| Chrome rims and other chrome parts are often used | | | | for auto parts, jewelry, hardware, hand tools and |
| to improve the appearance of vehicles. The bright | | | | appliances. |
| decorative finish of chrome plating is very familiar and | | | | Black Chrome |
| enhances the appearance as no other method of | | | | For black chrome an underlying base of metal is |
| customising your ride can. Chrome plating is used on | | | | plated with bright or mate nickel then the chromium |
| exhausts, handles, mirrors and trims as well as on the | | | | plating applied over this. Black chrome is not as hard |
| very popular chrome rims. Chrome plating is not just | | | | as bright chrome and not so long lasting. It is often |
| used for decoration however. The protective coating | | | | oiled or waxed to improve the appearance. Black |
| of the chrome makes the technique of chrome | | | | chrome is used in some auto parts, solar panels and |
| plating useful for other applications. Chrome plating | | | | some gun sights and other optical components. |
| can be used to protect pistons and other engine | | | | Hard Chrome |
| parts. | | | | Unlike the other types hard chrome is not used to |
| Chrome plating consists of applying a thin layer of | | | | give a decorative finish but to give a very long lasting |
| chromium on to an iron, copper or other base metal | | | | protective coating for pistons, hydraulic rods, |
| to give a protective and decorative finish. Chromium | | | | cylinders and other engine parts. The chrome is |
| itself is a reactive metal that reacts readily with the | | | | plated more thickly than for the decorative finishes |
| oxygen in the air. Unlike iron which forms a very | | | | to make a strong protective layer. |
| unstable oxide that flakes and falls apart chromium | | | | The Electroplating Procedure |
| oxide is hard and stable and forms a protective layer | | | | Before the object can be plated it must be cleaned |
| which prevents the underlying metal from corroding. | | | | thoroughly by degreasing the cleaning manually to |
| Different electroplating techniques are used to | | | | remove any debris and impurities. Sulphuric acid or |
| produce different effects. The shiny highly decorative | | | | other strong acids are also used. Other |
| finish that we are all familiar with on chrome rims and | | | | pre-treatments may also be used. Once cleaned the |
| other auto parts is known as bright chrome. Other | | | | object is suspended in the plating solution. For bright |
| variations are black chrome and hard chrome. | | | | chrome a solution of sulphuric acid and chromic acid is |
| Bright chrome is used when a decorative finish is | | | | used and for black chrome, chromic acid with acetic |
| required, on car rims for instance, and is applied fairly | | | | acid and barium acetate. The temperature of the |
| thinly. Decorative chrome is applied after a nickel | | | | bath must be kept within 45C to 50C for bright |
| coating is plated to a base of steel, copper alloys, | | | | chrome and 32C to 46C for black chrome. The |
| steel and aluminum alloys and plastic. The nickel | | | | thickness of the plating is controlled by the current |
| provides the luster and the chrome provides the | | | | used. |
| hardness and protection. This kind of process is used | | | | |