Design & Technology - 0445 CIE

Composites

Overview

Some of the highest-performing materials in the world are not single substances at all but clever combinations. A composite is made by joining two or more different materials so that the result outperforms either one alone, usually by embedding strong fibres in a surrounding material that holds them in place. From the carbon-fibre frame of a racing bike to the fibreglass hull of a boat and the tough surface of a kitchen worktop, composites let designers tailor a material to a job.

This note covers the 0445 Materials-option composites objectives: what the term composite means, how composites are classified, and their properties, environmental impact and uses. It then works through the three named composites you must understand - carbon fibre reinforced polymer (CFRP), glass reinforced polymer (GRP) and melamine formaldehyde (MF) - with the real applications that explain why each exists.

Objectives

  1. demonstrate knowledge of composite materials and understand their classification, properties, environmental impact and uses
  2. show an understanding of the term composite and be aware of the practical applications for each of the following composite materials: - carbon fibre reinforced polymer (CFRP) - glass reinforced polymer (GRP) - melamine formaldehyde (MF).

Lesson Note

A composite is a material made by combining two or more different materials that stay separate and distinct within the finished material, so that the combination has better properties than any of the parts on its own. The two key parts are the reinforcement, usually strong fibres that carry the load, and the matrix, the surrounding material (often a resin) that bonds the fibres together, holds them in position, spreads the load between them and protects them. The fibres give strength and stiffness; the matrix gives shape, holds everything together and resists compression. Neither could do the job alone: loose carbon fibres are useless without a matrix, and cured resin alone is weak and brittle.

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Lesson Evaluation

Congratulations on completing the lesson on Composites. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.

You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.

Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.

  1. Which statement best defines a composite material? A. A single pure metal B. A material made by combining two or more different materials so the result outperforms either alone C. A polymer that can be re-melted D. A timber made from one species of tree Answer: B
  2. In a fibre-reinforced composite, what is the role of the matrix? A. It carries all the tensile load B. It holds and aligns the fibres, spreads load and gives the part its shape C. It makes the composite magnetic D. It allows the composite to be recycled by melting Answer: B
  3. Which composite would be the best choice for a lightweight, very stiff Formula 1 car part where cost is not the main concern? A. GRP B. Melamine formaldehyde C. CFRP D. Chipboard Answer: C
  4. What does GRP stand for and what is it commonly used for? A. Glass reinforced polymer, used for boat hulls and water tanks B. Graphite reinforced plastic, used for batteries C. General recycled polymer, used for bags D. Glass refined paper, used for laminates Answer: A
  5. Why are composites such as CFRP and GRP very difficult to recycle? A. The fibres are magnetic B. The thermoset resin matrix cannot be re-melted and the fibres cannot easily be separated from it C. They contain too much metal D. They biodegrade too quickly Answer: B

Available on the Green Bridge App

Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.

Full lesson notes with diagrams
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Available on Android, Windows, macOS, and Linux

Available on the Green Bridge App

Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.

Full lesson notes with diagrams
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Study offline, anytime, anywhere
Available on Android, Windows, macOS, and Linux

Practice Mock Questions

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