Advancements in cold extrusion anti-fatigue manufacturing technology for connecting holes

Abstract

Requirements for connection reliability, stability, and service of components in the design and manufacturing process for aeronautical equipment are progressively growing stricter. The utilization of cold extrusion technology significantly contributes to the improvement of hole strength in the anti-fatigue manufacturing process of perforated specimens. The assessment of part quality frequently depends on residual stress, representing the mechanical stress encountered by materials during machining processes. Understanding the underlying mechanism of extrusion-induced residual stress is equally crucial. This comprehensively study aims to analyze the influential factors in the generation of residual stress, with the objective of elucidating the multifaceted mechanism behind anti-fatigue processing. Firstly, a comprehensive analysis of the mechanisms and influential factors governing residual stress during extrusion is presented, followed by a concise overview of commonly employed detection techniques. Subsequently, the micro-deformation behavior of typical materials under various extrusion methods is investigated and a comprehensive analysis is conducted on their characteristics and application range. Finally, the gain of extrusion and the mechanism of anti-fatigue manufacturing technology are further elucidated from the perspectives of stress, plastic deformation, surface integrity, and fatigue life. This present research contributes to enhancing the understanding of residual stress in hole extrusion and accurately predicting their developmental trajectory.