Textured and toughened high-entropy (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)C-SiCw ceramics

doi:10.1016/j.jmst.2021.02.073

Abstract

Abstract:

High-entropy (Ti_0.2Zr_0.2Hf_0.2Nb_0.2Ta_0.2)C ceramics, with different contents (0, 5, 10, and 20 vol.%) of SiC whiskers (SiC_w), were fabricated by spark plasma sintering using raw powders synthesized via carbothermal reduction. The application of a uniaxial compaction force led to texture development of the SiC_w within the (Ti_0.2Zr_0.2Hf_0.2Nb_0.2Ta_0.2)C matrix. Fracture toughness increased with the increase in SiC_w content, while Vickers hardness remains almost unchanged. The toughness of (Ti_0.2Zr_0.2Hf_0.2Nb_0.2Ta_0.2)C-20 vol.% SiC_w ceramics reached 4.3 ± 0.3 MPa∙m^1/2, which was approximately 43% higher than that of the monolithic (Ti_0.2Zr_0.2Hf_0.2Nb_0.2Ta_0.2)C ceramic (3.0 ± 0.2 MPa∙m^1/2). The main toughening mechanisms were attributed to crack deflection, whisker debonding, and whisker pullout.

Key words: High-entropy carbide ceramics, Silican carbide whiskers, Microstructure, Mechanical properties, Toughening mechanism

Si-Chun Luo, Wei-Ming Guo, Yu-Zhang Zhou, Kevin Plucknett, Hua-Tay Lin. Textured and toughened high-entropy (Ti_0.2Zr_0.2Hf_0.2Nb_0.2Ta_0.2)C-SiC_w ceramics[J]. J. Mater. Sci. Technol., 2021, 94: 99-103.

Figures/Tables 5

Fig. 1. XRD patterns collected on the top surface (TS) of the high-entropy ceramics after SPS consolidation at 2000 °C: (a) HEC, (b) HEC-5S, (c) HEC-10S, and (d) HEC-20S compositions. (e) The corresponding X-ray diffraction pattern from the side surface (SS) of the HEC-20S composition. The insets show the relative compaction direction during SPS and the associated the powder diffraction standard (PDF #73-1708) for β-SiC.

Fig. 2. SEM images of the polished and thermally etched side surfaces ((a) HEC, (c) HEC-5S, (e) HEC-10S, and (g) HEC-20S), and fracture side surfaces ((b) HEC, (d) HEC-5S, (f) HEC-10S, and (h) HEC-20S) for the monolithic and composite ceramics. (i) SEM image of the polished top surface of HEC-20S. (j) SEM image of the raw SiC whiskers. The insets show the relative pressing direction during SPS.

Fig. 3. (a) SEM image of the polished top surface, and corresponding elemental compositional EDS maps, for the as-fabricated HEC-20S sample. (b) EDS spectrum analysis from (a).

Table 1 Vickers hardness and fracture toughness of the sintered high entropy carbide ceramics in this work, with comparison to prior published literature values.

Composition	Vickers hardness (GPa)		Fracture toughness (MPa∙m^1/2)
Composition	Top surface	Side surface	Top surface	Side surface
HEC	24.4 ± 0.7	-	3.0 ± 0.2	-
HEC-5S	24.8 ± 0.6	24.7 ± 0.6	3.4 ± 0.1	3.3 ± 0.2
HEC-10S	24.6 ± 0.5	24.6 ± 0.9	3.7 ± 0.3	3.5 ± 0.2
HEC-20S	24.5 ± 0.9	24.9 ± 0.5	4.3 ± 0.3	4.0 ± 0.3
(Hf,Zr,Ti,Ta,Nb)C [4]	25.0 ± 1.0^a		3.5 ± 0.3^c
(Ta,Zr,Nb)C [7]	-		~2.9^c
(Hf,Zr,Ta,Nb,Ti)C [10]	~21.6		3.0 ± 0.2
(Ti,Zr,Nb,Ta,Mo)C [9]	25.3 ± 0.3^b		3.3 ± 0.1^c

Fig. 4. Representative SEM images of the crack propagation path on the top surfaces of the sintered specimens: (a) HEC, and (b) HEC-20S. Arrows show examples of crack deflection and whisker pullout.

