MOLECULAR-DYNAMICS SIMULATION OF THE PRECISION MACHINING PROCESS INCLUDING RADIATIVE AND CONVECTIVE HEAT-TRANSFER MECHANISMS

During the machining process, extreme temperatures can occur in the va rious heat generation zones of the material. These temperatures can so metimes reach or exceed the melting point. To accurately represent the influence of this heating, heat transfer mechanisms must be incorpora ted into simulation models. The simulation model described in this pap er provides a new feature that includes heat transfer to the environme nt by the application of a finite-temperature molecular dynamics (MD) simulation technique. The modelled system is not adiabatic. The simula ted thermal environment described herein produces realistic simulation s of the material surfaces. The exposed surfaces are cooler than the b ulk as expected. The process simulations obtain realistic levels of th ermal activation, which affect the material properties and the machini ng process parameters, e.g. friction forces, etc. Heat transfer with t he environment is found to be of the same order of magnitude as the th ermostat boundary layer for the simulations performed. As expected, at the temperatures that occur during machining, radiative heat transfer dominates over convective transport. The thermal model also clearly s hows the heat associated with the various machining regions, due to pl astic deformation and friction.