Effect of gage of length on tensile strength and failure strain of woven fabric Al_2O_3 fiber-ZrO_2 minicomposite-reinforced Al_2O_3 matrix composite

摘要

Oxide fiber-reinforced oxide ceramic-matrix composites are of growing interest for use in engineering application in high temperature oxidation environments because they have attractive properties, which are difficult to achieve the monolithic ceramics and non-oxide fiber-reinforced composites [1-8]. Among commercially available oxide fiber-reinforced oxide matrix composites, a new type of Al_2O_3 fiber reinforced Al_2O_3 matrix composite has been developed recently and is termed as "Soft-Cera" [9]. The "Soft-Cera" composite consisted of woven fabric Almax Al_2O_3 fiber bundle-ZrO_2 matrix minicomposite and porous Al_2O_3 matrix, i.e., the Al_2O_3 matrix is reinforced with the minicomposite. The advantage of this material combination is to prevent strong bonding between Al_2O_3 fiber and Al_2O_3 matrix by intro-ducing ZrO_2 matrix in the minicomposite. Therefore, the composite is expected to have stable interface at elevated temperatures. The preliminary studies have shown some mechanical properties [7, 8], however, detailed mechanical properties of the composite the still unclear. For practical applications, it is required to understand the size effect of mechanical properties of the composite. However, the size effect of tensile mechanical properties of the composite is not yet examined. The attention of the present study has been focused on the examination of the effect of gage length on the tensile strength and strain at failure of the composite because size dependence of strength is important for the application point of view.