Tribological and corrosion behaviors of Mg56.5Cu27Ag5Dy11.5 bulk metallic glass in NaCl solution

Abstract In this study, the tribological behaviors of Mg 56.5 Cu 27 Ag 5 Dy 11.5 bulk metallic glass (BMG) in air and NaCl solution were investigated using ball-on-disk reciprocating friction. The Mg 56.5 Cu 27 Ag 5 Dy 11.5 BMG exhibits higher strength and hardness than those of commercial AZ31B alloy and pure Mg. The wear rate of the Mg 56.5 Cu 27 Ag 5 Dy 11.5 in air is 3.8 × 10 − 7 mm 3 ·mm − 1 ·N − 1 , which is superior to those of AZ31B alloy (7.3 × 10 − 7 mm 3 ·mm − 1 ·N − 1 ) and pure Mg (6.5 × 10 − 7 mm 3 ·mm − 1 ·N − 1 ). The wear mechanism of Mg 56.5 Cu 27 Ag 5 Dy 11.5 , AZ31B, and pure Mg sliding in air is dominated by oxidation and abrasive wear. The wear rates of alloys in NaCl decrease in the following order: 8.3 × 10 − 7 mm 3 ·mm − 1 ·N − 1 for pure Mg, 6.3 × 10 − 7 mm 3 ·mm − 1 ·N − 1 for AZ31B, and 5.4 × 10 − 7 mm 3 ·mm − 1 ·N − 1 for Mg 56.5 Cu 27 Ag 5 Dy 11.5 . The Mg 56.5 Cu 27 Ag 5 Dy 11.5 and pure Mg demonstrate inferior corrosion resistance in NaCl to that of AZ31B. Thus, the Mg 56.5 Cu 27 Ag 5 Dy 11.5 and pure Mg subject to tribocorrosion controlled by synergistic effects of abrasive and corrosive wear, which results in a large wear rate during sliding in NaCl. The possible mechanism of corrosion accelerating wear deterioration is discussed, which provides the guidance for the improvement in the tribocorrosion resistance of Mg-based BMGs for further load-bearing applications.