Strain-gradient crystal-plasticity modelling of micro-cutting of b.c.c. single crystal

In recent years thanks to enhancements in design of advanced machines, laser metrology and computer control, ultra-precision machining has become increasingly important. In micromachining of metals the depth of cut is usually less than the average grain size of a polycrystalline aggregate; hence, a cutting process can occur entirely within a single crystal. The respective effect of crystallographic anisotropy requires development of machining models that incorporate crystal plasticity for an accurate prediction of micro-scale material removal under such conditions. To achieve this, a 3D finite-element model of orthogonal micro-cutting of a single crystal of b.c.c. brass was implemented in a commercial software ABAQUS/Explicit using a user-defined subroutine VUMAT. Strain-gradient crystal-plasticity theories were used to demonstrate the influence of evolved strain gradients on the cutting process for different cutting directions.