Abstract
Hardcoatings of WC/12Co and Al2O3/13TiO2, produced by High Velocity Oxy-Fuel (HVOF) and High Energy Plasma (HEP) spraying, have been investigated. In HVOF spraying, nanostructured WC/Co coatings experience more extensive decarburization than conventional coatings, whereas in HEP spraying, just the opposite effect occurs. This is explained in terms of the influence of temperature on the decarburization mechanism. In the Al2O3/13TiO2 case, HEP spraying generates a metastable coating, due to rapid quenching of the plasma melted particles on the substrate. The metastable phase has a defect spinel structure and a nanocrystalline grain size. When heated, it decomposes into an equilibrium two-phase structure, consisting of α-Al2O3 and β-Al2O3.TiO2. Both nanostructured cermets and ceramics have potential as wear-resistant coatings.
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References
Gleiter, H. (1989) Nanocrystalline materials, Progress in Materials Science, 33, (4) 223.
Kear, B.H. and Strutt, P.R. (1995) Nanostructures, the next generation of high performance bulk materials and coatings, KONA Powder and Particle, 13, pp. 45–55.
Siegel, R.W. (1993) Synthesis and properties of nanophase materials, Mat. Sci. Eng. A: Structural Materials: Properties, Microstructure and Processing, 2, pp. 189–197.
Sadangi, R.K., McCandlish, L.E., Kear, B.H. and Seegopaul, P. (1998) Grain growth inhibition in liquid phase sintered nanophase WC/Co alloys, in Oakes, J.J. and Reinshagen, J.H. (eds.) Proc. 1998 Int. Conf on Powder Metallurgy and Particulate Materials, MPIF, pp. 1–51.
McCandlish, L.E., Kear, B.H. and Bhatia, J., Spray conversion process for production of nanophase WC-Co powders, US Patent No. 5,352,269.
McCandlish, L.E., Kear, B.H. and Kim, B.K. (1990) Chemical processing of nanophase WC-Co composite powders, Mats. Sci. & Tech., 6, pp. 953–957.
German, R.M. (1985) Liquid Phase Sintering, Plenum Press, New York.
Schwarzkopf, P. and Keiffer, R. (1960) Cemented Carbides, Macmillan, London.
McCandlish, L.E., Kear, B.H., Kim, B.K. and Wu, L. (1990) Low pressure plasma sprayed coatings of nanophase WC-Co, in Yazici, R.M. (ed.), Protective Coatings: Processing and Characterization, The Minerals, Metals and Materials Society, pp. 113–143.
Li, C.J., Ohmori, A. and Harada, Y. (1996) Formation of an amorphous phase in thermally sprayed WC-Co coatings, Journal of Thermal Spray Technology 5,(1), pp. 69–73.
Binary phase diagram of W-C, (1992) ASM Handbook, 3, p. 2–115.
Sampath, S. and Herman, H. (1992) Thermal Spray Technology, ASM, Materials Park, OH.
Cohen, M., Kear, B.H. and Mehrabian, R. (1980) Rapid solidification processing--an outlook, Proc. Second Int. Conf. on Rapid Solidification Processing, Reston, VA, p. 1.
Zhou, R.-S. and Snyder, R.L. (1991) Structures and transformation mechanisms of then, y and 0 transition alumines, Acta Cryst. B47, pp. 617–630.
Lang, S.M., Fillmore, C.L. and Maxwell, L.H. (1952) J. Research NatnL Bur. Standards, 48, (4) p. 301; RP 2316.
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© 2000 Springer Science+Business Media Dordrecht
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Kear, B.H., Mayo, W.E. (2000). Thermal Sprayed Nanostructured Hard Coatings. In: Chow, GM., Ovid’ko, I.A., Tsakalakos, T. (eds) Nanostructured Films and Coatings. NATO Science Series, vol 78. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-4052-2_10
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DOI: https://doi.org/10.1007/978-94-011-4052-2_10
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