Energy studies of precipitation sequence in Ni_(75)Al_(10)Cr_(15) alloy based on the phase field theory

作     者：DONG WeiPing CHEN Zheng WANG YongXin 

作者机构：State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi'an 710072 China 

出 版 物：《Science China(Physics,Mechanics & Astronomy)》 (中国科学：物理学、力学、天文学（英文版）)

年 卷 期：2011年第54卷第5期

页      面：821-826页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 08[工学] 080502[工学-材料学] 0706[理学-大气科学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 10902086, 51075335 and 50875217) the Basic Re-search Fund of the Northwestern Polytechnical University (Grant No. JC201005) the Doctoral Foundation of Northwestern Polytechnical University (Grant No. CX201103) 

主　　题：precipitation sequence pre-precipitation phase equilibrium phase interatomic potentials free energy phase field theory 

摘      要：Based on the phase field theory, the phase precipitation sequence of Ni75A110Cr15 alloy and the free energy of each phase were studied. Moreover, the interatomic potentials of Llo phase, L12 phase and DO22 phase changing with temperature and concen- trations were computed through utilizing the interatomic potentials equations induced by Khachaturyan＇s relational equations between the interatomic potentials and the long-range order （LRO） parameters. Results match preceding work and demonstrate that the phase precipitation sequence of Ni75AlloCr15 alloy is the disordered phase -L10 pre-precipitation phase -L12 equilibrium phase -L12＋DO22 equilibrium phase. Free energies of Llo pre-precipitation phase are higher and interatomic potentials are smaller than those of L12 equilibrium phase; therefore, it is concluded that Llo phase is unstable, and phase transformation would occur to L12 which is more stable; L12 phase precipitates earlier than DO22 phase because L12＇s interaction potentials are larger than DO22＇s.