タングステン焼結合金の破壊挙動と破壊靭性 Fracture Behavior and Fracture Toughness of W Sintered Alloys
Fracture toughness behavior of W-Ni-Fe sintered alloys with three strength levels was investigated. With increasing tensile strength, dynamic fracture toughness K<SUB>ld</SUB> decreases dramatically, especially in the upper shelf. In low strength material, cracks propagate by the coalescence of boids created in binder, whereas in high strength material, cleavage fractures of W particles precede the void formation of binder. Fracture toughness K<SUB>max</SUB> significantly depends on specimen size. The K<SUB>max</SUB> increases with increasing specimen size, which is caused by larger amount of stable crack extension in larger specimens. No effect of loading rate on K<SUB>max</SUB> was observed.<BR>Relationship between the Charpy absorbed energy and dynamic fracture toughness was also investigated.
粉体および粉末冶金 43(5), 643-648, 1996-05-15
Japan Society of Powder and Powder Metallurgy