磷对NiAl弹性模量和韧塑性影响的第一原理研究  

Effect of P on mechanical properties of NiAl intermetallics

作　　者：胡雪兰[1] 罗阳[1] 赵若汐 宋庆功[2] HU Xuelana LUO Yanga ZHA O Ruoxia SONG Qinggongb(a. Sino-European Institute of Aviation Engineerin b. College of Science, CA UC, Tianjin 300300, Chin)

机构地区：[1]中国民航大学中欧航空工程师学院,天津300300 [2]中国民航大学理学院,天津300300

出　　处：《中国民航大学学报》2016年第6期61-64,共4页Journal of Civil Aviation University of China

基　　金：国家自然科学基金项目(51201181)

摘　　要：NiAl金属间化合物是航空航天工业中用来制造航空发动机涡轮叶片等关键部件的新型高温材料,但室温脆性严重阻碍了其应用。杂质效应是影响其力学性能的一个重要因素。本研究应用量子力学第一原理的方法,利用Vienna Ab-inito Simulation Package(VASP)软件研究了杂质元素磷(P)对NiAl金属间化合物的结构和力学性能的影响。通过计算P原子在NiAl中的溶解能,得出P原子既可以替代NiAl中的Ni原子又可以替代Al原子,主要取决于P原子在NiAl中的周围环境中Ni和Al的化学计量比。在大多数化学计量范围内P更易于占据Al替代位,只有在极其富Al的情况下,P原子才会占据Ni原子位置。通过计算纯NiAl体系和加入P后的NiAl体系的弹性模量并结合经验判据,得出P的存在增大了NiAl的局域硬度,并且增大了NiAl的局部脆性和塑性变形阻力,在NiAl中为有害元素。NiAl intermetallics is a new type of high-temperature structural material that can be applied in aerospace industry to fabricate key parts of air engine turbine blades. However, poor ductility at low temperatures limits its technolog- ical assignments and applications. Impurity is one of those important factors that can have strong effects on the me- chanical properties of NiAl. By using a first-principle method, the effect of P on the structure and mechanical properties of NiAI intermetallics is studied with VASP. By calculating the dissolution energy of P atoms in NiAl, it can be concluded that the P atom can either replace the Ni atom site or the Al atom site, which mainly depends on the stoichiometric ratio of Al and Ni in the surrounding environment of P atoms in NiAl. In most stoichiometric range P prefers to occupy Al substitution, except in the case of Al-rich. The ＇local elastic constants＇ results to- gether with the empirical criterions indicate the presence of P can cause an increase of the local brittleness and a decrease of the local ductility of NiAl which is a harmful element in NiAl.

关 键 词：NIAL金属间化合物 杂质P 力学性能 第一性原理 

分 类 号：TG135[一般工业技术—材料科学与工程]