Ultrasonic material dispensing-based selective laser melting for 3D printing of metallic components and the effect of powder compression

Abstract

Selective laser melting (SLM) is one of the most commonly used metallic component 3D printing techniques. In a previous investigation of multiple materials SLM reported by The University of Manchester, high porosities and cracks were found in the regions where the powder was deposited via an ultrasonic powder dispenser. The low powder packing density was identified as a critical reason for this. In this paper, we report a new method to compress the ultrasonically deposited powder layer in order to increase the powder packing density. The effects of powder deposition velocity, powder track overlap distance and powder compression force on the deposited powder characteristics were investigated. The microstructure, tensile strengths, and porosity of the laser-fused samples were analyzed. The results indicated that powder compression could reduce porosity and component distortion and increase the mechanical strength of the printed parts.