A review of recent advances in integrated laser remelting and laser cladding processes

Laser cladding uses a high-energy laser beam as a heat source to rapidly melt and solidify the cladding material onto the substrate to form a high-performance coating. This technology provides an efficient and economical method to repair and remanufacture precision equipment such as engines and spacecraft. However, the inherent non-equilibrium solidification properties of laser cladding often lead to problems such as coating anisotropy, high porosity, and elemental segregation. Optimizing process parameters and heat treatment do not always eliminate these defects. Therefore, it is necessary to seek a more appropriate solution. Introducing laser remelting on the surface or between the layers of the coating to cause it to remelt and redistribute can refine the grain size, reduce defects, and improve the uniformity of the composition, thus enhancing the performance of the coating. This paper reviews and summarizes the application and development status of laser remelting technology in laser cladding and discusses it in terms of surface quality, hardness, wear resistance, and corrosion resistance of the coating. It also identifies the potential of external field-assisted laser remelting technology in further optimizing coating performance. Finally, based on the review, suggestions are provided for selecting remelting parameters.