Synthesis of High Entropy Carbide Nano Powders via Liquid Polymer Precursor Route

doi:10.15541/jim20200391

Abstract

Abstract:

High entropy carbide ceramics have been proposed in recent years for their promising properties as high hardness, high modulus and low thermal conductivity. Liquid polymer precursor method, of which multiple elements distribute homogeneously during the pyrolysis process, is considered to be favorable in fabricating high entropy ceramics. However, few reports have studied the synthesis of liquid precursor. In this work, liquid polymer precursor of (Ti, Zr, Hf, Ta)C were synthesized by co-hydrolysis and polycondensation of equiatomic metal containing monomers, and adding allyl-functional novolac resin (AN) as carbon source. The obtained polymer precursors of high entropy carbide ceramics (PHECs) were soluble in propyl alcohol and stable for months. The corresponding high entropy carbide ceramic nano powders were obtained by pyrolyzing PHEC at 1800 ℃ for 2 h in vacuum. The precursors and ceramic powders were characterized by different methods. Results reveal that the ceramic sample pyrolyzed at 800 ℃ are composed of t-ZrO₂ and oxide solid solutions, and carbothermal reduction reaction began after pyrolyzed at 1000 ℃, with carbide solid solutions being generated. After being pyrolyzed at 1800 ℃, the samples convert to target high entropy carbide ceramics. As-obtained ceramics are characterized to be high purity with uniform distribution of nanosized particles (~100 nm). The synthesized precursor has high ceramic yield (28.6wt%), low viscosity (150 mPa·s), and good solubility in polar solvents. Therefore, the proposed liquid polymer precursor method is reliable in preparation of high entropy ceramic nano powders, ceramic fibers and ceramic matrix composites.

Key words: high entropy ceramic, carbide, solid solution, nano powder, liquid precursor

CLC Number:

TB383

SUN Yanan, YE Li, ZHAO Wenying, CHEN Fenghua, QIU Wenfeng, HAN Weijian, LIU Wei, ZHAO Tong. Synthesis of High Entropy Carbide Nano Powders via Liquid Polymer Precursor Route[J]. Journal of Inorganic Materials, 2021, 36(4): 393-398.

Figures/Tables 9

Fig. 1 Photograph of PHEC

Table 1 Metal content, yield and viscosity of PHEC

Item	Metal content/wt%	Yield/ wt%	Viscosity/(mPa∙s)
Item	Metal content/wt%	Yield/ wt%	1	2
(Ti, Zr, Hf, Ta)C	28	28.6	150	162

Fig. 2 FT-IR spectrum of PHEC

Fig. 3 1H NMR spectra of PHEC

Fig. 4 TGA curves of cured PHEC

Fig. 5 Characterization of pyrolysis process for PHEC (A) XRD patterns of products pyrolyzed at different temperatures; (B) Enlarged images of XRD patterns of products pyrolyzed at 1400~ 1800 ℃; (C) Lattice parameter and crystallite size of samples pyrolyzed at 1400-1800 ℃

Fig. 6 Schematic diagram of pyrolysis process for PHEC and possible reactions

Fig. 7 SEM analyses of PHEC ceramic powders pyrolyzed at 1800 ℃ (A) SEM image; (B) EDS mapping of selected pattern marked with rectangle

Fig. 8 TEM analyses of PHEC ceramic powders pyrolyzed at 1800 ℃ (A) TEM image; (B) HR-TEM image; (C) EDS mapping of Ti, Zr, Hf and Ta

