TY - JOUR
T1 - Solubility, crystal growth, and film-formation mechanism of NbC-modified ZrC coating under oxyacetylene flame
AU - He, Ruixiang
AU - Li, Kezhi
AU - Liu, Longqi
N1 - Publisher Copyright:
© 2023 Elsevier B.V.
PY - 2023/7/15
Y1 - 2023/7/15
N2 - Herein, the ablation resistance of plasma-sprayed NbC-modified ZrC (ZrC-NbC) coatings was firstly tested using an oxyacetylene flame. Next, the phase composition of the ZrO2-Nb2O5 (NbO2.5) plates heat-treated at 2100 °C in an argon atmosphere was determined. The results indicated that, the ZrC-20 mol% NbC coating formed a dense oxide layer after ablation for 120 s and a composite film consisting of self-bridged ZrO2 columnar crystals up to 300 s, achieving the best ablation property. At 2100 °C, the solubility (solid solubility and adsorption capacity) of niobium suboxide in ZrO2 was 30 mol%. The stable phases were t-ZrO2 and Nb as the NbO2.5-addition was no more than 20 mol%, and t-ZrO2, Nb, and NbO when it ranged from 25 to 40 mol%. Furthermore, ZrO2 increased the viscosity of Nb-O liquids and ensured the transformation of NbO2.5 into Nb and NbO phases, improving the thermal stability. Nb-O liquids improved the transfer of Zr and formed gradients of temperature and oxygen concentration, strengthening the film-forming ability of the ZrC coating under an oxyacetylene flame.
AB - Herein, the ablation resistance of plasma-sprayed NbC-modified ZrC (ZrC-NbC) coatings was firstly tested using an oxyacetylene flame. Next, the phase composition of the ZrO2-Nb2O5 (NbO2.5) plates heat-treated at 2100 °C in an argon atmosphere was determined. The results indicated that, the ZrC-20 mol% NbC coating formed a dense oxide layer after ablation for 120 s and a composite film consisting of self-bridged ZrO2 columnar crystals up to 300 s, achieving the best ablation property. At 2100 °C, the solubility (solid solubility and adsorption capacity) of niobium suboxide in ZrO2 was 30 mol%. The stable phases were t-ZrO2 and Nb as the NbO2.5-addition was no more than 20 mol%, and t-ZrO2, Nb, and NbO when it ranged from 25 to 40 mol%. Furthermore, ZrO2 increased the viscosity of Nb-O liquids and ensured the transformation of NbO2.5 into Nb and NbO phases, improving the thermal stability. Nb-O liquids improved the transfer of Zr and formed gradients of temperature and oxygen concentration, strengthening the film-forming ability of the ZrC coating under an oxyacetylene flame.
KW - Ablation resistance
KW - Carbon/carbon composites
KW - Film-formation mechanism
KW - Thermal stability
KW - ZrC-NbC coating
UR - http://www.scopus.com/inward/record.url?scp=85152603201&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2023.157123
DO - 10.1016/j.apsusc.2023.157123
M3 - 文章
AN - SCOPUS:85152603201
SN - 0169-4332
VL - 625
JO - Applied Surface Science
JF - Applied Surface Science
M1 - 157123
ER -