Definition of brightness temperature and restoration of true temperature in laser cladding using infrared camera

Laser cladding is a surface engineering technique allowing depositing material of a different nature in the form of a powder or a wire on the surface of a metallic part.In this study, the laser cladding technique was used to deposit TiAl6V4 coating on TiAl6V4 substrate to study repairing of worn parts. An infrared camera was applied to measure radiation emission field that was transformed into brightness temperature after camera calibration by a black body. The emissivity value was found using known temperature of liquid–solid transition. True temperature profiles in cladded bead, temperature evolution at liquid–solid transition and cooling rates were found using gray body assumption.