Upward modulus trend in NiAl and NiFeAl single crystals

The behaviour of light interstitial elements dissolved in transition metals of the face-centred cubic structure has been studied by measurements of mechanical relaxation. Those interstitial solute atoms such as C and H give rise to anelastic relaxation effects as they form complexes, such as close pairs. Detailed characterization of such complexes is possible by examining the effects of crystal orientation, solute concentration and temperature on the relaxation effect. Recent experimental results on Ni-C, Ni-C-H and Pd-C systems are presented.