Materials: History, Types, and Properties

Materials: A Historical Perspective

Material is anything used to create something, any conglomeration of matter and mass. The history of civilization is linked to the history of materials.

The Stone Age

The Stone Age is the prehistoric period in which humans created tools from natural materials like stone, leather, and wood.

The Bronze Age

The Bronze Age marks the period when humans developed and created the first metal tools.

The Iron Age

The Iron Age represents a significant leap forward, with humans creating more advanced tools and weapons like spears and knives.

The Industrial Revolution

The Industrial Revolution, spanning the 19th and 20th centuries, was driven by discoveries such as plastics, silicon derivatives, computers, and textile fibers. This era also saw advancements in materials for aviation. Each civilization has specific material needs.

Types of Materials

Metals

Metals are elements that occupy the left side of the periodic table (80%). Their properties include:

• Ductility
• Good conductors of electricity and heat
• Malleability
• Most are solids (except mercury)
• Susceptible to corrosion

Applications of metals include:

• Modern transportation (aircraft)
• Electricity
• Water systems
• Construction
• Media and industrial systems

Polymers

Polymers (derived from plastics) are macromolecules containing repeating molecular structures, such as polyethylene.

Types of Polymers:

• Thermostable: These polymers remain stable after being heated and can be used for various applications.
• Thermoplastic: These polymers can be melted and reshaped after their initial use.
• Elastomers: These polymers exhibit high elasticity.

Polymer Sources:

• Natural: Examples include starch and natural rubber.
• Artificial: Examples include plastic bags.

Properties of Plastics:

• Insulate heat and resist electricity
• Lightweight
• Easy to mold
• Corrosion-resistant
• Not biodegradable or easily recyclable

Composites

Composites are formed by combining two materials: a binder (the material that holds the union) and a reinforcement (the material being joined). An example is fiberglass, where plastic acts as the binder.

Ceramics

Ceramics are materials made from three elements:

• Clay
• Glass
• Aluminum oxide

Properties of Ceramics:

• Heat-resistant
• Good insulators
• Lightweight
• Hard but fragile
• Resistant to corrosion
• Some are transparent (glass)