Preparation and properties of dense ZrB2 composite reinforced by elongated SiC and Al3BC3 grains. Issue 6 (13th May 2019)

• Record Type: Journal Article
• Authors: Chen, Zhibo; Zhao, Xiaotong; Wang, Hailong; Shao, Gang; Liu, Wen; Zhang, Rui; Xu, Hongliang; Fan, Bingbing; Lu, Hongxia; Chu, Yanhui; Lee, Sea‐Hoon
• Is Part Of: International journal of applied ceramic technology. Volume 16:Issue 6(2019)
• Page Start: 2190
• Page End: 2196
• Publication Date: 2019-05-13
• Subjects: elongated SiC -- hot pressing -- mechanical properties -- oxidation resistance; Ceramics -- Periodicals; Ceramics -- Technological innovations -- Periodicals; 620.1405
• DOI: 10.1111/ijac.13265
• Languages: English
• ISSNs: 1546-542X

Abstract

Abstract: Dense ZrB2 ‐SiC‐Al3 BC3 ultra‐high temperature ceramic composite was fabricated by hot pressing sintering at 1900°C for 1 hour under a pressure of 20 MPa using Zirconium diboride (ZrB2 ) as the raw material and a powder mixture of SiC, B4 C, Al, and carbon as the sintering additive. Al and B4 C underwent in situ reaction with carbon powder to produce Al3 BC3, which promoted the densification of ZrB2 ceramic. SiC grains were found to be elongated during sintering. The ZrB2 ‐SiC‐Al3 BC3 composite exhibited excellent mechanical properties, such as high flexural strength of 589 ± 147 MPa and fracture toughness of 7.81 ± 1.09 MPa m 1/2 . Oxidation behavior of the ZrB2 ‐SiC‐Al3 BC3 composite was studied in air at 1500°C for 1 hour. A continuous layer of oxides consisting of a mixture of SiO2, Al2 SiO5, and Al2 O3 was formed on the surface of the ZrB2 ‐SiC‐Al3 BC3 composite. This layer of oxides efficiently prevented oxygen from diffusing into the specimens during oxidation, which improved the oxidation resistance of the ZrB2 ceramics.