The relaxation of Cu60Zr40 metallic glass under tensile stress
A new experimental technique was used for dilatometric measurements of Cu60Zr40 metallic glass samples under applied tensile stress. The measurements were performed on unrelaxed samples at 473K and gave a detailed insight into the low-temperature relaxation processes. The measurements indicate that the length change is a superposition of two competing processes: (i) low-temperature relaxation which is responsible for sample contraction and (ii) creep which leads to sample elongation. Using a special procedure they were able to discover the contribution of each of the above processes. On the basis of these data it was possible to evaluate the coefficient of viscosity as well as to find its dependence on the applied tensile stress.