Metals & Chemicals

Chrome is a metal, but it is not useful for solid or pure substance. Chrome really means that it has a thin layer and a plating of chrome on the object (the bulk of the object has steel, but sometimes brass, aluminium, copper, plastic or stainless steel). People generally think that any shiny finish is chrome even when it has nothing to do with chromium. For example, electro polished stainless steel boat rigging, shiny painted wheels, vacuum metallized balloons and helmets, brightly polished aluminum motorcycle parts, are sometimes called 'chrome' by the common person. Chrome plating is bluer, reflective and more specular than other finishes. If we put one end of the yardstick in a bright finish then the clouds reflection can be seen in the chrome plating.

There are two types of chromium plating; one is industrial and the other being decorative. Industrial chromium plating is divided into two such as hexavalent and the other being trivalent plating. The decorative plating is a mixture of chrome and nickel. It has a mirror finish. Its thickness range from 0.002 to 0.020 miles. In jewelry, plastic knobs, hardware and hard tools the decorative chrome is used. The process for hexavalent chromium is first the activation bath is done, and then chromium bath then it is rinsed twice. While using activation bath a separate tank of chromic acid is used. Occasionally the activation step takes place in the chromium bath itself. Other than bath the other important things that matter are temperature and current density. These two affects the brightness and coverage. Trivalent chromium plating process is divided into three such as the single electrolyte bath is done then sulfate based bath using shielded anodes and at last sulfate ba...