Analysis of coaxial laser micro cladding processing conditions

The laser build-up cladding is a well-known technique for repair, coatings and additive manufacturing tasks. Modern equipment for the laser cladding enables material to be deposited with the lateral resolution of about 100 mm and to manufacture miniature precise parts. However, the micro cladding regimes are unknown. Determination of these regimes is an expensive task as a well-known relation between laser cladding parameters and melt pool dimensions are changing by technology micro-miniaturization. These relations cannot be more used for the laser micro cladding parameters determination. In this paper the formation of single clad track on a Al-alloy substrate by coaxial laser micro cladding using Yb: YAG continuous laser was studied both from a theoretical and experimental point of view. The theoretical analysis concentrated on the laser beam energy transfer using a simple model of heat transfer to the substrate. This approach provides laser micro cladding parameter values required for the formation of desired width clad track to be predicted. For an appropriate experimental analysis of the main process parameters involved, a method based on a gradual change of a single processing parameter was examined. Correlations between the main micro cladding parameters and geometrical characteristics of a single clad track have been found.