1 materials and processes- Metals

Question 1

Ferrous

Answer 1

Ferrous metals are metals that consist mostly of iron and small amounts of other elements. Ferrous metals are prone to rusting if exposed to moisture. Ferrous metals can also be picked up by a magnet.

Question 2

Non-Ferrous

Answer 2

Non-ferrous metals are metals that do not have any iron in them at all. This means that Non-ferrous metals are not attracted to a magnet and they also do not rust in the same way when exposed to moisture.

Question 3

Alloy

Answer 3

Alloys are substances that contain two or more different metals and occasionally other elements.

Question 4

pure Metals

Answer 4

A pure metal only consists of a single element. This means that it only has one type of atom in it.

The common pure metals are: aluminium, copper, iron, lead, zinc, tin, silver and gold.

Question 5

Why is carbon added?

Answer 5

Generally, carbon is the most important commercial steel alloy.

Increasing carbon content increases hardness and strength and improves hardenability. But carbon also increases brittleness and reduces weldability.

Question 6

Low Carbon

Answer 6

Often called mild steels, low-carbon steels have less than 0.30 percent carbon and are the most commonly used grades. They machine and weld nicely and are more ductile than higher-carbon steels.

Question 7

High carbon

Answer 7

With 0.45 to 0.75 percent carbon, these steels can be challenging to weld. Preheating, post-heating (to control cooling rate), and sometimes even heating during welding become necessary to produce acceptable welds and to control the mechanical properties of the steel after welding.

Question 8

Very High carbon

Answer 8

With up to 1.50 percent carbon content, very high-carbon steels are used for hard steel products such as metal cutting tools and truck springs. Like high-carbon steels, they require heat treating before, during, and after welding to maintain their mechanical properties.

Question 9

Common types of alloys

Answer 9

steel- a combination of iron and carbon
Bronze- copper and tin
Brass- copper and zinc

Question 10

Aluminum alloys

Answer 10

duralumin

uses: aircrafts, airships, spirit levels
properties: strong, hard, lightweight, relatively soft ductile, can be rolled

Question 11

Aluminum

Answer 11

Pure metal

good strength weight ratio, malleable and ductile, difficult to weld, non-toxic, resists corrosion, heat, and electricity well, polishes well

Kitchen foil, saucepans, and drinks cans

Question 12

Copper

Answer 12

Pure metal

tought, ductile, malleable, conducts heat and electricity. Corrosion-resistant, welds well, polishes well

electrical wires, central heating pipes, circuit boards, saucepan bases

Question 13

Brass

Answer 13

Copper and zinc

Hard, rigid, solders easily, good conductor of heat and electricity, polishes well

Water taps, lamps, boat fittings, ornaments, door knockers

Question 14

Bronze

Answer 14

Copper and tin

Tough, strong, wears well, good corrosion resistance

Coins, wheel bearings, statues, boat fittings

Question 15

Tin

Answer 15

Pure metal

weak, soft, malleable, ductile, excellent corrosion resistance, low melting point

solder, coating over mild steel

Question 16

Lead

Answer 16

Pure metal

soft, malleable, very heavy, corrosion resistant, low melting pint, casts well, conducts electricity well

Roof covering, solder, car battery plates

Question 17

Zinc

Answer 17

Pure metal

poor strength to weight ratio, weak, ductile, malleable, low melting point, casts well

Coating over mild-steel, die casting (Used in cars)

Question 18

Ferrous metals

Answer 18

Aluminum
duralumin  
copper 
brass
bronze 
tin 
zinc

Question 19

Non- ferrous metals

Answer 19

cast iron
mild steel
high carbon steel 
high-speed steel 
Stainless steel

Question 20

Cast iron

Answer 20

iron + 3.5% carbon

smooth skin with softcore, strong when compressed, self-lubricating, cannot be bent or forged

Vices, lathe beds, garden bench ends, car brake drums

Question 21

Mild steel

Answer 21

iron + o.15 -0.35 % carbon

ductile, malleable, thought, high tensile strength, poor resistance to corrosion, easily welded

car bodies, washing machine bodies, nuts and bolts, screws, nails, girders

Question 22

High carbon steel

Answer 22

iron +0.8 - 1.5% carbon

very hard, rather brittle, difficult to cut, poor resistance to corrosion

Tool blades e.g. saws, chisels, screwdrivers

Question 23

High-speed steel

Answer 23

iron + tungsten chronium vanadium

very hard, heat resistant remains warm when red

rills, lather cutting tools, milling cutters d

Question 24

stainless steel

Answer 24

iron + chromium, nickel, magnesium

tough, hard, corrosion-resistant, wears well, difficult to cut, bend and file

cutlery, sinks, teapots, dishes, saucepans