Wear behaviour of alpha- and alpha/beta-SiAlON ceramics stabilized with Nd2O3 and Y2O3

Abstract

alpha- and alpha/beta-SiAlON compositions, doped with Y2O3 or Nd2O3, were densified by gas pressure sintering (GPS). The wear and mechanical properties of the materials were investigated and compared to beta-Si3N4 materials. Microstructure evolution and its change with composition as well as the influence of the microstructural changes on the mechanical and tribological properties were reported. Wear tests were performed using a tribometer with ball-on-plate geometry in reciprocating sliding contact under dry condition. It was observed that alpha/beta-SiAlON compositions, doped with Y2O3, have better wear properties in comparison to alpha-SiAlON and beta-Si3N4 samples. Field emission scanning electron microscopy (FESEM) was used to analyse the worn surfaces after wear tests. The results showed that alpha/beta-SiAlON and beta-Si3N4 materials have different wear behaviour