Alloys and Their Mechanical Properties

______ In engineering work, alloys, rather than pure metals, are generally used because of their superior properties. Ordinary steels, for example, are alloys of iron and carbon and are preferred to pure iron because of strength and other considerations. Important mechanical properties of alloys are related to the solid phases, or homogenous parts, that form from the combination of elements. Such phases are observable on the microscopic scale, and their study is important in understanding alloy properties. 1.1 Types of Alloying Interstitial is where the alloy elements are located in spaces between atoms in the unit cell. For instance, when carbon (Atomic radius 0.129 nm) is added to iron (0.075nm), the carbon fits into the gap between the Fe atoms (interstitial site). The solubility depends on the size of these gaps and the crystal structure. Substitutional is where the alloying elements are located in vacancies in the unit cell. An atom of one element substitutes for another in the crystal structure.

Ordinary steels, for example, are alloys of iron and ______ and are preferred to pure iron because of strength and other considerations.

Interstitial is where the alloy elements are located in spaces between ______ in the unit cell.

For instance, when carbon (Atomic radius 0.129 nm) is added to iron (0.075nm), the carbon fits into the gap between the Fe ______ (interstitial site).

Substitutional is where the alloying elements are located in ______ in the unit cell.