Evaluation of joint strength in laser transmission welding of PMMA polymer

Abstract

This study reports on an experimental investigation of laser transmission welding of Polymethylmethacrylate (PMMA) using two different welding path strategies: box and spiral. The influence of laser welding parameters, such as laser power, welding speed, and laser pass number, on the weld strength was investigated by applying Response Surface Methodology (RSM) based on Box-Behnken Design (BBD) methodology in the design of the experiments. A series of carefully designed tests and evaluations have been used to create mathematical models that show how the responses and the process parameters are related. These sequential analysis-of-variance (ANOVA) approaches were applied also to evaluate the developed models' appropriateness. Tensile tests were conducted after welding to evaluate the effect of the kind of joint and the weld passes on the weld stresses strain curve of the weld joint and its strength. The results showed that high-quality welding was produced under process parameters appear in run number 8 the parameters for this run are (V=10 mm/min, P=20 Watt and one passes number) for the box weld path while for the spiral was shown in run number 4 (V=40 mm/min, P=30 Watt and two passes number).