Gao Shubo, Li Zhi, Van Petegem Steven, Ge Junyu, Goel Sneha, Vas Joseph Vimal, Luzin Vladimir, Hu Zhiheng, Seet Hang Li, Sanchez Dario Ferreira, Van Swygenhoven Helena, Gao Huajian, Seita Matteo
School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Republic of Singapore.
Additive Manufacturing Division, Singapore Institute of Manufacturing Technology (SIMTech), Agency for Science, Technology and Research (A*STAR), Singapore, 636732, Republic of Singapore.
Nat Commun. 2023 Oct 30;14(1):6752. doi: 10.1038/s41467-023-42326-y.
In metallurgy, mechanical deformation is essential to engineer the microstructure of metals and to tailor their mechanical properties. However, this practice is inapplicable to near-net-shape metal parts produced by additive manufacturing (AM), since it would irremediably compromise their carefully designed geometries. In this work, we show how to circumvent this limitation by controlling the dislocation density and thermal stability of a steel alloy produced by laser powder bed fusion (LPBF) technology. We show that by manipulating the alloy's solidification structure, we can 'program' recrystallization upon heat treatment without using mechanical deformation. When employed site-specifically, our strategy enables designing and creating complex microstructure architectures that combine recrystallized and non-recrystallized regions with different microstructural features and properties. We show how this heterogeneity may be conducive to materials with superior performance compared to those with monolithic microstructure. Our work inspires the design of high-performance metal parts with artificially engineered microstructures by AM.
在冶金学中，机械变形对于设计金属的微观结构和调整其机械性能至关重要。然而，这种做法不适用于通过增材制造（AM）生产的近净形金属部件，因为这将不可避免地损害其精心设计的几何形状。在这项工作中，我们展示了如何通过控制激光粉末床熔融（LPBF）技术生产的钢合金的位错密度和热稳定性来规避这一限制。我们表明，通过操纵合金的凝固结构，我们可以在不使用机械变形的情况下，在热处理时“编程”再结晶。当在特定位置应用时，我们的策略能够设计和创建复杂的微观结构架构，将具有不同微观结构特征和性能的再结晶区域和未再结晶区域结合起来。我们展示了这种异质性如何可能有助于制造出性能优于具有整体微观结构的材料。我们的工作为通过增材制造设计具有人工工程微观结构的高性能金属部件带来了启发。
