Slag inclusion-free flux cored wire arc directed energy deposition process

Abstract

Wire arc directed energy deposition (Arc–DED) of metal components has gained considerable attention in different industries, including construction and landscaping. However, the deposition of single metal materials and associated constrained fabrication environments limit their potential in industrial applications. Furthermore, inherent solidification defects in the melting-based Arc–DED processes must be addressed. In this study, a flux cored wire (FCW)-based Arc–DED, which enables the manufacturing of components in outdoor environments, was presented. In addition to the basic Arc–DED equipment, FCW material and an ultrasonic needle peening (UNP) device for slag crushing were incorporated in the essential work tools. By investigating the flow behavior of molten slag and examining the internal solidification defects, the mechanism of slag inclusion based on physical phenomena was determined. Additionally, the microstructure and mechanical properties resulting from the droplet transfer mode were examined based on the variations in the transfer conditions of the molten slag. Further, the microstructure of the deposited layer induced by the slag crushing process of the UNP was characterized by equiaxed particles, which effectively mitigated the degradation of the mechanical properties caused by slag.

Keywords

• Directed energy deposition
• Slag inclusion
• Flux cored wire
• Metal transfer
• Ultrasonic needle peening