Often, people want to coat a relatively cheap metal with a more beautiful and more expensive metal. A thing layer of silver or gold can be used to beautify metal objects. To limit the cost, a method of applying a thing layer only is needed. Electrolysis can be used to produce a thing even film of metal which adheres well to the surface being coated. The technique is called electroplating.
Electroplating is used for protection as well as for decoration e.g. steel is chromium plated to prevent it from rusting. Chromium does not stick well to steel. Before steel is chromium plated, it is first electroplated with copper, which does adhere well to steel. It is then nickel plated. Nickel is not corroded by air or water. The final step is chromium plating. The result is a bright, non corrodible surface.
The rusting of iron is a serious and expensive problem. In the manufacture of food cans, a layer of tin is electroplated on to iron. Tin is an unreactive metal, and the juices in foods do not react with it. A layer of zinc is applied to iron in the manufacture of galvanized iron. Electroplating is often employed in doing so.
Electroplating is used for protection as well as for decoration e.g. steel is chromium plated to prevent it from rusting. Chromium does not stick well to steel. Before steel is chromium plated, it is first electroplated with copper, which does adhere well to steel. It is then nickel plated. Nickel is not corroded by air or water. The final step is chromium plating. The result is a bright, non corrodible surface.
The rusting of iron is a serious and expensive problem. In the manufacture of food cans, a layer of tin is electroplated on to iron. Tin is an unreactive metal, and the juices in foods do not react with it. A layer of zinc is applied to iron in the manufacture of galvanized iron. Electroplating is often employed in doing so.
