YOUR AIMS

On completion of this lesson you should be able to:
- appreciate the historical development of materials
- understand how materials are classified
- recognise the properties and characteristics of the different classes of materials
- appreciate the relevance of materials to present and future engineering practice.

SELF-ASSESSMENT QUESTIONS

1. Name two situations in which surgeons regularly replace body parts with implant materials. Suggest possible materials for the implants.
What is a major consideration when selecting a biomaterial to be used as an implant in the human body?

2. Material developments in the future will include the so-called 'smart' materials. State why are they regarded as 'smart' and provide some examples of such materials.

3. What are the three traditional basic groups into which materials have been classified? Why is it that nowadays these classifications are regarded as somewhat blurred?

4. Outline how thermoplastic materials differ from thermosets. Give examples of both polymer types and suggest some possible applications.

5. Complete the comparative table opposite using such terms as variable, good, high, low, moderate, insulator and conductor, as you think
appropriate.