Name: Properties of Metals and Alloys
Uploaded: 2019-07-19
Duration: 4 min 45 s
Description: An alloy is a mixture of two or more elements, where at least one element is a metal. Many alloys are mixtures of two or more metals. Let's watch the video.

Question

Describe the structures of interstitial and substitutional alloys and outline the factors determining which is formed.

Accepted Answer

An alloy is a mixture of two of more metallic elements. There are two main types of alloys as substitutional alloys and interstitial alloys.

Substitutional alloys are metal alloys formed by substituting one metal atom for another metal atom of similar size. Examples: Brass is an example of a substitutional alloy. Here, brass is composed of Cu and Sn which has a similar size. So here, one can easily substitute or replace it into another atom.

An interstitial alloy is formed when a metal is mixed with another substance composed of small atoms (having small radii) that can reside in the holes of the metal lattice. Steel is an example of an interstitial alloy, because the very small carbon atoms fit into interstices of the iron matrix. When in a metal lattice the holes or voids are occupied by atoms of small radius then that type of interstitial compound is called as Interstitial Alloy.Since the atoms like carbon, nitrogen, hydrogen and boron are small, they cannot replace the other atoms; instead, they can occupy the interstitial sites.

Describe the structures of interstitial and substitutional alloys and outline the factors determining which is formed.

Important Questions on The Metallic Bond

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