2023-05-31 パデュー大学
◆処理によって生成された超微細金属結晶は、応力下で伸び、回転し、さらに伸びる特異な挙動を示し、パデュー大学の研究者たちが完全に説明できない超可塑性を提供します。
◆この処理は、核および石油化学の用途で使用されるT-91という鋼合金に適用され、自動車のアクスルや構造部品など、強くて延性のある鋼が必要な他の場所でも使用できる可能性があります。この研究は、Sandia National Laboratoriesとの共同研究であり、特許が取得されています。
＜関連情報＞
- https://www.purdue.edu/newsroom/releases/2023/Q2/treatment-creates-steel-alloys-with-superior-strength-and-plasticity.html
- https://www.science.org/doi/10.1126/sciadv.add9780
優れた引張塑性を持つグラディエントナノ構造スチール Gradient nanostructured steel with superior tensile plasticity
Zhongxia Shang,Tianyi Sun,Jie Ding,Nicholas A. Richter,Nathan M. Heckman,Benjamin C. White,Brad L. Boyce,Khalid Hattar,Haiyan Wang and Xinghang Zhang
Science Advances Published:31 May 2023
Abstract
Nanostructured metallic materials with abundant high-angle grain boundaries exhibit high strength and good radiation resistance. While the nanoscale grains induce high strength, they also degrade tensile ductility. We show that a gradient nanostructured ferritic steel exhibits simultaneous improvement in yield strength by 36% and uniform elongation by 50% compared to the homogenously structured counterpart. In situ tension studies coupled with electron backscattered diffraction analyses reveal intricate coordinated deformation mechanisms in the gradient structures. The outermost nanolaminate grains sustain a substantial plastic strain via a profound deformation mechanism involving prominent grain reorientation. This synergistic plastic co-deformation process alters the rupture mode in the post-necking regime, thus delaying the onset of fracture. The present discovery highlights the intrinsic plasticity of nanolaminate grains and their significance in simultaneous improvement of strength and tensile ductility of structural metallic materials.
