A parametric analysis of direct laser deposition process using vibration control feeding system

Abstract

In the current economic situation, the major concern of the manufacturing companies is to produce components of high quality with low cost. Direct laser deposition (DLD) is a blown-powder laser deposition process and an emerging technology which is commonly used in the manufacturing industries to join different components of metals. In order to reduce the cost of the DLD process, it is important to optimize the deposition efficiency which is the main objective of current study. Experimental tests were performed to investigate the effect of different powder mass flow rate, laser power intensities, and laser scanning speed on powder deposition efficiency. A newly designed coaxial powder nozzle was used to deliver fine size of powder to a targeted small focal point, and desired flow rate of the metallic powder was achieved by vibrating the powder delivery nozzle at sonic frequencies. From the experimental results, it was observed that the powder mass flow rate which can be affected by vibration frequency has a significant effect on deposition efficiency. With the increase of laser power intensities, deposition efficiency and deposition quality increased while powder flow rate have a negative effect on the material deposition efficiency. By selecting the appropriate parameters, up to 90 % of maximum deposition efficiency was achieved which is a significant improvement as compared with deposition efficiency obtained by conventional gas feed system used by other researchers.