I remember that stuff. Many years ago I had a 1952 Land Rover, and had to replace some brake pipes. The dealer sold me a steel one, right length but not bent to shape. I found it impossible to do a 3-D bend in it, under the floor, without kinking it. In the end I managed to buy the copper alloy stuff, get the unions, flares etc. put on, and found that much better. But more expensive!
Just wear an old asbestos face mask....
How does that work? As I understand it, annealing happens while the metal is hot: the domains grow. A fast quench (of metals that go this way) causes rapid contraction which puts unconformities into the domains as they cool, so hardening (outer) parts. I suppose in copper this doesn?t happen as much for some reason?
kinked too easily. I
You can get a pipe bending tool for 10mm copper pipe. Works nicely.
Robert
Oh god. [/me tries to recall Metallurgy from when we were both at Cambridge]. =20
In both copper and ferrous metals, heating a work-hardened piece allows the dislocations to move around, untangle themselves, and dissipate. This removes the work hardening.
When you heat ferrous metals, they undergo a phase change to a different crystalline form (which happens to be hard). If you then cool them fast, they don't have time to change crystal layout, so they stay hard. If you cool them slowly, they /do/ have time to change crystal form, so end up soft.
Copper doesn't undergo this phase change, so can be annealed quickly.
That?s essentially what I thought, but probably a more accurate description than my memory of it (I didn?t do much metallurgy, switching to compsci).
Thanks. That makes sense.
The copper bit is OK, with iron and steel it is all a bit more complicated and depends on the carbon level. Plenty of stuff on the web!
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