Investigations of laser microwelding using low power fibre laser for thin 304 stainless steel sheets

Abstract

Experimental investigation of laser beam butt welding of thin 304 stainless steel sheets (200 μm) using low power Yb-doped fibre Laser of 1090 nm wavelength is reported. Effect of various process parameters on ultimate tensile strength (UTS), width and depth are obtained. The laser power has been varied in order 60 (5) 85 W to understand its effect on the weld strength at different scanning speeds 4(2.0)10:00 mm/s. Beam spot diameter was varied between 200 (50) 300 μm. These governing parameters have been combined in the form of energy density (J/mm2) to present the results. It is observed that with an increase in the energy density the weld strength increases and reaches to maxima at around 80 J/mm2. At same value, the ratio of spot diameter to depth (D/d) is = 1.0 which is in tune with a value of energy density for maximum weld strength.