corrosion of chromate conversion coatings on aluminum alloys in electrical and electronic equipment

Corrosion-Resistant, Chromate-Free Talc Coatings for Aluminum

Aluminum (Al) and Al alloys exhibit unusual passivity when immersed in alkaline lithium (Li) salt solutions. This passivity is a result of precipitation of a continuous, polycrystalline talc coating. Talc coatings persist when removed from the Li salt solution and offer increased corrosion protection during exposure to aggressive environments. Efforts to develop a low-cost, low-toxicity, easily...

Morphology and Corrosion Performance of Chromate Conversion Coatings on Different Substrates

The aqueous corrosion resistances of galvalume (FeAl+Zn) and steel galvanized (Fe-Zn) alloys, passivated by immersion in chromating solution with different immersion times (0, 10, 30 y 60 s) are compared. The electrochemical behaviour of various chromated and non-chromated coatings was investigated in 3 wt-% NaCl solution using polarization techniques. For comparison, AISI 1010 carbon steel sub...

Corrosion Protection of Al Alloys: Organic Coatings and Inhibitors

High-temperature Corrosion Behavior of Iron Aluminide Alloys and Coatings

A multi-year effort has been focused on optimizing the long-term oxidation performance of ingot-processed (IP) and oxide-dispersion strengthened (ODS) Fe3Al and iron aluminidebased coatings. Based on results from several composition iterations, a Hf-doped alloy (Fe28Al-2Cr-0.05at.%Hf) has been developed with significantly better high temperature oxidation resistance than other iron aluminides. ...

Microstructure and Corrosion Performance of Silica Coatings on Aluminum Surface Prepared by Plasma Electrolysis Technique

Silica phases were precipitated on aluminum surface by potentiostatic plasma electrolysis technique. Aqueous sodium silicate solutions with different concentrations were used for this purpose. SEM, EDS, XRD, surface profiles and polarization curves were used to study coatings properties. The results showed that the growth of the silica containing phases on aluminum surface was promoted by incre...

Anti-corrosive Properties of CeO2 Conversion Coatings on Aluminum Alloy 2024 Prepared by Dip Immersion Method

As an alternative to chromate conversion coatings, rare-earth coatings especially cerium, because of the low toxicity, have attracted considerable attention. Using dip immersion method, cerium-based conversion coating was deposited on aluminum 2024. Corrosion resistance was studied in 3.5 wt.% NaCl solution using potentiodynamic polarization, electrochemical impedance spectroscopy, and surface ...