TY - JOUR
T1 - Hot pressing and oxidation behavior of ZrB2–SiC–TaC composites
AU - Ghassemi Kakroudi, Mahdi
AU - Dehghanzadeh Alvari, Masoumeh
AU - Shahedi Asl, Mehdi
AU - Pourmohammadie Vafa, Nasser
AU - Rabizadeh, Taher
N1 - Publisher Copyright:
© 2019 Elsevier Ltd and Techna Group S.r.l.
PY - 2020/2/15
Y1 - 2020/2/15
N2 - A ZrB2–20 vol% SiC–5 vol% TaC ceramic was sintered through the hot pressing process. By sintering for 60 min at 1850 °C under 40 MPa in a vacuum atmosphere, an almost fully dense specimen with a relative density of 97.5% was achieved. The phase and microstructural investigations revealed that alongside the ZrB2, SiC and TaC as the starting materials, two new phases of ZrC and TaSi2 were synthesized in-situ during the hot pressing. The oxidation behavior of as-sintered hybrid composites was investigated at three temperatures in an atmospheric furnace for 1-, 4- and 10-h cycles. Parabolic oxidation rate constants of 2.25, 30.69 and 1309.70 mg2/cm4.h were calculated for the samples oxidized at the temperatures of 1000, 1400 and 1700 °C, respectively. The activation energy of 178.7 kJ/mol was kinetically calculated for the oxidation of ZrB2–SiC–TaC ceramics. Four oxidized layers on the unaffected ZrB2–SiC–TaC matrix were also detected and microstructurally characterized.
AB - A ZrB2–20 vol% SiC–5 vol% TaC ceramic was sintered through the hot pressing process. By sintering for 60 min at 1850 °C under 40 MPa in a vacuum atmosphere, an almost fully dense specimen with a relative density of 97.5% was achieved. The phase and microstructural investigations revealed that alongside the ZrB2, SiC and TaC as the starting materials, two new phases of ZrC and TaSi2 were synthesized in-situ during the hot pressing. The oxidation behavior of as-sintered hybrid composites was investigated at three temperatures in an atmospheric furnace for 1-, 4- and 10-h cycles. Parabolic oxidation rate constants of 2.25, 30.69 and 1309.70 mg2/cm4.h were calculated for the samples oxidized at the temperatures of 1000, 1400 and 1700 °C, respectively. The activation energy of 178.7 kJ/mol was kinetically calculated for the oxidation of ZrB2–SiC–TaC ceramics. Four oxidized layers on the unaffected ZrB2–SiC–TaC matrix were also detected and microstructurally characterized.
KW - Microstructure
KW - Oxidation rate
KW - Sintering
KW - Tantalum carbide
KW - Ultrahigh temperature ceramics
UR - http://www.scopus.com/inward/record.url?scp=85073573958&partnerID=8YFLogxK
U2 - 10.1016/j.ceramint.2019.10.093
DO - 10.1016/j.ceramint.2019.10.093
M3 - Article
AN - SCOPUS:85073573958
SN - 0272-8842
VL - 46
SP - 3725
EP - 3730
JO - Ceramics International
JF - Ceramics International
IS - 3
ER -