Laser cladding remanufacturing belongs to recycling economy. The damaged parts are repaired and manufactured by using the energy of laser beam to melt the alloy powder and matrix material of cladding instantly. Due to the high scanning speed of the laser beam and the interaction of multiple parameters, melting and instantaneous cooling are an extremely cold and extremely hot metallurgical process. They are easily caused the defects such as deformation, cracks, bubbles, uneven organizational structure and large residual stress in the remanufactured parts, which limit their application range. Therefore, it is important to study the thermal stress evolution of laser cladding process. In this study, based on the finite element analysis, the thermodynamic coupling process was constructed, the laser cladding process object was designed, and the dynamic temperature and stress field were analyzed. The dynamic formation process of laser cladding pool, the influence of process parameters on temperature field and the evolution of thermal stress were studied by analyzing the relationship between temperature and stress in cladding process. The simulation results show that the maximum temperature is at the center of the spot, that is, the temperature gradient at the solid-liquid interface of the molten pool changes greatly. The cladding effect is best when the cladding material with the same matrix material was used. The residual stress of the coating is larger near the substrate, which is the main reason for cracking of the coating in the laser cladding process.
 

laser cladding, thermodynamic couple, thermal stress, dynamic simulation