Influence of Aluminum–Oxygen–Yttrium Solid Solution on the Aqueous Tribological Behavior of Silicon Nitride

To investigate the influence of crystal structure and solid solutions of certain elements in Si 3 N 4 on aqueous tribological properties, seven specimens were fabricated. Solid solutions of aluminum and oxygen made the friction coefficient and wear increase in both α-type and β-type crystal structures. In particular, α-SiAlON, in which yttrium is also incorporated into the α-Si 3 N 4 lattice, showed a higher friction coefficient and wear than other specimens containing the same concentration of Al or O.