Metals, Sources and Origins Flashcards
Most metals are found within the………………and is known as………
Earth’s crust
Ore
What ore does Aluminium come from
Bauxite - Australia
Are metals renewable
No
What process is ore taken out of the Earths crust
Mining
What is surface mining
Stripping away the Earth using large evacuation equipment to remove earth
Where does steel mainly come from
Hematite ores in Brazil
Once the metals have been extracted from the ground, how do they get extracted from the ore
Smelting - either by blast furnace or electrolysis
How is Iron extracted from Hematite
Extracted in a blast furnace. Crushed hematite are loaded into a main section of a blast furnace and heated to very hight temperatures
Manufacture of iron uses vas amounts of fossil fuel;s . Once the furnace reaches the right temperature, its cost effective to keep it going as long as possible
How is aluminium extracted
Electrolysis
Must be molten first so that ions can move
Aluminium has a very high melting point so very expensive
Instead it’s dissolved in a Aluminium compound s that it has a lower melting point
Reduces energy used
Give some factors to consider when selecting a material for a commercial product
Cost
Availability
Environmental impact
What is stainless steel mainly used for
Cutlery and cooking utensils due to its resistance to corrosion and hardness
The aluminium alloy is…………
Lightweight
The properties of metals can be altered by the process of………….and…………..
Heating and Cooling
What happens if a metal is constantly being bent or hammered
Likely to split or fracture Brittle
This is known as hardening and i possible to remove this by annealing
With aluminium rub with soap, when the soap turns black it’s the correct temperature for annealing
How do you anneal
heat up to certain temperature, allow to cool down then start working with it
What do have to do before drilling
Use centre punch to stop drill from slipping
A small drill through a soft metal will require a ………speed, but a large drill through a hard metal will require a………speed
High
Slow
What is the easiest and safest way of drilling a metal
In a machine vice
What is a non-permanent method of joining
Can be taken apart
Particularly useful for maintenance as worn out parts can be replaced
Nuts and bolts
What are rivets
Small metal pins used to fasten sheets of sheet material
Cheaper and less visible from nuts and bolts
How do we permanently join metals
Heat
What is plain riveting
Soft steel or aluminium rivet is pushed through a pre-drilled hole in the sheet material
Second end is then hammered into shape of a rivet head
What is pop riveting
Pre-formed Aluminium rivet with steel pin trapped inside
Pushed though a pre drilled hole
Pop rivet gun pulls out the steel pin which swells the rivet and the pin pops off
Can pivot with pa[er washer between metal
When is soft soldering used
Commonly used when manufacturing electrical circuits and when plumbing wit copper pipework
230˚C
Essential that joint is perfectley clean before parts are soldered together as the dirt will prevent the solder joining to the metal
What is hard soldering
Silver soldering is a similar process but is used to join precious metals together
600-800˚C
Heat is applied by using a blow torch
Solder ia an alloy of Silver, copper and Zinc
What is welding
Very wrong method of permanently going two metals together
What is spot welding
Used for thin sheets
