Numerical simulation and experimental analysis of wide-beam laser cladding

This paper aims to investigate the temperature field evolution of the single track clad in wide-beam laser cladding. By using the birth and death element technique, a 3D transient finite element (FE) model was established to study the temperature field evolution, temperature gradient (G), cooling rate (ε), and solidifying rate (R) of the molten pool. The temperature field results of the molten pool were also validated by the temperature measurement and characteristics of the clad. Meanwhile, the effect of main parameters namely as laser power, scanning speed, laser absorptivity, laser power efficiency, and preheat temperature on the peak temperature of the molten pool and temperature variation rate were discussed in detail. Then, the effect of laser power and scanning speed on G, ε, R, and G/R were also investigated and the corresponding microstructure was analyzed. The results show that from the top surface of the clad to the interface between the clad and substrate, G/R decreases slightly at first and then increases sharply while the cooling rate continues to decrease. Moreover, the peak temperature of the molten pool increases with an increase of laser power, laser absorptivity, laser power efficiency, and preheat temperature, while with the increasing of scanning speed, the peak temperature decreases.