Improving high-temperature wear resistance of NiCr matrix self-lubricating composites by controlling oxidation and surface texturing

doi:10.1016/j.jmst.2022.05.041

Abstract

Abstract:

Self-lubricating composites (SLCs) are widely used in the fields of aerospace and marine, but the conventional NiCr matrix SLCs with sulfide as solid lubricant often suffer from low wear resistance at high temperatures. In view of its high affinity with oxygen and also the high oxidation rate, appropriate amount of nano Ti was added to NiCr-WS₂ composites prepared by spark plasma sintering (SPS) to adjust the oxidation behavior and surface texture. When exposed to high temperature, Ti was preferentially oxidized in comparison to Ni and Cr, resulting in abundant TiO₂ protrusions and microdimples on the surface, i.e. in situ surface texturing. Besides, TiO₂ was of high chemical activity and readily to react with other oxide debris during high temperature sliding process to form compounds of NiTiO₃ and CrTi₂O₅. The high chemical activity of oxide debris that was conducive to sintering, combining with the special surface texture that stores as many wear debris as possible, promoted the rapid formation of a protective glaze layer on the sliding surface. The NiCr-WS₂-Ti composite exhibited low friction coefficient but high wear resistance at elevated temperatures. Especially at 800 °C, it presented a wear rate of as low as (2.1 ± 0.3) × 10⁻⁵ mm³ N⁻¹ m⁻¹, accounting for only 2.7% of that of NiCr-WS₂ composite.

Key words: Self-lubricating composites, High temperature oxidation, Glaze layer, Surface texturing

Xuan Kong, Wenyao Sun, Qunchang Wang, Minghui Chen, Tao Zhang, Fuhui Wang. Improving high-temperature wear resistance of NiCr matrix self-lubricating composites by controlling oxidation and surface texturing[J]. J. Mater. Sci. Technol., 2022, 131: 253-263.

Figures/Tables 15

Table 1. Composition of the mixed powders or composites.

Sample	Composition (wt%)
N	Ni20Cr
NW	Ni20Cr + 15% WS₂
NW15T	Ni20Cr + 15% WS₂ + 15% Ti

Fig. 1. Phase constituents and microstructures: (a) XRD patterns, (b) and (c) SEM microstructures of NW and NW15T, respectively.

Table 2. EDS analysis at spots denoted in Fig. 1 (at.%).

Spot	Ni	Cr	W	Ti	S
1	36.65	31.69	1.18	/	30.48
2	24.52	25.53	41.70	/	8.25
3	59.68	17.55	4.41	18.14	0.22
4	3.12	17.53	0.26	45.78	33.31

Fig. 2. Tribological properties of NiCr alloy and the composites NW and NW15T at high temperatures: frication coefficient at (a) 600 °C and (b) 800 °C, (c) wear rate.

Fig. 3. Surface morphologies (a, b, d, e) and cross sectional profiles (c, f) of wear scar after sliding at high temperatures on the composites: (a-c) NW, (d-f) NW15T.

Fig. 4. Cross-section microstructures under worn scar after sliding at high temperatures: (a) NW, 600 °C, (b) NW, 800 °C, (c) NW15T, 600 °C, and (d) NW15T, 800 °C.

Fig. 5. Morphologies at wear surface of coupled balls (a, b) and wear debris (c, d) of the two composites after sliding at 800 °C for 30 min: (a, c) NW and (b, d) NW15T.

Fig. 6. (a) Micro hardness at places inside or outside the wear scar, and (b) Raman spectra inside wear scar of the composites NW and NW15T after sliding at 800 °C.

Fig. 7. Microstructures of glaze layer formed on NW15T after sliding at 800 °C: (a) low magnification TEM image, (b) enlarged view of the yellow boxed area in (a) and correspongding EDS analysis; (c-f) high resolution TEM micrograph and diffraction patterns at areas noted by yellow marks in (b).

Table 3. EDS analysis at spots denoted in Fig. 7 (at.%).

Spot	Ni	Cr	W	Ti	O	S
1	84.12	6.48	8.46	0.48	0.40	0.06
2	67.64	18.95	1.05	1.96	9.79	0.61
3	0.50	42.60	1.27	10.87	44.76	0
4	37.20	22.63	1.23	6.88	31.45	0.61

Fig. 8. Oxidation kinetics of the composites NW and NW15T at 800 °C in air.

Fig. 9. (a) Surface morphology and EDS analysis, (b) GI-XRD pattern, and (c) 3D mapping of scale formed on the composite NW after oxidation at 800 °C for 30 min.

Fig. 10. (a) surface morphology and EDS analysis, (b) GI-XRD pattern, and (c) 3D mapping of scale formed on the composite NW15T after oxidation at 800 °C for 30 min.

Table 4. Ionic potentials of certain oxides [38].

Oxide	Electronic charge (Z)	Radius of cation (r, Å)	Ionic potential (Z/r)
TiO₂	4	0.64	5.8
NiO	2	0.69	2.8
Cr₂O₃	3	0.61	4.9

Fig. 11. (a) Typical wear surface morphology, (b, c) schematic images showing the formation process of glaze layer on sliding.

