作者：Gu, S.;Maeng, S.;Suh, Y.;Levy, R.A.;Deavenport, D.L.;Gómez, F.J.;Newberg, S.S.;Brooman, E.W.;Berman, E.S.;Kleek, J.J.;Beatty, J.H.;Schwartz, A.S.;Gaydos, S.P.;

作者单位：Department of Physics, New Jersey Institute of Technology, Newark, NJ 07102, United States;Department of Physics, New Jersey Institute of Technology, Newark, NJ 07102, United States;Department of Physics, New Jersey Institute of Technology, Newark, NJ 071

刊名：Chemical vapor deposition

ISSN：0948-1907

出版年：2010-01-05

卷：16

期：41099

起页：231

止页：238

分类号：TQ175

语种：英文

关键词：Aluminum;APCVD;Corrosion protection;Step coverage;TIBAL;

内容简介

This study investigates the use of atmospheric pressure (AP)CVD-produced aluminum (Al) coatings for the protection of steel from corrosion. Coatings produced through thermal decomposition of a triisobutylaluminum (TIBAL)-based precursor at 548 and 573 K are shown to exhibit growth rates of 0.5 and 1.1 μm min ~(-1), respectively. Glow discharge optical emission spectroscopy (GDOES) reveals that, in the main, the coatings consist of pure Al with oxygen present as a minor constituent. Results of the structural, morphological, electrical, and mechanical characterization reveal that the APCVD Al coatings exhibit a face center cubic (fcc) structure with no preferred orientation, a non-columnar grain structure with grain size ranging from 3 to 10 μm, and a surface roughness close to 2μm. Such coatings are also shown to offer an electrical resistivity of 3.5 μΩcm, a density of 2.60 g cm ~(-3), and an adhesive strength of 703 kg cm ~(-2). Cross-sectional examination of coated samples indicate that the APCVD process can yield excellent step coverage and throwing power. Hydrogen embrittlement (HE) tests reveal that Al-coated bars with no post baking experience premature failure due to the presence of incorporated reaction product, hydrogen, in the steel substrate. Samples post-baked at 463 K for 23 h to remove the hydrogen from the substrate are shown to withstand the load for as long as 202 h. Corrosion studies conducted using potentiodynamic polarization measurements, electrochemical impedance spectroscopy, and salt fog tests show that the corrosion resistance of the APCVD Al coatings is comparable to that of pure Al foils, and that such coatings provide acceptable sacrificial protection for steel substrates.