High-Temperature Tensile Properties of a Cobalt-Based Co-20Cr-15W-10Ni Superalloy with a Bimodal Grain Structure

Cobalt-based superalloys are common materials for the manufacturing of various components used in aerospace applications. Conventional cobalt-based with a unimodal grain structure generally exhibit low strength and ductility at high temperatures. A bimodal superalloy, Co–20Cr–15W–10Ni (CCWN), was designed to achieve both The deformation behavior tensile properties CCWN alloy fine-grain (FG), coarse-grain (CG), (FG/CG) structures were investigated 900 °C. microstructures substructures after high-temperature examined via electron backscatter diffraction (EBSD) channeling contrast imaging (ECCI) determine mechanisms. microstructural observation showed that consisted FG CG domains. During °C, mainly deformed by dynamic recrystallization (DRX), maintaining similar structure. DRV, resulting small amount DRX grains large recovery (DRV) grains. However, softened transformed into new structure, ultrafine (UFG) FG. domains tended deform dislocations, twinning. tests revealed bimodal-structured exhibited higher than those samples or This is associated newly developed UFG/FG grain-structured during deformation. work may provide insight development alloys structures.