Metals And Alloys Flashcards
(48 cards)
What is aluminium
Aluminium is a pure metal that is soft, malleable and conductive
What is low carbon steel
Low carbon steel (mild steel) is an alloy that is soft and weak but it is very ductile
What is high carbon steel
High carbon steel (Tool steel) is an alloy that has very high stength, resistance and moderate ductility
What is zinc
Zinc is a pure metal that is brittle and is malleable at temperatures between 100-150°C
What is copper
Copper is a strong pure metal that has very good heat and electricity conductivity but it isn’t magnetic
What is cast iron
Cast iron is an alloy which is high in strength extremely hard and also very brittle
What is brass
Brass is the generic term for a range of copper-zinc alloys they are all electrically and thermally conductive and most are strong
What are the 3 types of metals
Ferrous (containing iron)
Non-ferrous (doesn’t contain iron)
Alloys
Name 3 ferrous metals
Low carbon steel, medium carbon steel, tool steel, cast iron
Name 3 non ferrous metals
Aluminium, zinc, copper, tin, titanium
Name 3 ferrous and 3 non ferrous alloys
Ferrous:
Steel-stainless, die, tool,low carbon
Non ferrous:
Bronze, brass, pewter, duralumin
What are the 3 types of press forming and briefly explain them
Regular press forming-shapes SHEET metals by pressing them using a driving force and vices to hold the edges
Cupping-shapes TUBE metals by pressing them into shape the same way
Deep drawing-shapes tube metals by pressing them but it the depth of the press exceeds the diameter of the tube
What is spinning
Spinning is when a metal blank (sheet) is spun
and pressed over a rotating mould called a mandrel
then a roller tool is used to apply uniform pressure on the metal sheet while it is spinning
this forms the metal around the mandrel
What is the difference between forging and drop forging
Forging is done by hand with a hammer therefore it takes more skill
Drop forging is done using an upper and lower die with the heated metal in between and therefore takes less skill
What is rolling
Rolling is when a metal is passed through sets of rollers to reduce the thickness
What are the 4 types of casting
Sand casting
Investment casting
Die casting
Low temperature casting
Describe sand casting
Sand casting is the process where a compressed sand mould is made by using a replica of the product and making a sand mould in two halves.
Then on the second half, a pouring cavity, vents and a riser are dug out and molten metal is poured in until the riser is full which indicates to the worker enough metal had been poured in.
Then the sand is removed and the metal piece is machined
Describe investment casting (lost wax process)
A wax replica of the product is made and then dipped in clay mould
this is then put in a kiln which both melts the wax and hardens the clay
molten metal is then poured into the clay mould and left to cool
Describe die casting
Die casting involves injecting molten metal into a mould
using a plunger and pressure chamber (similar to injection moulding)
and then the metal is left to cool
Describe low temperature casting
Low temperature casting is a process which involves heating up metals such as pewter of silver that have low melting points
then pouring them into moulds and leaving them to cool
The low temperatures allow the moulds to be made of different materials such as MDF
What are the 4 types of welding
MIG, TIG, Spot and oxy-acetylene
What are the similarities and differences between MIG and TIG welding
Both melt metal and stick the edges together while molten then leave the joint to cool
MIG welding uses a wire which is heated in the welding gun and fed through into a molten weld pool
TIG welding generates heat by electricity jumping between a tungsten electrode and the metal surface, a filler rod is then fed in externally
What is spot welding
An addition processes which uses a nugget in between two sheets where two electrodes apply pressure and heat to melt the nugget and join the sheets
What is oxy-acetylene welding
A welding process that uses two gasses-oxygen and acetylene to create an intense flame that burns at 3,500°C
This is then used to melt a filler metal rod along a ‘v’ shaped valley in between the two metals you want to join