Microstructural characterization of Yb-α-sialon ceramics prepared by post sintering HIP treatments

The Yb-α-sialon containing β-silicon nitride grains, i. e. partially stabilized α-sialon was prepared by sintering at 1700° and subsequent HIP treatments at 1600–1900° under 10 or 200MPa N 2 . The size and shape of α-sialon and β-Si 3 N 4 grains were determined from polished surfaces statistically. The decrease of fracture toughness and strength was observed with the increase of grain size.