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Effect of Oxygen Segregation at Grain Boundaries on Deformation of B, C‐Doped Silicon Carbides at Elevated Temperatures
Author(s) -
Ohtsuka Shigehiro,
Shinoda Yutaka,
Akatsu Takashi,
Wakai Fumihiro
Publication year - 2005
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.1551-2916.2005.00326.x
Subject(s) - materials science , grain boundary , oxygen , boron , metallurgy , silicon carbide , grain size , carbide , doping , impurity , deformation (meteorology) , silicon , composite material , microstructure , chemistry , optoelectronics , organic chemistry
The effect of oxygen segregation at grain boundaries on the deformation of 1 wt% boron (B)‐ and carbon (C)‐doped β‐silicon carbide (B, C‐doped SiC) was investigated by compression testing at 2073 K. We studied the deformation of sinter‐forged B, C‐doped SiC (sinter‐forged SiC), which contained the minimum amount (0.07 wt%) of oxygen as an impurity, and that of hot isostatically pressed B, C‐doped SiC (HIPed SiC), which contained 1 wt% oxygen. Oxygen was detected at grain boundary in HIPed SiC by energy‐dispersive X‐ray spectroscopy, but it was not detected in sinter‐forged SiC. The strain rate of sinter‐forged SiC was one order of magnitude lower than that of HIPed SiC at the same grain size. The grain growth rate of sinter‐forged SiC was lower than that of HIPed SiC also. These results suggest that the oxygen segregation at grain boundaries, together with boron segregation, promoted the grain‐boundary diffusion in B, C‐doped SiC. But, the oxygen segregation without boron was less effective in promoting deformation than the boron segregation without oxygen.