Material-Independent Mechanochemical Effect in the Deformation of Highly-Strain-Hardening Metals

Abstract

``Gummy'' metals that are both soft and highly strain-hardening, like aluminum, iron, nickel, and stainless steels, are quite difficult to cut, owing to very large deformation forces and poor surface quality. The authors show how this difficulty, a consequence of unsteady plastic flow, can be overcome using a mechanochemical effect: changes in deformation promoted by a suitable coating. From glues to inks, applying any of a host of household media to the metal's surface induces a change in flow mode via a local ductile-to-brittle transition, which strongly enhances cutting. These results have wide-ranging implications for industrial machining and forming processes.