Alex Bennett-Ford

 

Electro plating





 

Electroplating, the process of coating a metal object with a thin layer of another metal by means of electrolysis. Electroplating is used to give metal objects a better appearance or to protect them from corrosion, wear, or rust. Tableware, trays, decorative pieces and jewelry are plated with gold or silver to make them more attractive.It's done by filling a container with a solution of salt that will be the coating, this is called an electrolytic bath. The object to be plated is immersed in the bath. A metal bar, composed either of the metal that is to form the coating or of a metal that is not affected by the electrolytic bath, is also immersed in the bath. The entire apparatus is called an electrolytic cell.

 

 

 

 

http://science.howstuffworks.com/electroplating-info.htm

 

 

Anodising

 

Anodising is an electrolyic passivation process that is used to increase the thickness of the natural oxide layer on the surface of the metal parts. Anodising is done through positive and negative charge, the cathode's material is transfered to the anode creating a thickeroxide layer on the surface metal. This is so that it has increased corrosion resistance and wear resistance and also provides a better surface adhesive for paint primers and glues. Anodization changes the microscopic texture of the surface and changes the crystal structure of the metal near the surface. Thick coatings are normally porous, so a sealing process is often needed to achieve corrosion resistance. The positive electrode called anode is the material that is to be treated as if it attracts all of the wanted material and the cathode, the negative electrode attracts all of the unwanted materials. The thickness of the oxide layer is determined by the amount of time you leave the anode in their for.