微观相场法研究应变能对Ni_(68.2)Al_(22.7)V_(9.1)合金中两相沉淀及原子占位的影响

Study for the Effect of Strain Energy on Two-phase Precipitation and Atoms Occupying in Ni_(68.2)Al_(22.7)V_(9.1) Alloy Using the Microscopic Phase-field Method

采用微观相场方法,以 Ni68.2Al22.7V9.1 合金为例研究了应变能对两相沉淀及原子占位的影响。研究结果显示:沉淀过程中应变能明显使 L12沉淀相增加,对DO22相的沉淀有一定的抑制作用;由于 DO22相减少,V原子在L12相中各个位置的占位几率增大,而且应变能越大占位几率越高;应变能对Al原子在L12相中的α1位的占位几率影响不大,只有小幅度的降低,但明显降低了Al原子在α2位和β位的占位几率;各种情况下V原子在 L12相β位的占位几率始终高于α位。

The effect of strain energy on Two-phase precipitation and Atoms occupying in Ni68.2Al22.7V9.1 alloy was studied, using the microscopic phase-field method. It is found that the strain energy significantly extend the precipitation process of L12 phase, and restrain the precipitation of DO22 phase. As DO22 phase decreases, the occupation probability of V atom at different sites in L12 phase increases, and the higher the strain energy, the greater the chance of occupying. The effect of strain energy on occupation probability of AI atom at α1 site in L12 phase is little, only a small reduction in amplitude, but it significantly reduces occupation probability of A1 atom at α2 site and β3 site. In all cases, the occupation probability of V atom at fl site in L 12 phase is always higher than that at a site.