Material and Their Common Uses

 

FIRST TERM 

 

 

SCHEME OF WORK WITH LESSON NOTES

Subject : 

BASIC TECHNOLOGY

Term :

FIRST TERMTERM 

Week:

WEEK 6

Class :

JSS 2 (BASIC 8)

Previous lesson: 

The pupils have previous knowledge of

First Aid and Materials

Topic:

Material and Their Common Uses

.

Behavioural objectives:

By the end of the lesson, the pupils should be able to

  • define material
  • say the uses of wood
  • explain the types of iron

 

Instructional Materials:

  • Wall charts
  • Pictures
  • Related Online Video
  • Flash Cards

Methods of Teaching:

  • Class Discussion
  • Group Discussion
  • Asking Questions
  • Explanation
  • Role Modelling
  • Role Delegation

 

Reference Materials:

  • Scheme of Work
  • Online Information
  • Textbooks
  • Workbooks
  • 9 Year Basic Education Curriculum
  • Workbooks

 

Content:

 

  1. Uses of Wood
  2. Uses of Metals

Uses of Wood

Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic material, wood is sometimes defined more broadly to include the same type of tissue elsewhere such as in the roots of trees or shrubs.In a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between the leaves, other growing tissues, and the roots.

Wood is used today in the following industries and processes.

Housing: The doors, windows and roofing of our houses.

Industrial Building: Many industries are constructed with wood, or they have wooden parts.

Joinery: The stair case in our homes.

Packaging: Crates, pallets, packing and cases, etc.

Furniture: Chairs, beds, wardrobes, tables, bookcases.

Transport: Railway wagons, coaches, lorry bodies.

Bridges and poles: Most farm bridges across the roads in villages are made of wood, Also, some electric poles and railway sleepers are made of wood.

Pulp and Paper: Exercise books, textbooks, newspapers, magazines, are made from pulp and paper derived from wood.

Medicine: When people have their arms or legs amputated (cut off), such are usually replaced by artificial limbs made from wood.

Clothing: Most heels and some soles of shoes are made from wood. The rayon stockings and shirts that we wear are made from wood.

Tool Making: Handles for hampers, pick axes, felling axes, screwdrivers, and many other tools are made from wood.

Some of the uses of ‘Softwoods and hardwoods

Softwoods

NAME AND ORIGIN PROPERTIES USES
Cedar (Asia and Africa) Reddish-pink colour, Low density, Little grain pattern, Hardwearing under outdoor conditions In the building industry for roofing and garages, doors and partitions
Pine (North America) Yellow-brown colour, Clear growth rings, Durable and strong, with high resin content, Weather well Railway sleepers, heavy gate posts. Decorative panels and stairways. Pattern making joinery.

 

Spruce (North America and Canada) Very pale straw/yellow, Fairly durable Aircraft industry, Ship masts, Interior joinery, Ladders, Packing cases.

Hardwoods

NAME AND ORIGIN PROPERTIES USES
Afromosia (Africa) Dark brown colour, Similar appearance to teak, Durable, Easy to work Ship building, Good quality furniture
Agba (Nigeria and Angola) Yellow to reddish brown, Straight grinned, Resists decay Joinery and Furniture, General construction
Balsa (America) Creamy colour, One of the softest, and lightest of woods. Model making, Life rafts, life belts, insulation (noise or heat)
Beech (Europe) Pale pink colour, Hard and close-grained, Good bending qualities, Is attacked by fungus, Weathers well Furniture mallets, Kitchen utensils, e.g. bread boards, rolling pins.
Ekki (Africa) Red or dark brown colour, Tough and durable, Resists attack by insects. Piers pile, dock gates, Bridge building.
Gaboon ( Africa) Pale mahogany colour, Fairly soft and easy to work,  
Iroko (Africa) Yellowish brown colour, strong and durable, Hard and heavy. Joinery
Mahogany (Africa, Spain, Honduras) Lightish to deep red colour, Durable, very good working, qualities. Cabinet making, Ship building, Panelling, Carving, Wood turnery, Veneers.
Oak (England and Northern Europe) Golden brown colour, Strong and durable with pronounced grain. Distinctive figure pattern when quarter sawn. Furniture making, Boat building,

Veneers, plywood.

