Characterization of nickel-based microlattice materials with structural hierarchy from the nanometer to the millimeter scale

• Published in: Acta materialia 2012-05, Vol.60 (8), p.3511-3523
• Main Authors: Torrents, A., Schaedler, T.A., Jacobsen, A.J., Carter, W.B., Valdevit, L.
• Format: Article
• Language: English
• Subjects: Applied sciences; Cellular materials; EBSD; Exact sciences and technology; Mechanical characterization; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Microlattice materials; Nanocrystalline nickel
• ISSN: 1359-6454; 1873-2453
• DOI: 10.1016/j.actamat.2012.03.007

Novel nickel-based microlattice materials with structural hierarchy spanning three different length scales (nm, μm, mm) are characterized microstructurally and mechanically. These materials are produced by plating a sacrificial template obtained by self-propagating photopolymer waveguide prototyping. Ni–P films with a thickness of 120nm to 3μm are deposited by electroless plating, whereas thicker films (5–26μm) are obtained by subsequent electrodeposition of a pure Ni layer. This results in cellular materials spanning three orders of magnitude in relative density, from 0.01% to 8.5%. The thin electroless Ni–P films have ultra-fine grain size (7nm) and a yield strength of ∼2.5GPa, whereas the thicker electrodeposited Ni films exhibit a much broader distribution with average grain size of 116nm and strong (100) texture in the plating direction, resulting in a yield strength of ∼1GPa. Uniaxial compression experiments reveal two distinct mechanical responses. At ultra-low densities (