Room temperature tensile behaviour of K640S Co-based superalloy

The room-temperature tensile properties of K640S cobalt-based superalloy were investigated by tensile tests and microstructure observation. The experimental results showed that the deformation mechanism of K640S alloy is dislocation slip; that the dislocation could be decomposed into continuous stacking faults with different orientations; and that with the increase of the number of dislocations, the dislocation tangle interacts with the decomposed stacking fault to increase the tensile strength of the alloy. As the stretching proceeded further, a plurality of slip systems were activated between different grains to coordinate the deformation, and the grains were gradually plastically deformed. The stress concentration occurred at the carbide interfaces, and microcracks were formed, causing mixed crystal fracture to the alloy.