Methods of Measuring Flash Temperatures in the Grinding of MgO-Doped PSZ

Abstract

This study is based on results of a test to determine mechanisms in the grinding of partially stabilized zirconia. The grinding mechanism tests, which are outlined, suggest involvement of a thermal mechanism, a hypothesis of which is outlined. In order to validate this hypothesis, an investigation of flash grinding temperatures, an indicator of heat generation and thereby a means to validate the hypothesis, was conducted.The theoretical background, actual implementation, and results of each of three different temperature analysis methods are presented. The first method, a single-wavelength infrared camera, provided indications of temperature distribution. However, it did not provide temperature indications because of uncertainties in the grinding process that make calibrations ambiguous. The second method, a dual-wavelength ratio method, verified the possibility for fast time-response analysis of the grinding process. As an adequate calibration was not achieved for this method, it provides no quantitative results. The third method is the implementation of a spectrometer, which provided repeatable calibrated flash temperature indications. Results from this portion of the study indicate temperatures that, for the range of wheel speeds and downfeed rates tested, depend solely on the wheel and workpiece used. For these tests, dense vitreous bond silicon carbide grinding wheels generate temperatures of 3000 K for grinding MgO-doped zirconia and temperatures of 2400 K for grinding alumina. When grinding these materials with a diamond abrasive wheel, temperatures of 3000 K for grinding zirconia were registered, and no signal was registered for grinding alumina. Finally, the implications of the results of these various tests are discussed.