References 24

[1]	D. Liu, H.H. Liu, S.S. Ning, Y.H. Chu, J. Adv. Ceram. 9 (2020) 339-348. DOI URL
[2]	P. Sarker, T. Harrington, C. Toher, C. Oses, M. Samiee, J.P. Maria, D.W. Brenner, K.S. Vecchio, S. Curtarolo, Nat. Commun. 9 (2018) 4980. DOI URL
[3]	R.Z. Zhang, M.J. Reece, J. Mater. Chem. A 7 (2019) 22148-22162.
[4]	L. Feng, W.T. Chen, W.G. Fahrenholtz, G.E. Hilmas, J. Am. Ceram. Soc. 104 (2021) 419-427. DOI URL
[5]	Y.C. Wang, M.J. Reece, Scr. Mater. 193 (2021) 86-90. DOI URL
[6]	B.L. Ye, T.Q. Wen, D. Liu, Y.H. Chu, Corros. Sci. 153 (2019) 327-332. DOI URL
[7]	D. Demirskyi, H. Borodianska, T.S. Suzuki, Y. Sakka, K. Yoshimi, O. Vasylkiv, Scr. Mater. 164 (2019) 12-16. DOI URL
[8]	D. Demirskyi, T.S. Suzuki, K. Yoshimi, O. Vasylkiv, Open Ceram 2 (2020) 10 0 015.
[9]	K. Wang, L. Chen, C.G. Xu, W. Zhang, Z.G. Liu, Y.J. Wang, J.H. Ouyang, X.H. Zhang, Y.D. Fu, Y. Zhou, J. Mater. Sci. Technol. 39 (2020) 99-105. DOI
[10]	T.Q. Wen, B.L. Ye, M.C. Nguyen, M.D. Ma, Y.H. Chu, J. Am. Ceram. Soc. 103 (2020) 6475-6489. DOI URL
[11]	J.X. Deng, J. Mater. Process. Technol. 98 (20 0 0) 292-298. DOI URL
[12]	X.H. Zhang, L. Xu, S.Y. Du, J.C. Han, P. Hu, W.B. Han, Mater. Lett. 62 (2008) 1059-1060.
[13]	T. Zhu, L. Xu, X.H. Zhang, W.B. Han, P. Hu, L. Weng, J. Eur. Ceram. Soc. 29 (2009) 2893-2901. DOI URL
[14]	P. Zhang, P. Hu, X.H. Zhang, J.C. Han, S.H. Meng, J. Alloys Compd. 427 (2009) 358-362.
[15]	Y.M. An, X.H. Xu, K.X. Gui, Ceram. Int. 42 (2016) 14066-14070.
[16]	M. Fattahi, A. Mohammadzadeh, Y. Pazhouhanfar, S. Shaddel, M.S. Asl, A.S. Namini, Ceram. Int. 46 (2020) 11735-11742.
[17]	P.F. Becher, G.C. Wei, J. Am. Ceram. Soc. 67 (1984) 267-269.
[18]	Y. Luo, S.L. Zheng, S.H. Ma, C.L. Liu, X.H. Wang, J. Eur. Ceram. Soc. 38 (2018) 5282-5293. DOI URL
[19]	G.D. Portu Bellosi, Mater. Sci. Eng. A 109 (1989) 357-362. DOI URL
[20]	X.B. Zhou, L. Jing, Y.D. Kwon, J.Y. Kim, Z.G. Huang, D.H. Yoon, J. Lee, Q. Huang. J. Adv. Ceram. 9 (2020) 462-470.
[21]	S.C. Luo, W.M. Guo, K. Plucknett, H.T. Lin, J. Eur. Ceram. Soc. 41 (2021) 3189-3195. DOI URL
[22]	A.G. Evans, E.A. Charles, J. Am. Ceram. Soc. 59 (1976) 371-372. DOI URL
[23]	B.Z. Song, B. Zhao, Y.F. Lu, S.G. Wei, B.B. Fan, X.Y. Zhang, R. Zhang, Phys. Chem. Chem. Phys. 28 (2018) 25799-25805.
[24]	P. Šajgalík, J. Sedláček, Z. Lenčéš, J. Dusza, H.T. Lin, J. Eur. Ceram. Soc. 36 (2016) 1333-1341. DOI URL