STRENGTHENING AND TOUGHENING OF METALS AND ALLOYS ¹⁾

In this paper, the traditional strengthening methods, such as the solution strengthening, the precipitation strengthening, the transformation strengthening and the grain refinement strengthening, are briefly reviewed. It is shown that an increase in strength is generally accompanied with a sacrifice of ductility in these traditional methods. Metals and alloys with heterogeneous structures have drawn a great deal of attentions recently, because of their excellent synergy of strength and ductility due to the strain gradient effect and the back stress hardening. The recent progresses in the metals and alloys with heterogeneous structures are briefly reviewed, and the perspectives of the structure applications of metals and alloys are provided.