Novel refractory high-entropy ceramics: Transition metal carbonitrides with superior ablation resistance
•Novel ultra-high-temperature-ceramic (UHTC) as well as high-entropy material with superior ablation resistance was proposed.•Special micro-segregation is found in the HECN, where Ta, Hf, Zr, Ti elements aggregated inside of grains and Nb segregated at the grain boundary.•There is the compact multi-...
Saved in:
Published in | Corrosion science Vol. 184; p. 109359 |
---|---|
Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Amsterdam
Elsevier Ltd
15.05.2021
Elsevier BV |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | •Novel ultra-high-temperature-ceramic (UHTC) as well as high-entropy material with superior ablation resistance was proposed.•Special micro-segregation is found in the HECN, where Ta, Hf, Zr, Ti elements aggregated inside of grains and Nb segregated at the grain boundary.•There is the compact multi-oxide scale that involves Hf-Zr-rich grains skeleton and continuous molten-like phase with Ta-Ti-Nb segregation.
A novel high-entropy material as well as ultra-high temperature ceramic (Ta0.2Hf0.2Zr0.2Ti0.2Nb0.2)C0.8N0.2 was synthesized from ten kinds of transition metal carbides and nitrides, via high-energy ball-milling and spark plasma sintering. Besides, the ablation behavior of high-entropy ceramic was first studied by oxy-acetylene torch system at 2500 K. The results showed that optimized nitrogen substituted in sublattice could remarkably improve the ablation resistance by an impressive 57±1 % and 72 ±1 % in mass ablation rate and linear ablation rate compared to high-entropy carbides, since the highly dense multiple oxides scale with large Hf-Zr-rich grains skeleton surrounded by continuous secondary-phase in the boundaries that was able to retard the diffusion of oxygen. |
---|---|
ISSN: | 0010-938X 1879-0496 |
DOI: | 10.1016/j.corsci.2021.109359 |