Accordance between fracture toughness and strength difference in TC21 titanium alloy with equiaxed microstructure

As well known, the properties of strength and toughness were mutually exclusive in the metal materials. Therefore, few investigations focusing on the accordance relationship between the strength and the fracture toughness had been carried out. In this paper, the related insight was discussed by the microstructure characteristic, strain-hardening effect and slip band morphology at different scales. The accordance between the plane fracture toughness (KIC) and the strength difference (SD) (the difference between the yield strength and the tensile strength) was found. All datasets showed a linear KIC-SD with the slope of 0.31, which was not reported by other researchers for TC21 titanium alloy with the equiaxed microstructure. Finally, this accordance relationship could be further identified in other alloys, such as aluminum alloy, magnesium alloy and steel.