Tribo-mechanical response of Ni-Cu-Al ternary alloy fabricated by concurrent three-wire WAAM-TIG

Abstract

The growing demand for application-specific materials with tailored properties has led this experimental research to the in-situ fabrication of a ternary alloy. The in-house-developed concurrent multi-wire feed mechanism, integrated with a tungsten inert gas-based wire arc additive manufacturing (WAAM-TIG) system, has been successfully utilised to fabricate a Ni-Cu-Al ternary alloy with uniform elemental composition. It was observed that the deposited multilayer wall showed enhanced tribo-mechanical behaviour, as multi-material alloying triggers synergistic strengthening across the structure. The alloy exhibited an average hardness of ~233.0 ± 7.4 HV, a yield strength of ~395 MPa, a tensile strength of ~445 MPa, and ~40% elongation, indicating an excellent strength–ductility balance. Whereas the average ultimate compressive strength and strain were found to be ~1425 MPa and ~ 18%, respectively. The incorporation of Ni into the Cu-Al alloy system significantly enhanced the mechanical properties, indicating a strengthening effect within the matrix, and it also improved its tribological performance. Scratch hardness and fracture toughness, estimated through scratch analysis, varied with increasing load but remained nearly constant with only slight reductions across different scratch speeds. The specific wear rate and CoF were found to be ~4.83 × 10−5 mm3/N·m and ~0.356, respectively. The findings underscore the significant influence of alloying elements on the modulation of mechanical properties, providing a foundation for the rational design and optimisation of advanced structural materials for various applications. © 2026 Elsevier Ltd.