SIMULATIVE INVESTIGATION OF GRAIN BOUNDARIES IN NiAl ALLOY

来源期刊：中国有色金属学报(英文版)1999年第1期

论文作者：Liu Zhenyun Huang Baiyun Lin Dongliang

Key words：NiAl; grain boundary structure; computer simulation

Abstract: Using embedded atom potentials and molecular static relaxation method or Monte Carlo relaxation method, the grain boundary atomic structures of a series of , and symmetric tilt grain boundaries in NiAl with different geometrical indexes and compositions were studied. The grain boundary energies, grain boundary cohesive energies and point defects formation energies at the grain boundary were calculated. The results show that the grain boundaries of NiAl alloy have a periodic unit structure. Grain boundary energies of Al rich grain boundary is very high, but the cohesive energies are lower than those of others. The interaction of point defects and grain boundaries shows that grain boundaries incline to absorb point defects to decrease their orders and to relax the distortions caused by point defects.The boundary atommic structures relaxed by Monte Carlo method show taht the disorder of them, grain boundary energies and cohesive energies increase with increasing temperature.