Scholarlink

<p>Solidification in fusion-based metal additive manufacturing (AM) occurs under non-equilibrium conditions, often producing microstructures that deviate from classical theories, such as refined grains with high twin density arising from abnormal columnar-to-equiaxed transition (CET). While such feature has been linked to liquid atomic orderings, direct mechanistic evidence has been lacking. Here, we perform operando synchrotron X-ray total scattering measurement with rapid pair distribution function (PDF) analysis to probe atomic structures in AM melt pools. We resolve the evolution of short- and medium-range orderings and connect their selective consumption to distinct solidification pathways in Inconel 718 and other alloys. Our findings not only confirm the importance of icosahedral clusters in controlling solidification behavior, but also suggest a distinct nucleation and growth pathway responsible for abnormal CET. This insight offers opportunities for alloy design and microstructure control in metal AM.</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

Operando X-ray scattering reveals ordering-mediated solidification in additive manufacturing

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年5月22日

查看全文
  • Lin Gao,
  • Kyle Mumm,
  • Zhongshu Ren,
  • Zhou Yu,
  • Xingyang Li,
  • Chihpin Andrew Chuang,
  • Tao Sun

摘要

Solidification in fusion-based metal additive manufacturing (AM) occurs under non-equilibrium conditions, often producing microstructures that deviate from classical theories, such as refined grains with high twin density arising from abnormal columnar-to-equiaxed transition (CET). While such feature has been linked to liquid atomic orderings, direct mechanistic evidence has been lacking. Here, we perform operando synchrotron X-ray total scattering measurement with rapid pair distribution function (PDF) analysis to probe atomic structures in AM melt pools. We resolve the evolution of short- and medium-range orderings and connect their selective consumption to distinct solidification pathways in Inconel 718 and other alloys. Our findings not only confirm the importance of icosahedral clusters in controlling solidification behavior, but also suggest a distinct nucleation and growth pathway responsible for abnormal CET. This insight offers opportunities for alloy design and microstructure control in metal AM.