Thermal Shock Resistance of Plasma Sprayed Multi-Layered Functionally Graded Cr3C2-NiCr Coatings

Abstract:

The interface properties of multi-layered functionally graded Cr₃C₂-NiCr coatings deposited by plasma spraying technique were experimentally studied in this paper. The microstructure and phase structure of coatings were studied with scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The thermal shock resistance was investigated by cyclic heating and cooling tests using an electro-calefaction furnace. The crack appearances of the coatings were observed carefully. Results show that the plasma sprayed multi-layered functionally graded coatings are compact and the adhesion between the layers and the substrate is good. The coatings have better macro-hardness than the substrate, and the 6-layers coating has the highest macro-hardness and the best wear resistance. Besides, the micro-hardness of coatings increases with increasing content of Cr₂C₃ in coating materials. Results of cyclic thermal shock show that the main failure styles of the coatings are crack and desquamation and the thermal shock resistance of the coatings is improved obviously by increasing the number of coating layers.

• Periodical: Materials Science Forum (Volume 852)
• Pages: 1000-1005
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.852.1000
• Online since: April 2016
• Authors: Dong Xing Fu, Jing Na Liu, Er Bao Liu, Zhao Bin Cai, Xiu Fang Cui, Guo Jin
• Keywords: Cr₃C₂-NiCr Coating, Crack, Desquamation, Plasma Spraying, Thermal Shock Resistance

References

[1] H. Liao, B. Normand and C. Coddet: Surface and Coatings Technology, 124(2000): 235-242.

[2] J. Karthikeyan, C. C. Berndt, J. Tikkanen, S. Reddy, and H. Herman: Materials Science and Engineering, A238(1997): 275.

[3] S.X. Hou, Z.D. Liu and D.Y. Liu: Surface and Coatings Technology, 205(2011): 4562-4568.

[4] F. Alonso, I. Fagoaga and P. Oregui: Surface and Coatings Technology, 49(1991): 482-488.

DOI: 10.1016/0257-8972(91)90104-5

[5] Z. L. Dong, K. A. Khor and Y. W. Gu: Surface and Coatings Technology, 114(1999): 181-186.

[6] L. Fu, K. A. Khor, H. W. Ng and T. N. Teo: Surface and Coatings Technology, 130(2000): 233.

[7] S. Eroglu and C. Duran: Scripta Materialia, 37(1997): 991-997.

[8] J.H. He, M. ICE and E.J. Lavernia: Metallurgical and Materials Transactions A, 31A (2000): 555-564.

[9] J. J. Li, Y. Zhang, J. Huang and C. Ding: Journal of Thermal Spray Technology, 7(1998): 242.

[10] G. Geiger: American Ceramic Society Bulletin, 71(1992): 1470-1481.

[11] M. H. Staia, T. Valente, C. Bartuli, D.B. Lewis, et al.: Surface and Coatings Technology, 146-147 (2001): 563.