Epitaxial growth of single crystal superalloy by a novel spot-cutting laser cladding method

A spot-cutting laser cladding process was proposed to repair the thin wall single crystal superalloy in this paper. The effects of spot cutting and its gap width on the dimensions and microstructure of cladding layers were studied. The results demonstrate that the cladding layers exhibit directionally epitaxial dendrites throughout the layer, reducing the formation of "stray grains" and significantly decreasing the machining allowance compared to samples without spot cutting. By optimizing the parameters, continuous epitaxial grains were achieved in the cladding layer, reaching a height of 1173 mu m. The layer dimensions increased initially with weld height, but then decreased with a flattening morphology as the base metal width increased.