Effect of density on mechanical properties and ductile fracture in a high strength sintered steel.

Abstract

Tensile tests and fracture toughness tests of high strength sintered steel have been carried out to investigate the effect of density on mechanical properties, fracture strain and fracture toughness JIC. Young's modulus was measured in two ways including tensile test with extensometer and ultrasonic pulse time method. Experimental data for Young's modulus, 0.2% proof stress, tensile strength, elongation, true fracture strain and JIC were presented simply in the form after Salak et al with narrow scatter. Theoretical predictions for Young's modulus, where it is assumed that the porosity is distributed as independent spherical holes in a homogeneous and isotropic matrix, gave higher values than the experimental data in the lower density region. The predictions of fracture strain and JIC were successfully performed by using a void model with effective diameter d and spacing 1 and a fracture criterion of δ=λo (=1-d).