Laser welding of dissimilar material

Abstract

Very less work has been done on laser welding of dissimilar material. This project addresses optimization of process parameters in laser welding operation. Two sheets of stainless steel and copper are cut into small pieces. The small sheets of dimension 80mm*30mm*1mm were cut from the bigger sheet. Good surface finish is required for laser welding. So the small sheets are machined to remove bur. The small sheets were machined in grinding machine. Then they were filed to remove rest amount of bur present. Very less bur may also affect the welding output. So the surfaces to be welded were finished properly. Then the two small sheets were aligned on the table of the welding machine. The joint was placed in the right place by looking the joint in the eyepiece provided in the welding machine. Then the welding is simulated without laser. The simulation was seen on a screen attached with the welding machine. Simulation was done until the alignment was perfect. After simulation the two sheets of stainless steel and copper are welded together using laser beam. Similarly various pair of sheets of copper and stainless steel were welded. Two sets of experiment were done one with varying welding speed and the other with varying welding power. Tensile test and hardness test was done to each and every specimen. From those two sets of experiment the variation of harness and tensile strength with change in welding speed and welding power was observed.