The objectives of the proposed research are to systematically and individually study the effects of anisotropy, heterogeneity and length scale effects in microscale material deformation processes which are encountered in microscale manufacturing. While the techniques to be employed in this research could be applied to any microscale manufacturing process, the PIs will focus efforts Micro Laser Peen Forming (mLPF). The approach is to experimentally characterize materials subjected to mLSP and mLPF processes by measuring the induced residual stresses with microscale x-ray diffraction techniques, by measuring the distributions and degrees of plastic deformation with Electron Backscatter Diffraction (EBSD), and also to measure the final shape of the deformed specimens using various commercial techniques. In order to isolate the effects of anisotropy the processes will be performed on single crystals. To isolate the effects of heterogeneity, the processes will be performed near the grain boundary of a bicrystal. Potential length scale effects of the plastic deformation will be probed with electron backscatter diffraction (EBSD) which allows estimates of the density of geometrically necessary dislocations. The two processes will be numerically simulated using the finite element technique, taking into account rate effects, hardening effects, the anisotropic, heterogeneous nature of the material, and will incorporate length scale effects if deemed necessary by the experimental results.
Expected results will help micro manufacturing processes to make higher quality micro components. The significantly improved understanding of process capability and limitations will open up opportunities for new micro part designs. Personnel development and dissemination of results will improve national competitiveness in micro manufacturing. A significant effort will be made to involve students from traditionally underrepresented backgrounds in the research.
