Simulation of Precipitate Coalescence in the Solidification Structures of Superalloys.

A recently published criterion to predict anisotropic coarsening in single crystal nickel-base superalloys under multiaxial stress conditions, based on the interfacial mismatch dislocations between the 2 phases present in these materials has been incorporated into an anisotropic lattice gas employed in a Monte Carlo simulation. This has been used to simulate the effect of residual stresses within the casting mesostructure on the anisotropy coalescence of precipitates within the commercial alloy SRR99 under thermal and thermo-mechanical treatment. A series of lattice configurations reproducing a sequence of cross sections through the casting structure are presented. Modelling results are found to compare well with experimental data.

ARRELL Douglas James; 

1997-06-26

JRC14474