On 02.08.16 22:35, Peter Blodow wrote: ... > Everyone knows that brass and other copper alloys harden by mechanical > stress and soften by heating. Just try to straighten a copper wire by > bending. Ferrous metals act different because of their crystal > structure, changing from martensic to austenic (that right in English?)
Very close, Peter. Just to be difficult (a goal English often achieves), martensite becomes martensitic as adjective, and austenite becomes austenitic. It's about 44 years since I studied what the terms mean, though, so I'm extremely rusty now on precisely what they comprise, and where they'll predominate in a phase diagram. > and back, which copper alloys don't have. Indeed. Even though there's up to 6% iron in some of the Al bronzes I've heard of, it's there to manage phase composition during cooling, and as you say, doesn't form either of the abovementioned phases. The only Al bronze I've alloyed myself was 89% Cu, 9% Al, 2% Iron, IIRC, and its skin chill cast so hard that a big angle grinder skated off surprisingly. I've read that the chill cast shifts the Brinell hardness from 90 to 130. Does that count as "heat treatment"? Erik ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
