Development of wear-resistant dual-phase high-entropy alloys enhanced by C15 Laves phase

High entropy alloys (HEAs) containing Laves phase, regarded as an in-situ composite material, have aroused widespread interest in industrial fields according to the intrinsic superiority of Laves phase. Hence, we develop (AlCoCrFeNi)_100-xZr_x (x = 0–2, at.%) HEAs and focus on their microstructures and wear properties. The microstructures of (AlCoCrFeNi)_100-xZr_x HEAs evolve from an original BCC phase (Zr-free HEA) to a hypoeutectic structure consisting of BCC and Laves phases (Zr-alloyed HEAs). Vickers hardness enhances with increasing Zr content, which is associated with solid solution strengthening, fine-grain strengthening and second phase strengthening. The coefficient of friction (COF) value reduces from 0.44 to 0.35 by adding Zr element. Al₂O₃ + Cr₂O₃ mixture oxides caused by wear heating and Laves phase support a decreased wear rate from 6.50 × 10⁻⁵ to 3.25 × 10⁻⁵ m³·N⁻¹·m⁻¹ (50% reduction) when only 2 at.% Zr is added to this alloy system. Furthermore, the wear mechanism converts from adhesive wear and oxidative wear to abrasive wear and oxidative wear with the addition of Zr element.