Abstract
The effect of substrate preheat temperature on the dynamic wetting of 55Al-43.4Zn-1.6Si hot dip coating melts on low-carbon steel substrates has been investigated. An experimental apparatus based on the sessile drop technique was developed, which allowed the substrate to be preheated to a different temperature than that of the droplet. The initial wetting and spreading of the molten metal droplet on the substrate was recorded at 1000 frames per second using a high-speed digital camera. Wetting was improved (ϑ decreased from 120 to 25 deg) as the substrate preheat temperature was increased from room temperature and approached the droplet temperature, beyond which the improvement in wetting was negligible. Immersion experiments using a thermocouple instrumented substrate dipped into a coating bath were performed for various substrate preheat temperatures. Interfacial heat fluxes and interfacial resistances were calculated from the temperature responses. The “minimum” interfacial resistance was decreased by an order of magnitude (1 × 10−4 to 2 × 10−5 m2 K/W) as the substrate preheat temperature was increased from room to bath temperature. The reduction in interfacial resistance was related to the improvement of the initial wetting and the increase in mass transfer of iron atoms from the substrate across the interface. There was an apparent increase in the minimum interfacial resistance for substrate temperatures greater than the bath temperature. This was due to the increased rate of alloy layer formation and the exothermic nature of the Fe-Al interfacial reactions. The significance of these findings was discussed with respect to the mechanism of alloy layer formation at the interface during the initial stages of solid-liquid contact.
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References
T.D. Blake and K.J. Ruschak: Liquid Film Coating, Chapman & Hall, London, 1997, pp. 63–98.
W.J. Boettinger, C.A. Handwerker, and U.R. Kattner: The Mechanics of Solder Alloy Wetting & Spreading, Van Nostrand Reinhold, New York, NY, 1993, pp. 103–39.
N. Eustathopoulos, M. Nicholas, and B. Drevet: Pergamon Materials Series, Pergamon Press, Elmsford, NY, vol. 3, Elsevier Science, Netherlands.
S.I. Popel: Surface Phenomena in Melts, Metallurgiya, Moscow, 1994, pp. 273–321 (in Russian).
Y. Hirose, H. Togawa, and J. Sumiya: Tetsu-to-Hagané, 1982, vol. 68(6), pp. 114–20 (in Japanese).
T.V. Zakharova and S.I. Popel: Iz. VUZ Chem. Metall., 1972, No. 3, pp. 17–20 (in Russian).
A.A. Tarasova and A. Yu Novozhilov: Adgez. Rasplavov Paika Mater., 1983, vol. 11, pp. 24–26. (in Russian).
A.A. Tarasova and L.P. Kidyashkina: Naukova Dumka, 1976, pp. 117–22 (in Russian).
Y. Durandet, L. Strezov, and N. Ebrill: Proc. 4th Int. Conf. of Zinc and Zinc Alloy Coated Steel Sheet (GALVATECH ’98), Chiba, Japan, The Iron and Steel Institute of Japan, Tokyo, 1998, pp. 147–52.
N. Ebrill: Ph.D. Thesis, University of Newcastle, Newcastle, Australia, 2000.
T.V. Zakharova, S.I. Popel, A.G. Zalazanskii, and A.V. Simonov: Russian Patent SU 928199, 1982 (in Russian).
N. Eustathopoulos: Instit National Polytechnique de Grenoble, ENSEEG, LTPCM, Grenoble, France, 1998.
B.P. Bardes: Properties and Selection: Irons and Steels, 9th ed., ASM, Metals Park, OH, 1978, vol. 1, pp. 148–49.
L. Strezov: Ph.D. Thesis, University of Newcastle, Newcastle, Australia, 1995.
E.O. Doebelin: Measurement Systems—Application and Design, 3rd ed., McGraw-Hill Book Co., New York, NY, 1983, pp. 588–604.
L. Strezov and J. Herbertson: Iron Steel Inst. Jpn. Int., 1998, vol. 38(9), pp. 959–66.
S.J. Smithells and E.A. Brandes: Metals Reference Book, 5th ed., Butterworth Publishers, Boston, MA, 1979, pp. 14-1–14-28.
X.Z. Zou, X.F. Liao, Y. Duan, Durandet, and D.J.H. Cockayne: Proc. 14th Int. Congr. on Electron Microscopy, Cancun, Mexico, 1998.
H. Baker: ASM Handbook, ASM International, Materials Park, OH, 1992, vol. 3.
R.W. Richards, R.D. Jones, P.D. Clements, and H. Clare: Int. Mater. Rev., 1994, vol. 39(5), pp. 191–212.
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This article is based on a presentation made in the “Geoffrey Belton Memorial Symposium,” held in January 2000, in Sydney, Australia, under the joint sponsorship of ISS and TMS.
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Ebrill, N., Durandet, Y. & Strezov, L. Dynamic reactive wetting and its role in hot dip coating of steel sheet with an Al-Zn-Si alloy. Metall Mater Trans B 31, 1069–1079 (2000). https://doi.org/10.1007/s11663-000-0082-3
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DOI: https://doi.org/10.1007/s11663-000-0082-3