using resources - corrosion and alloys Flashcards
(17 cards)
define corrosion
the destruction of materials by chemical reactions with substances in the environment
example of corrosion
rusting
what does rusting apply to
iron and the alloys or iron such as steel
how can you carry out a test for corrosion
- 3 test tubes: 1 open test tube containing and iron nail in distilled water, iron nail in boiled distilled water with a layer of oil on top and anhydrous calcium chloride power with a rubber bung
- leave for several days
1. rust
2 and 3 no rust
what does rust require
both air and water
why is erosion a problem
- damages materials
how can we stop corrosion
a barrier between the item and the air
such as…
great, paint, metal
why is aluminum used
it reacts with the oxygen in the air to form a thin layer of aluminum oxide protecting the metal form further erosion
what is called when you coat a metal in zinc
galvanizing
what is an alloy
contains a metal bended with other elements, it is a mixture
how do we make an alloy
melting out metal, mixing it in with other elements and allowing it to cool
are alloys harder or softer then pure metals
harder
why is this
the layers in an alloy are disjointed due to different sized atoms stopping them from sliding
what is steel
an alloy of iron containing specific amounts of the non-metal carbon
what is one problem of steel
- alloy of iron meaning it can rust
stainless steel is resistant to corrosion
why are alloys of aluminum useful
extremely light weight meaning they can be used for things like areoplanes
