Grain Boundary Damping II: Iron Interstitial Alloys

Internal friction measurements of the grain boundary relaxation peak have been carried out on alloys of high purity iron containing carbon or nitrogen. The influence of these impurities on peak height, peak temperature and on the activation energy for the mechanism giving rise to the damping has been determined. The results differ from those reported on the influence of substitutional impurities. The explanation of these effects is discussed qualitatively in terms of the boundary sliding and boundary migration mechanisms.