Phase-Field Simulation on Coarsening of the γ'Phase Particles in Ni-Based Superalloys Considering Elastic Inhomogeneity

2010 ◽  
Vol 297-301 ◽  
pp. 376-383 ◽  
Author(s):  
Yuhki Tsukada ◽  
Yoshinori Murata ◽  
Toshiyuki Koyama ◽  
Masahiko Morinaga

A phase-field simulation is performed to examine the effect of elastic inhomogeneity between the  and ’ phases on coarsening of the ’ phase in Ni-based superalloys. In the calculation of elastic strain energy, the mechanical equilibrium equation in elastically inhomogeneous system is solved by an iterative-perturbation scheme. On the basis of the elastic constants of a practical Ni-based superalloy, a series of simulations is performed in which both elastic anisotropy and shear modulus are varied independently. The variation of elastic anisotropy gives significant effect on both morphology and size distribution function of the ’ particles, whereas the variation of shear modulus gives little effect on them. Furthermore, it is found that the coarsening rate constant of the cubic growth raw changes and increases with increasing the standard deviation of the ’ size distribution.

2012 ◽  
Vol 326-328 ◽  
pp. 446-451 ◽  
Author(s):  
Toshiya Tanimoto ◽  
Yuhki Tsukada ◽  
Yoshinori Murata ◽  
Toshiyuki Koyama

Microstructural evolution in single crystal Ni-based superalloys is investigated by the phase field simulation. During creep, the morphology of theγphase changed from the cuboidal shape to the rafted one, and the rafted structure was collapsed in the late stage of creep. The simulation on the microstructural evolution is based on thermodynamic information, diffusion equation, elastic anisotropy and a homogeneous lattice misfit. It is found that caused by external stress result in the morphological change of theγphase to the rafted structure, and this rafted structure is collapsed by inhomogeneous lattice misfit. These morphological changes can be explained by the change in stable morphology of theγphase.


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