Investigation of Co-Cr-Fe-Mn-Ni Non-Equiatomic High-Entropy Alloy Fabricated by Wire Arc Additive Manufacturing

Abstract

Fabrication of high-entropy alloys (HEAs) is a crucial area of interest for materials scientists since these metallic materials may have many practical uses. Wire arc additive manufacturing (WAAM), unlike other additive technologies, has tangible benefits for making large-sized components, but manufacturing the wire from HEAs is still very limited. Recent studies suggested tackling this problem using a combined cable composed of wires consisting of pure elements as feeding material. However, not all compositions of HEAs can be obtained by the pure elements’ wires because the number of them is limited. This study aims to examine phase composition, chemical elements distribution, microstructure, and mechanical properties of a Co-Cr-Fe-Mn-Ni HEA, which was not previously obtained by the WAAM. The cable-type wire used in this study is composed of two wires which consist of Cr, Fe, Mn, and Ni, and one pure Co wire. The phase composition, chemical elements distribution, microstructure, and mechanical properties were investigated. The prepared high-entropy alloy has non-equiatomic chemical composition with a single-phase FCC crystal structure with homogeneously distributed elements inside the grains. The microstructure examinations showed dendrite structure which is typical for WAAM processes. The compressive yield strength of the alloy is ~279 MPa, the ultimate compressive strength is ~1689 MPa, the elongation is 63%, and the microhardness is ~150 HV, which was found to be similar to the previously fabricated Co-Cr-Fe-Mn-Ni alloys by other methods. Fracture analysis confirmed the ductile behavior of deformation by the presence of dimples.

As-Cast Microstructures of High Entropy Alloys Designed to Be TaC-Strengthened

“…These five elements constitute a quinary system, the thermodynamic description of which was studied until recently [6,7] . Beside the conventional foundry of equimolar FeCoNiCrMn alloys, different ways of elaboration of superalloys were recently applied to HEAs: single crystalline growth [8] , additive manufacturing [9] or thin film deposition [10] . Their behaviors in case of extreme conditions of solicitations were also explored, mechanical properties [11,12] or chemical reactivity at high temperature [13] .…”

Wire and Arc Additive Manufacturing of a CoCrFeMoNiV Complex Concentrated Alloy Using Metal-Cored Wire—Process, Properties, and Wear Resistance

“…Further research on the manufacturing of complex concentrated metal-cored wire, as a well-established filler for welding, needs to be done, although an alternative for alloydevelopment and the determination of the mechanical properties has been established using cable-like wires [31][32][33].…”

“…Here, too, the degrees of freedom in composition are significantly greater for small quantities of filler compared to solid wires. These cable-like fillers have been realized for complex concentrated alloys; demonstrated in [31][32][33]. Here, the limiting factor is the available diameter of the different alloying elements.…”

Additive Manufacturing Technologies of High Entropy Alloys (HEA): Review and Prospects

“…According to Shen et al [ 201 ], the AM HEA produced using wire DED with seven different wires (one Fe wires, two Ni wires, two Al wires, one Co wire and one 304 stainless steel wire) had similar mechanical properties to those of the cast alloy made with the same wires as feedstock material for the AMF process. Other studies [ 202 , 203 ] have demonstrated that the use of three non-pure welding wires can form a single solid solution, as shown in Figure 14 .…”