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[MetSci]

The data show that the electrical resistivity of metals and metal alloys change with elastic deformation, but not during plastic deformation. Furthermore, during positive elastic deformation, the electrical resistivity increases in some metals and decreases in others. At first thought, it seems like the resistivity during plastic deformation should increase because of the generation of dislocations. (Note that the resistivity might increase with plastic deformation at very, very high levels of deformation.) What causes these phenomena?