This chapter covers material from Option A of the syllabus.

CORE

SPREAD 1: An introduction to material science

Materials are classified based on their uses, properties or bonding and structure.

The properties of a material based on the degree of covalent, ionic or metallic character in a compound can be deduced from its position on a bonding triangle.

Composites are mixtures in which materials are composed of two distinct phases, a reinforcing phase that is embedded in a matrix phase.

What is a material?

A material is a substance that is intended to be used for certain applications. This doesn't get us very far, so let's subdivide further. Materials can generally be divided into two classes: crystalline and noncrystalline and the traditional types of materials encountered are metals, ceramics and polymers. New materials that are being developed include semiconductors and nano-materials.

It is important for a material scientist to understand the structure of materials, and relate them to their properties. This can lead to a better understanding of the relative performance of the material and its suitability for the task required. As with all chemical substance the structure of a material and its properties will be determined by its constituent chemical elements, the bonding in the material and the way in which it has been processed.

Classification of materials

There are many types of materials. This course covers the following:

A quick glance over this list, adding other common materials such as ceramic or glass and you can see there is a wide variety shown in the properties of these materials. In fact, one of the most important skills is classifying the materials so that the right material can be found for the right job.

All chemical substances are made of atoms, and all chemical compounds are made of two different types of atom bonding together. The Bondin. chapter of the core covers this ground, but in summary the different type of bonding gives rise to a huge amount of difference in properties. Simply think about carbon dioxide, a gas and the oxide of the element below it, silicon to realize how structure and bonding have an effect. Silicon dioxide is a giant covalent solid with a very high melting point.