Question

A tin (Sn) component, cadmium (Cd a copper (Cu) component are coupled together in seawater. Rank the four in which one will suffer from the greatest corrosion. What type of corrosion is this? material (different from the first four) could you use as a sacrificial layer to protect the one that suffers from the greatest corrosion? ) component, a pure aluminum (Al) component, and terms of Which

Answer 1

The four given elements, tin. cadmium, aluminum and copper, can be ranked in terms of which one will suffer from the greatest corrosion in accordance to the galvanic series.

The rank of the four elements is as follows-

1. Tin

2. Copper

3. Aluminum

4. Cadmium

When these materials are coupled and placed in seawater then they undergo corrosion due to the presence of chlorine in the seawater although ample amount of oxygen required for the corrosion is not present deep under the sea.

The type of corrosion that takes place in the seawater are General Corrosion as well as Localized Corrosion.

General corrosion can be termed as the simplest form of corrosion in which the electrochemical reactions take place on the surface of the metal dipped inside a solution which ultimately leads to the corrosion of the metal.

Localized corrosion is the type of corrosion in which the specific part of metal which is in contact with the corrosive environment undergoes corrosion.

The sacrificial layer is the layer provided on the metal to retard the process of corrosion in presence of corrosive environment. The basic function of the sacrificial layer is to prevent the oxidation of the surface of the metal.

In the given case, the metal which corroded the most is Tin and hence, a sacrificial layer of ZINC is provided to retard the process of corrosion in the presence of corrosive environment.