在铱铑合金中存在一种"伪共价键",从而导致其力学性质的异常.
[Abstract]:By using the first-principle plane-wave pseudopotential method of density functional theory and based on the approximation of virtual crystal potential function, the elastic constants, volume modulus, shear modulus, Young's modulus, Poisson's ratio and other mechanical constants of Ir-xRh _ XX _ (10) 10 ~ (10) 10 ~ (20) C _ (30) C _ (30) C _ (60) C _ (70) C _ (90) C _ (100) alloy are calculated. The effects of Rh content on the mechanical properties of Ir-Rh alloy were investigated by experiments, and the calculated results were verified by experiments. It is proved that it is reasonable to apply the virtual crystal approximation method to the calculation of mechanical properties of Ir-Rh alloy. The results show that the strength and hardness of Ir-Rh alloy increase rapidly with the increase of Rh content. The brittleness of the material increased with the increase of Rh content and then decreased with the increase of Rh content, and then reached the maximum at Ir-50 Rh. In addition, the brittleness increased with the increase of Rh content, and reached the maximum at Ir-50 Rh. The difference charge density and the energy density of states of pure Ir-10 Rh-10 Rh-50 Rhand pure Rh are calculated. The results show that there is a "pseudo-covalent bond" in iridium rhodium alloy, which leads to the abnormality of its mechanical properties.
【作者单位】：昆明贵金属研究所稀贵金属综合利用新技术国家重点实验室;
【基金】：国家自然科学基金(批准号:51361014) 云南省应用基础重点项目(批准号:2016FA053) 云南省技术创新人才(批准号:2013HB112) 稀贵金属综合利用新技术国家重点实验室开放课题资助(批准号:SKL-SPM-201527)资助的课题~~
【分类号】：TG146.34

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