Casting Microporosity Growth Simulation in Single-Crystal Superalloys
Wan jiansong,Lv zhenzhou,Yue zhufeng
(Northwestern Polytechnical University, Xi’an 710072, China)

Abstract: Finite element analysis is employed to investigate casting microporosity behavior in nickel-base single-crystal superalloys. Based on finite deforma tion rate-dependent crystallographic constitutive equation, the growth simulation of casting microporosity in a unit cell model is carried out within a range of parameters including deviation orientation, type of different slip systems activated. The results show that the deviation orientation exerts remarkable effects on the growth behavior and volume fraction of casting microporosity, but the shape transform of casting microporosity is slightly affected. To ensure the perf orming safety of the single-crystal superalloy components, it is necessary to control the deviation orientation which may lead to the obvious change of casting microporosity volume during deformation. Similarily, it is important to determine the operative slip systems type associated with Schmid Factor and loading orientation to evaluate accurately the hot spot life.
Keywords: casting microporosity, single-crystal superalloy, crystallographic constitutive equation，unit cell model.