Dependence of the high-frequency components of the magnetoelastic voltage on plastic deformation and stress amplitude during stepwise cyclic stressing of ferromagnetic material

Abstract

Abstract The high-frequency components F H of the magnetoelastic voltage u B induced during cyclic stressing of ferromagnetic material has been investigated. The true root mean square value B M of the high-frequency components was measured as a function of stress amplitude σ. The effect of strain ageing on the behaviour of B M was also studied. It was found that B M depends on the stress amplitude, plastic deformation, the dislocation arrangements and the mobility of individual dislocations. During successive stepwise increases in the stress amplitude it was found that the B M value of F H increases in the elastic and microplastic deformation range. B M reaches a maximum at a stress amplitude corresponding to the onset of the macroscopic plastic deformation Δepl. In technically pure iron the onset of the macroscopic deformation range Δepl was measured to be 0.5 × 10−4. The B M value of the high-frequency components F H decreases when the stress amplitude exceeds the value σB corresponding to the onset of ...