On the Mechanism of Fracture in Grey Cast Iron

Abstract

This paper presents the results of both experimental and analytical investigations into the conditions of failure for lamellar-graphite case iron under various modes of loading. The orientation of fracture planes is experimentally determined and surfaces of fracture zones are carefully examined with the help of a scanning electron microscope. While fracture for a tensile test takes place along its cross section, fracture in the compression test is herein shown to insist on developing along a plane inclined at some 55 to 65 deg to the cross section, irrespective of notches or grooves intentionally machined to persuade fracture to pursue certain preassigned paths. For the case of uniaxial compression, the present analysis correlates the ratio of compressive to tensile strengths to both rupture and friction angles. Relevant values are in conformity with earlier findings.