Realizing a full volume component by in-situ welding during electron beam melting process

Abstract

As one of the powder-bed-fusion additive manufacturing processes, electron beam melting (EBM) is able to produce metal parts directly. Many small volume components with high quality have been fabricated using the EBM technology. However, there are only few reports on the EBM fabrication of medium-sized components. One of the reasons is the lack of energy issue when the scan length is too long, which results in the generation of lack of fusion pores. This, in turn, drastically degrades the mechanical properties of the EBM printed parts. Here, we firstly report an in-situ welding process to overcome the lack of energy issue caused by the long scan length during EBM process. After the investigation of the corresponding microstructure, microhardness and tensile properties, it is revealed that the in-situ welding zone is fully joined and the mechanical properties of the in-situ welded part are comparable to that of the wrought counterpart. This implies that medium-sized components can be successfully fabricated using the EBM, with no compromise on the mechanical properties.