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High‐Temperature Deformation Mechanisms in Monolithic 3 YTZP and 3 YTZP Containing Single‐Walled Carbon Nanotubes
Author(s) -
CastilloRodríguez Miguel,
Muñoz Antonio,
DomínguezRodríguez Arturo
Publication year - 2016
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/jace.13974
Subject(s) - materials science , spark plasma sintering , grain boundary , raman spectroscopy , composite material , carbon nanotube , grain boundary sliding , yttrium , ceramic , deformation (meteorology) , creep , deformation mechanism , activation energy , ceramic matrix composite , scanning electron microscope , nanocomposite , transmission electron microscopy , sintering , microstructure , nanotechnology , metallurgy , oxide , chemistry , physics , optics , organic chemistry
Monolithic 3 YTZP and 3 YTZP containing 2.5 vol% of single‐walled carbon nanotubes ( SWCNT ) were fabricated by Spark Plasma Sintering ( SPS ) at 1250°C. Microstructural characterization of the as‐fabricated 3 YTZP / SWCNT s composite shows a homogeneous CNT s dispersion throughout the ceramic matrix. The specimens have been crept at temperatures between 1100°C and 1200°C in order to investigate the influence of the SWCNT s addition on high‐temperature deformation mechanisms in zirconia. Slightly higher stress exponent values are found for 3 YTZP / SWCNT s nanocomposites ( n ~2.5) compared to monolithic 3 YTZP ( n ~2.0). However, the activation energy in 3 YTZP ( Q = 715 ± 60 kJ/mol) experiences a reduction of about 25% by the addition of 2.5 vol% of SWCNT s ( Q = 540 ± 40 kJ/mol). Scanning electron microscopy studies indicate that there is no microstructural evolution in crept specimens, and Raman spectroscopy measurements show that SWCNT s preserved their integrity during the creep tests. All these results seem to indicate that the high‐temperature deformation mechanism is grain‐boundary sliding ( GBS ) accommodated by grain‐boundary diffusion, which is influenced by yttrium segregation and the presence of SWCNT s at the grain boundary.