Corrosion-Wear Mechanism of (AlTiV)_100-xCr_x Lightweight High-Entropy Alloy in the 3.5 wt.% NaCl Solution

(AlTiV)_100-xCr_x high-entropy alloys (HEAs) is expected to solve the problem of poor corrosion-wear resistance of lightweight alloys. To elucidate its corrosion-wear mechanism, three (AlTiV)_100-xCr_x alloys were prepared by vacuum arc melting method by repeating the melting five times at 240 A current.and their microstructures, mechanics, corrosion, wear, and corrosion-wear behaviors were investigated. The results indicate that (AlTiV)_100-xCr_x is a single-phase with BCC structure and the VEC of Cr5, Cr10 and Cr15 were 4.0, 4.1 and 4.2 respectively. Their hardness increase and toughness and corrosion resistance decrease with the increase of Cr content (Cr5:537.5 HV_0.2/6.7%/1.86 × 10^-8 A/cm²; Cr10:572.3 HV_0.2/5.6%/2.09 × 10⁸ A/cm²; Cr15:617.6 HV_0.2/3.8%/2.51 × 10^-8 A/cm²). The wear volume and the corrosion-wear volume of AlTiVCr alloys are mainly caused by the abrasive wear. However, the fatigue wear of AlTiVCr alloys could be exacerbated by a decrease in material's toughness, corrosion resistance, and an increase in solution corrosivity. Therefore, Cr10 presents the optimal wear resistance in the deionized water, while the optimal corrosion-wear resistance in the 3.5 wt.% NaCl solution is presented by Cr5. Compared to TC4, the wear and corrosion-wear resistance were improved by 56.4% and 65.5%, respectively.