Joining Technologies for Metal Additive Manufacturing in the Energy Industry

Abstract

Additive manufacturing (AM) has captured the imagination of the manufacturing community and has revolutionary potential across a number of energy applications. One particular challenge for these applications is the large size of metal AM components that are compelling to be printed. This necessitates welding and joining processes to integrate metal AM parts into larger assemblies, as well as the ability to repair and rework metal AM parts that may have defects. This work characterizes the microstructural and mechanical properties of metal parts produced through laser-based powder bed fusion (L-PBF) and electron beam powder bed fusion (EB-PBF) and then subsequently welded. The results show possibilities for gas tungsten arc welding (GTAW) and friction stir welding (FSW) as feasible rework and repair solutions for AM-printed AlSi10Mg, Ni 718, and Ti64. More research attention to this area will improve the viability of L-PBF and electron beam melting AM technology for energy applications.

A Review on the Weldability of Additively Manufactured Aluminium Parts by Fusion and Solid-State Welding Processes

“…This pore-rich region is observed in the weld zone (WZ) near the fusion line in the PBF-LB parts. This critical and weak region, which has also been observed by other authors [35][36][37]39,[43][44][45]52] and affects the quality of the joint itself, will be referred to as a pore belt for future reference.…”

“…Although the formation of the pore belt region is more pronounced in arc-welded specimens [35][36][37], it has also been observed in LBW-welded specimens [39,[43][44][45] and in EBW-welded specimens [52]. Based on the reported ultimate tensile strength values of the welds made by fusion welding processes, the EBW process appears to be the most suitable for welding Al alloys produced by additive PBF-LB (Figure 18).…”

“…In their study, Gill et al [37] compared fusion and solid-state welding processes by evaluating the mechanical properties of the as-built PBF-LB AlSi10Mg BM, GTAW welds, and friction stir welds. As has been shown in detail previously, porosity is highlighted as the major challenge for the GTAW process [35,36].…”

“…Although the formation of the pore belt region is more pronounced in arc-welded specimens [35][36][37], it has also been observed in LBW-welded specimens [39,[43][44][45] and in EBW-welded specimens [52]. In addition to the need to adjust the welding parameters from conventional cast Al welding to AM Al welding, Michler et al [54] observed that the electron beam three-spot welding technique achieved a significant porosity reduction in joints made by electron beam welding.…”

Influence of Sheet Covers on Filling Behavior in Electrochemical Joining of Additively Manufactured Components

“…They found that gas tungsten arc welding (GTAW) and friction stir welding (FSW) are feasible joining techniques for these additively manufactured components. These methods have shown potential in providing reliable joining capabilities and preserving the integrity of the metal parts [10]. Hassanin et al investigated the joining process of additively manufactured parts made of Ti6Al4V and AlSi10Mg.…”