Metals Flashcards
what does conductivity mean?
Ability for electricity to pass through
what is malleability
the ability of a material to deform by bending, twisting or stretching; ability to be drawn out without breaking. It increases with temperature
what is hardness
Is the ability of a material to resist wear, scratching and indentation
toughness
The ability of a material to withstand blows or sudden shocks without breaking
ductility
Ability of a material to be permanently deformed in all directions without fracture. It increases with temperature
What are the 2 different types of metals
Ferrous and non-ferrous
What is a ferrous metal
a metal that contains iron and t=so therefore are magnetic
what is a non-ferrous metal
a metal not containing with iron, often pure metals
name 3 ferrous metals
tungsten steel
high carbon steel
cast iron
name 3 non-ferrous metals
tin
titanium
copper
name the 6 manufacturing processes
Sand casting
extrusion
die casting
welding
forging
hardening, tempering and annealing
name the 4 stock forms
bar, sheet, plate, pipe
How do you extract metals from their ore
furnace heating- the ore is heated to such a high temperature( above the metals melting point) that the metal separates from the other substances in the ore.
where can you find metals
in ores within the earths crust
What is sand casting
Sand casting is another way of creating metal products using a mould. A pattern shape of the product to be manufactured is made in sand. Molten metal is then poured in and allowed to cool before being removed from the sand. Sand casting is one of the oldest forms of metal casting.
What is annealing?
this is heating a metal to a specific temperature and then allowing it to cool slowly.It is often used to make metal more malleable and ductile tobe worked on. it can be carried out repeatedly.
Name the different head shapes for the machine screws
Slotted
Pozidriv
Phillips
Allen
what is the difference between a nut and a bolt
nut= metal fastener with a threaded hole
bolt= is a type of screw that fits the thread in the nut
what are nuts and bolts used for and what are they made from
they are used to join metal, wood and plastic together. they are usually made of carbon steel but some a coated with zinc to make them resistant to corrosion - usually when being used outdoors.
what needs to be done to a metal before it can be treated
it needs to be smoothed and cleaned with abrasives (e.g metal wool) and chemical cleaners (e.g degrease)
what is dip coating
This is the process of covering a metal with plastic. The metal is heated to between 180°-1200°C and then dipped into fluidised plastic powder. this is powder that has air blown through to make it act like liquid. The coated metal is returned to the oven where the plastic melts and gives a smooth finish.. This is used to cover tool handles and wheelchair parts.
what is powder coating
This is spraying a plastic powder onto a metal part and heating it to fuse the powder to the metal. The powder is sprayed onto the metal with an electrostatic gun which gives it an electrical charge and makes it attracted to the metal. This is commonly used for bike frames, wheels and outdoor play equipment.
Galvanising
This is used to protect a base metal like iron or steel from corrosion.This is done by coating the base metal with a more reactive metal, such as zinc. The zinc creates a barrier and protects the base metal from corrosion. However, if it is scratched or damaged, the base metal can be exposed. Gates and metal pails are often galvanised.
name the properties and composition of mild steel
ductile, tough, easy to shape, good conductor
This is an alloy of iron containing carbon and some other metals-used on car bodies and nuts/bolts
name the properties and composition of stainless steel
doesn’t rust, easy to clean, hard, smooth
alloy of iron and chromium (from 10.57 to 27%). The chromium produces an oxide layer to prevent corrosion. used for kitchen utensils
name composition and uses of cast iron
2.5-4% carbon
1-3%silicon
remainder is iron
brake discs, manhole covers, large casting
name properties and composition of aluminum
soft and malleable, excellent
what is a scale layer?
Oxidized layer that forms during heating and forging of steel
How do you die cast?
- Mold design- create a mold called a die. Usually made from steel or aluminum. Develop a CAD design and create with a CNC machine
- Metal is melted in a furnace and poured into a ladle
- Injection- once the metal is liquidized, it is injected into the mold under high pressure. Once collide and is taken out and trimmed
- finishing is applied
