Synergetic Strengthening by Gradient Structure

TLDR

Gradient structures are characterized by a systematic change in microstructures on a macroscopic scale. The study proposes a novel strategy for designing material structures with superior properties. The strengthening arises from a macroscopic stress gradient and bi‑axial stress due to mechanical incompatibility between layers. Gradient structures in engineering materials, such as metals, produce intrinsic synergetic strengthening far exceeding the sum of separate gradient layers, revealing a new mechanism that leverages both mechanics and materials science.

Abstract

Gradient structures are characterized with a systematic change in microstructures on a macroscopic scale. Here, we report that gradient structures in engineering materials such as metals produce an intrinsic synergetic strengthening, which is much higher than the sum of separate gradient layers. This is caused by macroscopic stress gradient and the bi-axial stress generated by mechanical incompatibility between different layers. This represents a new mechanism for strengthening that exploits the principles of both mechanics and materials science. It may provide for a novel strategy for designing material structures with superior properties.