Abstract
Relationship between rupture strength and fracture toughness determined by Bridge Indentation method for WC-(5.5-40) mass%Co alloys was studied.
The results obtained are as follows:
(1) Fracture toughness estimated by taking account of the yielding of the plastic zone at the tip of defect agrees with the measured value by the BI method.
(2) On the relationship between rupture strength and fracture toughness, the rupture strength follows a linear elastic fracture mechanics and increases with fracture toughness in the case of large defect. While in the case of small defect, the rupture strength increases to the maximum strength which reaches near the yield strength, and decreases with an increase in fracture toughness. Rupture strength variation with fracture toughness depends on the defect size and the plastic zone.