References 38

[1]	W. Duan, Y. Sun, C. Liu, G. Ran, L. Yu, Tribol. Int. 95 (2016) 324-332. DOI URL
[2]	J. Luo, W. Sun, R. Duan, W. Yang, K. Chan, F. Ren, X. Yang, J. Mater. Sci. Technol. 110 (2022) 43-56. DOI URL
[3]	B. Parveez, M. Wani, Tribol. Int. 159 (2021) 106969.
[4]	N. Espallargas, S. Mischler, Tribol. Int. 43 (2010) 1209-1217. DOI URL
[5]	M. Rahman, J. Ding, A. Beheshti, A. Polycarpou, Tribol. Int. 123 (2018) 372-384. DOI URL
[6]	F. Li, J. Chen, Z. Qiao, J. Ma, Tribol. Lett. 49 (2013) 573-577. DOI URL
[7]	P. Kaline, N. Aloisio, Tribol. Int. 120 (2018) 280-298. DOI URL
[8]	E. Hao, Y. An, J. Chen, X. Zhao, G. Hou, J. Chen, M. Gao, J. Mater. Sci. Technol. 75 (2021) 164-173. DOI URL
[9]	A. Zhang, J. Han, B. Su, P. Li, J. Meng, Mater. Des. 114 (2017) 253-263. DOI URL
[10]	M. Yang, X. Liu, J. Fan, X. He, S. Shi, G. Fu, M. Wang, S. Chen, Appl. Surf. Sci. 258 (2012) 3757-3762. DOI URL
[11]	X. Lu, X. Liu, P. Yu, G. Fu, G. Zhu, Y. Wang, Y. Chen, Tribol. Int. 101 (2016) 356-363. DOI URL
[12]	Y. Zhai, X. Liu, S. Qiao, M. Wang, X. Lu, Y. Wang, Y. Chen, L. Ying, Opt. Laser Technol. 89 (2017) 97-107. DOI URL
[13]	J. Li, D. Xiong, Wear 265 (2008) 533-539. DOI URL
[14]	J. Zhen, J. Cheng, M. Li, S. Zhu, Tribol. Int. 109 (2017) 174-181. DOI URL
[15]	J. Jiang, F. Stott, M. Stack, Wear 256 (2004) 973-985. DOI URL
[16]	C. Yin, Y. Liang, W. Li, M. Yang, Acta Mater. 166 (2019) 208-220. DOI URL
[17]	I. Inman, S. Rose, P. Datta, Wear 260 (2006) 919-932. DOI URL
[18]	I. Inman, S. Datta, H. Du, J. Burnell-Gray, Q. Luo, Wear 254 (2003) 461-467. DOI URL
[19]	A. Dreano, S. Fouvry, S. Sao-Joao, J. Galipaud, Wear 440 (2019) 203101.
[20]	A. Dreano, S. Baydoun, S. Fouvry, S. Nar, P. Alvarez, Wear 488 (2022) 204144.
[21]	A. Viat, A. Dreano, S. Fouvry, Wear 376 (2017) 1043-1054.
[22]	Y. Xue, X. Shi, Q. Huang, K. Zhang, C. Wu, Tribol. Int. 161 (2021) 107099.
[23]	H. Costa, I. Hutchings, J. Mater, Process. Technol. 209 (2009) 3869-3878. DOI URL
[24]	U. Pettersson, S. Jacobson, Tribol. Int. 39 (2006) 695-700. DOI URL
[25]	I. Etsion, J. Tribol. 127 (2005) 248-253. DOI URL
[26]	X. Kong, Y. Liu, M. Chen, T. Zhang, Q. Wang, F. Wang, J. Mater. Sci. Technol. 105 (2022) 142-152. DOI URL
[27]	M. Yang, X. Liu, J. Fan, X. He, S. Shi, G. Fu, Appl. Surf. Sci. 258 (2012) 3757-3762. DOI URL
[28]	X. Liu, C. Zheng, Y. Liu, J. Fan, M. Yang, J. Mater. Process. Technol. 213 (2013) 51-58. DOI URL
[29]	C. Greiner, Z. Liu, R. Schneider, L. Pastewka, Scr. Mater. 153 (2018) 63-67. DOI URL
[30]	C. Greiner, J. Gagel, P. Gumbsch, Adv. Mater. 31 (2019) 1806705.
[31]	P.C. Machado, J.I. Pereira, A. Sinatora, Wear 486 (2021) 204111.
[32]	W. Zhu, C. Zhao, Y. Zhang, C. Kwok, J. Luan, Z. Jiao, Acta Mater. 188 (2020) 697-710. DOI URL
[33]	A.V. Murugan, S. Violet, S. Navale, C. Ravi, Mater. Lett. 60 (2006) 1791-1792. DOI URL
[34]	D. Taylor, P. Fleig, R. Page, Thin Solid Films 408 (2002) 104-110. DOI URL
[35]	G. Danappa, C. Raghavendra, R. Swamy, N. Kishan, Mater. Today Proc. 38 (2021) 2797-2802.
[36]	X. Chen, Z. Han, X. Li, K. Lu, Sci. Adv. 2 (2016) 1-7.
[37]	H. Padilla, B. Boyce, C. Battaile, Wear 297 (2013) 860. DOI URL
[38]	A. Erdemir, Tribol. Lett. 8 (2000) 97-102. DOI URL