Effect of Sintering Temperature on Density and Mechanical Properties of Solid-State Sintered Silicon Carbide Ceramics and Evaluation of Failure Origin

Journal Article · Fri Jun 15 04:00:00 EDT 2018 · Journal of Materials Engineering and Performance

DOI:https://doi.org/10.1007/S11665-018-3397-4· OSTI ID:22860308

Barick, Prasenjit; Saha, Bhaskar Prasad ^[1]

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1. International Advanced Research Centre for Powder Metallurgy & New Materials (ARCI), Centre for Non-Oxide Ceramics (India)

Densified silicon carbide (SiC) is prepared through dry pressing of SiC powder followed by pressureless sintering in the presence of boron carbide and carbon as the additives. Sintering of SiC parts shows the increase in density with the increase in temperature (1950-2180 °C) by resulting in higher than 98% relative density (RD) at 2150 °C and above for 1 h. Sintered specimens are evaluated concerning the phase, microstructure and mechanical properties including hardness and flexural strength. The machined surface of SiC parts with about 98% RD is studied for the origin of failure. The estimated size of critical flaws (32-110 µm) based on flexural strength and fracture toughness indicates that machining defects are one of the primary reasons for failure in SiC ceramics. The order of magnitude of defects on machined surfaces of sintered SiC by SEM studies is found to be comparable with the estimated size of critical flaws. The failure behavior of SiC is discussed with the help of Weibull statistics with respect to the variation of four-point flexural strength.

• OSTI ID: 22860308
• Journal Information: Journal of Materials Engineering and Performance, Journal Name: Journal of Materials Engineering and Performance Journal Issue: 6 Vol. 27; ISSN 1059-9495; ISSN JMEPEG
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ADDITIVES
BORON CARBIDES
CARBON
CERAMICS
COMPARATIVE EVALUATIONS
CRACKS
DEFECTS
DENSITY
FLEXURAL STRENGTH
FRACTURE PROPERTIES
HARDNESS
MICROSTRUCTURE
SCANNING ELECTRON MICROSCOPY
SILICON CARBIDES
SINTERING
TEMPERATURE DEPENDENCE