Coarsening Behavior of Gamma Prime Precipitates in a Nickel Based Single Crystal Superalloy

The gamma/gamma microstructural evolution in a nickel based single crystal superalloy during load-free thermal exposure at 900 degrees C has been further investigated in this paper. The growth characteristics of gamma precipitates were discussed in detail. The generation of interfacial dislocations would accelerate the rate of coalescence in the dendrite arms. The average sizes of precipitates were used to compare interface with diffusion controlled growth mechanism and no mechanism seems obviously dominant, although the square rate law gives slightly better fit. The coarsening behavior may be controlled by diffusion through the ragged interface between the gamma precipitate and the gamma matrix. Copyright (C) 2015, The editorial office of Journal of Materials Science & Technology. Published by Elsevier Limited. All rights reserved.