The correlation between the power-law coefficients in creep: the temperature dependence

In this study we investigated the relationship between the coefficients of the Norton law for low-stress high-temperature deformation results of diffe rent materials reported in the literature. These coefficients are interrela ted and it is shown that this relation can be theoretically deduced from th e assumption of a variation of the activation area with the inverse of the effective stress (i.e, a variation of the activation energy with the logari thm of the stress). As a consequence, all the straight lines In(strain-rate )-In (stress) intersected at the same point, named the pivot point. This pi vot point is characteristic of each material. Such a correlation can be fou nd in the field of the mechanics of materials when a power-law relation hol ds. (C) 1998 Kluwer Academic Publishers.