High-frequency diamond imprinting of fine-crystallized micro-structured surfaces

Fine-crystallized micro-structured surfaces have excellent physical and antifatigue properties. However, flexible fabrication of fine-crystallized micro-structured surfaces is still a challenge for current additive and subtractive machining technologies. This study proposes a high-frequency diamond imprinting (HFDI) technology and a principle for generating micro-structured surfaces based on splicing simple geometry shapes. Micro-structured surfaces, such as micro-images with anti-counterfeiting codes, microscopic QR codes and biomimetic surfaces, were successfully machined by HFDI on polycrystalline nickel. The size of subsurface grains is highly reduced from over 30 mu m to less than 1 mu m, and a fine-crystallized layer with a thickness of 10 mu m is formed. In addition, a cross-scale coupling model of HFDI, based on discrete dislocation dynamics, is constructed to realize dynamic simulation of subsurface dislocation motion and to explore fine crystallization mechanisms. This research holds theoretical and practical significance for realizing high performance and high precision machining. (c) 2024 Published by Elsevier Ltd on behalf of CIRP.