References 32

[1]	YEH JIEN-WEI, CHEN SWE-KAI, LIN SU-JIEN, et al. Nanostructured high-entropy alloys with multiple principal elements:novel alloydesign concepts andoutcomes. Advanced Engineering Materials, 2004,6:299-303.
[2]	CANTOR B, CHANG ITH, KNIGHT P, et al. Microstructural development in equiatomic multicomponent alloys. Materials Science and Engineering: A, 2004,377:213-218.
[3]	CHEN LEI, WANG KAI, SU WEN-TAO, et al. Research progress of transition metal non-oxide high-entropy ceramics. Journal of Inorganic Materials, 2020,35(7):748-758.
[4]	OSES C, TOHER C, CURTAROLO S. High-entropy ceramics. Nature Reviews Materials, 2020,5(4):295-309.
[5]	GILD J, ZHANG YUAN-YAO, HARRINGTON T, et al. High- entropy metal diborides: a new class of high-entropy materials and a new type of ultrahigh temperature ceramics. Scientific Reports, 2016,6(1):37946.
[6]	ZHANG RUI-ZHI, REECE M J. Review of high entropy ceramics: design, synthesis, structure and properties. Journal of Materials Chemistry A, 2019,7(39):22148-22162.
[7]	SARKER P, HARRINGTON T, TOHER C, et al. High-entropy high-hardness metal carbides discovered by entropy descriptors. Nature Communications, 2018,9(1):4980. URL PMID
[8]	顾俊峰, 邹冀, 张帆, 等. 高熵陶瓷材料研究进展. 中国材料进展, 2019,38(9):855-886.
[9]	YE BEI-LIN, WEN TONG-QI, CHU YAN-HUI. High-temperature oxidation behavior of (Hf_0.2Zr_0.2Ta_0.2Nb_0.2Ti_0.2)C high-entropy ceramics in air. Journal of the American Ceramic Society, 2019,103(1):500-507.
[10]	YAN XUE-LIANG, CONSTANTIN L, LU YONG-FENG, et al. (Hf_0.2Zr_0.2Ta_0.2Nb_0.2Ti_0.2)C high-entropy ceramics with low thermal conductivity. Journal of the American Ceramic Society, 2018,101(10):4486-4491.
[11]	ROST C M, BORMAN T, HOSSAIN M D, et al. Electron and phonon thermal conductivity in high entropy carbides with variable carbon content. Acta Materialia, 2020,196:231-239.
[12]	CHEN HENG, XIANG HUI-MIN, DAI FU-ZHI, et al. High porosity and low thermal conductivity high entropy (Zr_0.2Hf_0.2Ti_0.2Nb_0.2Ta_0.2)C. Journal of Materials Science & Technology, 2019,35(8):1700-1705.
[13]	CSANÁDI T, VOJTKO M, DANKHÁZI Z, et al. Small scale fracture and strength of high-entropy carbide grains during microcantilever bending experiments. Journal of the European Ceramic Society, 2020,40(14):4774-4782.
[14]	WEI XIAO-FENG, LIU JI-XUAN, LI FEI, et al. High entropy carbide ceramics from different starting materials. Journal of the European Ceramic Society, 2019,39(10):2989-2994.
[15]	PENG CHONG, GAO XIANG, WANG MING-ZHI, et al. Diffusion- controlled alloying of single-phase multi-principal transition metal carbides with high toughness and low thermal diffusivity. Applied Physics Letters, 2019,114(1):011905-1-5.
[16]	MOSKOVSKIKH D O, VOROTILO S, SEDEGOV A S, et al. High- entropy (HfTaTiNbZr)C and (HfTaTiNbMo)C carbides fabricated through reactive high-energy ball milling and spark plasma sintering. Ceramics International, 2020,46(11):19008-19014.
[17]	SURE J, SRI MAHA VISHNU D, KIM H K, et al. Facile electrochemical synthesis of nanoscale (TiNbTaZrHf)C high-entropy carbide powder. Angewandte Chemie International Edition, 2020,59(29):11830-11835. URL PMID
[18]	WANG KAI, CHEN LEI, XU CHEN-GUANG, et al. Microstructure and mechanical properties of (TiZrNbTaMo)C high-entropy ceramic. Journal of Materials Science & Technology, 2020,39:99-105.
[19]	CHICARDI E, GARCÍA-GARRIDO C, GOTOR F J. Low temperature synthesis of an equiatomic (TiZrHfVNb)C₅ high entropy carbide by a mechanically-induced carbon diffusion route. Ceramics International, 2019,45(17):21858-21863.
[20]	CHICARDI E, GARCÍA-GARRIDO C, HERNÁNDEZ-SAZ J, et al. Synthesis of all equiatomic five-transition metals high entropy carbides of the IVB (Ti, Zr, Hf) and VB (V, Nb, Ta) groups by a low temperature route. Ceramics International, 2020,46(13):21421-21430. DOI URL
[21]	GILD J, KAUFMANN K, VECCHIO K, et al. Reactive flash spark plasma sintering of high-entropy ultrahigh temperature ceramics. Scripta Materialia, 2019,170:106-110.
[22]	CASTLE E, CSANADI T, GRASSO S, et al. Processing and properties of high-entropy ultra-high temperature carbides. Scientific Reports, 2018,8(1):8609. URL PMID
[23]	FENG LUN, FAHRENHOLTZ W G, HILMAS G E, et al. Synthesis of single-phase high-entropy carbide powders. Scripta Materialia, 2019,162:90-93.
[24]	YE BEI-LIN, NING SHAN-SHAN, LIU DA, et al. One-step synthesis of coral-like high-entropy metal carbide powders. Journal of the American Ceramic Society, 2019,102(10):6372-6378.
[25]	ZHOU JIE-YANG, ZHANG JIN-YONG, ZHANG FAN, et al. High-entropy carbide: a novel class of multicomponent ceramics. Ceramics International, 2018,44(17):22014-22018.
[26]	LU YAN, SUN YA-NAN, ZHANG TU-ZI, et al. Polymer-derived Ta₄HfC₅ nanoscale ultrahigh-temperature ceramics: synthesis, microstructure and properties. Journal of the European Ceramic Society, 2019,39(2/3):205-211.
[27]	SUN YA-NAN, YANG CHUN-MING, LU YAN, et al. Transformation of metallic polymer precursor into nanosized HfTaC₂ ceramics. Ceramics International, 2020,46(5):6022-6028.
[28]	LI FEI, LU YING, WANG XIN-GANG, et al. Liquid precursor- derived high-entropy carbide nanopowders. Ceramics International, 2019,45(17):22437-22441.
[29]	LIU HONG-HUA, DU BIN, CHU YAN-HUI. Synthesis of the ternary metal carbide solid-solution ceramics by polymer-derived- ceramic route. Journal of the American Ceramic Society, 2020,103(5):2970-2974.
[30]	DU BIN, LIU HONG-HUA, CHU YAN-HUI. Fabrication and characterization of polymer-derived high-entropy carbide ceramic powders. Journal of the American Ceramic Society, 2020,103(8):4063-4068.
[31]	LU YAN, YE LI, HAN WEI-JIAN, et al. Synthesis, characterization and microstructure of tantalum carbide-based ceramics by liquid polymeric precursor method. Ceramics International, 2015,41(9):12475-12479.
[32]	LIU DAN, CAI TAO, QIU WEN-FENG, et al. Synthesis, characterization, and microstructure of ZrC/SiC composite ceramics via liquid precursor conversion method. Journal of the American Ceramic Society, 2014,97(4):1242-1247.