Laser direct metal forming (LDMF), curve radius, thin-wall part, residual stress. ☆

To discuss the influence of curve radius change on the vertical and horizontal direction residual stress of thin-wall parts by laser direct metal forming (LDMF), the numerical simulation and experiment were studied. Results shows that: with the increasing of curvature radius (R) from 2.5 to 15 mm, vertical direction stress (σV) decreases gradually, horizontal direction stress (σH) increases rapidly; when R rises to 15 mm, σV basically remains at 280300 MPa, σH basically remains at 460480 MPa. This is because curvature radius influences the maximum temperature of the molten pool, which subsequently affects the magnitude and direction of temperature gradients. The experimental results were in well agreement to the simulation