Can High-Entropy Interlayers Develop Intermetallic-Free Welded Joints of Dissimilar Metals?

Abstract

The joining of two chemically dissimilar metals is a challenge due to the formation of hard and brittle intermetallic compounds (IMCs) in the diffusion layer. The joining of steel/Fe with aluminum (Al) and zirconium (Zr) alloy is particularly important for the automobile and nuclear industries, respectively. The Al–steel and Zr–steel joints produced by conventional fusion welding exhibit IMCs. The IMCs can enhance brittleness and cause catastrophic failure. This concept paper presents a novel idea of suppressing IMCs in welded joints using a high-entropy interlayer (HEI). It also discusses the potential candidates for HEIs and inspires research to exploit this new and promising research area.

Predicting the thermal expansion of body-centred cubic (BCC) high entropy alloys in the Mo–Nb–Ta–Ti–W system

“…The introduction of a refractory HEA (RHEA) by Senkov et al [17,18] paved the way for potential high temperature structural applications, for example in aerospace [19] and potentially in advanced nuclear applications such as fusion [20]. HEAs are also being investigated for use as weld fillers [21][22][23] in the joining of dissimilar metals. In all of these systems, thermal expansion is an important consideration in the choice of material, especially when designing adjacent components or complex component geometries which are subject to regular and/or severe heat cycles (e.g.…”