The Role of Microcracks in Large Plastic Deformation

This paper describes the results obtained from shear-compression tests carried out at low strain rates and at strain rates equivalent to those in a typical machining operation. These tests together with metallographic work are used to explain the influence of microcracks on the flow stress of work material. It is shown that the negative work-hardening effect observed at large strain deformation in the presence of compressive stresses is associated with the behavior of microcracks. A mechanism is proposed to account for this phenomenon.