Microscopic phase-field study on growth orientation during the effect of thermal-elastic coupling in nickel based alloy

Abstract:

Based on microscopic phase-field model which is coupling both exterior load and cyclical temperature, growth orientation for phases and distribution of elements during precipitation in nickel based alloy was studied. The result showed that: the effect of cyclical temperature cannot change the growth orientation and the precipitation order of phases. With the effect of cyclical temperature, L1₂ precipitated first when the content of Al was higher, DO₂₂ precipitated first when the content of V was higher, and both L1₂ and DO₂₂grew perpendicular to the direction of tensile stress. When tensile stress existed in [001] and L1₂ precipitated first, DO₂₂ prefer to grow along [100]. When tensile stress existed in [100] and DO₂₂ precipitated first, L12₂ prefer to grow along [100]. With the reducing of higher temperature of cyclical temperature, the fluctuation range of volume fraction for L1₂ during cyclical temperature decreased obviously and the fluctuation range of volume fraction for DO₂₂ during cyclical temperature changed a little.