metals Flashcards
(18 cards)
what are most metals extracted from?
an ore
what is an ore?
a type of rock containing pure metals
what is the difference between ferrous and non-ferrous metals?
- ferrous metals contain iron and are mostly magnetic, non-ferrous metals don’t contain iron, and are generally non-magnetic
- ferrous metals will also rust if exposed to moisture so often protective coatings applied, and can be hardened with carbon
- however non-ferrous metals don’t rust but can oxidise
- non-ferrous metals also come in many colours
what are alloys?
a mixture of at least one pure metals with another element
why are alloys used?
they improve the working properties or aesthetic of the metals
list the non-ferrous metals
aluminium, copper, tin, zinc
list the ferrous metals
low carbon steel, high carbon steel, cast iron
list the alloys
brass, stainless steel, high speed steel
aluminium
A: light grey in colours, mirror or matte finish
C: lightweight but strong, ductile, durable, resistant to corrosion, good conductor, expensive
U: drink cans, pots and pans, foil, aircrafts
copper
A: light reddish brown, polishes well
C: ductile, malleable, good electric conductor, relatively soft
U: electrical wiring, central heating pipes
tin
A: dark silver, shiny if polished
C: soft, malleable, ductile, high resistance to corrosion, low melting point
U: canned food, plating other surfaces
zinc
A: silvery grey with matte finish
C: not very strong, malleable once heated, high resistance to corrosion, low mp, ductile
U: galvanise steel
low carbon steel
A: bright grey, oxidises if not protected
C: tough and ductile, easy to work with, cheap, rusts easily, can’t be hardened, malleable, reasonably tough
U: girders, screws, nails, car bodies
high carbon steel / tool steel
A: bright grey, doesn’t rust easily
C: hard wearing, not as ductile due to carbon, brittle, difficult to cut and work, can be hardened, prone to rust
U: garden/workshop tools, blades, drill bits
cast iron
A: dull grey, doesn’t rust easily
C: hard but brittle so can’t be bent, can be cast, resistant to deformation, wear and tear, strong under compression but not tension
U: pots and pans, vices, post boxes, manhole covers, car brake discs
brass
copper + zinc
A: yellow/gold, polishes well
C: malleable, easy to cast, low friction, harder and stronger than copper and zinc, ductile, resistant to corrosion
U: musical instruments, ornament
stainless steel
iron, carbon, nickel, chromium
A: silver, can be polished for mirror finish
C: hard, smooth doesn’t rust, difficult to weld, tough, hard, high resistance to corrosion
U: cutlery, kitchen sinks, medical equipment
high speed steel
iron, carbon and other metals including chromium, tungsten
A: variation of colours (grey/silver/gold)
C: able to withstand high temperatures, strong, remains hard even when heated, can cut at high speeds and temp
U: cutting tools such as drill bits
