The role of microstructural morphology on creep properties of a [001] oriented nickel-base single crystal superalloy

摘要

The experimentally observed microstructure of nickel-base single crystal alloy consists of a large volume of cuboidal precipitates coherently embedded in the matrix. In calculation, a representative volume element is usually used to represent the whole structures due to the regular / topological structures. Here, three experimentally found microstructures have been extracted to generate the representative volume elements. One is constituted by one cuboidal phase surrounded by phase. The other two consisted of two cuboidal phases and one rectangle phase with different arrangement of the two phases. The misfit stress is taken into consideration by different thermal expansion coefficients of the two phases. The influences of different microstructures on the macro-creep strain evolution, rafting and stress distributions are discussed.