Science Behind Metallurgy
By: Mason Lonborg, Lindsey Shaw, Chisom U.
What is it?
-Bend all three paper clips so that the paperclips make a hook shape to hold weight
-Leave one paper clip untouched and non-heated
-Heat another one of the paperclips until its orange, but let the paperclip cool on its own
-Heat the third paperclip until it is orange, but directly after dunk it into a glass of water
-You will notice the different properties to the paperclips
Carrying Out the Experiment
How it works!
Metals form as crystals, meaning that their atoms form in repeating patterns.
Work Hardening: As you do more work on a metal, it becomes harder and more brittle.
Dislocations: Where the atoms in the crystal dont quiet meet line up properly.
Annealing: Is when you heat up the metal giving it a lot of energy. This allows any dislocations in the atoms pattern to move past each other.
Quenching: Iron has two different stable crystal structures and it switches between them at about 700 degrees Celsius. If you cool the metal slowly, there is plenty of time for the metal to change from one to the other, but if the metal is cooled very rapidly by dipping it in cold water, knows as quenching, the atoms don't have time to reorganize themselves and the metal will form a third structure called martensite. This is very hard and very brittle, which makes the paperclip very stiff. Quench hardening is a mechanical process in which steel and cast iron alloys are strengthened and hardened. These metals consist of ferrous metals and alloys. This is done by heating the material to a certain temperature, differing upon material, and then rapidly cooling the material. This produces a harder material by either surface hardening or through-hardening varying on the rate at which the material is cooled. The material is then often tempered to reduce the brittleness that may increase from the quench hardening process. Items that may be quenched include gears, shafts, and wear blocks.
Metal cooled slowly
Cubic structure formed which is quiet malleable, and flexible
Metal cooled fast
Plate like Martensite structure that traps a lot of carbon, so it is strong and brittle.