过渡元素掺杂NiTi合金的第一性原理研究  

First Principle Study on NiTi Alloyed with Transition Elements

作　　者：席蒙 尚家香[1] 

机构地区：[1]北京航空航天大学,北京100191

出　　处：《稀有金属材料与工程》2016年第8期2041-2045,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51371017)

摘　　要：采用基于密度泛函理论的第一性原理方法系统的计算了3d、4d和5d过渡元素掺杂的Ni Ti合金晶格参数、形成能、弹性常数和电荷密度,探讨了合金元素的占位倾向以及对马氏体相变温度的影响。计算结果表明,V、Cr、Mn、Fe、Co、Pd、Cu各族元素倾向于占据Ni位;Sc、Y、Zr、Hf倾向于占据Ti位。V、Cr、Mn、Fe、Co各族元素和Pd、Pt取代Ni,V、Cr、Mn、Fe各族取代Ti能够不同程度的降低NiTi合金的相变温度M_s;Hf、Zr、Au、Ag取代Ni以及Sc、Y、Hf、Zr取代Ti为能够升高NiTi合金的相变温度M_s;Cu取代Ni则基本不改变NiTi合金的相变温度M_s。这些结果与实验结果一致,进而从微观角度解释了合金元素对相变温度的影响规律。Lattice parameters,formation energy,elastic modulus and deformation charge density of NiTi alloyed by 3d,4d,5d transition elements have been calculated by the first principle method based on density functional theory（DFT）.Then we discussed the site preference of transition elements in NiTi and their influence on the martensitic transformation temperature of NiTi.The results show that when the transition elements are added to NiTi alloy：（1） the groups of V,Cr,Mn,Fe,Co,Pd,Cu prefer the Ni-sites;（2） Sc,Y,Zr,Hf prefer the Ti-sites;（3） Zn and Cd can＇t form a stable structure.In the martensitic phase transformation process,the bigger C44 /C and stronger bonding interaction mean the stronger transition resistance,which lead to a lower transformation temperature.By analyzing the elastics modulus and the differential charge density map of NiTi,we can infer that：（1） the replacement of Ni by the groups of V,Cr,Mn,Fe,Co or by Pd,Pt and the replacement of Ti by V,Cr,Mn,Fe will lower the transformation temperature M_s;（2） substitution of Hf,Zr,Ag,Au for Ni and substitution of Sc,Y,Hf,Zr for Ti will increase the transformation temperature M_s;（3） transformation temperature will be almost unchanged when Cu substitutes for Ni.These results are consistent with the experimental and we can understand the influence of alloying elements on the phase transformation temperature of NiTi from the microscopic point of view.

关 键 词：过渡元素 NITI合金 第一性原理计算 

分 类 号：TG139.6[一般工业技术—材料科学与工程]