TY - JOUR
T1 - Strengthening of TiC ceramics sintered by spark plasma via nano-graphite addition
AU - Fattahi, Mehdi
AU - Babapoor, Aziz
AU - Delbari, Seyed Ali
AU - Ahmadi, Zohre
AU - Sabahi Namini, Abbas
AU - Shahedi Asl, Mehdi
N1 - Publisher Copyright:
© 2020 Elsevier Ltd and Techna Group S.r.l.
PY - 2020/6/1
Y1 - 2020/6/1
N2 - In this research, 5 wt% nano-graphite was added to titanium carbide and its impacts on the microstructure and mechanical qualifications were evaluated. Monolithic and graphite-doped TiC samples were manufactured at 1900 °C under 40 MPa for 10 min by spark plasma sintering method. Graphite nano-flakes enhanced the densification behavior, flexural strength, and friction coefficient of TiC ceramics. The XRD, microstructural, and thermodynamical assessments revealed the occurrence of a chemical reaction between the carbonaceous phase and TiC oxide layers, namely TiO2, and the formation of non-stochiometric TiCx and in-situ TiC. Although introducing nano-graphite as an additive decreased the Vickers hardness of TiC by ~34% (2071 HV0.1 Kg for the doped specimen), it had a positive influence on the flexural strength (504 and 633 MPa for monolithic and graphite doped samples; respectively). Finally, an average friction coefficient of 0.35 was obtained for TiC-5 wt% graphite ceramic, ~13% higher than that of the monolithic TiC sample.
AB - In this research, 5 wt% nano-graphite was added to titanium carbide and its impacts on the microstructure and mechanical qualifications were evaluated. Monolithic and graphite-doped TiC samples were manufactured at 1900 °C under 40 MPa for 10 min by spark plasma sintering method. Graphite nano-flakes enhanced the densification behavior, flexural strength, and friction coefficient of TiC ceramics. The XRD, microstructural, and thermodynamical assessments revealed the occurrence of a chemical reaction between the carbonaceous phase and TiC oxide layers, namely TiO2, and the formation of non-stochiometric TiCx and in-situ TiC. Although introducing nano-graphite as an additive decreased the Vickers hardness of TiC by ~34% (2071 HV0.1 Kg for the doped specimen), it had a positive influence on the flexural strength (504 and 633 MPa for monolithic and graphite doped samples; respectively). Finally, an average friction coefficient of 0.35 was obtained for TiC-5 wt% graphite ceramic, ~13% higher than that of the monolithic TiC sample.
KW - Graphite nano-flakes
KW - Mechanical properties
KW - Microstructure
KW - Spark plasma sintering
KW - Titanium carbide
UR - http://www.scopus.com/inward/record.url?scp=85078917191&partnerID=8YFLogxK
U2 - 10.1016/j.ceramint.2020.01.291
DO - 10.1016/j.ceramint.2020.01.291
M3 - Article
AN - SCOPUS:85078917191
SN - 0272-8842
VL - 46
SP - 12400
EP - 12408
JO - Ceramics International
JF - Ceramics International
IS - 8
ER -