9700095 Liu It was recently shown feasible to use hard turning in selected conditions to superfinish surfaces. However, just like grinding, hard turning as a finish process may produce thermal damage to the integrity of a machined surface if the machining conditions create too much heat conducted into the machined surface. The objectives of this research project are: (1) to study the integrity of machined surface by hard turning; (2) to develop a model to estimate the onset and upper bound of the thermally damaged layer as a function of machining conditions including flank wear; and (3) to study various innovative methods of extending the limit imposed by surface damage (resulted by flank wear) for the purpose of longer tool utilization. This research addresses the problem of thermal damage in hard turning, with the potential practical result of removing thermal burn as a major obstacle toward widespread application of hard turning. It holds the promise of replacing separate grinding and abrasive-based superfinish as a process for finishing hardened workpieces.
