The formation of nanometer coherent structures during spinodal decomposition and ordering coexistence phase transformation in Fe-24Al alloys
The nanometer coherent structures evolution of spinodal decomposition and ordering coexistence phase transformation in Fe-24Al alloys is investigated by the microscopic phase field model considering long range elastic interaction. The composition and long-range order parameters all continuously changes towards to their equilibrium values, which is the characteristics of the special spinodal decomposition and ordering coexistence phase transformation. During this process, the crystal lattice of parent and product phases are arrangement and the crystal lattice constants changes during this process. The special spinodal decomposition and ordering coexistence phase transformation is attributed to the long-range elastic interaction energy induced by atom size difference or crystal lattice constants difference. With the increase of elastic interaction energy, the anisotropy along 01 or 10 elastic soft direction is more obvious and the time reaching equilibrium state is also shortened. When elastic interaction energy is higher, the coalescence growth along 01 or 10 elastic soft direction occurs at later aging stage. According to the results, the spinodal decomposition and ordering coexistence phase transformation is composed of the initial decreasing stage of order degree stage, the incubation stages, the continuous increasing stage of concentration order parameter and long-range order parameter, and the later stable stage. The spinodal decomposition and ordering is interaction, the initial ordering stage is the necessary condition of the coexistence phase transformation. Only that the interaction of the two phase transformation, the nanometer coherent structures are not found to grow during the whole aging process. The simulation results are in accord with the results in experiment obtained by the two temperature aging in Fe-24Al alloys.
Rongda Zhao Jingchuan Zhu Zhonghong Lai Yong Liu HaiLiang Liu
School of Materials Science and Engineering, Harbin Institute of Technology Harbin 150001, Peoples Republic of China
国际会议
武汉
英文
719-735
2010-09-01（万方平台首次上网日期，不代表论文的发表时间）