US Patent 9315903 Laser microcladding using powdered flux and metal

A laser microcladding process utilizing powdered flux material (93b). A jet (92) of propellant gas containing powdered alloy material (93a) and the powdered flux material are directed toward a substrate (94). The powdered materials are melted by a laser beam (96) to form a weld pool (98) which separates into a layer of slag (100) covering a layer of clad alloy material (102). The flux material deoxidizes the weld pool and protects the layer of clad alloy material as it cools, thereby allowing the propellant gas to be nitrogen or air rather than an inert gas. In one embodiment, the substrate and alloy materials are superalloys with compositions beyond the traditional zone of weldability.