TY - JOUR
T1 - High-temperature strength of boron carbide with Pt grain-boundary framework in situ synthesized during spark plasma sintering
AU - Vasylkiv, O.
AU - Demirskyi, D.
AU - Borodianska, H.
AU - Kuncser, A.
AU - Badica, P.
N1 - Funding Information:
PB acknowledges MEC-UEFISCDI project POC 37_697 no. 28/01.09.2016 REBMAT, Romania. DD was supported by World Premier International Research Center Initiative (WPI), MEXT, Japan .
Funding Information:
PB acknowledges MEC-UEFISCDI project POC 37_697 no. 28/01.09.2016 REBMAT, Romania. DD was supported by World Premier International Research Center Initiative (WPI), MEXT, Japan.
Publisher Copyright:
© 2020 Elsevier Ltd and Techna Group S.r.l.
PY - 2020/5
Y1 - 2020/5
N2 - Grain boundaries, twins, and defects are considered to influence the thermomechanical behavior of any covalent ceramic, as a result, monolithic B4C samples show different curve shapes of bending strength vs temperature and the present theoretical models fail to fit them over the entire temperature range. To overcome these issues, we fabricated a novel high-density boron carbide and evaluated its high-temperature bending strength. The as-obtained ceramic is composed of boron carbide grains and a fine grain-boundary metal Pt framework. The material shows a decreased strength, which is due to a non-linear increase in the volume expansion coefficient of the B4C. Recovery in strength above 1000 °C is due to the presence of twins, their growth and rearrangements. We consider twins rearrangements are the pieces of evidence for a novel ‘micro’ mechanism of high-temperature stress accommodation for the boron carbide bulks.
AB - Grain boundaries, twins, and defects are considered to influence the thermomechanical behavior of any covalent ceramic, as a result, monolithic B4C samples show different curve shapes of bending strength vs temperature and the present theoretical models fail to fit them over the entire temperature range. To overcome these issues, we fabricated a novel high-density boron carbide and evaluated its high-temperature bending strength. The as-obtained ceramic is composed of boron carbide grains and a fine grain-boundary metal Pt framework. The material shows a decreased strength, which is due to a non-linear increase in the volume expansion coefficient of the B4C. Recovery in strength above 1000 °C is due to the presence of twins, their growth and rearrangements. We consider twins rearrangements are the pieces of evidence for a novel ‘micro’ mechanism of high-temperature stress accommodation for the boron carbide bulks.
KW - Asymmetric twins
KW - Bending strength
KW - Boron carbide
KW - Modified grain boundaries
KW - Pt framework
KW - Spark plasma sintering
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U2 - 10.1016/j.ceramint.2019.12.163
DO - 10.1016/j.ceramint.2019.12.163
M3 - Article
AN - SCOPUS:85076837698
SN - 0272-8842
VL - 46
SP - 9136
EP - 9144
JO - Ceramics International
JF - Ceramics International
IS - 7
ER -