This is a proposal to renew the University of Michigan's participation in the Lasers and Plasmas for Advanced Manufacturing center, an I/UCRC center that was created in 2002. The center was initially established as a single university center and currently has grown to a multi-university center with participation from the University of Michigan, Ann Arbor and Southern Methodist University. The main focus of the center's research is in laser applications for advanced manufacturing.
The intellectual merit of the proposed work is to develop atomic level understanding of the laser materials processing needed for intelligent manufacturing. The knowledge gained will lead to new and novel materials and manufacturing methodology. In the past four years, the University of Michigan site has made a big stride in developing and implementing application-driven basic research for laser-based advanced manufacturing. The University of Michigan site is working effectively as it is well supported by industrial members and the projects are challenging and clearly important. The equipment at the University of Michigan is substantial and the projects discussed, ranging from laser welding to mathematical modeling of residual stresses in direct metal deposition, are ambitious and worthwhile.
Laser processing techniques are expected to increase well beyond the applications of today as research provides improved development of this important process. The integrated effort of multi-university center for laser applications provides a great benefit to the society in terms of helping US industries to be more competitive in advanced manufacturing. The University of Michigan site will provide education and training to prepare students to meet future workforce needs. The university will provide a unique experience to graduate students who can interact and collaborate with industrial researchers and engineers. The university will continue to involve undergraduate students through REUs.
Plasmas in Advance Manufacturing is a multi university program including The Industry University Co-Operative Research Center (IUCRC) on Lasers and University of Virginia, University of Michigan, Southern Methodist University and university of Illinois. The main scientific and technological outcomes of the center at the University of Michigan site are as follows: 1) Theoretical and experimental studies of Emission spectroscopy based in situ diagnostics of weld quality and defects. Figure 1 shows one of the typical outcome of this research . This was conducted mainly in collaboration with Industrial partner Toyota USA Inc. This led us to two patents and one pending patents in addition to 5 journal papers and numerous conference papers. Three of the patents were licensed to Ford for a three yrs and a start up company called SenSigma LLC is formed using the IP generated in the program and licensed to SenSigma by the university of Michigan. SenSigma is now developing commercial software called SOMS. 2) Theoretical and experimental studies of Laser micromachining with nanosecond and femptosecond lasers to create totally implantable artificial Lungs. Prototype was tested at Medical School and uninterrupted blood flow for 24hrs were observed. Figure 2 shows important outcome of this research. Theoretical analysis revealed uniform Shear flow when Murray’s Law is followed to design fluid channel array. This work was carried out with the partnership of IMRA USA. One Ph.D and three journal papers came out of the project. 3)Thin Ceramics film deposition by laser ablation for potential application for thermal barrier coating was explored with the help of GE aircraft group. Surface roughness of these deposits was in the range of 10s of nanometers. Two journal papers and a Ph.D. was produced. 4)An experimental investigation was carried out on On-line diagnostics of composition and temperature during drilling and additive manufacturing of aerospace Nickel super-alloys. This work was carried out in co-operation with GE aircraft group and Global research center. As a natural extension of this work further work is continuing with GE aircraft to develop Nickel superalloy components with prescribed crystal structure. Figure 3 shows data from the drilling depth monitoring. 5)An experimental and theoretical study was carried out in co-operation with Focus Hope, Advance Technology center to understand the evolution of Residual stress during an Additive Manufacturing process called "Direct Metal deposition. This is a critical issue for any additive manufacturing process. A preliminary mathematical model is developed and validated experimentally using X-Ray crystallography. Figure 4 shows typical residual stress history as predicted by mathematical simulation. Four journal papers on the process were published one is pending. A student completed his Ph.D. on the topic and presently waiting for OTP for starting his postdoctoral research on the same topic with GM support. The Scientific Merit of this program was the common theme of mathematical simulation of processes of interest to Industry along with development of on line diagnostics tools using basic physics principle. We now can model and measure the quality and defects of the manufactured products during the process. . During the tenure of this program six students received Ph.D. contributing to the fundamental understanding of the laser based processes along with development of tools for online diagnostics and theoretical prediction minimizing lead time for future implementation. The Broader Impact of this program include the following: Invention and Commercialization of the technology developed under the program to help American industries to certify the products as they build by forming a start up company SenSigma LLC. Trained 6 Ph.D students and three post doctoral fellows in the critical areas of Advanced Manufacturing. The most important training of these group is how to work with team of multiple universities and industries. Moreover they learn how to address a real life industrial problem with basic scientific approach. All of them are meaningfully employed in responsible positions.
