High temperature creep properties of alumina composites

Abstract

Experiments were conducted to determine the creep properties at high temperatures of three different alumina composites containing 9.3, 18 or 30 vol% of SiC whiskers, respectively. Specimens were tested in air in four-point bending with the displacement recorded continuously. The experimental results show the normal three stages of creep, with primary, secondary and tertiary regions. Specimens were pulled to fracture and then examined using scanning electron microscopy. These observations show that the fracture behavior depends upon the volume percentage of SiC whiskers. In the material with 30 vol% SiC whiskers, the fracture surface shows much evidence for whisker pull out; whereas in the m..