Original paper(Vol.48 No.7 pp.686)

Abstract:Residual stress generating in each component phase is formed due to the disturbance strain by interaction between the composition phases as for Fe-Cr steel/TiN system composite prepared by powder metallurgy (P/M). We can obtain macro- and microstresses by using X-ray stress measurement method. And X-ray fractography technique was advanced in the field of the fracture analysis. In this study, we tried to fracture toughness test by using three points bending test pieces which have a different notch radius. Effects of notch radius on stress intensity factor when the crack arisen were discussed. Distributions of residual stress and plastic zone depths near fracture surface were evaluated. Experiment results obtained were approved to the equation of the fracture mechanics.

Key Words:Power metallurgy, X-ray stress measurement, Composite material, Micromechanics, Residual stress, Experimental stress analysis, X-ray fractography