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Fabrication of Nanograined Silicon Carbide by Ultrahigh‐Pressure Hot Isostatic Pressing
Author(s) -
Shinoda Yutaka,
Nagano Takayuki,
Wakai Fumihiro
Publication year - 1999
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1999.tb01833.x
Subject(s) - hot isostatic pressing , materials science , boron carbide , silicon carbide , boron , grain size , ceramic , doping , hot pressing , carbon fibers , metallurgy , fabrication , relative density , composite material , microstructure , composite number , optoelectronics , medicine , chemistry , alternative medicine , organic chemistry , pathology
Dense nanograined SiC ceramics were obtained by using hot isostatic pressing (HIP). The starting powder was ultrafine β‐SiC powder, which had a mean particle size of 30 nm and contained 3.5 wt% free carbon. SiC powders‐both boron‐doped and undoped‐were densified via HIP under an ultrahigh pressure of 980 MPa at a temperature of 1600°C. Both doped and undoped SiC attained the same density (3.12 g/cm 3 ) (relative density of 97.1%). The average grain sizes of boron‐doped and undoped SiC were 200 and 30 nm, respectively. The compressive flow stress of undoped SiC was 3 times higher than that of boron‐doped SiC at temperatures of 1800° and 1700°C; however, the flow stresses of both materials were almost the same at 1600°C. The HIPed SiC that was doped with boron could be deformed at a stress that was one‐third lower than that of hot‐pressed boron‐ and carbon‐doped SiC with a grain size of 0.8 µm.