Microsegregation Induced Inhomogeneity of Coarsening of γ’ Precipitates in a Nickel-Based Single Crystal Superalloy
Microsegregation induced inhomogeneity of the coarsening of cuboidal γ’(Ni3(Al,Ti)) precipitates was studied in a single crystal nickel-based superalloy CMSX-4 at temperatures ranging from 850 to 1000 °C and for an ageing time up to 5000 h. Experimental results showed a significant statistical difference in the size of the γ’ precipitates between the dendrites and interdendritic region. The achieved results are analyzed and discussed from the point of chemical heterogeneity, activation energy for coarsening, time exponent, effective diffusion coefficient and γ/γ’ interfacial energy which control coarsening kinetics of the cuboidal γ’ precipitates within the dendrites and interdendritic region.
Andreas Öchsner, Graeme E. Murch, Ali Shokuhfar and João M.P.Q. Delgado
M. Gebura and J. Lapin, "Microsegregation Induced Inhomogeneity of Coarsening of γ’ Precipitates in a Nickel-Based Single Crystal Superalloy", Defect and Diffusion Forum, Vols. 297-301, pp. 826-831, 2010