"This study examines the use of laser surface treatment to repair surface and subsurface defects. Numerical analysis was performed on laser surface melting using Gaussian heat distribution equations to analyze the depth of the melt pool created by the phenomena. Concurrently, a process map was developed with a planned set of experiments by varying the ranges of laser power and travel speed to determine the dimensions of the melt pool across the gamut. The data generated from both the process studies and the numerical analysis was then used to determine the ideal operating ranges of the process parameters to repair surface and subsurface defects. These parameters were then used to validate the repair of surface and subsurface defects of varying dimensions artificially created on stainless steel 304 substrates. The surfaces of these repaired samples were topologically mapped to geometrically assess and quantify the repair achieved. Measured standard deviations of these topological profiles before and after the repair have shown that the laser surface treatment can be used as a viable option for repair of surface imperfections. After completing the surface study the samples were cross-sectioned to volumetrically analyze the internal regions for the occurrence of voids. This final part of research justified the ability of the laser surface treatment in the repair of sub-surface defects. This work has successfully repaired surface defects of sizes of 1mm*1mm*1mm and has identified the ideal process parameters needed to achieve successful repair. It has also led to successful repair of 0.2mm-0.6mm size subsurface defects up to depths of 0.5mm."--Abstract, page iii.
Liou, Frank W.
Kinzel, Edward C.
Materials Science and Engineering
M.S. in Manufacturing Engineering
Missouri University of Science and Technology
ix, 48 pages
© 2015 Prudvi Teja Ravi, All rights reserved.
Thesis - Open Access
Lasers -- Industrial applications
Electronic OCLC #
Link to Catalog Record
Ravi, Prudvi Teja, "Laser surface and sub-surface repair during metal additive manufacturing" (2015). Masters Theses. 7410.