Mechanical properties and ablation behavior of ZrB2–SiC ceramics fabricated by spark plasma sintering. (January 2015)

• Record Type: Journal Article
• Authors: Zhang, Xiang; Liu, Rutie; Xiong, Xiang; Chen, Zhaoke
• Is Part Of: International journal of refractory metals & hard materials. Volume 48(2015:Jan.)
• Page Start: 120
• Page End: 125
• Publication Date: 2015-01
• Subjects: Zirconium diboride -- Mechanical properties -- Ablation resistance; Heat resistant alloys -- Periodicals; Refractory materials -- Periodicals; Metallography -- Periodicals; Alliages réfractaires -- Périodiques; Matériaux réfractaires -- Périodiques; Métallographie -- Périodiques; Heat resistant alloys; Metallography; Refractory materials; Periodicals; Electronic journals; 669.73
• DOI: 10.1016/j.ijrmhm.2014.08.006
• Languages: English
• ISSNs: 0263-4368

Abstract

Abstract: ZrB2 –SiC ceramics were prepared by spark plasma sintering at 1375 °C for 5 min under a uniaxial load of 25 MPa. Mechanical properties and ablation behavior of ZrB2 –SiC ceramics were investigated. The results showed that the flexural strength of ZrB2 –30 vol.% SiC ceramic was significantly higher than that of ZrB2 –15 vol.% SiC ceramic due to the larger amount of SiC whereas the ablation resistance was reduced. The increase in flexural strength was attributed to the sintering of SiC particles which located in the boundary of ZrB2 and enhanced the binding force between ZrB2 particles. The decrease in the ablation resistance at 3000 °C was due to the increase in weight loss and voids which were mainly caused by the rapid evaporation of SiO2 . Ablation mechanism revealed that excessive SiC could supply much flaws and was hard to form continuous layer to seal the defects, which led to the dissatisfactory resistance to ablation for the ZrB2 –30 vol.% SiC. The different ablation behaviors of central and outer ablation regions were also discussed. Highlights: We investigate the ablation resistance (at about 3000 °C ) of ZrB2 –SiC ceramics which were fabricated at 1375 °C. The results show that the excessive SiC is hard to form a continuous ZrSiO4 layer under this ablation condition. The ZrB2 –15 vol.% SiC ceramic possesses outstanding ablation resistance at about 3000 °C.