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This content will become publicly available on December 30, 2016

Title: Additive-free hot-pressed silicon carbide ceramics-A material with exceptional mechanical properties

Densification of silicon carbide without any sintering aids by hot-pressing and rapid hot pressing was investigated. Full density (>99% t.d.) has been reached at 1850 °C, a temperature of at least 150-200 °C lower compared to the up to now known solid state sintered silicon carbide powders. Silicon carbide was freeze granulated and heat treated prior the densification. Furthermore, evolution of microstructure, mechanical properties and creep behavior were evaluated and compared to reference ceramics from as received silicon carbide powder as well as those of commercial one. Novel method results in dense ceramics with Vickers hardness and indentation fracture toughness of 29.0 GPa and 5.25 MPam1/2, respectively. Moreover, the creep rate of 3.8 x 10–9 s–1 at 1450 °C and the load of 100 MPa is comparable to the commercial α-SiC solid state sintered at 2150 °C.
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [3]
  1. Slovak Academy of Sciences, Bratislava (Slovakia)
  2. Slovak Academy of Sciences, Kosice (Slovakia)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
OSTI Identifier:
1266860
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Journal of the European Ceramic Society
Additional Journal Information:
Journal Volume: 36; Journal Issue: 6; Journal ID: ISSN 0955-2219
Publisher:
Elsevier
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE silicon carbide; hot pressing; microstructure; mechanical properties; creep resistance