@article {2007,
	title = {Microstructural effects on the formation and degradation of zinc phosphate coatings on 2024-Al alloy},
	journal = {Applied Surface Science},
	volume = {254},
	number = {15},
	year = {2008},
	note = {ISI Document Delivery No.: 295YWTimes Cited: 2Cited Reference Count: 26Akhtar, A. S. Wong, P. C. Wong, K. C. Mitchell, K. A. R.},
	month = {May},
	pages = {4813-4819},
	type = {Article},
	abstract = {The formation of zinc phosphate (ZPO) coatings on 2024-T3 aluminum alloy was studied using scanning electron microscopy (SEM), scanning Auger microscopy (SAM) and X-ray photoelectron spectroscopy (XPS), with an emphasis on microstructural effects involving second-phase particles and the alloy matrix. Surface polishing results in an Al-Cu-Mg particle surface that contains metallic Cu as well as an overlayer of aluminum and magnesium oxide, while larger amounts of aluminum oxide are present on the Al-Cu-Fe-Mn particle and matrix. When dipped in an acidic ZPO coating solution, the oxide covering the Al-Cu-Mg particle is etched most easily, and metallic Cu near the surface makes that region most cathodic, allowing more coating deposition compared with the other regions. The oxides on the Al-Cu-Fe-Mn and matrix regions are similar, thereby confirming that the observed differences in ZPO coating characteristics at these two regions arise from their underlying electrochemical characteristics. Immersion of a coated 2024-Al sample in corrosive NaCl solution for extended periods indicates that the ZPO provides better protection to the second-phase particles than to the matrix. (C) 2008 Elsevier B.V. All rights reserved.},
	keywords = {7075-T6, ALKALINE STABILITY, aluminum alloy, ALUMINUM-ALLOY, Auger electron spectroscopy, BEHAVIOR, corrosion, CORROSION PROTECTION, INITIATION, MICROSTRUCTURE, NI2+, PARTICLES, PHASE, surface oxide, zinc phosphating},
	isbn = {0169-4332},
	url = {<Go to ISI>://000255511700063},
	author = {Akhtar, A. S. and Wong, P. C. and Wong, K. C. and Mitchell, K. A. R.}
}
@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.}
}
