cromação

Cromação, also known as chromium plating, is an electrochemical process used to deposit a layer of chromium onto a metal or plastic surface. This coating serves several purposes, primarily to enhance the material's durability, corrosion resistance, and aesthetic appeal.

The process typically involves immersing the object to be plated into an acidic chromic acid solution. An electric current is then passed through the solution, with the object acting as the cathode and a lead alloy serving as the anode. The chromium ions in the solution migrate to the cathode and deposit onto the surface, forming a thin, hard layer.

There are two main types of chromium plating: decorative chromium plating and hard chromium plating. Decorative chromium plating is applied in thin layers, often over a nickel or copper underlayer, to provide a bright, reflective, and tarnish-resistant finish. This is commonly seen on automotive parts, bathroom fixtures, and household appliances. Hard chromium plating, on the other hand, involves thicker deposits and is primarily used for its wear resistance and low friction properties. It is applied to industrial components like hydraulic cylinders, engine parts, and cutting tools to extend their lifespan and improve performance.

While beneficial, chromium plating also has environmental considerations. Chromic acid is a hazardous substance, and proper waste treatment and handling are crucial to prevent pollution. Regulations exist to control the emissions and disposal of chromium-containing waste.