Research on Process in Laser Cladding of Width-Changing Single Layer Based on Coaxial Inside-Beam Powder Feeding

In this paper, coaxial inside-beam powder feeding technique was used. According to theoretical analysis and the single layer cladding experiments, the initial parameters and experimental scheme of width-changing layer cladding based on the coaxial inside-beam powder feeding were confirmed. The theory model of piecewise transition was established. The real-time control of scanning speed and the defocus amount to carry out the experiments were used while the laser power and powder feed rate were not changed. Finally, the layers with uniformly width changing and stable layer height were achieved. Performance analysis showed that the formed layer had smooth surface and a high rigidity without powder paste outside the surface, and the size was basically as same as the design value. Its microstructure was small and dense and good metallurgical combination was formed between part and substrate.