2. INTRODUCTION TO MATERIALS
➢A materials is a chemical substance or mixture
of substances that constitutes an object.
➢Materials can be pure or impure, living or non-
living matter
➢Without materials , there is no engineering
4. CRYSTALLINE MATERIALS
➢These are materials containing one or many
crystals . In each crystal , atoms or ions show a
long range periodic arrangement .
➢All metals and alloys are crystalline materials .
➢These include iron , steel , copper , brass ,
bronze , aluminum , duralumin , uranium ,
thorium etc.
5. AMORPHOUS MATERIALS
➢The term amorphous refers to material that
do not have regular , periodic arrangement of
atoms .
➢Glass is an amorphous material.
6. ANOTHER CLASSIFICATION OF MATERIALS
Another useful classification of materials is
➢Metals
➢Ceramics
➢Polymers
➢Composites