1. Material Science
Metals

2. Metallic Materials
Metallic materials have a wide range of properties, pure metallic materials have quite limited commercial use
Metal alloys, which are combinations of at least two elements, are far more versatile and for this reason are the form in which more metals are produced and used by industry
In general, they are classified into two broad families – ferrous and non-ferrous

3. Ferrous Materials The type of steel depends on two factors:
The carbon content
The alloy element

4. Classification of Ferrous Materials
High Speed Steel

5. Plain Carbon Steel Divided into 3 categories:
Low Carbon Steel : up to 0.3% carbon
Medium Carbon Steel : 0.3 – 0.6% carbon
High Carbon Steel : 0.6 – 1.4% carbon

6. Low Carbon Steel Plain Carbon Steel
The hardness of a steel is increased by the addition of the carbon
Since the proportion of carbon is low the hardness figure is low
These materials normally have good ductility and are easily worked
Steel with carbon content between 0.15 and 0.3% are called mild steel
This is a very common steel extensively used throughout industrial

7. Low Carbon Steel Plain Carbon Steel
Application:
Rivet, wire, nail, chain, seam-welded pipes,
I-beam, U-channel, angle iron,
sheet and plate,
Levers, shafts

8. Medium Carbon Steel Plain Carbon Steel
Since the carbon content is increased, the hardness of the steel also increases
This increase means that the material loses some of its ductility
It is offset by an increase in strength
The hardness can be increased by ‘Heat treatment’
It is also called ‘Yellow label steel’

9. Medium Carbon Steel Plain Carbon Steel
Application:
Shafts, connecting rods, crane hooks
Gears, crankshaft
Rails, wire rope, leaf spring

10. High Carbon Steel Plain Carbon Steel
Since the carbon content is very the steel is much harder
Further degree of hardness can be achieved by heat treatment
Used extensively in the manufacture of hand and machine cutting tools

11. High Carbon Steel Plain Carbon Steel
Application:
Dies, saw blades, anvil faces
Chisels, punches, shear blades
Drills, lathe tools, taps, reamers

12. Stainless Steel Alloy Steel
Stainless Steels contain a minimum of about 12% Chromium, which permits a thin, protective surface layer of chromium oxide to form when steel is exposed to oxygen.
The addition of chromium and sometimes nickel to the steel greatly improves the resistance to corrosion.
The ’18-8’ stainless steel often refers to a steel having about 18% chromium and 8% nickel

13. Stainless Steel Alloy Steel
Application:
Wire, tubing, sheets
Surgical and dental instrument
Poppet valves for internal-combustion engines, turbine blades, pump shafts
Chemical, dairy, laundry, and oil equipment

14. High Speed Steel Alloy Steel
High Speed Steel (HSS) designates a number of steels that have several properties which enhance their value as cutting tool material
They can be hardened to a hardness ranging from 63 Rc to 70 Rc
The principal alloying elements of HSS are tungsten, molybdenum, chromium, vanadium and carbon
HSS can be used for cutting tools such as drills, reamers, taps, dies, milling and turning cutters

15. Cast Irons The carbon content of CI is between 2 – 4%
It is hard and brittle
When molten it has good fluidity, producing good component features
It is rigid and has very good compressive strength

16. White Cast Irons Cast Iron
It is given the name because the appearance of a fracture surface is bright and silvery
It is very hard with good strength but there is a tendency to brittleness
Very difficult to machine
Its most common applications are grinding mill part, rolls for cement, ceramic and mining industrial and as a basis when producing malleable irons

17. Grey Cast Irons Cast Iron
It is given the name because the appearance of a fracture surface is dull grey
It is softer with a lower tensile strength
Grey irons are very strong in compression and also absorb vibration
It has low point and with good fluidity giving good casting properties
Good machinability
Typical applications are cylinder blocks for cars, machine tool beds, wheel drum, industrial furnace parts, water pipes and pistons

