Fracture strength of the particulate-reinforced ultra-high temperature ceramics based on a temperature dependent fracture toughness model. (October 2017)

• Record Type: Journal Article
• Authors: Wang, Ruzhuan; Li, Weiguo; Ji, Baohua; Fang, Daining
• Is Part Of: Journal of the mechanics and physics of solids. Volume 107(2017:Oct.)
• Page Start: 365
• Page End: 378
• Publication Date: 2017-10
• Subjects: A. fracture -- A. fracture toughness -- A. microstructures -- B. ceramic material -- Temperature dependent model; Mechanics, Applied -- Periodicals; Solids -- Periodicals; Mechanics -- Periodicals; Mécanique appliquée -- Périodiques; Solides -- Périodiques; Mechanics, Applied; Solids; Periodicals; 531.05
• DOI: 10.1016/j.jmps.2017.07.012
• Languages: English
• ISSNs: 0022-5096

Abstract

Highlights: A new model for depicting temperature dependent fracture toughness is proposed. Temperature dependent fracture strength model for pUHTCs is developed. Effects of temperature, microstructures and residual stress are included in model. The model has no any fitting parameters. Excellent agreement is obtained between prediction and experimental measurements. Abstract: The particulate-reinforced ultra-high temperature ceramics (pUHTCs) have been particularly developed for fabricating the leading edge and nose cap of hypersonic vehicles. They have drawn intensive attention of scientific community for their superior fracture strength at high temperatures. However, there is no proper model for predicting the fracture strength of the ceramic composites and its dependency on temperature. In order to account for the effect of temperature on the fracture strength, we proposed a concept called energy storage capacity, by which we derived a new model for depicting the temperature dependent fracture toughness of the composites. This model gives a quantitative relationship between the fracture toughness and temperature. Based on this temperature dependent fracture toughness model and Griffith criterion, we developed a new fracture strength model for predicting the temperature dependent fracture strength of pUHTCs at different temperatures. The model takes into account the effects of temperature, flaw size and residual stress without any fitting parameters. The predictions of the fracture strength of pUHTCs in argon or air agreed well with the experimental measurements. Additionally, our model offers a mechanism of monitoring the strength of materials at different temperatures by testing the change of flaw size. This study provides a quantitative tool for design, evaluation and monitoring of the fracture properties of pUHTCs at high temperatures.