Microstructure and mechanical properties of hot-pressed SiC nanofiber reinforced SiC composites. Issue 11 (1st June 2022)

• Record Type: Journal Article
• Authors: Yang, Jiahao; Ma, Ruiqi; Zhu, Mingming; Xiong, Yilian; Shi, Jiahui; Li, Xiaohong; Li, Haolin; Chen, Jianjun
• Is Part Of: Ceramics international. Volume 48:Issue 11(2022)
• Page Start: 15364
• Page End: 15370
• Publication Date: 2022-06-01
• Subjects: SiC ceramics -- SiC nanofibers -- SiCnf/SiC CMC -- Hot pressing -- Microstructure -- Fracture toughness; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.02.070
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: This study reports on the preparation and mechanical properties of a novel SiCnf /SiC composite. The single crystal SiC nanofiber(SiCnf ) reinforced SiC ceramic matrix composites (CMC) were successfully fabricated by hot pressing the mixture of β -SiC powders, SiCnf and Al–B–C powder. The effects of SiCnf mass fraction as well as the hot-pressing temperature on the microstructure and mechanical properties of SiCnf /SiC CMC were systematically investigated. The results demonstrated that the 15 wt% SiCnf /SiC CMC obtained by hot pressing (HP) at 1850 °C with 30 MPa for 60 min possessed the maximum flexural strength and fracture toughness of 678.2 MPa and 8.33 MPa m 1/2, respectively. The nanofibers pull out, nanofibers bridging and cracks deflection were found by scanning electron microscopy, which are believed can strengthen and toughen the SiCnf /SiC CMC via consuming plenty of the fracture energy. Besides, although the relative density of the prepared SiCnf /SiC CMC further increased with the sintering temperature rose to 1900 °C, the further coarsend composites grains results in the deterioration of the mechanical properties for the obtained composites compared to 1850 °C.