Scholarlink

<p>This study focuses on the fatigue reliability of high-strength aluminum alloys under complex service conditions, proposes and constructs a combined ultrasonic impact–solid-particle-enhanced water jet (UIT–SPEWJ) surface modification technology, and systematically explores its influence on the fatigue performance and fracture microstructure evolution mechanism of 7075 aluminum alloy. Through comparative analysis using transmission electron microscopy (TEM) and high-resolution TEM (HRTEM), the mechanisms of fatigue microstructure transformation under individual treatments—ultrasonic impact treatment (UIT) and solid-particle-enhanced water jet (SPEWJ)—and their combination (UIT–SPEWJ) were systematically examined. The results reveal that fatigue cracks in specimens treated with UIT and SPEWJ typically initiate at the surface and propagate in a discontinuous, abrupt manner. In contrast, the UIT–SPEWJ combined treatment shifts crack initiation sites to the subsurface region and significantly reduces crack density. Moreover, UIT promotes the formation of fine and homogeneously distributed second-phase particles, accompanied by dense dislocation structures with lattice fringe spacing measured at 0.2046&#xa0;nm. SPEWJ alone, however, results in larger, irregularly distributed precipitates and relatively sparse dislocation networks, with a slightly reduced lattice spacing of 0.2023&#xa0;nm. Notably, the integrated UIT–SPEWJ modification induces refined, dispersed precipitation, and significantly enhances both dislocation density and entanglement, culminating in a compact and complex dislocation mesh with a minimum observed lattice spacing of 0.167&#xa0;nm.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Effects of Multi-field Synergistic Surface Modification on Fatigue Damage and Nanoscale Precipitation Mechanisms of 7075 Aluminum Alloy

  • 期刊论文

  • 发表日期：

    2025年10月9日

查看全文
  • Xiujie Yue,
  • Youqiang Wang,
  • Ping Zhang

摘要

This study focuses on the fatigue reliability of high-strength aluminum alloys under complex service conditions, proposes and constructs a combined ultrasonic impact–solid-particle-enhanced water jet (UIT–SPEWJ) surface modification technology, and systematically explores its influence on the fatigue performance and fracture microstructure evolution mechanism of 7075 aluminum alloy. Through comparative analysis using transmission electron microscopy (TEM) and high-resolution TEM (HRTEM), the mechanisms of fatigue microstructure transformation under individual treatments—ultrasonic impact treatment (UIT) and solid-particle-enhanced water jet (SPEWJ)—and their combination (UIT–SPEWJ) were systematically examined. The results reveal that fatigue cracks in specimens treated with UIT and SPEWJ typically initiate at the surface and propagate in a discontinuous, abrupt manner. In contrast, the UIT–SPEWJ combined treatment shifts crack initiation sites to the subsurface region and significantly reduces crack density. Moreover, UIT promotes the formation of fine and homogeneously distributed second-phase particles, accompanied by dense dislocation structures with lattice fringe spacing measured at 0.2046 nm. SPEWJ alone, however, results in larger, irregularly distributed precipitates and relatively sparse dislocation networks, with a slightly reduced lattice spacing of 0.2023 nm. Notably, the integrated UIT–SPEWJ modification induces refined, dispersed precipitation, and significantly enhances both dislocation density and entanglement, culminating in a compact and complex dislocation mesh with a minimum observed lattice spacing of 0.167 nm.