Processing Of Alloys Materials JSS3 Basic Technology Lesson Note

TOPIC: PROCESSING OF MATERIALS: ALLOYS

CONTENT

1.         Metal processing methods
2.         Metal alloys, examples, properties, and uses.

Metals are materials used in producing some equipment used in everyday life. Metals are usually solid but a few ones are liquid or powder form. They are made of raw forms called ore. 

METHODS OF PROCESSING METALS

Most metals do not occur in a pure state; they are usually combined with other metals and earthly impurities to form what is called mineral ore. The ore is then mined and processed to extract the metal of interest. The methods of processing metals include:

1.         Casting 
2.         Smelting 
3.         Annealing 

CASTING

This is the process of melting and pouring molten metal into the mould to take the shape of the mould when it cools down or solidifies. 

SMELTING

This is the process of extracting metals from iron ore dug from the ground.

ANNEALING

This is the process by which metals can be softened.

EVALUATION

1.         Explain the following terms: (a) casting (b) annealing (c) smelting.
2.         Briefly describe metals 

STAGES OF METAL PRODUCTION

There are three stages in the production of metals.

STAGE ONE: EXTRACTION STAGE: The rock containing the metal is dug from the ground with drilling and excavating. The rock and the metal mixed are called the metal ore(the impure metal)

STAGE TWO: SMELTING STAGE: The metal ore is heated in a furnace( e. g blast furnace ) until the metal melts into liquid form with other impurities that have mixed with it.

STAGE THREE: CASTING STAGE: The hot molten (liquid) metal is poured into a container of different lengths and sizes called moulds.it is left there to solidify to take up the shape of the mould, this is called casting. This is how round bars, square bars, wires, and others are produced.

EVALUATION

Briefly explain the three stages of metal production.

METAL ALLOYS, EXAMPLES PROPERTIES, AND USES

An alloy is a metal that is obtained by mixing two or more metals examples are ferrous alloys and non-ferrous alloys

NON FERROUS ALLOYS

EVALUATION

1.         What is an alloy?
2.         State three examples of alloy ferrous metals and mention (2) practical uses of each.
3.         State three (3) examples of non-ferrous metal and mention (2) practical uses of each.

GENERAL EVALUATION

1.         Defines metals.
2.         Mention the classes of metals with examples.
3.         Differentiate between ferrous metals and non-ferrous metals.
4.         Describe the processes of processing metals.

READING ASSIGNMENT

Read about ‘processing clay, ceramics, plastics, rubber and glass

REFERENCE BOOKS

(i) EVANS Basic Technology for JSS book 3.

(ii) NERDC Basic Technology for JSS book 3. pg.22-36.

WEEKEND ASSIGNMENT

1.         The metal obtained from the processing of iron ore in a blast furnace is __ (a) limestone (b) steel (c) pig iron (d) coke.
2.         The best material for making cooking pots is ___ (a) Tin  (b) steel (c) clay (d) aluminum.
3.         The process of melting and pouring molten metal into the mould to take the shape of the mould when it cools down or solidifies is called ______ (a) smelting (b) casting (c) annealing (d) furnishing.
4.         Which of the following is not a stage in metal production? (a) extraction stage (b)fabrication stage (c)smelting stage (d)casting stage.
5.         The following are examples of alloys except(a) bass (b) bronze (c)copper (d) duralumin. 

THEORY

1.         In tabular form, mention two examples of ferrous alloys and non-ferrous alloys, state their components, properties, and uses
2.         Explain the process of processing metal.