What are interstitial compounds give the classification of alloys with examples?

Question: What are interstitial compounds give the classification of alloys with examples?

Interstitial compounds are a type of compound where small atoms or molecules fill the spaces between the atoms of a metallic lattice. They are formed when the interstitial sites in the lattice of a metal are occupied by atoms or molecules of a nonmetal. These interstitial atoms or molecules do not substitute for the metal atoms in the lattice but occupy the spaces between them.

Classification of Alloys:-

1. Substitutional Alloys: In these alloys, some of the metal atoms in the lattice are replaced by other metal atoms of a similar size. Examples include brass, which is an alloy of copper and zinc, and stainless steel, which is an alloy of iron, chromium, and nickel.

2. Interstitial Alloys: In these alloys, the interstitial spaces between the metal atoms in the lattice are filled with atoms or molecules of a different element. Examples include carbon steel, which is an alloy of iron and carbon, and titanium carbide, which is an interstitial alloy of titanium and carbon.

Examples of interstitial compounds:-

1. Iron carbide (Fe3C): This is a compound formed by the interstitial occupation of carbon atoms between iron atoms in the lattice. It is also known as cementite and is a constituent of steel.

2. Titanium nitride (TiN): This is an interstitial compound of titanium and nitrogen. It has a high melting point and is used as a coating material for cutting tools and wear-resistant surfaces.

3. Zirconium hydride (ZrH2): This is an interstitial compound of zirconium and hydrogen. It is used in nuclear reactor fuel rods as a moderator and a coolant.

4. Tungsten carbide (WC): This is an interstitial compound of tungsten and carbon. It is a very hard and wear-resistant material and is used in cutting tools, drills, and milling machines.

5. Titanium carbonitride (TiCN): This is an interstitial compound of titanium, carbon, and nitrogen. It is used as a coating material for cutting tools and wear-resistant surfaces.