Effect of SiC Particle Size on the Microstructural, Mechanical and Oxidation Properties of In-situ Synthesized HfB2-SiC Composites

Authors : Kübra GÜRCAN, Bora DERİN, Erhan AYAS

Pages : 503-510

Doi:10.2339/politeknik.682256

View : 57 | Download : 13

Publication Date : 2021-06-01

Article Type : Research Paper

Abstract :In-situ synthesis and densification of hafnium diboride - silicon carbide insert ignore into journalissuearticles values(HfB2-SiC); ceramic composites were studied by the spark plasma sintering insert ignore into journalissuearticles values(SPS); method using HfO2, B, and SiC as starting powders. Influence of SiC particle size insert ignore into journalissuearticles values(∼2 µm and ∼10 µm); on mechanical properties and oxidation resistance of in-situ composites were extensively investigated. According to the achieved results, the highest densification insert ignore into journalissuearticles values(∼95 % TD); was obtained with fine SiC particle reinforcement. The measured Vickers hardness and fracture toughness of the composites containing fine SiC were 14.3 GPa and 5.42 MPa.m1/2, respectively. The fracture mode changed from transgranular cleavage to a mixed-mode, and the crack deflection was believed to be the primary toughening mechanism. From oxidation test result, the composite with fine SiC particles exhibited more inhomogeneous oxide scales compared to that of coarse SiC containing composite. 
Keywords : Ultra high temperature ceramics, HfB2 SiC, in situ synthesis, SPS

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