Microcladding of hypereutectic Al-Si alloys: technological aspects and structure features

This study aims to investigate the technological possibility to generate high precision microrange structure from aluminium alloys using laser microcladding. Clad tracks of Al-Si alloys with different silicon contents with lateral resolution of similar to 200 mu m were produced using co-axial laser microcladding. Particle size distribution with surface morphology and microstructure of the initial powders were investigated. Mechanisms of structure formation in Al-Si alloys during laser microcladding were studied. It was revealed that the chemical composition of the powder material influences the structure formation process and microhardness of hypereutectic Al-Si alloys produced by microcladding. In addition, the effect of processing parameters on the microstructure and geometry of the resulted tracks is discovered. The conclusions on technological possibility of manufacturing the single tracks with width of <500 mu m from hypereutectic Al-Si alloys were made.