September 2016

A constitutive model on flow stress prediction from the contribution of twin and grain refinement, strain and strain rate during surface mechanical attrition treatment of metals

A new constitutive equation is developed to model the flow stress on a metal surface undergone high speed impacts that result in strain hardening. The new equation is based on the Johnson-Cook model and has considered the effects of strain, strain rate, grain refinement, twin formation and twin spacing. Two mechanisms for the strain hardening are proposed: Grain refinement or twin formation, depending on the strain...

Author(s): Wing Yan LEUNG, San Qiang SHI, Jian LU, Hai Hui RUAN and Li Min ZHOU