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 ...

Anodizing metals is an electrolytic process inorder to produce controlled aluminum oxide films on aluminum. Oxide will form naturally on an untreated aluminum, but the process of anodizing produces a coating that is uniform, much harder, and more dense than natural oxidation. Aluminium oxide will also possess superb thermal and electrical insulating qualities also. This anodic film is produced by converting the exterior of the part into aluminum oxide. Not like paint, which will flake off if not applied correctly, anodized aluminum finishes are in fact formed from the original stuff and cannot peel off. The aluminum oxide finish is so hard and exceptionally will wear anodizing resistant. Anodizing coating on Houston is best for many consumer products and various sporting goods due to its aesthetic and corrosion protection property. It is the primary finish for aluminum aircraft parts together with major components before congregation and painting. Parts can be dyed during the proce...

The extensive use of zinc, both as a sacrificial coating on steel and also as a stand-alone material, require a high level of corrosion resistance in order to increase the product life cycle and to avoid ecological pollution by metal ions. Zinc coatings and castings on steel can be anodized so as to produce a tough and stable coating. The corrosion resistance is said to be superb. Being used by the military immersed on the subs for high corrosion problem areas such as mooring cleats with good results. A special zinc anodizing handling is available for zinc castings. This coating is entirely different than that for aluminum alloys. Anodizing zinc is a practical coating providing maximum corrosion resistance in both atmospheric and marine environments. As the process uniformly coats deep recess and threaded areas, anodized zinc alloy castings could serve as an economical alternative when replacing traditional bronze, brass and stainless steel components. Steel items could be fabricat...

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,...

The practice of anodizing, or the controlled oxidation, of aluminum and its alloys are more than seven decades old. The main intention behind anodizing aluminum and its alloy parts is to guard the highly reactive surface against corrosion in aqueous environments, like moist air and sea water. Since the anodic coating could be produced in a range of colors, the painted parts are generally used in architectural applications. Further, as the process of aluminum anodization on CA would produce a hard ceramic covering, harder than that of the substrate from which it is formed, the anodic coatings are also used to shield aluminum parts from abrasions, especially sand abrasion. Traditional anodizing process is electrochemical oxidation. The part which is to be anodized is then connected to the positive terminal of a Direct Current (DC) power source and a non reactive metal, like stainless steel, is coupled to the negative terminal. The aluminum anode, and the stainless steel cathode are...