Sliding wear characteristics of Mg/Si3N4 nanocomposites at room and elevated temperatures

Abstract

• Mg/Si 3 N 4 nanocomposites were prepared through ultrasonic-assisted stir casting. • A uniform dispersion of Si 3 N 4 nanoparticles was achieved for the composites. • Si 3 N 4 nanoparticles increased the microhardness at room and elevated temperatures. • The wear rate of the Mg/Si 3 N 4 nanocomposites was almost constant up to 200 °C. Magnesium's future use in automobile powertrain applications will necessitate superior wear resistance at elevated temperatures. To address this problem, the current work utilized Silicon Nitride (Si 3 N 4 ) nanoparticles to increase the wear resistance of magnesium at room and elevated temperatures (100 °C, 150 °C, and 200 °C). Using the ultrasonic-assisted stir casting process, 1.5 vol% of Si 3 N 4 nanoparticles were homogeneously reinforced in the pure magnesium matrix. Notably, the hardness of the nanocomposites increased at both room and higher temperatures. Furthermore, the inclusion of Si 3 N 4 nanoparticles resulted in a nearly constant wear rate up to 200 °C, indicating enhanced wear resistance of nanocomposites at high temperatures. The worn pin surfaces of pure magnesium revealed abrasion, severe adhesion, and delamination wear as the dominant mechanisms, whereas oxidation was prevalent in nanocomposites.