Please use this identifier to cite or link to this item: http://hdl.handle.net/1783.1/5278

Use of actively cooled megasonic coolant for precision machining

Authors Lai, Honkeung
Issue Date 2006
Summary With the development of modern manufacturing industries, surface grinding is an important machining process. Great care of quality requirement for engineering surfaces is needed. Many industrial products can be benefit and performance enhancement by improving engineering surface quality, such as, optical mold surface, grinding process of silicon wafer for IC industries and MEMS application, precision equipment application and even medical usage in artificial joints, etc. Improvement in cooling approaches can enhance engineering surface quality, reliability, machining accuracy and efficiency. Adequate cooling approach is a must for those engineering processes. Effects of Actively Cooled Megasonic Coolant cooling approach for surface quality enhancement is developed and studied. Different types of coolant conditions were generated throughout the application of heat pump and megasonic actuating nozzle. Normal, actively cooled, megasonic and actively cooled megasonic coolant were obtained. Simulation results shown that almost all heat generated from the grinding zone is taken away by the cooled coolant. . Megasonic and actively cooled megasonic coolant can act as better machines not only provide better surface quality, but also reduce the stress containing inside the machined workpiece even if deeper depth of cut is applied. Summarizing the experimental, computational, morphology measurement results, actively cooled megasonic is advantageous in enhancing the surface quality of engineering surfaces. The experimental results show that the actively cooled coolant can provide better surface quality with an average reduction up to 29.95% in surface roughness Ra, averaged reduction up to 30.94% improvement in Ra for megasonic coolant. Actively cooled megasonic coolant provided the best performance of cooling, averaged improvement up to 36.68% in roughness value Ra was obtained. Best improvement occurs when temperature is between room temperature and 21°C. Improvement about 5 to 8% is achieved for every 3°C lower in coolant temperature under 21°C. Surface quality after grinding can be selected as the needs of the product specifications.
Note Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2006
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Language English
Format Thesis
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