Research on Microstructure of Laser-Remelted Cold-Sprayed Inconel 625 Coatings on Copper

This study demonstrates a two-step laser cladding process for copper substrates in which cold spraying is used as a powder preplacing method to overcome problems associated with the high laser reflectivity of copper as well as the effects of high-temperature oxidation. In the first step of the process, Inconel powders are cold sprayed onto pure copper, producing a layer with a thickness of about 250 μm and a porosity of 0.88%. This is followed by a 3.5 kW laser remelting treatment using a 1030 nm laser with a spot size of 2.5 mm. Examination and testing of the as-sprayed and remelted layers show how the laser treatment improves coating microstructure, hardness, density, and metallurgical bonding.