Preparation and properties of low friction silicon carbide ceramic seals by pore creation

Low friction silicon carbide (SiC) ceramic seals were prepared by combining liquid phase sintering (LPS) with pore creation, the effects of polyethylene oxide (PEO) as pore former on the sintering and mechanical properties, microstructure, and friction properties of LPS–SiC ceramic seals were investigated. The PEO firstly forms cross-linking aggregates with loose structure in SiC granules, which uniformly creates macropores on the surface and inside of LPS–SiC ceramic seals during the sintering. The addition of PEO decreases the sintering and mechanical properties of LPS–SiC ceramic seals obviously, while significantly reduces the dry friction coefficient of LPS–SiC ceramic seals. When the PEO content increases from 0 to 15 wt-%, the dry friction coefficient drops from 0·403 to 0·126. The pore creation of PEO improves the friction performances of SiC ceramic seals in sliding wear applications.