> You can take a piece of 304(usually not> ferromagnetic) and beat the >crap out of it with a hammer and it'll > > become > ferromagnetic because you've changed the structure I think you'll find that a metal (or iron-bearing rock) is magnetic when the charged grains (crystals, when speaking about metals) are aligned so that the magnetic fields of each particle are aligned and in the same orientation. The more particles so-aligned, the more magnetic the whole appear. It's not that "nonmagnetic" stainless isn't magnetic... it's just that the particles' fields are random in orientation, so no overall field is displayed. Malleating or intense heating can alter the orientation of particles so that they increase in alignment; heat will do so by melting the metal, and the particles will tend to realign themselves while molten (this is how ocean-floor magnetism creates strips of like-charged basaltic rock on either side of the midoceanic ridge system, which can be poicked up by magnetometers). Malleating (pouning metal in sucha way as to cause it to effectively flow (yes, solids DO flow under sufficient pressure, as can be seen in the Earth's mantle) probably realigns the field by causing the particles' fields to be altered in direction, rather than the particles themselves reorienting; after all, the particles themselves cannot align when being mashed. -- Andrew Grebneff Dunedin New Zealand Fossil preparator <andrew.grebneff@stonebow.otago.ac.nz> Seashell, Macintosh, VW/Toyota van nut HUMANITY: THE ULTIMATE VON NEUMANN MACHINE DEMOCRACY: RULE BY THE LOWEST COMMON DENOMINATOR |
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