18. Copper Non-ferrous metal
Copper is a material which has been used for thousands of years
It can be used as pure metal or in combination with other elements as an alloy
The pure metal possesses desirable properties:
High electrical conductivity
High thermal conductivity
High ductility
Good malleability
High corrosion resistance
Typical applications are conductors, electrical components, tubing, wire, sheet, electrodes

19. Brass Non-ferrous metal
Brass is an alloy of copper and zinc but also contain small amounts of other alloying elements
70/30 brass, because of its ductility, can be used in pressing and drawing operations, and is used for condenser tubes
60/40 brass is used where the material is to be hot-worked. It is ideal for producing hot stampings and extruded bars, rods and sections
High tensile brass, is basically a 60/40 brass with additional alloying elements such as tin, iron and aluminium. This material can be cast, forged, and extruded. Uses include valves, pumps, propellers, screws

20. Bronze Non-ferrous metal
Bronze is essentially an alloy of copper and tin, but also contain additional elements such as zinc and phosphorus
Bronze with 5% tin and 0.4% phosphorus, it has good elastic properties and is used for springs
Bronze with 10% tin and 0.5% phosphorus, it is used for bearing applications
Bronze with 10% tin and 2% zinc, is largely used for naval purposes – valves, pump bodies, and fittings of water and steam

21. Aluminium and its alloys Non-ferrous metal
Light metal, having approximately 1/3 of the density of steel
The oxide film gives excellent corrosion resistance
High thermal and electrical conductivity
High malleability, possible to produce very thin foil
Major disadvantage: lack of strength
To overcome the problem aluminium is therefore alloyed with magnesium, manganese, copper, silicon and tin
Increase the strength and hardness and enables the material to be heat-treated to give additional properities

22. Aluminium and its alloys Non-ferrous metal
Applications:
Plate, tube, wire, bars, extruded sections
Floor section, superstructure of hovercraft, variety of components in aircraft
Large and small cable, foil, strip winding for coil and transformer
Roofing and structural applications, door and window frame, decorative items
Watches, photographic equipment, component for machine tools
Pans, furniture, packaging uses for food and drink

23. Magnesium and its alloys Non-ferrous metal
Density is approximately 2/3 of aluminium
Highly reactive when contact with oxygen
Weak and unsuitable for general use, so alloys are formed
aluminium and zinc are commonly added
After alloying, obtained a high strength-weight ratio
Its most important applications are in the aircraft industrial or other areas where weight is a limiting factor
Can be supplied in a number of forms: sand or die-cast, forged, extruded, rolled in sheet or plate
Typical applications: wheels for racing cars, crankcase and gearbox for aircraft and cars, airframe components, camera cases, business machines

24. Lead Non-ferrous metal
Lead in its pure state is very soft and has low mechanical strength
High corrosion resistance, widely used in chemical industrial
Used for radiation shielding
Two of its largest uses are as cable sheaths for power cables and in the manufacture of connectors and grids in lead-acid batteries
Lead-tin alloys give a range of soft solders

25. Zinc Non-ferrous metal
Its largest single use is as a zinc coating (galvanizing) on iron and steel.
Zinc alloy containing 4% aluminium is most widely used for die-casting alloys
The low cost and low melting point of zinc alloys make them especially suitable for die-cast parts
Their excellent castability allows production of smooth-surface
Machinability is good, but zinc alloys are difficult to weld and solder.
Uses include the mass production of car parts, camera parts, power tools, clock parts and domestic appliances

26. Tin Non-ferrous metal
Tin is a white or silvery metal with a density close to that of steel.
Commercially pure tin is rarely used alone except as a coating material.
Tin with the addition of 0.4% copper is used as foil and for collapsible tubes.
The major use of tin and its alloys is in corrosion-resistant products. More than 40% of the world's tin is used as a coating for steels and copper.
Tinfoil is used for liners for bottle caps and electrical condensers. Heavy-walled tin pipe and tin-lined copper pipe is used in the food and beverage industries.
And, tin wire is used for electrical fuses and for packing glands in pumps of food machinery.
Alloys of tin and lead are used extensively as solders