Residual Stress Developments During Laser Welding of Commercially Pure Titanium Sheets

Abstract

The laser welding of cp-ti sheet was done by using a continuous wave welding and gas laser (CO2).Laser welding is operating at different conditions like laser power at 2kW & 2.5kW, range of welding speed is from 4m/min to 8m/min and laser intensity distribution by Gaussian Mode and Donut Mode. Macrostructure of weld size and fusion zone were examined by using optical microscope. It is found that weld size was decreased with increasing welding speed and increased with increasing laser power and spot diameter and weld size for donut mode is higher than the Gaussian mode. Residual stress which is developed due to thermal gradient is measured by X-Ray Diffraction Technique. These residual stress measurements were taken at a series on the top surface covering the fusion zone, heat affected zone (HAZ) and base metal. Here residual stress is compressive in nature. Residual stress at weld pool for Gaussian mode is lower compared to Donut mode.