Different Types of Chromium Coatings

Industrial chromium plating is used for many reasons.main ingredient is chromium sulfate and chromium
Some of the reason they use this hard chrome orchloride. This particular type of bath is not very
engineered chrome is because it reduces friction, itcommon yet. There are some concerns about the
also adds wear resistance and the last reason iscolor, brittleness, and plating thickness. It is also referred
because it increases corrosion resistance. The hardto as tri-chrome and chrome (III). It was first used to
chrome has a tendency to be thicker than the otherplate decorative things but it was not liked because of
type of decorative coating. It is not uncommon for tothe color tones. But they can adjust the color tones to
use thinner and thicker layer of coating.meet their needs.
There are two types of industrial chrome plating baths.It is a replacement for the hexavalent chromium bath. It
The first is hexavalent chromium baths, and theclosely resembles the coating that the hex-chrome
second is trivalent chromium baths. In the article wecoating on decorative applications. The trivalent
are going to explain the two different types of platingchromium has overcome the shortcomings of the
baths.hex-chrome bath. In certain general areas it has higher
Well hexavalent bath uses the main ingredient chromiccathode efficiency, it has better throwing power, and
anhydride. It is also referred to as hex-chrome. Almostlower toxicity. The tri-chrome has a similar hardness to
all chromium ore is processed thru the conversion tothe hex-chrome.
sodium dichromate. The other hex-chrome compoundsThe tri-chrome can be divided up into three basic
are assorted salts of chromate and dichromate. It alsogroups. The first group is the single electrolyte bath
uses the compound chromium trioxide.(chloride- or sulfate-based) using graphite or composite
Hexavalent chromium is used in the production ofanodes and additives to prevent oxidation of trivalent
many things. Some of the things that it has been usedchromium at the anodes. The second is the
for is stainless steel, textile dyes, wood preservation,Sulfate-based bath using shielded anodes (lead anodes
leather tanning, and as an anti-corrosion. This bath issurrounded by boxes filled with sulfuric acid) which help
not safe to inhale if it is in haled it can cause manyprevent the trivalent chromium from reaching the
health problems. In the European union you are notanodes, thus preventing their oxidation. And last is the
allowed to use the hexavalent chromium in electronicSulfate-based using insoluble catalytic anode that
equipment.maintains an electrode potential level that preventions
The second type of bath trivalent chromium uses theoxidation of the trivalent chromium.