Metals & Chemicals

Chromate conversion is a type of conversion coating that is applied to passivate aluminium, zinc, copper, silver, cadmium, magnesium, tin and their alloys to slow down corrosion. This process use different deadly chromium compounds which may consist of hexavalent chromium. Now the industry is developing less toxic alternative so as to comply with substance restriction legislation. One choice is trivalent chromate conversion that is not as effective but it is less environmentally damaging. It is also usually used on aluminium alloy parts in aircraft industry where it is frequently called chemical film. This has an added value as a primer for following organic coatings, as raw metal, particularly aluminium, is so difficult to paint or glue. The chromated parts keep their electrical conductivity to changeable degrees, depending upon the coating thickness. This process can be used to add color for enhancing or identification purpose. Chromate coatings are very soft and gelatinous when ...

Chromate Conversion on Houston like Alodine or Iridite is a chemical treatment for aluminum used to present corrosion protection and also surface preparation for paint and other adhesives. Chromate is a superb treatment for paint or adhesives as it greatly enhances the product's ability inorder to form a bond with the aluminum. It is often used on electrical and electronic equipment as it provides increased corrosion resistance even as remaining electrically conductive. The oxide film formed by this process varies in color, depending on the aluminum alloy that is being treated, surface conditions, and type of chromate. The key benefits of alodine are. 1. It resists corrosion. It is indicated that the alodine treated surface withstands corrosion in a five percent of salt spray test for 168 hours. Results vary depending on the alloy of the material and surface finish. 2. Alodine is an outstanding paint base. As the coating is not applied electrically and could be applied quickly,...

In the chromate conversion process, part of the metal surface is converted to a superficial layer containing a complex combination of chromium compounds. The chromate film will be soft when freshly formed, but once it gets dried and aged, the layer becomes more rough resistant. Chromate conversion coatings provide excellent corrosion resistance. Paint, polish, and organic finishes will bond exceedingly well to chromate conversion coatings. Additionally, the chromate coatings will prevent loss of plain adhesion due to under film corrosion. The most common use for chromating is to impart corrosion resistance to zinc aluminium parts and zinc plated steel. These films will vary in color depending upon the chemicals being used and the bottom metal being coated. Colors vary from clear, to light shining, to gold. Greater corrosion protection is given with formulations that gives a golden color, since these coatings tends to be thicker. A multicolored appearance will be obtained when the b...

Chromate conversion on Chicago coatings are a type of conversion coating which is applied to passivate zinc, aluminum, cadmium, silver, copper, magnesium, tin and their alloys to slow corrosion. The process involves the use of various toxic chromium compounds which might include hexavalent chromium. The industry is now developing less toxic alternatives so as to comply with substance restriction legislation. One option is trivalent chromate conversion which is less environmentally damaging. Chromating is normally used on zinc-plated parts to defend the zinc from white corrosion, which is mainly a cosmetic issue. It can't be applied directly to steel or iron, and it does not enhance zinc's anodic protection of the underlying steel from brown corrosion. It is also most commonly used on aluminum alloy parts in the aircraft industry where it is often called as chemical film. It also has an additional value as a primer for subsequent organic coatings, as any untreated metal, esp...