Metals Sources/ Commercial Manu. Flashcards
Life Cycle Assessment
- Extracting Material
- Manufacturing
- Transporting
- Using
- Recycling or End of life
Step 1- Mining Metals
Metal ores are mined from Earth.
Mined either by surface or underground mining which are energy intensive.
Step 2- Refining Metals
The impure metal needs to be refined
- mined metals aren’t usable in raw state
- smelting chemically alters the raw material
- refining, only purifies the material
Step 3- Smelting Metal
-after ore is mined, waste material must be separated.
- e.g. extracting iron from iron core uses a blast furnace which can reach temperatures of 1,700 degrees Celsius.
- iron melts, liquefies and sinks to the bottom of furnace, known as “pig iron”
- the waste product is known as slag, is tapped off
Step 4- Pig Iron
It runs off the blast furnace into rectangular moulds
- has very high carbon content
- this makes it very brittle
- some of carbon and other impurities are removed to make it into steel
Step 5- Bauxite
Bauxite ore is the primary source of aluminium
- to extract aluminium, the ore must first be chemically refined to produce an intermediate product.
- product is smelted using electrolysis for pure aluminium
Step 6- Duralumin
It is lightweight, but hard alloy of aluminium
- has aluminium and small quantity of copper, magnesium and manganese
- malleable= easily rolled or folded
- high strength
Step 7- Recycling Material
Most metals can be recycled
- can be recycled without altering its properties
- it is then processed, shredded, melted, purified and ready again for use.
Step 8- Dumping Metal
Recycling material is very beneficial to the planet= metals are sustainable
Stainless Steel
Stainless Steel is suitable for a huge range of products
- available in many diff finishes
- costs of different grades varies
- often used for kitchen utensils e.g. saucepans, sinks
Copper Cookware
good for cookware because:
- resistant to microbes
- good at heat distribution
- good conductor
Hardening Steel
Hardening medium- a high carbon steel makes it harder but more brittle
The workpiece is heated to a pre-determined temperature and rapidly quenched in water or special oil.
Tempering Steel
Tempering makes steel tougher and less brittle:
The workplace is reheated again and left to air cool which tempers it
Metals for Hand Tools
- Hand tools need strength and longevity
- be suitable for heavy use
- be hard wearing
be tough
have good tensile and compressive strength
Commercial casting
process of making objects by pouring molten metal into an empty shaped space. The metal then cools and hardens into the form given to it by this shaped mold. Casting is often a less expensive way to manufacture a piece compared with machining the part out of a piece of solid metal.