Effects of latent heat of fusion on thermal processes in laser welding of aluminium alloys

Based on the Green's function method, a mathematical model allowing for the latent heat of fusion and solidification is developed to describe the steady state, two-dimensional heat flow during welding of thin plates. It is demonstrated that the latent heat has a pronounced effect on shape and size of the weld pool and mushy zone. The thermal efficiency of base metal fusion by a line heat source η t can exceed 0·4839 considerably if the latent heat is taken into account. It is shown that the known simplified approaches for considering the latent heat can introduce large errors into the estimation of η t . The calculated and experimental weld pool shapes are compared.