Composite Materials: Define, Types, Components, Pros

What is Composite Material?

A composite material is created by combining two substances with various physical and chemical properties. When combined, a material is produced specially designed to carry out a specific task, such as becoming stronger, lighter, or electrically resistant.

Composite Material Definition

A material that is created from two or more constituent materials is called a composite material. A composite material can increase stiffness and strength. They are preferred over conventional materials because they enhance the underlying material’s qualities and can be used in various contexts.

These constituent materials are combined to produce a material with characteristics that are distinct from the constituent parts despite having chemical or physical qualities that are noticeably different. The finished structure’s components stay distinct and independent, setting composites apart from mixes and solid solutions.

Components of Composite Material

Composite materials, often called Fiber-Reinforced Polymer (FRP) composites, are constructed from a polymer matrix that has been reinforced with an artificial, natural, or synthetic fibre (such as glass, carbon, or aramid) or other strengthening substance. The matrix distributes the load among the fibres while shielding them from external and environmental harm. In turn, the fibres give the matrix reinforcement and stiffness to prevent cracks and fractures.

Polyester resin serves as the matrix and glass fibre as the reinforcement in many items in our business. However, a variety of resin and reinforcement combinations are employed in composites, and each material adds to the particular characteristics of the finished product: Strength and stiffness are provided by fibre, which is strong but fragile, while the fibre is shaped and covered by resin, which is more flexible. Additionally, FRP composites may include fillers, additives, core materials, or surface finishes intended to enhance the production process, the finished product’s look, and its functionality.

Types of Composite Material

Currently, composites are widely used in consumer goods and construction materials as a lightweight, economical replacement for metals. Composite materials are being used to create parts that are as massive as passenger aeroplane fuselages. The various types of composite materials are as follows:

• Ceramic matrix composite
• Metal matrix composite
• Reinforced concrete
• Glass fibre reinforced concrete
• Translucent concrete
• Engineered wood
• Plywood
• Engineered bamboo
• Parquetry
• Wood-plastic composite
• Cement-bonded wood fibre
• Fibreglass
• Carbon Fiber reinforced polymer
• Sandwich panel
• Composite honeycomb
• Papier-mache
• Plastic coated paper
• Syntactic foams

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Properties of Composite Materials

Each of the different forms of composites includes a broad and expanding range of materials; however, composites as a class of materials typically exhibit the following qualities: a low coefficient of thermal expansion, high strength, high modulus, low density, and exceptional fatigue resistance, creep, creep rupture, corrosion, and wear.

Physical Properties

The physical properties of the composite are not isotropic in nature. But typically, they are anisotropic. For instance, the stiffness of the composite panel will often depend on the direction of the applied forces and/or moments. By applying the rule of mixtures, it is possible to find the condition that sets the upper limit for composite strength. There are two rules of mixture:

• Isostrain rule of mixtures
• Isostress rule of mixtures

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Mechanical Properties of Composite Materials

High-strength, high-modulus fibres are incorporated into a matrix to create a composite material (polymer, metal, or ceramic). The fibres’ orientation can result in various in-plane characteristics (longitudinal, transverse-stress, strain, and modulus of elasticity).

• Particle Reinforcement: Particle reinforcement generally strengthens composites less than fibre reinforcement. It improves the composites’ stiffness while boosting their toughness and strength. They are utilised in applications that demand resistance because of their mechanical characteristics.
• Continuous Fiber Reinforcement: Generally, a matrix with a weak phase and a fiber acting as the strong phase is used to accomplish continuous fiber reinforcement. The availability of materials in their fibre form, which can be obtained, accounts for the popularity of fiber utilisation. Due to the covalent nature of their linkages, non-metallic fibers typically exhibit a relatively high strength to density ratio when compared to metal fibers. The most well-known example of this is carbon fibers, which have numerous uses in the space industry, sports gear, and protective gear.

Advantages of Composite Material

Our daily lives are surrounded by composites: they are found in the vehicles we drive, the golf clubs we use, the pipelines that transport sewage from our communities, and much more. Some applications, like rocket ships, might not even exist without composite materials.

Composites have a lot of advantages. Strength, lightness, resistance to corrosion, design flexibility, and durability are essential attributes among them.

Strength

Composites outperform traditional materials like steel in terms of strength per kilogram. Composites’ two main ingredients, fibres and resins, both contribute to their tensile strength. The weight is carried by the fibres, and the resins distribute it appropriately throughout the composite part.

Lightweight

Compared to most woods and metals, composite materials are lightweight. In both automobiles and aircraft, lighter weight improves fuel efficiency. Furthermore, lighter materials, from bridge decks to utility poles, are simpler to carry and assemble.

Durable

Composite-built structures are durable and require little care. Boats and other items built of composites have been in use for more than 50 years.

Flexible

Composites have a broad range of material combinations that can be used, which promotes design flexibility. The materials can be specially made to meet the particular requirements of each application. Additionally, composites are simple to mould into complex designs.

Resistant

Unlike other materials, composites are resistant to weather damage and corrosive substances. Because of this, they are suitable for situations where salt water, hazardous chemicals, temperature changes, and other harsh conditions are present constantly.

Important Topics for Gate Exam
Internal and External Forces	Lami’s theorem
Psychrometry	Sand Casting
Types of Patterns	Gear Design
Ceramics	System of Forces
Principle of Virtual Work	Metal Casting