Thermal aspects of machining: A BEM approach

Elevated temperatures generated in machining operations significantly influence the chip formation mechanics, the process efficiency and the surface quality of the machined part. A BEM approach is used here to analyse the thermal aspects of machining processes. Particular attention is given to modeling of the tool-chip, chip-workpiece, and tool-workpiece interfaces. An exact expression for matching the boundary conditions across these interfaces is developed to avoid any iterations. A direct differentiation approach (DDA) is used to determine the sensitivities of temperature and flux distributions with respect to various design parameters. The numerical results obtained by the BEM are first verified against existing analytical and FEM results.s The temperature and flux fields for various machining conditions, along with their sensitivities, are presented next. The situations of progressive flank and crater wear of the tool with continued machining are also considered, and their effects on thermal fields are investigated. The BEM is found to be very robust and efficient for this class of steady-state conduction-convection problems. The application of DDA with BEM allows efficient determination of design sensitivities and avoids strongly singular kernels. This approach also provides a new avenue toward efficient optimization of the thermal aspects of machining processes.