Scholarlink

<p>This study investigates the influence of natural aging on the formability and plastic deformation behavior of AA 2198, a third-generation Al-Li alloy, under W-temper conditions to address its low formability. Mechanical tests, including uniaxial tensile, bulge, and Nakazima tests, were performed to evaluate the evolution of mechanical properties, anisotropy, and formability during natural aging. A phenomenological hardening model was developed and validated through yield surfaces and finite element simulations, incorporating insights from forming limit tests. During natural aging, yield strength and ultimate tensile strength increased, while elongation decreased. Natural aging was completed within 7.6&#xa0;days, with solute and precipitation strengthening identified as primary mechanisms. Anisotropy appeared during early natural aging but remained stable, attributed to the aluminum crystal structure and rolling-induced crystallographic texture, independent of natural aging effects. The proposed hardening model effectively predicted the evolution of yield strength, anisotropy, and formability across natural aging conditions. The forming limit curve for natural aging at 0.5&#xa0;h was significantly higher than other conditions, demonstrating enhanced formability through W-temper heat treatment. Finite element simulations and forming tests revealed that natural aging at 0.5 and 6.0&#xa0;h supported stable forming, with natural aging at 6.0&#xa0;h offering optimal thickness distribution and safety margins. Beyond 24.0&#xa0;h of natural aging, formability diminished significantly due to wrinkling and fractures. This study highlights the utility of the hardening model and numerical framework as efficient virtual tools for optimizing the W-temper forming of aerospace components.</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

Constitutive modeling and formability insights for AA 2198 during natural aging and its application to stretch forming

  • 期刊论文

  • 发表日期：

    2025年6月9日

查看全文
  • Sook Lee,
  • Taek Jin Jang,
  • Deok Chan Ahn,
  • Jeong Whan Yoon

摘要

This study investigates the influence of natural aging on the formability and plastic deformation behavior of AA 2198, a third-generation Al-Li alloy, under W-temper conditions to address its low formability. Mechanical tests, including uniaxial tensile, bulge, and Nakazima tests, were performed to evaluate the evolution of mechanical properties, anisotropy, and formability during natural aging. A phenomenological hardening model was developed and validated through yield surfaces and finite element simulations, incorporating insights from forming limit tests. During natural aging, yield strength and ultimate tensile strength increased, while elongation decreased. Natural aging was completed within 7.6 days, with solute and precipitation strengthening identified as primary mechanisms. Anisotropy appeared during early natural aging but remained stable, attributed to the aluminum crystal structure and rolling-induced crystallographic texture, independent of natural aging effects. The proposed hardening model effectively predicted the evolution of yield strength, anisotropy, and formability across natural aging conditions. The forming limit curve for natural aging at 0.5 h was significantly higher than other conditions, demonstrating enhanced formability through W-temper heat treatment. Finite element simulations and forming tests revealed that natural aging at 0.5 and 6.0 h supported stable forming, with natural aging at 6.0 h offering optimal thickness distribution and safety margins. Beyond 24.0 h of natural aging, formability diminished significantly due to wrinkling and fractures. This study highlights the utility of the hardening model and numerical framework as efficient virtual tools for optimizing the W-temper forming of aerospace components.