Laser Developed Al-Cr Surface Alloys: Microstructure, Mechanical and Wear Behaviour

Article Preview

Abstract:

Surface alloys with composition ranging from 10 to 20% Cr were produced by laser surface alloying. Their microstructure consists of faceted plate-like Al4Cr intermetallic compound particles dispersed in a matrix of α-Al solid solution. During remelting, heterogeneous nucleation of eutectic Al7Cr/α-Al occurred in the undercooled liquid ahead of the columnar solid-liquid interface, followed by equiaxial solidification, resulting in a microstructure formed of equiaxed cells. Al-Cr alloys present Young’s modulus and hardness values that increase with increasing volume fraction of intermetallic compounds. Wear resistance, measured in dry sliding conditions, increases with increasing load due to the protective effect of a stable mechanically mixed layer that forms at the surface of the samples and the steel counterbody. Alloys formed of equiaxed eutectic cells provide better wear resistance than those formed of large plate-like particles since a thinner, more stable and harder mechanically mixed layer is formed, which offers best protection against wear.

You might also be interested in these eBooks

Info:

Periodical:

Materials Science Forum (Volumes 514-516)

Pages:

490-494

Citation:

Online since:

May 2006

Export:

Price:

Permissions CCC:

Permissions PLS:

Сopyright:

© 2006 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

[1] D.K. Das, K.S. Prasad and A.G. Paradkar: Mater. Sci. Engn. A Vol. 174 (1994), p.75.

Google Scholar

[2] A. Almeida, M. Anjos, R. Vilar, R. Li, M.G.S. Ferreira, W.M. Steen and K.G. Watkins: Surf. Coat. Techn. Vol. 70 (1995), p.221.

Google Scholar

[3] H. Warlimont, W. Zingg and P. Furrer: Mater. Sci. Engn. A Vol. 23 (1976), p.101.

Google Scholar

[4] P. Furrer and H. Warlimont: Mater. Sci. Engn. A Vol. 28 (1977), p.127.

Google Scholar

[5] L. Bendersky, R.J. Schaefer, F.S. Biancaniello and D. Shechtman: J. Mater. Sci. Vol. 21 (1986), p.1889.

Google Scholar

[6] J.L. Murray: J. Phase Equilibria Vol. 19 (1998), p.368.

Google Scholar

[7] K. Mahdouk and J. -C. Gachon: J. Phase Equilibria Vol. 21 (2000), p.157.

Google Scholar

[8] V.T. Swamy, S. Ranganathan and K. Chattopadhyay: J. Mater. Res. Vol. 4 (1989), p.539.

Google Scholar

[9] M.C. McConnell and P.G. Partridge: Acta Metall. Vol. 35 (1987), p. (1973).

Google Scholar

[10] P.G. Partridge and M.C. McConnell: Acta Metall. Vol. 35 (1987), p. (1981).

Google Scholar

[11] A. Almeida, B. Triep, R. Vilar, R. Li, M.G.S. Ferreira, K.G. Watkins and W.M. Steen: ATTT-9th Int. Congr. Heat Treatment and Surface Engn. (PYC Edition, Nice, France 1994), p.483.

Google Scholar

[12] A. Kassman, S. Jacobson, L. Erickson, P. Hedenqvist and M. Olson: Surf. Coat. Techn. Vol. 50 (1991), p.75.

Google Scholar

[13] T. Chande and J. Mazumder: Metall. Trans. B Vol. 14 (1983), p.181.

Google Scholar

[14] B.J. Keene: Int. Mater. Rev. Vol. 38 (1993), p.157.

Google Scholar

[15] M. Audier, M. D. -Charre, E. Laclau and H. Klein: J. Alloys Comp. Vol. 220 (1995), p.225.

Google Scholar

[16] M.J. Cooper: Acta Cryst. Vol. 13 (1960), p.257.

Google Scholar

[17] A. Almeida: Ph.D. Thesis (Instituto Superior Tecnico, Lisbon 2005).

Google Scholar

[18] W.D. Nix and H. Gao: J. Mech. Phys. Solids Vol. 46 (1998), p.411.

Google Scholar

[19] B. Venkataraman and G. Sundararajan: Wear Vol. 245 (2000), p.22.

Google Scholar

[20] X.Y. Li and K.N. Tandon: Wear Vol. 245 (2000), p.148.

Google Scholar

[21] B. Venkataraman and G. Sundararajan: Acta Mater. Vol. 44 (1996), p.461.

Google Scholar