Cu掺杂对高熵合金FeCrVTi相结构的影响

基于CALPHAD方法，建立了高熵合金FeCrVTiCux(x=0-1)的热力学计算模型，对Cu掺杂的高熵合金FeCrVTi相结构和屈服强度进行了讨论分析. 研究发现当x=0时，室温下FeCrVTi的相结构为BCC-A2、LAV-C14和NITI2相. 在815-1380K温度区域，该体系发生有序-无序LAVES->BCC-A2转变. 当x增加到0.2时，室温下FeCrVTiCu0.2的 LAV-C14相消失，出现了LAVES和HCP-A3相. 当x增加到0.4时，室温下FeCrVTiCu0.4出现FCC-A1相. 600K温度时，随Cu含量的不断增加FeCrVTiCux在x=0.0-1.0之间HCP-A3相成分呈线性增长，其相含量最大值位于x=1.0的位置. Cu的掺杂提高了高熵合金FeCrVTi的室温塑性和高温强度，使得FeCrVTi的室温屈服强度高于FeCrVTiCu，在600K温度下，FeCrVTiCu的屈服强度高于FeCrVTi.

Effect of Cu doping on the phase structure of FeCrVTi

Based on the CALPHAD method, the thermodynamic calculation model of high entropy alloy FeCrVTiCux(x=0-1) is established, and the phase structures and yield strengths of FeCrVTi are discussed. The results show that for x=0, the phase structures of FeCrVTi are BCC-A2, Lav-C14 and NITI2 at room temperature. In the temperature range of 815-1380 K, the system undergoes an order-disorder transition (LAVES->BCC-A2). When x increases to 0.2, the LAV-C14 phase of FeCrVTiCu0.2 disappears at room temperature, and both the LAVES and HCP-A3 phases appear. When x increased to 0.4, the FCC-A1 phase appears in FeCrVTiCu0.4 at room temperature. At 600 K, with the increase of Cu content, the composition of HCP-A3 phase of FeCrVTiCux increases linearly between x=0.0-1.0, and the maximum content of HCP-A3 phase is at x=1.0. The Cu-doping improves the room-temperature plasticity and high temperature strength of FeCrVTi, which makes the room-temperature yield strength of FeCrVTi higher than that of FeCrVTiCu and the yield strength of FeCrVTiCu at 600 K is higher than that of FeCrVTi.