Sliding tribological characteristics of in-situ dendrite-reinforced Zr-based metallic glass matrix composites in the acid rain

The tribological properties of in-situ dendrite-reinforced metallic glass matrix composites (MGMCs) with the composition of Zr58.5Ti14.3Nb5.2Cu6.1Ni4.9Be11.0 under different normal loads and sliding velocities in the acid rain (PH = 2) were investigated. The results showed that the friction coefficient and wear rate of the Zr-based MGMCs obtained a minimum 0.385 and a maximum 8.85 x 10(-4) mm(3)/(N m) at 10 N, respectively. In addition, the friction coefficient of composites initially increased with the increase of the sliding velocity and achieved a maximum of 0.522 at 0.3 m/s, then reduced. Simultaneously, the wear rate of composites increased monotonically with increasing the sliding velocity and reached a maximum of 22.77 x 10(-4) mm(3)/(N m). The wear mechanism of composites was dominated by abrasive wear at lower normal load and sliding velocity. Nevertheless, the wear mechanism of composites transformed from abrasive wear to adhesive wear and viscous flow with increasing the sliding velocity and normal load. Oxidation and corrosion occurred during the process of the wear tests in acid rain solution. (C) 2016 Elsevier B.V. All rights reserved.