Difference Between Alloy and Composite

Main Difference – Alloy vs Composite

Alloys and composites are mixtures of elements. The main difference between alloy and composite is that alloy has at least one metal in its composition whereas composites do not have metal components. Both alloys and composites indicate different characteristics than their starting materials. Although both of them are composed of at least two types of elements, they have several distinct properties which make them different from each other.

Key Areas Covered

1. What is an Alloy
      – Definition, Composition, Properties and Uses
2. What is a Composite
       – Definition, Composition, Properties and Uses
3. What is the difference between Alloy and Composite
      – Comparison of Key Differences

Key Terms: Alloy, Brass, Bronze, Composite, Luster, Metal, Mineral, Steel

Difference Between Alloy and Composite - Comparison Summary

What is an Alloy

Alloys are metallic compounds. An alloy contains at least one metal element along with other elements. Alloys have improved properties when compared to properties of each single element they are made of. These properties are obtained by mixing elements in different percentages. Therefore, the desired properties can be obtained by mixing different metals and elements in different amounts. Alloys may be homogenous or heterogeneous. Almost all alloys have a luster due to the presence of the metal component. Alloys are also able to conduct electricity due to the presence of a metal component.

Common Alloys

Name of Alloy

Composition

Properties

Uses

Steel

Mainly iron, carbon and other elements such as phosphorous or sulfur.

Strength, toughness, durability, weldability.

Used as building material

Brass

Mainly copper, zinc sometimes with aluminium or lead.

Malleability, softness, low friction

Decoration purposes

Bronze

Mainly copper, tin sometimes with arsenic, aluminium, phosphorous.

Corrosion resistance, hard and brittle

Ship and boat fittings

Duralumin

Copper, manganese, magnesium and sometimes silicon.

Light, strong

To make airplane body

Difference Between Alloy and Composite

Figure 01: A musical instrument made of brass

What is a Composite?

A composite is also a mixture of two or more elements, but it does not contain metal components. Unlike alloys, composites are always heterogeneous. Most composites are found naturally while some composites are synthetic. Composites are made out of components which have significantly different physical properties. Wood is a natural composite and concrete is a synthetic composite. Some common composites and their properties are shown below.

Common Composites

Name of the composite

composition

Properties

Wood

Cellulose fibers and lignin

Strong

Bones of human body 

Calcium phosphate and collagen

Hard, but brittle

Fiberglass

Plastic matrix and glass

Suitable for boat hulls and car bodies due to light weight

Concrete

Stones, cement, and sand

Good compressive strength

 

Main Difference - Alloy vs  Composite

Figure 2: Benches made of Wood

Difference Between Alloy and Composite

Definition

Alloy: Alloy is a mixture of two or more metallic components with other elements.

Composite: Composite is a mixture of non-metallic components.

Composition

Alloy: Alloys always have at least one metal element.

Composite: Composites do not have any metal atoms.

Arrangement

Alloy:  Alloys can be either homogeneous or heterogeneous.

Composite: Composites are always heterogeneous.

Appearance

Alloy: Alloys have a luster due to the presence of a metal.

Composite: Composites do not have a luster.

Electrical Conductance

Alloy: Almost all the alloys can conduct electricity due to the presence of a metal.

Composite: Polymeric composites can conduct electricity whereas other composites cannot. 

Conclusion

Both alloys and composites are mixtures of elements. Alloys can be found naturally although they are very rare. Composites occur naturally almost everywhere. The main difference between alloy and composite is that alloy has at least one metal in its composition whereas composites do not have metal components.

References:

1.Johnson, Todd. “What Is a Composite Material?” ThoughtCo. N.p., n.d. Web. Available here. 15 June 2017. 
2.Shiwakoti, Ritesh. “Metals and Alloy.” LinkedIn SlideShare. N.p., 31 Oct. 2014. Web. Available here. 15 June 2017. 

Image Courtesy:

1. “Bench Wooden Bench Wood Click Forest Seat Out” (CC0) via Max Pixel
2. “Valves Rotary Valves Tuba Stimmzug Brass Instrument” (CC0) via Max Pixel

About the Author: Madhusha

Madhusha is a BSc (Hons) graduate in the field of Biological Sciences and is currently pursuing for her Masters in Industrial and Environmental Chemistry. Her interest areas for writing and research include Biochemistry and Environmental Chemistry.

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