Obeche (West Africa) Weathers well Creamy white to pale yellow Soft, fairly light Easy to work. Interior joinery, Furniture, Model making.
Teak (INdis, Burma, Africa) Darkish brown colour, Strong and durable, Feels greasy because of its oil content. Weather well, Resists attack by insects. Ship building, Furniture, Laboratory benches, veneers.

Uses of Metals

Metals are some element that is typically hard, opaque, shiny, and has good electrical and thermal conductivity. Metals are generally malleable—that is, they can be hammered or pressed permanently out of shape without breaking or cracking—as well as fusible (able to be fused or melted) and ductile (able to be drawn out into a thin wire). Most metals are solid at room temperature, but this does not have to be the case.

Metals could be ferrous when it contains iron and non-ferrous when it does not contain iron.

Ferrous Metals

Name Melting Point 0C Composition Properties Uses
Cast iron 1240 Mixture of carbon and iron, Carbon content 1.5-5% Vary with carbon content. Brittle with a hard skin. Feel carbon content. Very suitable for moving parts of machinery because use of the ability of one piece to slide on another due to another the carbon content.
Wrought iron 2000 99% iron with small amounts of impurities. Malleable and ducile, Elastic, Not very hard, Can be shaped, easily when red hot (forged). Engine blocks, Haulage gear, Vices, Crane hooks, and chains.
High carbon steel (Tool steel, cast steel) Varies 99% iron with small amounts of impurities. Mixture of carbon and iron. Carbon content 0.1-0.5% Malleable and ductile, Elastic, Not very hard, Can be shaped easily, when red hot (forged). Malleable and ductile. Very good working qualities: bends, files. Haulage gear, Crane hooks and chains, Anchor chains, General constructional works Nuts, bolts, screws, Non-cutting tools steel sheets.
Low carbon steel (Mild steel) Varies Mixture of carbon and iron. Forges and machines well, Harder than low, Carbon steel, Harder as carbon. All kinds of cutting tools: Steel sheets.

Metals are very useful to people. They are used to make tools because they can be strong and easy to shape. Iron and steel (which are a variation of metal) have been used to make bridges, buildings, or ships. Some metals are used to make items like coins because they are hard and will not wear away quickly. For example copper (which is shiny and red in color), aluminium (which is shiny and white), gold (which is yellow and shiny), and silver and nickel (also white and shiny). Some metals, like steel, can be made sharp and stay sharp, so they can be used to make knives, axes or razors. Rare metals with high value, like gold, silver and platinum are often used to make jewellery. Metals are also used to make fasteners and screws. Pots used for cooking can be made from copper, aluminium, steel or iron. Lead is very heavy and dense and can be used as ballast in boats to stop them from turning over.

Many things that are made of metals may, in fact, be made of mixtures of at least one metal with either other metals, or with non-metals. These mixtures are called alloys. Some common alloys are:

  • Steel (iron and carbon) (Carbon is a non-metal)
  • Brass (copper and zinc)
  • Bronze (copper and tin)

People first began making things from metal over 9000 years ago, when they discovered how to get copper from its ore. They then learned how to make a harder alloy, bronze, by adding tin to the copper. About 3000 years ago, they discovered iron. By adding small amounts of carbon to iron, they found that they could make a particularly useful alloy – steel.

Uses of Brass

Brass is a general term for a set of copper-zinc alloys that may include additional metals such as lead. Different types of brass have different properties, but all brass is strong, machinable, tough, conductive, and corrosion resistant. This along with beauty and ease of production make brass one of the most widely used alloys.

Brass has, for centuries, been the metal of choice for many musical instruments. It’s an ideal alloy for the transport of water through pipes and fittings. It’s also appropriate for use in marine engines and pump parts. It should not be surprising that one of the first commercial uses of brass was on naval ships.

