Study on Grain Boundary Internal Friction of Iron-base Binary Alloys

Abstract

The temperature dependence of the internal friction and the shear modulus of several iron binary alloys (alloying elements: C, Co, V, Al, Ti, Zr) was measured under cold-worked and primarily recrystallized condition. Some resemblance was seen between the temperature dependence of as-cold-worked internal friction or shear modulus and that of as-annealed.
The effects of the alloying elements on the so-called grain boundary internal friction phenomena are as follows:
1) With increasing size-factor and content of the alloying element, the activation energy of the solvent peaks and the solute peaks increases.
2) If the size-factor is large, even a small addition of the alloying element causes at ransition from solvent peak to solute peak.
3) The alloying elements increase half-value width of the peak.
4) The correspondence of the internal friction peak height and the 4M effect is missed in some cases.
In place of the grain boundary sliding model which has many difficulties on its application, a new mechanism was proposed based on movement of the sub-boundary dislocation or migration of a special boundary i. e. a coincidence site lattice boundary on which sub-boundary dislocation net-work is superimposed.