Presentation - electroplating.ppt

Electroplating U.S. Federal Mil. Specs Presented by Kam Fai Electroplating Factory Limited What is Electroplating? Electroplating is the deposition of a metallic coating onto an object by putting a negative charge onto the object and immersing it into a solution which contains a salt of the metal to be deposited. The metallic ions of the salt carry a positive charge and are attracted to the part. When they reach it, the negatively charged part provides the electrons to reduce the positively charged ions to metallic form. Metal irons supplied by the dissolution of metal from anodes or other pieces, are reduced on the work pieces (cathodes) while in either acid, alkaline, or neutral solutions. Ferrous or nonferrous basis materials may be coated by a variety of common (copper, nickel, lead, Tin or combinations thereof) or precious (gold, silver, platinum, osmium, iridium, palladium, rhodium, indium, ruthenium, or combinations thereof) metals. How does it work? Look at the figure below, and then follow the written explanation. Imagine that we have an object that is made of copper or steel, and that it has been properly cleaned, and that we now want to plate it with nickel. A wire is attached to the object, and the other end of the wire is attached to the negative pole of a battery (the wire is blue in this picture). To the positive pole of the battery we connect the red wire; the other end of the red wire we connect to a rod made of Nickel What is Electroless Plating? The chemical deposition of a metal coating on a work piece by immersion in an appropriate plating solution in which electricity is not involved. Copper and nickel electroless plating for printed circuit boards are the most common operations. Immersion plating, which for purposes of the Metal Finishing regulation is considered part of electroless plating, produces a metal deposit by chemical displacement. Anodizing An electrochemical process which converts the metal surface to a coating of