High temperature creep-rupture features of nickel-base single crystal superalloy
(1.沈阳工业学院 材料系，沈阳1100062.Department of Superalloys, Institute of Metal Research, Chinese Academy of Sciences,Shenyang 110016, China3.School of Materials Science and Engineering, Shenyang Institute of Technology, Shenyang 110168, China4.中国科学院 金属研究所, 沈阳 110016)
Abstract: The creep and rupture behavior of a nickel-base single crystal superalloy with [001] orientation was investigated at temperature of 10001040℃ and stress in the range of 150320MPa. The creep features and microstructure were studied by means of the measurement of creep curves and TEM observation. The results show that all creep curves exhibit a short primary and a dominant accelerated creep stage. From the creep parameters and TEM observations, it is suggested that the primary deformation mechanism has a change from precipitatation shearing by pairs of dislocation in the high applied stress region to dislocations climb around the γ′ particles in the low applied stress region. Furthermore, the detailed failure process and fracture surfaces were analyzed by SEM observation.
Key words: single crystal nickel-base superalloy； tensile creep； microstructure； fracture