1. 4.2 Metals and Metallic alloys
IB Design Technology
4.2 Metals and Metallic alloys

2. Objectives
Discuss metals and metallic alloys placing emphasis on their extraction, categorization, utilization, and recovery and disposal
Understand the role of metals and metallic alloys in design

3. Characteristics and Importance of Metals
Hard and shiny
Electrical and thermal conductivity
Pure metals are:
Brittle
Soft
Chemically reactive
Have to manipulated to be useful
Highly useful resource

4. Ferrous vs. Non-Ferrous
Contains Iron
High tensile strength and high durability
Magnetic
Subject to oxidation
Non-Ferrous
No Iron
Strong, but malleable
Non-magnetic
Resistant to oxidation
Light

5. Ferrous
Carbon Steel

6. Ferrous
Cast Iron Engine Block

7. Non-Ferrous
Aluminum

8. Non-Ferrous
Copper

9. How is This Resource Obtained?
Three steps:
Concentrating Ore
Reduction to Crude Metal
Electrolysis
Reducing the amount oxides using carbon
Heating ore
Refining to obtain pure metal

11. Making Steel

12. Grain Size Refers to the individual size of the metal General Rule:
Why is this important?
The grain size affects the strength and ductility of a metal
General Rule:
As grain size decreases the strength of the metal increases and it ductility decreases

13. Steel

14. Copper

15. Microscope Eye Piece for Analysis

16. Your Turn
Due to pure metal’s softness, brittleness, and chemical reactivity, it must be modified to be utilized.
Research
Alloys
Work Hardening
Tempering
Write a brief description of each. Be sure to provide an example and/or use.

17. Super Alloys Resist Can withstand higher temperatures and stress.
oxidation
creep (permanent deformation, usually as a result of exposure to high temps)
Can withstand higher temperatures and stress.
Lets take a look at this:

18. Recovery and Disposal of Metal and Metal Alloys
Ferrous metals are one of the most recyclable resources on the planet
Recycling helps to circumvent the limited availability of metals
Metals are gathered and melted down in order to reuse them for a different application

19. Reflection
What impacts does the characteristics of metal and metallic alloys have on design?