Grinding titanium aluminide: subsurface damage

This paper presents a study on subsurface damage induced during the surface grinding of titanium aluminide. As grinding occurs, workpiece temperatures rise at the interface between the grinding wheel and the workpiece. Three material properties – thermal diffusivity, thermal conductivity and Vickers hardness – are presented as functions of temperature, ranging from room temperature to 800°C. A theoretical model, based on moving heat source theory, is presented to predict maximum workpiece temperatures, followed by experimental results, using an embedded thermocouple technique, to validate the model. Finally, a model based on indentation of brittle materials is offered to predict the depth of plastic deformation during grinding, with experimental validation in the form of the bonded interface technique. The information presented in this paper adds to the knowledge base on titanium aluminide, which has the potential to become a key material in the aerospace industry, as well as many others.