Dry Sliding Tribological Properties of a Dendrite-reinforced Zr-based Bulk Metallic Glass Matrix Composite

In-situ dendrite-reinforced metallic glass matrix(MGM) composites with the composition of Zr58.5Ti14.3Nb5.2Cu6.1Ni4.9Be11.0were prepared with a vacuum arc melter by the copper mold suction casting.Effect of different normal loads and sliding velocities on the tribological properties of MGM composites was studied. The results showed that the friction coefficient and wear rate of composites initially descended with increasing the normal load and reached a minimum of 0.339 and 1.826 10 4mm3/(N m) at 10 N,respectively, then ascended. Similarly, the friction coefficient and wear rate of composites initially decreased with the increase in the sliding velocity and reached a minimum of 0.330 and 2.389 10 4mm3/(N m) at0.4 m/s and 0.3 m/s, respectively, then raised. The wear mechanism of composites was mainly adhesive wear accompanied by abrasive wear at lower normal load and sliding velocity. However, the wear mechanism of composites was abrasive wear and adhesive wear as well as delamination at higher normal load and sliding velocity due to the nucleation and propagation of surface and subsurface cracks during the wear process. The flake-like and particle-like wear debris was the dominant shapes of debris observed.