ZOU Wenjing, YANG Ping, LV Donglin, CHU Luojing
(School of Electrolmechanical Engineering, Guangdong University of Technology, Guangzhou 51006, Guangdong, China)
Abstract: The low toughness of Si3N4 ceramics would lead to catastrophic fracture in use, which limits practical applications.High toughness Si3N4 ceramics must be prepared by using liquid phase sintering, where the quality of the powder, sintering aids and sintering process all have affect the sintering process and properties of the final products. The toughening mechanisms of Si3N4 ceramics mainly include particle dispersion toughening, whisker or fiber toughening, phase change toughening and self-toughening. This article is aimed to offer an overview on the effects of powder quality, sintering aids and sintering process on the fracture toughness of Si3N4 ceramics. The development trend of high fracture toughness Si3N4 ceramic parts was discussed.
Key words: Si3N4 ceramic; high toughness; toughening mechanism; metal toughening