Improvement of Mechanical Properties of Lightweight Ceramics with the Addition of Alumina Fiber

Lightweight ceramics have a low density, which leads to a decrease in strength and toughness. In the development of lightweight ceramics, high-strengthening technology is necessary. Alumina fiber was mixed with raw materials for the purpose of producing high-strength lightweight ceramics. After adding alumina fiber at 1, 3, and 5 wt% and sintering at 1300 degrees C, we found that strength and toughness increased in proportion to the amount. Instead of the high melting temperature of alumina fiber, it is reacted with matrix and generated mullite phase. And lots of alumina fiber remains in the matrix, thereby allowing improvements in strength and toughness. When alumina fiber was not added, we found a low density of 1.35 similar to 1.80 g/m(3), along with low values for strength and toughness at 30 similar to 60 MPa and 0.7 similar to 1.2 MPam(1/2) respectively. With 1 wt% addition of alumina fiber, we obtained a higher strength of 92 MPa at 1300 degrees C, which is close to the strength of general white porcelains at 112 MPa.