Another common usage of the metal comes from its non-magnetic nature. Clock and watch components, electrical terminals and munitions all require a metal that will not be affected by magnetism.

While compiling a complete list of all of brass’s applications would be a colossal task, we can get an idea of the breadth of industries and the types of products in which brass is found by categorizing and summarizing some end-uses based on the grade of brass used.

Free Cutting Brass

Alloy C-360 brass, also called “free cutting brass,” is alloyed with copper, zinc, and lead. Free cutting brass is very easy to machine, but also offers the same toughness and corrosion resistance as other forms of brass.

Some uses for free cutting brass include:

  • Nuts, bolts, threaded parts
  • Terminals
  • Jets
  • Taps
  • Injectors
  • Valve bodies
  • Balance weights
  • Pipe/water fittings

Gilding Metal (Red Brass)

Gilding metal is a form of brass that is made up of 95% copper and 5% zinc. A soft brass alloy, gilding metal can be hammered or easily formed into desired shapes.

Its unusual deep bronze color and ease of use make it ideal for craft-related projects. It’s also commonly used for artillery shells. Some other uses include:

  • Architectural fascias
  • Grillwork
  • Jewelry
  • Ornamental trim
  • Badges
  • Door handles
  • Marine hardware
  • Primer caps
  • Pen, pencil and lipstick tubes

Engraving Brass

Engraving Brass, also referred to as alloy C35600 or C37000, contains either 1% or 2% lead. Its name, not surprising, comes from its use in the creation of engraved nameplates and plaques. It may also be used for:

  • Appliance trim
  • Clock components
  • Builders hardware
  • Gear meters

Arsenical Brass

Arsenical brass (C26000, C26130 or 70/30 brass) contains about .03% arsenic to improve corrosion resistance in water. Like other forms of brass, arsenical brass is bright yellow, strong, and easy to machine. It’s also an appropriate metal to use in plumbing. Other uses include:

  • Heat exchangers
  • Drawn and spun containers
  • Radiator cores, tubes, and tanks
  • Electrical terminals
  • Plugs and lamp fittings
  • Locks
  • Cartridge casings

High Tensile Brass

High tensile brass is a particularly strong alloy which includes a small percentage of manganese. Because of its strength and non-corrosive qualities, it is often used for products that undergo a good deal of stress.

Some examples include:

  • Marine engines
  • Hydraulic equipment fittings
  • Locomotive axle boxes
  • Pump casting
  • Heavy rolling mill housing nuts
  • Heavy load wheels
  • Valve guides
  • Bushes bearings
  • Swash plates
  • Battery clamps

Uses of Bronze

bronze is typically used in outdoor sculpture. Its forms are almost limitless since it may be cast in any shape for which a mold can be devised. The most common types of forms include the human figure, landscapes, battle scenes, animals, weapons, decorative elements such as stars, rosettes, etc., and plaques.

Architectural bronze is typically used for:

Door and window frames

Door and window hardware

Mail boxes and chutes

Trim or rails

Furniture hardware

As a general rule, architectural applications seek to preserve the natural, highly polished “pinkish” finish of raw bronze, in contrast to the patination of outdoor sculpture/ornament. This is achieved by the frequent polishing and oiling of bronze/brass decorative and structural elements, or the application of clear lacquers which must be renewed on a periodic basis.

 

 

 

 

Presentation: The topic is presented step by step

 

Step 1:

The class teacher revises the previous topics

 

Step 2.

He introduces the new topic

 

Step 3:

The class teacher allows the pupils to give their own examples and he corrects them when the needs arise.

 

 

 

Evaluation

  1. Give two examples of softwood and their uses.
  2. Give two examples of hardwood and their uses.
  3. List 5 uses of bronze
  4. List 4 types of brass
  5. List 5 uses of brass
  6. List 5 uses of wood
  7. List 5 uses of metals

 

 

 

 

Conclusion:

The class teacher wraps up or concludes the lesson by giving out a short note to summarize the topic that he or she has just taught.

The class teacher also goes round to make sure that the notes are well copied or well written by the pupils.

He or she makes the necessary corrections when and where the needs arise.