Thermal modeling and temperature measurement of dry grinding.

摘要

It is essential to limit the amount of heat that enters a workpiece during grinding to reduce the incidence of thermal damage. A sound understanding of the heat transfer mechanisms, and hence, the temperatures involved during grinding may lead to improved process parameter selection and coolant delivery systems.; A temperature measurement system consisting of an infrared video camera and a thermocouple mounted to a constant temperature source were used to measure workpiece surface temperatures during dry grinding. A thermal partition analytical model was implemented to predict the heat partition ratios and the maximum temperature in the contact zone. A contact zone analytical model was implemented to predict the temperature profiles in the contact zone. 2D, 3D shell, and full 3D numerical models were created to predict the temperature profiles in the contact zone and the subsurface temperatures.; The contact zone temperatures predicted by the analytical and numerical models showed excellent agreement, indicating that both models were implemented correctly. The subsurface temperatures predicted by the numerical models and the experimental temperatures recorded by the infrared camera were shown to agree only in general shape with errors in magnitude ranging from 16% to 43%, depending on the process parameters. The error was found to be a combination of the limitations of the temperature measurement system, the predicted thermal partition ratios, and the applied boundary conditions of the numerical models. By comparing the subsurface temperature profiles predicted by the numerical models and the experimental temperatures it was found that a triangular heat source profile should be used to describe the heat flux profile in the contact zone.; The results showed that the temperature measurement system may be useful to capture the temperature gradients experienced during grinding. The results also showed that each of the models fell into its own niche. The thermal partition model was adequate for predicting the heat partition ratios, for quick maximum contact zone temperature estimation, and for online temperature measurement. The contact zone model was adequate to quickly predict the temperature profile in the contact zone. The numerical models were useful for predicting the entire workpiece temperatures.