Abstract
Metal matrix/carbide particulate composite surface layers were produced on Ti–6Al–4V alloy samples by injecting metal carbide particles into laser-melted surfaces followed by rapid solidification. Hard, wear-resistant surfaces were produced on a strong alloy which normally has poor wear resistance. The corrosion behaviour of the composite surface was evaluated after a month's exposure to flowing sea water. A variety of solidification products was found in the laser-deposited surface layers, but corrosion was observed only in the carbide particulate phase in the WC-injected sample. No corrosion was observed in the TiC-injected sample nor in the Ti–6Al–4V base alloy. Corrosion in the WC-injected sample was related to the formation of a narrow interphase zone surrounding the particulate phase and a thin reaction zone on the surface of the particulate phase during solidification. The titanium-rich interphase zone formed a galvanic couple with the WC particulate. Crevice-type corrosion initiated at the interface between the two phases and proceeded into the particulate phase assisted by the reaction zone. Electrochemical test results revealed a high corrosion rate for the WC-injected sample and almost none for both the TiC-injected sample and the Ti–6A1–4V base alloy, confirming the microstructural observations.
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References
C. W. Draper and P. Mazzoldi (eds), Laser Surface Treatment of Metals (Martinus Nijhoff, Dordrecht, The Netherlands 1986.
K. P. Cooper, in “Friction, Lubrication and Wear Technology”, ASM Handbook Vol. 18, edited by P. J. Blau (ASM International, Materials Park, OH, 1992) p. 861.
Idem, in “Laser Beam Surface Treating and Coating”, Vol. 957, edited by G. Sepold (SPIE, Bellingham, WA, 1988) p. 42.
K. P. Cooper and J. D. Ayers, in “Laser Surface Modification”, edited by F. D. Seaman (AWS, Miami, FL, 1988) p. 115.
K. P. Cooper, P. Slebodnick and E. D. Thomas, Mater. Sci. Eng. A206 (1996) 138.
“Properties and Processing Ti–6Al–4V”, Technical Publication (TIMET, Pittsburgh, PA, 1986) p. 8.
P. Rohatgi, in “Casting” Metals Handbook, Vol. 15, 9th Edn, edited by D. M. Stefanescu (ASM International, Materials Park, OH, 1988) p. 840.
R. Baboian and S. L. Pohlman, in “Corrosion”, Metals Handbook, Vol. 13, 9th Edn, edited by L. J. Korb and D. L. Olson (ASM International, Materials Park, OH, 1987) p. 83.
D. R. Lide (ed.), “Handbook of Chemistry and Physics”, 75th Edn (CRC Press, Boca Raton, FL, 1994) pp. 4–108.
E. K. Storms, “Refractory Carbides” (Academic Press, New York, NY, 1986).
“Corrosion”, Metals Handbook, Vol. 13, 9th Edn, edited by L. J. Korb and D. L. Olson (ASM International, Materials Park, OH, 1987) pp. 677, 850.
L. H. Hihara and R. M. Latanision, Int. Mater. Rev. 39 (1994) 245.
D. M. Aylor and R. M. Kain, in “Recent Advances in Composites in the United States and Japan”, ASTM STP 864, edited by J. R. Vinson and M. Taya (American Society for Testing and Materials, Philadelphia, PA, 1985) p. 632.
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Cooper, K.P., Slebodnick, P.L., Lucas, K.E. et al. Microstructural inhomogeneities and sea water corrosion in laser-deposited Ti–6Al–4V alloy matrix/carbide particulate composite surfaces. Journal of Materials Science 33, 3805–3816 (1998). https://doi.org/10.1023/A:1004682915135
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DOI: https://doi.org/10.1023/A:1004682915135