Additive manufacturing by wire based laser metal deposition

Abstract

Laser additive manufacturing with metals is gaining more and more attention, and represents a large market in industrial applications, specifically for the aerospace sector in the future. The increasing diversity of applications requires the continuous development of specific process implementations: For high metal deposition rates, developments have focused on arc technologies (Wire Arc Additive Manufacturing, WAAM), based on conventional welding techniques. For high definition 3D parts, the development of laser technologies allowed the implementation of layer-based metal solidification on powder beds known as Selective Laser Melting (SLM). These two processes have specific characteristics, such as high deposition rate with low accuracy for WAAM and low deposition rate with high accuracy for SLM. In this paper, we will present the interest of wire-based deposition technologies with lasers, often referred to as laser metals deposition by wire (LMD-W). This new approach presents the best compromise between high deposition rates and good accuracy which corresponds to the need of the aerospace industry to build “cubic meter sized” parts. It meets the requests in terms of mechanical resistance and process duration. The first tests of the present study are carried out on aluminum alloy. The results show a good aptitude of aluminum despite of a recognized difficulty to implement this alloy in additive manufacturing due to problems with process stability at the edge of the deposit, filling strategies, and many more. In the present paper we focus our developments on the deposition rate in order to realize large aeronautics components.