An Elasticity Model Considering Grain Boundaries and Tensile Orientations for Directionally Solidified Superalloys
In order to investigate the elastic properties of directionally solidified(DS)superalloys,an elasticity model called boundaries elastic model(GBE model),considering grain boundaries and tensile orientations,is proposed in this paper. Two assumptions are adopted in the GBE model:(1)The displacement of grains,which moves along the perpendicular direction,is restricted by the grain boundaries;(2) Grain boundaries influence region(GBIR) is formed around the grain boundaries. Based on the single crystal(SC)calculation method of elastic properties,the GBE model can well predict macroscopic equivalent elastic modulus(Young’s modulus)of DS superalloys under different tensile orientations effectively. To demonstrate the correctness of the GBE model,3 D finite element simulation is adopted and tensile experiments on a Ni3 Al-base DS superalloy(IC10)along five tensile orientations are carried out. Meanwhile,the grain boundaries are observed by light microscopy and transmission electron microscope(TEM). Therefore,the GBE model is proved to be feasible by comparing the simulated results with the experiments.
supported by the National Natural Science Foundation of China (No.51205190)； the Fundamental Research Funds for the Central Universities (No.NS2016026)； the Aeronautical Power Science Fund Project (No. 6141B090317)； the Innovation Fund of Jiangsu Province, China (No.KYLX-0304)；