Wear properties of alpha- and alpha/beta-SiAlON ceramics obtained by gas pressure sintering and spark plasma sintering

Abstract

In this study, alpha- and alpha/beta-SiAlON materials, doped with Y(2)O(3) and Nd(2)O(3), were sintered using two different sintering processes: spark plasma sintering (SPS) and gas pressure sintering (GPS). The wear and mechanical properties of the samples were compared related to the composition, additives and sintering processes. The results show that the hardness was not affected by the processing type whereas the toughness values were lower for spark plasma sintered materials than gas pressure sintered materials. This can be explained by the changed microstructure of the two different types of material. Additionally, alpha/beta-SiAlON materials, sintered using gas pressure sintering, showed a lower wear than the spark plasma sintered materials. The results of the wear test were compared with beta-Si(3)N(4) materials and it was observed that alpha/beta-SiAlON, sintered by GPS, has better wear properties than the tested beta-Si(3)N(4) materials