1. Introduction to Engineering and Technology Concepts Unit Two Chapter Six – Types of Materials

2. Instructions for Success: Each chapter of every unit will begin with a “Mindjog.” This is a warm up question that you should answer in your workbook in the proper chapter. Please take notes as you move through the presentations in the notebook that has been provided. Sections will come up in each presentation with an assignment notice. Turn to the section detailed on the slide in your workbook and complete the assignment before proceeding. Good luck!

3. Objective Students will classify materials according to standards.

4. Mindjog! On your worksheet, please respond to the following question: “Recalling last chapter’s information on materials, what do you think the difference between natural, synthetic, and composite materials are?”

5. Material World Materials come in all shapes and sizes and they are everywhere – and each possesses specific properties. Materials can be classified as natural, synthetic, or composite. Natural materials occur naturally on the earth. Synthetic materials are human made, with the most common being plastics. They are developed from vegetable fibers (cellulose), natural gas, and petroleum. Composite materials are combinations of natural and synthetic. For example, concrete (Wright, 2004).

6. Classification Materials that come from living organisms are called organic materials. For example, wood, cotton, and flax are products of plant fibers. Wool and leather come from animals. Petroleum and coal are products of decayed organic matter. Inorganic materials do not come from living things. For example, metals and ceramics. Organic and inorganic is one way to classify material (Wright, 2004).

7. Classification Some materials naturally occur on earth in a specific amount. Another way to classify material is by how fast those materials regenerate. Those that occur in a specific amount will not regenerate. They are exhaustible. Other materials have a life cycle and can be regenerated – they are genetic materials (Wright, 2004).

8. Classification Materials can also be classified by physical state, in the form of solid, liquids, and gases. Solid materials hold their size and shape. They have an internal structure that causes them to be rigid. (Wright, 2004). They can be divided up into these categories: metals, plastics (polymeric), ceramics, and composites. Liquids are visible fluid materials that will not normally hold their size and shape. Gases are materials that easily disperse and expand to fill any space and have no physical shape (Wright, 2004).

9. Properties All materials exhibit a specific set of properties. They include: Physical properties – characteristics due to structure of the material. Mechanical Properties – the reaction of the material to a force or load. Chemical Properties – the reaction of the material to one or more chemicals. Thermal Properties – reaction to heating and cooling. Electrical/Magnetic Properties – reaction to electrical and magnetic forces. Acoustical Properties – reaction to sound waves. Optical Properties – reaction to visible light (Wright, 2004).

10. Information Knowing that materials can be categorized allows us to create information. As discussed, information is data that has been sorted and categorized for human use. Data is raw facts and figures collected by people and machines. There are three different types of “information:” Scientific Information – organized data about the laws and natural phenomena in the universe. Technological Information – Organized data about the design, production, operation, maintenance, and service of human-made products and structures. Humanities information – Organized data about the values and actions of individuals and society (Wright, 2004).

11. Assignment #1 Please turn to the section in your workbook entitled, “Unit Two, Chapter Six – Types of Materials.” Complete the extension questions under the “Assignment #1” header before moving onto the next section of slides.

12. BEFORE MOVING ON: Did you complete the “Assignment #1” Section under the “Unit Two, Chapter Six – Types of Materials” section of your workbook? If you have, please proceed to the next slide.

13. Unit Two Completed! Please close this presentation and launch the file entitled, “Unit 3, Chapter 1.”

14. References Wright, R. (2004) “Technology” The Goodheart-Willcox Company, Inc.