So I decided to try my hand at another experiment and it was at least half a success! I have to admit to only choosing this one as it was labelled as 'Metallurgy in the Kitchen' and metallurgy sounds like a pretty awesome word! Material science always seems a little more of chemistry that physics but hey with a word like metallurgy who cares?!
So I assembled my apparatus as shown here:
And put an orange paperclip in the egg cup of cold water and the other on a plate to cool. Then I tried bending each of them.
The paperclip that had nothing done to it was very difficult to bend (left) and actually part of it snapped off, the next difficult was the paper clip in the cold water (middle) and the most flexible was the one left to cool on the plate (right).
For the first paperclip, bending it backwards and forwards created a work hardening effect leading to it snapping. It gets harder and harder to bend because the atoms in the metal have to rearrange themselves and they become closer and there is less room to bend.
The process performed on the paper clip that was left to cool on the plate is called annealing. The heating gave the atoms lots of energy so they are able to deform more and therefore is more flexible.
The final paperclip is were my results are a little off... The process is called quenching and is supposed to leave the paperclip even less flexible. Apparently this occurs because iron has two stable crystal structures so before when we cooled the paper clip slowly the atoms have time to organise properly. When they are cooled quickly by the water there is no time and they form a third structure called martensite which is hard, brittle and stiff. So maybe my paperclips didn't have enough iron in them or maybe my water wasn't cold enough? Anyway, its no fun when it's perfect!
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