Product Design Ferrous and Non-Ferrous Metals

1. Product DesignFerrous and Non-Ferrous Metals These icons indicate that teacher’s notes or useful web addresses are available in the Notes Page. This icon indicates the slide contains activities created in Flash. These activities are not editable. For more detailed instructions, see the Getting Started presentation. 1 of 24 © Boardworks Ltd 2005

2. Learning objectives • To understand where metals come from and how they are prepared for use. • To look at examples of ferrous metals, non-ferrous metals and alloys, and to know the properties of different metals. • To understand how heat treatment can change the properties of metals. • To be able to use hand tools to work with metals. • To be familiar with the industrial processes used to manufacture metal goods. Learning objectives 2 of 24 © Boardworks Ltd 2005

3. Background on metals Metals are common in manufacturing today. From building and construction work to vehicles and leisure products, they are a vital material for product designers and engineers. The elements of all metals are found naturallyin the earth. However, they need to be extractedand processed before they can be used for manufacturing purposes. Because metals in their most basic form are natural resources, designers and manufacturers need to be careful and socially responsible about how much they use, and reuse or recyclemetals where possible.

4. Where do metals come from? Metals form part of the earth’s crust as metal ore. To obtain useful metals, the metal ore is mined and washedto remove other minerals and unwanted materials. Iron ore is the basis for most steels. To extract pure iron the iron ore is heated in a furnace in a process known as smelting.

5. Primary processes – rolling

6. Primary processes – extrusion

7. Stock forms of metals Metals are available in several raw forms. Each form is suitable for different manufacturing processes depending on the type of equipment used, the cost of the metal, the scale of production and the properties of the finished product. flat strip round rod round tube square square tube hexagonal angle channel octagonal sheet

8. Pure metals Alloys Alloys Categories of metals Metals can be broken down into these main categories: Ferrous metals Non-ferrous metals Pure metals do not contain any other metals or elements.

9. Ferrous metals Ferrous metals are obtained from iron ore. You might recognize the letters ‘Fe’ from the periodic table, where they represent iron. Ferrous facts Ferrous metals: • Iron replaced bronze as the principal metal by 1000 BC. • Early pots and pans made from iron poisoned the users! • Early steels were made by adding carbon to iron as it was melted over a charcoal fire. • contain iron • will corrode unless protected • are attracted by a magnet • are strong, rigid and cheap.

10. A closer look at ferrous metals

11. Non-ferrous metals Non-ferrous metals do not contain iron. These are pure metals used by designers, manufacturers and engineers in a wide variety of applications. Non-ferrous facts Non-ferrous metals: • Aluminium is the most common non-ferrous metal, found in abundance in bauxite ore. • Non-ferrous metals are not magnetic. • contain no iron • are not attracted by a magnet.

12. A closer look at non-ferrous metals

13. Alloys Sometimes ferrous and non-ferrous metals require different properties in order to function better in specific situations. Alloying metals involves mixing two or more metals and other elements to improve their properties. Alloying metals can: • lower the melting point • alter thermal and electrical properties • make a material harder for cutting purposes • improve resistance to corrosion • help metal to flow better into a cast.

14. A closer look at alloys

15. Random alloy generator

16. Metals and their properties

17. Changing the properties of metals

18. Heat treatment – hardening steel

19. Heat treatment – tempering

20. Heat treatment – annealing

21. Working with metals – hand tools

22. Industrial processes Milling machines are used to remove thin layers from a billet (block of material) which is clamped to the bed (base) of the machine. The material is fed past a cutting tool which has many sharp teeth and can remove material quickly. When manufacturers want to make cylindrical products, they use a centre lathe. Metals and plastics can be used on this machine. The work is held in a chuck and a cutting tool is moved towards the work while being held in a tool holder, mounted on the tool post.

23. Finishing techniques Several surface finishing techniques can be used on metals. The most common ones are detailed below: Paint Lacquering • Helps to prevent corrosion after polishing • A layer of cellulose or varnish is applied • Often used on jewellery. • Surface must be smooth andde-greased • Primer required • Hammerite is a good one-coat metal paint. Plastic Coating Enamelling • Suitable for most metals • Object is heated and dipped in a tank of powder paint • Object is returned to oven to ensure a smooth, glossy finish. • Powdered glass is melted onto the metal surface • Provides a hard (but brittle) finish with different colours and textures.

24. Key points • Metals are extracted from the earth’s crust and then prepared into standard shapes before being sold to manufacturers. • Ferrous metals are obtained from iron ore and include cast iron and steel. Non-ferrous metals include aluminium, copper and tin. • Alloys, such as brass and stainless steel, are formed from two or more metals and other elements. Different elements alter the properties of metals. • Heating metals also alters their properties. • Metals can be worked with hand and machine tools, including milling machines and centre lathes. Key points 24 of 24 © Boardworks Ltd 2005