Analysis on residual stress of hybrid laser-tungste inert gas arc welding of magnesium alloy

The residual stress of weld, in both parallel and perpendicular direction, was measured by impacted indentation method for hybrid laser-tungsten inert gas arc welding of magnesium alloy. Based on the date measured, residual stress field simulation was established with finite element method, which can provide a effective supplement to the data of actual measurement.Results showed that the maxium tension stress along the parallel direction of the weld existed at the middle area of the weld was 200-300 MPa, while the maximum compressive stress along perpendicular direction that exists at area of 5 mm and 10 mm to the weld fusion zone was no more than 100 MPa.Through the comparison between actual measurement and simulation, the residual stress distribution characteristics of hybrid laser-tungsten inert gas arc welding of magnesium alloy AZ31B have been well understood.