Portable Fiber Laser System and Method to Remove Pits and Cracks on Sensitized Surfaces of Aluminum Alloys.

摘要

The goal of this project is to develop a compact, portable fiber laser repair system integrated with the capabilities of surface cleaning, local heating, and peening using a single laser to remove pits and cracks in sensitized Al alloy surfaces and to condition those surfaces to improve resistance to further sensitization. The fiber laser repair system will have the advantages of being compact, portable, energy saving, chemical free, maintenance free, and easy to operate meeting the U.S. Navy s goal of reducing operation, maintenance, and support costs associated with 5000 series Al sensitization. During this reporting period (July 1, 2015 to July 30, 2015), the experimental setup for laser shock peening (LSP) was developed. The effects of LSP on the surface topography, nanohardness, and elastic modulus of the 5052 Mg-Al alloy samples were experimentally investigated and analyzed. The phased objectives and specific content are as follows: (1) Selection and Purchase of 5000 series Al alloys and temperature-controlled oven for sensitization experiment. (2) Developing the experimental setup for laser shock peening. (3) Optimization of processing parameters for laser shock peening. (4) Surface morphology study of the laser-peened surfaces using optical microscopy and scanning electron microscopy. (5) Study of the surface nanohardness and elastic modulus of the laser-peened 5052 Al alloy samples using the nanoindentation technique.