The research objective of this award is to determine the physical benefit of using lasers at the micro scale to improve the machining process of brittle semiconductors and ceramic materials through measurements of cutting forces and tool wear, complemented with numerical simulations for comparison. The approach will be to design and build the micro laser assisted machining tools and system and to evaluate their performance in actual cutting tests on materials such as silicon and silicon carbide. Process parameters including forces and wear measurements will be used to evaluate the effectiveness of the laser system and optimize its performance as a tool for improving the manufacturing process.
If successful this research will lead to a new cost effective process capability for producing advanced components from difficult to machine materials that will result in reduced component cost for semiconductors and engineered ceramics and provide an opportunity for extending the use of these materials to new products and markets. Reduced cost manufacturing and extended use of high performance semiconductors and engineered ceramics are vitally important in the advanced transportation market, especially for the development of the next generation of fuel efficient gas, hybrid and electric vehicles.
The work was successfully completed and it directly significantly impacted the education of 10 students (six undergrads, two MS and two PhD); summer research interns (4), senior design (2), full time MS and PhD (4). Note one of the summer interns and one of the senior design students (two total) were also REUs. The work involved a number of faculty (PI, Co-PI, other faculty at WMU from physics, chemistry, biology, electrical engineering, etc.) and several industrial partners (6 total) and government labs (ANL; APS and Materials). Interest in eventual commercialization of the results (technology) realized from this research is being generated internationally (Japan and US), and will likely result in product realization in the future. Successful proof of concept (and potential feasibility) has resulted from this research project: laser heating, thermal softening, and reduced brittleness of semiconductors (Silicon and Silicon Carbide) using the micro laser assisted machining (µ-LAM) process (indenting, scratching and simulated machining have been accomplished as part of the research effort). The feasibility of coupling the fiber laser with an actual cutting tool (and testing) has been successfully implemented; leading the way for full implementation of an actual machining system. In addition to the above education and engineering successes, scientific discoveries were also accomplished. Based upon our work at WMU and Argonne National Laboratory (and in partner labs), high pressure-high temperature phases (HPHTP) of silicon carbide were discovered, analyzed and evaluated. These HPHTP are believed to be the origin of the ductile (not brittle) response of Silicon Carbide (used for high power microelectronics and optical components), which provides the process mechanism enabling the machining of these materials using the µ-LAM system. To our knowledge, this is the first demonstration of HPHTP of Silicon Carbide, the first realization of a LAM process for single crystal semiconductors, used in microelectronics, and the first realization of the µ-LAM process with an actual cutting tool (diamond used as the tool material).