Evaluation for jointing interface between dissimilar metals welded in directed energy deposition

Abstract

Technologies for dissimilar metal jointing attract attentions from industries because of their possibilities to enhance the production functionality and reduce the manufacturing cost. In order to reduce assembling processes and achieve high applicability to complex-shape production, direct energy deposition is one of the suitable approaches because of its flexibility in design and functionality for material content change in process. In this paper, a joint between Inconel 625 and stainless alloy (SUS 316L) is produced in direct energy deposition and evaluated in terms of the jointing strength and metal crystal structure around the boundary. According to the results of tensile strength tests and metal crystal observations, the strength in deposited objects is enhanced by fine metal crystal structures, when the heat supply per volume is small during deposition.