The thermal shock resistance of the ZrB2.pdf

Materials and Design 32 (2011) 3499–3503Contents lists available at ScienceDirect Materials and Design journal homepage: www.elsevier .com/locate /matdesShort Communication The thermal shock resistance of the ZrB2–SiC–ZrC ceramic Wang Zhi a,?, Qu Qiang b, Wu Zhanjun a, Shi Guodong a a School of Aeronautics and Astronautics, Faculty of Vehicle Engineering and Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024, PR China bChina Academy of Launch Vehicle Technology RD Center, Beijing 100076, PR China a r t i c l e i n f oArticle history: Received 18 December 2010 Accepted 24 February 2011 Available online 1 March3069/$ - see front matter  2011 Elsevier Ltd. A doi:10.1016/j.matdes.2011.02.056 ? Corresponding author. Tel./fax: +86 411 8470679 E-mail address: wzdlut@ (W. Zhi).a b s t r a c t In the present work, the thermal shock resistance of the ZrB2–SiC–ZrC ceramic was estimated by the water quenching method and the flexural strength of the quenched specimen was measured. The mea- sured critical temperature difference of the ZrB2–SiC–ZrC ceramic was significantly greater than that of the ZrB2–15 vol.% SiC ceramic. The improvement in thermal shock resistance was attributed to its higher fracture toughness (6.7 MPa m1/2) and lower flexural strength (526 MPa) relative to the ZrB2–15 vol.% SiC ceramic (4.1 MPa m1/2 and 795 MPa) based on Griffith fracture criterion. Furthermore, the temperature and thermal stress distributions in the specimen during instantaneous water quenching were simulated by Finite element analysis.  2011 Elsevier Ltd. All rights reserved.1. Introduction After the recent tragedy of Space Shuttle Columbia, the findings of the Columbia Accident Investigation Board and the recent Space Exploration Initiative suggest that safety be put at the top of the priorities in the design of re-entry vehicles [1]. It is a necessary pre- requisite: a safe re-entry, at least from Lo