ABSTRACT
Synergetic strengthening induced by the coordinated deformation between mechanically incompatible zones of heterostructured (HS) materials is a new strengthening mechanism for materials, by which the strength can be significantly enhanced while retaining good ductility. This chapter proposes a simple method to quantitatively calculate the synergetic strengthening in gradient structures. The relationship between structural gradient and synergetic strengthening effect is comparatively analyzed in two types of gradient structures with different volume fractions of gradient surface layer. There often exists a quantitative relationship between microhardness and tensile strength for homogeneous structured material. The extra yield strength induced by synergetic strengthening in gradient-structured brass is quantitatively deduced basing on the relationship between hardness increment and yield strength increment of corresponding homogeneous materials. The gradient structure with higher volume fraction of gradient layers exhibits higher synergetic strengthening. This work provides a quantitative demonstration for the synergetic strengthening of structural heterogeneity, and the proposed derivation procedure can be used for other HS materials as well.
