Heat Transfer in Thermally Enhanced Machining of Ceramics

摘要CTS-9400654 Incropera 拟议的研究旨在实验和理论上描绘运输现象的处理技术，使用强烈的，局部的热源，以增强陶瓷材料的传统加工。具体而言，热增强加工（TEM）工艺将研究车削操作，涉及集成的车床与现有的CO2激光或等离子弧源加工氮化硅，氧化锆和氧化铝氧化锆的圆柱形试样。 TEM过程的理论处理将被用来描绘相关的物理机制的作用。模型将考虑局部加热和对流热传递从工件表面，工件内的传导，在工具-芯片接口的摩擦，和/或塑性流动。还将进行辅助实验，以确定模拟或实际工件表面的流动和对流传热条件。在线监测将包括工件和刀具温度的传感和切削力的系统操作参数和热源条件的广泛。离线测量还将用于确定加工表面的残余应力、刀具磨损、显微组织和硬度分布。的理论和实验研究的目的是获得一个更好的理解TEM过程的基本物理机制，并建立一系列合适的操作条件。

ABSTRACT CTS-9400654 Incropera The proposed study seeks to experimentally and theoretically delineate transport phenomena related to a processing technique which uses intense, localized sources of heat to augment conventional machining of ceramic materials. Specifically, thermally enhanced machining (TEM) processes will be studied for turning operations involving integration of a lathe with existing CO2 laser or plasma arc sources to machine cylindrical specimens of silicon nitride, zirconia and alumina-zirconia. Theoretical treatments of TEM processes will be used to delineate the role of pertinent physical mechanisms. Models will consider localized heating at and convection heat transfer from the workpiece surface, conduction within the workpiece, friction at the tool-chip interface, and/or plastic flow. Supporting experiments will also be performed to determine flow and convection heat transfer conditions at a simulated or actual workpiece surface. On-line monitoring will include sensing of workpiece and tool temperatures and cutting forces for a wide range of system operating parameters and heat source conditions. Off-line measurements will also be used to determine the residual stress, tool wear, microstructure and hardness distribution in the machined surface. The objective of the theoretical and experimental studies is to obtain an improved understanding of underlying physical mechanisms for TEM processes and to establish a range of suitable operating conditions.