M.S. (Master of Science)
Department of Mechanical Engineering
The most commonly used technique for machining ceramics is diamond grinding. It accounts for up to 75% of the manufacturing costs resulting in high cost of the product. An LED bulb offering increased brightness, energy saving and long life by using ceramic integration to LED chips costs around 10 times to a normal LED bulb. Complex geometries used in electronics, medical surgeries, aerospace, and automobile industries require the use of costly molds or powder metallurgy for low batch production which does not justify the cost. Laser Assisted Machining (LAM) is a process that uses a laser to locally heat the surface of a component (made of ceramic), making it more ductile and machinable using conventional machine tools. Recent studies have shown that LAM gives improved material removal rate and surface finishing, and reduces the cost of machining, i.e. around 50% reduction in the manufacturing costs.
Physical experiments require the use of advanced instruments and specialized tools making it a difficult and time-consuming process. It is necessary to have a predicting thermal study to help design more efficient physical experiments. In this study, Finite Element Analysis (FEA) has been used to analyze the thermal distribution of a workpiece under rotating and translating moving heat source. In LAM, there are many variables that greatly affect the temperature, such as laser size, laser power, translational velocity, etc. Extensive research has been performed on solid cylinders however many new applications such as thermocouple protection tube, cylinder lining, blasting nozzles, bone fusion in surgeries, etc., require application of hollow cylinders. Therefore, this work intends to perform a thermal study on a ceramic tube when a laser beam moving on its outer surface. As the generated heat due to the machining is insignificant compared to the heat created by the laser heat source, this study doesn’t consider the mechanical removal of the material. The ceramic chosen for this study is Silicon Nitride as it is widely used due to its excellent wide range of properties making it suitable for all industries. The FEA method and assumptions that will be used on this research has been verified with previous experimental and numerical research on a solid cylinder.
Mohammed, Mudassar Hussain Ansari, "Theoretical Study of Laser-assisted Machining on Silicon Nitride Hollow Ceramic Cylinder Using Finite Element Method" (2018). Graduate Research Theses & Dissertations. 7461.
Northern Illinois University
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