Additive manufacturing of alloys with programmable microstructure and properties.

Change log

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.

3403 Macromolecular and Materials Chemistry, 34 Chemical Sciences, 40 Engineering, 4014 Manufacturing Engineering, 4016 Materials Engineering
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Nat Commun
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Nature Portfolio
National Research Foundation (NRF) Singapore (NRF-NRFF2018-05) Swiss National Science Foundation (SNF Sinergia 193799). Science and Engineering Research Council, Agency for Science, Technology and Research (A*STAR), Singapore (142 68 00088). Advanced Models for Additive Manufacturing (AM2) programme under A*STAR (M22L2b0111)