PTIMIZIMG THE EFFICIENCY IN DIRECT LASER DEPOSITION PROCESS USING VIBRATION TO CONTROL THE FLOW OF POWDER

Abstract

In direct laser deposition, (DLD) metallic powder injected into a laser generated melt pool on the substrate surface, melts and after movement of the laser solidifies. By overlapping and offsetting these clads, construction of a three-dimensional, fully dense near net shape part is possible. The cost of powder wasted in commercial DLD machines has been a concern to the industries. The deposition efficiency of these machines has been limited to 5 – 40%. More than 60% of the powder is wasted and is being disposed off which makes the system economically and environmentally expensive. Although efforts to recycle the powder have been practiced but this has not been adopted in many sectors, including the aerospace industry, because of the fear that the re-use of powder may lead to a drop in part quality. The objective of this study is to investigate whether the deposition efficiency of DLD process can be enhanced. In previous studies, powder delivery nozzle diameter, table speed and powder carrying gas delivery rate were found to be the most influential parameters. All pointed towards the speed of powder particles and the powder stream diameter. In this study, it is aimed to achieve the powder flow by vibrating the powder delivery nozzle using sonic frequencies. The nozzles with different diameters, with different vibrating frequencies will be used to find the best flow.