Laser Transmission Welding (LTW) of Three-dimensional (3-D) Printed Polylactic Acid (PLA) Sheets
R. Girish Kumar, B. Anand, S. Jabiulla and H.N. Narasimha Murthy
The objective of this research was to investigate the influence of laser transmission welding (LTW) process parameters such as welding speed, laser power and stand-off distance on weld strength and weld seam width of polylactic acid (PLA) sheets fabricated using fused deposition modelling. Lap welds of PLA were fabricated using a fibre laser as per L9 orthogonal array. Three levels of input process parameters were considered for laser power (16, 18 and 20 W), scanning speed (5, 10 and 15 mm/s) and standoff distance (210, 230, 250 mm). Analysis of variance (ANOVA) and Grey relational analysis (GRA) were carried out on both weld width and weld strength. Maximum tensile strength and minimum weld seam width of 10.51 MPa and 2.76 mm, respectively, were observed in the specimens which were welded using a laser power of 20 W, welding speed of 5 mm/s and stand-off distance of 250 mm.
Keywords: Fibre laser, polylactic acid (PLA) sheet, laser transmission welding (LTW), weld strength, weld seam width, analysis of variance (ANOVA), Grey relation analysis (GRA)