温度对一种单晶高温合金 γ/γ′分配行为与错配度的影响

Based on three-dimensional atomic probe technology and thermodynamic calculation, the influences of temperature(850, 1100 and 1150 ℃) on microstructure and γ/γ′partitioning ratios of alloying elements, solid-solution strengthening degrees of γ and γ′phases and γ/γ′misfit in a W-rich second-generation Ni-based single-crystal superalloy were detailed investigated. The results show that, after quenching at 1100 ℃, the quenched microstructure is basically the same as that of heat-treated state. When temperature increases to 1150 ℃, γ′phase significantly re-dissolves. With increasing temperature, Co and Cr contents in γ phase decrease, W content firstly increases and then decreases, while Re, Al and Ta contents in γ phase increase. With increasing temperature, Co content in γ′phase decreases, Re content increases, Cr, Al and Ta contents firstly increase and then decrease, while W content in γ′phase firstly decreases and then increases. In addition, with increasing temperature, solid solution strengthening degree of γ phase increases, while solid solution strengthening degree of γ phase first increases and then decreases. Meanwhile, with increasing temperature, γ/γ′partitioning ratios of Co, Cr and Re elements decrease, γ/γ′partitioning ratio of Al element increases, partitioning ratio of Ta element firstly decreases and then increases, while partitioning ratio of W element firstly increases and then decreases. Moreover, with increasing temperature, lattice constants of both γ phase and γ′phases increase, while γ/γ′misfit decreases.