In-situ Particulate-Reinforced Al Matrix Composites: Effect of the Synergistic Mechanism of ZrB2 and Al3Zr on Tribological Behavior
Feng Wang, Hui Li, Xiaolong Zhang, Lei Jiao, Wei He, Xudong Han, Shcheretskyi Volodymyr
Abstract
Abstract To investigate the key factors that cause ZrB 2 /AA6111 and (ZrB 2 +Al 3 Zr)/AA6111 aluminum matrix composites (AMCs) made via in situ reaction to behave differently in terms of friction and wear. Room-temperature dry sliding tribological behavior of AA6111 Al alloys, ZrB 2 /AA6111, and (ZrB 2 +Al 3 Zr)/AA6111 AMCs against silicon nitride (Si 3 N 4 ) counterparts were investigated. The study showed that AA6111/Al alloy had the highest wear rate and the most unstable coefficient of friction (COF), indicating the worst abrasion resistance. (ZrB 2 +Al 3 Zr)/AA6111 AMCs exhibit a lower wear rate and higher COF than ZrB 2 /AA6111 AMCs. The result proved that the Al 3 Zr particles prepared by the in-situ reaction are strongly bonded (lattice misfit δ =2.7%) to the Al matrix and are not easily stripped from the substrate. ZrB 2 /AA6111 AMCs exhibited a lower COF attributed to the tribochemical reaction inducing the formation of more boric acid (H 3 BO 3 ) films with a graphite-like structure having a lubricating effect.