Fabrication of dense B4C-preceramic polymer derived SiC composite. Issue 4 (April 2019)

• Record Type: Journal Article
• Authors: Hwang, Chawon; Yang, Qirong; Xiang, Sisi; Domnich, Vladislav; Khan, Atta U.; Xie, Kelvin Y; Hemker, Kevin J.; Haber, Richard A.
• Is Part Of: Journal of the European Ceramic Society. Volume 39:Issue 4(2019)
• Page Start: 718
• Page End: 725
• Publication Date: 2019-04
• Subjects: B4C-SiC composite -- Preceramic polymer -- Sintering -- Pyrolysis -- Surface oxide -- Toughening mechanism; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2018.12.029
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: B4 C-SiC composites were fabricated via the preceramic polymer (PCP) route combined with pressure-assisted sintering. Fully dense bodies were achieved by controlling surface oxide on B4 C powder and pyrolysis conditions for PCP coated powder. We elucidate i) the microstructure and phase developments observed in the process of fabricating dense B4 C-PCP derived SiC composites and ii) the mechanical properties and crack deflection behavior of dense bodies. The incorporation of PCP derived SiC to B4 C decreases hardness due to the lower hardness value of SiC compared to B4 C and the residual carbon accompanied by SiC formation. Instead, the PCP derived SiC improved indentation fracture toughness. The main toughening mechanism supposed is a combination of crack impeding by SiC grains and crack deflection within SiC grains, likely due to the presence of subgrains or layered microstructure in the PCP derived SiC grains.