@article {1326,
	title = {The effect of pH and role of Ni2+ in zinc phosphating of 2024-Al alloy. Part I: Macroscopic studies with XPS and SEM},
	journal = {Applied Surface Science},
	volume = {253},
	number = {2},
	year = {2006},
	note = {ISI Document Delivery No.: 114DVTimes Cited: 10Cited Reference Count: 30Akhtar, A. S. Wong, K. C. Mitchell, K. A. R.},
	month = {Nov},
	pages = {493-501},
	type = {Article},
	abstract = {Coatings formed on 2024-T3 aluminum alloy were studied by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) after dipping in zinc phosphating (ZPO) baths at different acidities, for different lengths of time, and with or without Ni2+ additive. The overall objective was to learn more about the role of Ni2+ on the ZPO coating mechanism, particularly since this additive is believed to improve corrosion protection for the Al alloy. Secondary phosphates dominate the coatings when the Ni-containing solution is adjusted to starting pH values of either 3 or 5, while tertiary phosphate is predominant at pH 4. AlF3 precipitates during the early stages of the coating process. Ni2+ has two main roles in the mechanism. First, the rate of increase in local solution pH is retarded by the slower kinetics of reactions involving Ni2+ compared to Zn2+,leading to thinner ZPO coatings when Ni2+ is present in the coating solution. Second, most Ni2+ deposition occurs during the later stages of the coating process, by nickel phosphate deposition and/or by formation of a Ni-rich oxide. (c) 2006 Elsevier B.V. All rights reserved.},
	keywords = {ALKALINE STABILITY, aluminum alloy, ALUMINUM-ALLOY, CATALYSTS, COATINGS, CONVERSION COATINGS, FILMS, Ni2+ additive, NICKEL, OXIDATION, photoelectron spectroscopy, scanning electron microscopy, SPECTROSCOPY, STEEL, zinc phosphate},
	isbn = {0169-4332},
	url = {<Go to ISI>://000242647800017},
	author = {Akhtar, A. S. and Wong, K. C. and Mitchell, K. A. R.}
}
@article {1325,
	title = {The effect of pH and role of Ni2+ in zinc phosphating of 2024-Al alloy. Part II: Microscopic studies with SEM and SAM},
	journal = {Applied Surface Science},
	volume = {253},
	number = {2},
	year = {2006},
	note = {ISI Document Delivery No.: 114DVTimes Cited: 13Cited Reference Count: 11Akhtar, A. S. Susac, D. Wong, P. C. Mitchell, K. A. R.},
	month = {Nov},
	pages = {502-509},
	type = {Article},
	abstract = {Coatings formed on 2024-T3 aluminum alloy were studied by scanning electron microscopy (SEM) and scanning Auger microscopy (SAM) after dipping in zinc phosphating (ZPO) baths at different acidities, with or without the Ni2+ additive. The objective was to learn more about the ZPO coating mechanism on the different microstructural regions of 2024-T3. When the initial coating solution pH is 4 (optimal acidity), a slower etching rate at the Al-Cu-Fe-Mn intermetallic particle{\textquoteright}causes significant precipitation of ZnO, which differs from the coating on other regions of the surface where phosphate predominates. The larger crystals (similar to mu m dimension) on the matrix and the Al-Cu-Mg particle contain more phosphate compared to other areas on the surface. When Ni2+ is added to the coating solution, the Al-Cu-Mg particle is more thickly coated compared to when the Ni2+ is not present. The slower rate of precipitation when Ni2+ is present in the coating solution increases the exposure of the alloy substrate to the acidic environment, so allowing more dissolution of Mg and Al from the Al-Cu-Mg particle. This results in the particle becoming more cathodic in nature, and therefore more coating deposits at this location. Evidence from SAM supports the presence of NiAl2O4, hypothesized in Part I, forming at coating pores later in the process. (c) 2006 Elsevier B.V. All rights reserved.},
	keywords = {aluminum alloy, ALUMINUM-ALLOY, Auger electron spectroscopy, COATINGS, CONVERSION COATINGS, Ni2+ additive, scanning electron microscopy, zinc phosphate},
	isbn = {0169-4332},
	url = {<Go to ISI>://000242647800018},
	author = {Akhtar, A. S. and Susac, D. and Wong, P. C. and Mitchell, K. A. R.}
}
@inbook {1324,
	title = {Surface science studies of the effect of Mn2+ on zinc phosphating of 2024-T3 Al alloy},
	booktitle = {Aluminium Alloys 2006, Pts 1 and 2 - Research through Innovation and Technology},
	series = {Materials Science Forum},
	volume = {519-521},
	year = {2006},
	note = {ISI Document Delivery No.: BEZ41Times Cited: 1Cited Reference Count: 10Akhtar, A. S. Susac, D. Wong, K. C. Wong, P. C. Mitchell, K. A. R.Proceedings Paper10th International Conference on Aliminium Alloys (ICAA-10)JUL 09-13, 2006Vancouver, CANADABRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND},
	pages = {753-758},
	publisher = {Trans Tech Publications Ltd},
	organization = {Trans Tech Publications Ltd},
	address = {Zurich-Uetikon},
	abstract = {The present work is part of a broader investigation of the effects of additives in zinc phosphate (ZPO) coating solutions that are designed for specific applications to Al and its alloys. ZPO conversion coatings improve the corrosion resistance of the Al substrate and increase the adhesion of paint. Coatings formed on 2024-T3 aluminum alloy, after dipping in ZPO coating baths containing Mn2+, have been studied by X-ray photoelectron spectroscopy (XPS), SEM, and scanning Auger microscopy (SAM). Variations are observed in coating morphology and composition as the amount of Mn2+ in the coating solution increases through the 0 to 2500 ppm range. Adhesion tests give information on the relative strength of the coating-substrate interaction at different microstructural areas.},
	keywords = {aluminum alloy, ALUMINUM-ALLOY, Auger, COATINGS, CONVERSION COATINGS, electron spectroscopy, Mn2+ additive, photoelectron spectroscopy, scanning electron microscopy, STEEL, zinc phosphate},
	isbn = {0255-54760-87849-408-1},
	url = {<Go to ISI>://000240309000118},
	author = {Akhtar, A. S. and Susac, D. and Wong, K. C. and Wong, P. C. and Mitchell, K. A. R.},
	editor = {Poole, W. J. and Wells, M. A. and Lloyd, D. J.}
}
