Plating is a layer of metal coating an object of a different type of metal. The purpose can be decorative as in silver plating or practical with industrial parts for instance zinc or cadmium plating. Prevents the underlying metal from rusting while nickel or chrome plating protects against where you can play almost any type of metal. Let’s follow some steel aerospace parts as they’re about to be plated with cadmium to make them corrosion-resistant for the plating metal tube on properly the steel surface must be free of contaminants such as oil and grease workers suspend.
The parts over that of boiling chemical solvents as the hot vapor comes into contact with the colder metal it condenses dripping down into the vat and taking any contaminants along with it. The remaining solvent residues evaporate leaving the parts squeaky clean and dry. Next a worker wearing protective clothing sandblast the parts with aluminum oxide powder a strong abrasive. This Russians up the surface so that the plating metal will adhere better the most common plating metals for industrial purposes are zinc chrome and nickel think motorcycle parts or sink faucets decorative items on the other hand are more likely to be plated in 10 brass gold or silver.
Traditional tea sets for instance are often made of silver plated copper or zinc. The plating process is called electroplating because the key to it all is electricity. They start by tying strands of copper wire to a copper support frame copper being the best metal for conducting electricity then they attach the steel parts will be
plating when they hook up this support to an electric current electricity will run from the support through these wires right to the pieces.
They do the electroplating in a tank after filling it with water they add a handful of chemicals to help conduct electricity because water alone won’t conduct it sufficiently. Along the sides of the tank in bags are metal baskets they contain bars or balls of the plating metal in this case cadmium workers connect the support frame with the steel parts to the negative terminal of an electric source. The baskets of cadmium to the positive terminal then they switch on a steady DC current no stronger than 6 volts the electricity dissolves the cadmium lacing the particles with a positive charge. They travel through the water and attach themselves to the negative charge steel parts creating a smooth and even layer of cadmium thin plate and requires just a few minutes in the tank big plating several hours then workers rinse the parts and water for about a minute to remove.
The chemical residues to make the parts even more rust resistance workers immerse them in a series of compounds. This triggers a chemical reaction in the plating enhancing its ability to withstand corrosion. This reaction however changes the color a final rinse and hot water and this cadmium plated steel aerospace part is finally ready from start to finish the process has taken about 90 minutes to plate with chrome or gold they have to use a chemical compound containing gold or chromium that’s because electricity can’t dissolve solid chromium well enough and it can’t dissolve solid gold at all the compound dissolves in the bath like salt but then solidifies once it reaches the object being plated metal plating is very durable but it’s subjected to a lot of wear and tear the object will eventually have to be related.