Study on Scanning Pattern during Laser Metal Deposition Shaping

The fabrication of metal parts is the backbone of the modern manufacturing industry. Laser forming is the combination of five common technologies: lasers, rapid prototyping (RP), computer-aided design (CAD), computer-aided manufacturing (CAM), and powder metallurgy. The resulting process creates part by focusing an industrial laser beam on the surface of processing workpiece to create a molten pool of metal. A small stream of powdered alloy is then injected into the molten pool to build up the part gradually. By moving the laser beam back and forth and tracing out a pattern determined by a CAD, the solid metal part is fabricated line by line, one layer at a time. In the present work, a type of direct laser deposition process, called Laser Metal Deposition Shaping (LMDS), has been employed and developed to fabricate metal parts. Through the comprehensive experiments, it is found that this process is affected by many factors. Besides the processing parameters, scanning pattern is the one that strongly influences the quality and precision of as-fabricated parts. In comparison with the forming effects of different scanning patterns, the most suitable one can be selected to carry out this laser forming process. Finally, with the suitable scanning patterns, the high performance of the formed alloys is confirmed after the above studies.