The slab of Ni base single crystal superalloy was fabricated in 001 orientaion by selector technique.This slab was cut into stress rupture samples of which orientaion deviate from 001 within 20°.Under low temperature 750 ℃ and high stress 750 MPa condition,all samples with various misorientation acquire long creep lives and small creep strains.Although their primary creep strains are different,their creep rates in steady creep are equal roughly.Therefore,misorientations within 20° have little influence on whole creep lives.The common deformation feature of samples with different misorientation is formation of numerous stacking faults in γ′ phase and entangling large quantities of dislocations in matrix,while their configurations are different in detail.When the misorientation is smaller than 20°,it can only produce a little effect on microstructure evolution and deformation mechanism.
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