Abstract
Joining metals and alloys with different properties gives greater flexibility in design and production as compared to manufacturing with one type of material only. Due to this, expensive materials can be applied only at places where their use is indispensable. However, joining different combinations of metals become a challenge, due to the differences in physical and chemical properties. Laser welding, due to such advantages as good weldability and high quality of joints with narrow heat affected zone, allows for solving many problems appearing in traditional joining methods. The current paper concerns modelling of laser welding processes for materials with different physical and chemical properties. The model consists of a coupled set of incompressible fluid flow equations, heat equation and convectiondiffusion equations for different material types. The formulation takes into account the dependence of material properties on temperature and chemical composition. Discontinuity of density and viscosity, together with the chemical composition of fluid in weld pool influences the velocity and temperature distribution in the weld pool and in consequence determinesthe shape and properties of a joint.