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利用微观相场法研究了应力和温度共同耦合作用下Ni75Al21.5Nb3.5合金的原子有序行为。结果表明:弹性应变能参数ξ越大,L10相的孕育期越短,所析出的L10相的最大体积分数更大,存在时间也更长,单一取向性也更明显。在同一温度下,Ni原子在αⅡ位的最小占位几率随ξ的增加而降低,而Al、Nb原子则呈相反的变化趋势;L10最大体积分数随ξ的增大先增加而后趋于稳定。在同一畸变能下,Ni原子在αⅡ位的最小占位几率随温度的升高而增加,而Al、Nb原子则恰好相反;L10最大体积分数随温度的升高先增大后减小。
The atomic order behavior of Ni75Al21.5Nb3.5 alloy under the common coupling of stress and temperature was studied by using the micro phase field method. The results show that the larger the elastic strain energy parameter ξ is, the shorter the incubation period of L10 phase is, the larger the volume fraction of L10 phase precipitates is, the longer the L10 phase is, and the more uniform the orientation is. At the same temperature, the minimum occupancy of Ni atom in αⅡposition decreases with the increase of ξ, while Al and Nb atoms show the opposite trend. The maximum volume fraction of L10 first increases and then tends to be stable with the increase of ξ. Under the same distortion energy, the minimum probability of occupancy of Ni atoms in αⅡposition increases with the increase of temperature, while the Al and Nb atoms are just the opposite. The maximum volume fraction of L10 firstly increases and then decreases with the increase of temperature.