Alloys & Composites

Alloys

Most of the elements in the Periodic Table are metals. Some are extremely reactive, whereas other barely react at all.  However, sometimes a pure metal just isn't quite suited for a job. So we can melt two or more metals together, let them solidify and form an Alloy.

An alloy is a mixture of metals. They have superior properties to the pure metals they are made from. They might be stronger, lighter or better at conducting electricity or heat than pure metals. 

The table below shows some examples of common alloys:-

The videos below give more information on two alloys; Bronze and Steel. 

Composite Materials 

Like an Alloy, a 'Composite Material' is a combination of two or more materials with different physical and chemical properties. When combined, they create a new material with specialized properties, often tailored for a specific purpose. The goal is to achieve a material that is stronger, lighter, more durable, or has other desirable characteristics than the individual components. 

Unlike Alloys, which are a complete mixture, composite materials still remain destinguishable within the Composite. 

Composites have two distinct parts: 

• Matrix : Main material by volume, used to bind the composite together

• Reinforcement : Provides structural strength to the composite

Composites : Concrete

Concrete is a composite material made of aggregate (sand and gravel) mixed together with cement and water that cures to a solid over time. 

It is the second-most-used substance in the world after water, and is the most widely used building material. Concrete forms the foundations, walls and floors of many buildings, the structure of bridges and the walls of dams. 

Concrete is used because of it's high strength, it's durability, it's ability to be shaped in a mold when still liquid and it's resistance to fire damage. 

Concrete can be further stengthened by adding Steel bars within it to make a new compsosite, Steel-reinforced concrete. 

Medical Composites

Composite materials are used in a wide range of medical applications from dental implants and joint replacements to replacing lost limbs. These all depend on the composites properties of being lightweight, strong and unreactive to the body's tissues.