SiO2 shell thickness affects the tribological properties of Si3N4@SiO2/PEEK core–shell composite prepared by cold sintering

Abstract

• Si 3 N 4 @SiO 2 with SiO 2 shell thicknesses (12.5 nm, 25 nm, and 50 nm) were obtained. • Si 3 N 4 @SiO 2 /PEEK was successfully prepared at temperature 240 °C by cold sintering. • The friction coefficient and wear rate significant decrease with SiO 2 shell thickness. Silica (SiO 2 ) coated Silicon Nitride (Si 3 N 4 ) core–shell composite (Si 3 N 4 @SiO 2 ) was prepared by Stöber method. Three SiO 2 shell thicknesses (12.5 nm, 25 nm, and 50 nm) were obtained by adjusting the aqueous ammonia concentration. Polyetheretherketone (PEEK) filled Si 3 N 4 @SiO 2 core–shell composite (Si 3 N 4 @SiO 2 /PEEK) was successfully prepared at low temperature 240 °C by cold sintering. The influence of SiO 2 shell thickness on the dry tribological properties of Si 3 N 4 @SiO 2 /PEEK composite was studied. With SiO 2 shell thickness increasing, the density of Si 3 N 4 @SiO 2 /PEEK composite increases, and the hardness firstly increases, then changes little. The friction coefficient and wear rate of Si 3 N 4 @SiO 2 /PEEK composite with SiO 2 shell thickness of 50 nm decrease by 15% and 80%, respectively, comparing to that with SiO 2 shell thickness of 12.5 nm.