Dual beam laser control of flow in the weld pool

Abstract

Fluid flow and heat transfer during dual-beam laser welding have been investigated with a view to controlling flow in the weld pool and the resulting weld pool geometry and surface deformation. The investigation is based on a transient two-dimensional finite volume numerical simulation of flow in a moving plate for a dual heat source. Each of the two laser beams at the top surface of the weld pool is modeled as a Gaussian source. The heat transfer mechanisms considered includec onduction in the solid region, as well as natural and Marangoni convection in the liquid region. The convection patterns induced by the Marangoni convection in the liquid region are altered by imposing a second laser beam, thereby affecting the flow structure. This paper examines the validity of the numerical simulation by observing the wed pool geometry experimentally. Both the power levels and inter-beam spacings are varied and the material used is AISI 304 stainless steel. Representative results of the flow patterns in the weld pool for the dual-beam laser welding process are reported.Fluid flow and heat transfer during dual-beam laser welding have been investigated with a view to controlling flow in the weld pool and the resulting weld pool geometry and surface deformation. The investigation is based on a transient two-dimensional finite volume numerical simulation of flow in a moving plate for a dual heat source. Each of the two laser beams at the top surface of the weld pool is modeled as a Gaussian source. The heat transfer mechanisms considered includec onduction in the solid region, as well as natural and Marangoni convection in the liquid region. The convection patterns induced by the Marangoni convection in the liquid region are altered by imposing a second laser beam, thereby affecting the flow structure. This paper examines the validity of the numerical simulation by observing the wed pool geometry experimentally. Both the power levels and inter-beam spacings are varied and the material used is AISI 304 stainless steel. Representative results of the flow patterns in the weld ...