Study on Variable Spot Cladding for Large Area Laser Surface Modification

In modern surface modification manufacturing technology, laser cladding is a high-tech which has good prospects for development. However, for the large area laser cladding surface modification, there has the contradiction between cladding efficiency and cladding accuracy of the cladding. If using the smaller spot, it will be inefficient, if the spot increasing, the accuracy of marginal part of the cladding will be poor, the "stage effect" will be obvious. The variable spot powder feeder is designed, and the variable spot cladding process with small facula outlining border and big facula filling in central section is introduced, which resolves the contradiction between the two effectively. Experimental proves that surface quality with variable spot cladding is better. In the overlap area, due to the second lixiviation caused by repeated heating, the microhardness value of multi-track overlap cladding is higher than the structure in the non-overlap area.