Component mixing in laser cladding processes: From single-track to single-layer multi-track and multi-layer multi-track

In multi-layer multi-track laser cladding processes, the mechanical properties of the cladding layers are closely related to the microstructure and element distribution. However, the mixing process of the component cannot be predicted by the existing experimental conditions. A multi-layer multi-track laser cladding component prediction model is constructed to solve this problem. According to the multi-layer multi-track laser cladding model, the geometry of the cladding layer, and the element (Cr, Fe, and Ni) concentration distribution in the overlap zone and non-overlap zone are predicted. In addition, the effects of resistivity, dynamic viscosity, laser power, and active elements on the distribution of the cladding layer components were investigated. The results show that the uniformity of element distribution in the cladding layer is closely related to the convective mixing time and convective mixing intensity of the melt pool. Increasing the laser power, resistivity, or reducing the melt pool dynamic viscosity and sulfur concentration can increase the convective mixing time and convective mixing intensity of the melt layer, which helps to improve the uniformity of the melt layer group distribution. The concentration of Cr in the cladding layer increases with the number of the cladding tracks and layers, and the Cr concentration in the non-overlap zone of the first track of the first layer is lower than that in the overlap zone and other tracks. As the number of cladding layers increases, the concentration of elements in the overlap and non-overlap zones gradually tends to be uniform except at the edge of the cladding layer. In addition, the presence of sulfur in the melt pool can change the convection form of the melt pool.