Microscopic phase-field simulation on the effect of first-stage ageing temperature for Ni₇₅Al₁₀Cr₁₅ alloy

Based on the microscopic phase-field model, the first-stage ageing temperature effect of double-stage ageing is simulated for Ni₇₅Al₁₀Cr₁₅ alloy. When the first-stage ageing temperature is lower, a non-classical nucleation and growth mechanism occurs for L1₂ phase, while the precipitated mechanism of DO₂₂ phase is spinodal decomposition, the homogeneous and disperse precipitated phase is liable to acquire, the dimension of L1₂ phase is close to the DO₂₂ phase. When the first-stage ageing temperature is higher, the precipitated mechanism of L1₂ phase is spinodal decomposition, while the precipitated mechanism of DO₂₂ phase is non-classical nucleation and growth, and the dimension of L1₂ phase is obviously larger than that of DO₂₂ phase. The incubation period of precipitation becomes longer, and the grain densities of L1₂ and DO₂₂ decrease with the increase of first-stage ageing temperature.