Coarsening behavior of γ particles in a nickel-base superalloy

The coarsening behavior of γ' particles in a nickel-base superalloy FGH95 was investigated by means of experimental observations and growth kinetics calculations. The results show that when aging at 1000,1080 and 1140°C for different times,the relation of average particle size to time obeys the cube law ( a /2)3= kt,where k is 15.49 × 103,77.5 × 103 and 230.04 × 103 nm3/min,respectively. The particle size distributions are better fit to the LSW theoretical distributions when aging at 1000°C within 1440 min....

Coarsening behavior of γ particles in a nickel-base superalloy

The coarsening behavior of γparticles in a nickel-base superalloy FGH95 was investigated by means of experimental obser-vations and growth kinetics calculations. The results show that when aging at 1000, 1080 and 1140℃ for different times, the relation of average particle size to time obeys the cube law (a-/2)3 =kt, where.k is 15.49×103, 77.5×103 arid 230.04×103 nm3/min, respectively. The particle size distributions are better fit to the LSW theoretical distributions when aging at 1000℃ within 1440 min. The activation energy for γ particles coarsening is determined to be 288.20±1.79 kJ/mol, which correlates well to the diffusion activation energies of Al, Ti, and Nb in the nickel matrix. This indicates that the coarsening of γ particles is controlled by the diffusion of Al, Ti, and Nb in the nickel matrix. The coarsening kinetics of γparticles in FGH95 is pre-dicted as rt3 = 1.04×1016texp-(288200±1790)/RT].