Abstract Scope |
We have designed a series of cost-effective, precipitation-hardened aluminum alloys for additive manufacturing (AM), which exhibit ultra-high strengths and good ductility at ambient and high temperatures (~400 °C). These alloys (NUAdd Alloys), producible with different AM techniques, are strengthened by multiple mechanisms over a hierarchy of length scales, permitting the fabrication of compositionally graded components with tunable mechanical and physical properties. We outline the design principles guiding the development of these alloys, elucidating their unique characteristics and advantages, including the formation of structurally and chemically complex metastable phases under AM solidification conditions. By leveraging advanced characterization techniques such as atom-probe tomography, scanning/transmission electron microscopy, electron backscatter diffraction, and synchrotron X-ray diffraction, we study these materials at a hierarchy of relevant length scales, from millimeters to sub-nanometers, to gain a comprehensive understanding of their far-from-equilibrium structure. Tensile and creep tests are performed to evaluate their mechanical properties. |