Microlattices as architected thin films: Analysis of mechanical properties and high strain elastic recovery

Abstract

Ordered periodic microlattices with densities from 0.5 mg/cm3 to 500 mg/cm3 are fabricated by depositing various thin film materials (Au, Cu, Ni, SiO2, poly(C8H4F4)) onto sacrificial polymer lattice templates. Young's modulus and strength are measured in compression and the density scaling is determined. At low relative densities, recovery from compressive strains of 50% and higher is observed, independent of lattice material. An analytical model is shown to accurately predict the transition between recoverable “pseudo-superelastic” and irrecoverable plastic deformation for all constituent materials. These materials are of interest for energy storage applications, deployable structures, and for acoustic, shock, and vibration damping

Mechanical Response of Hollow Metallic Nanolattices: Combining Structural and Material Size Effects

“…This critical (t/D) crit is a function of the constituent material properties, tube angle, and maximum global strain of the microlattice [10]. Compression experiments showed that the microlattices fully recovered after 50% compressive strain for (t/D) < (t/D) crit , which has been demonstrated for a variety of materials [10,34]. While the geometric ratios of the microlattices impact the deformation mechanism of the individual tubes, macroscopic parameters of the overall lattice, such as the lattice angle, also affect the mechanical response of the structure.…”

“…While these structural effects do not fundamentally change the deformation mechanism of the entire lattice, deformation in the individual lattice tubes can be tuned by changing the geometry. For example, the compressive response of hollow thin-walled Ni-based microlattices demonstrated that its deformation behavior and recoverability depend on the geometric parameters of the lattice tubes, like the tube diameter-to-length ratio, D/l, and wall thickness-todiameter ratio, t/l [9][10][11]28,[32][33][34]. Valdevit et al proposed a model in which the deformation mechanism of the individual microlattice tubes transitions from Euler buckling to yielding of the constituent material at the nodes at a critical relative density, which is directly proportional to (D/l) and (t/l) [9].…”

Reexamining the mechanical property space of three-dimensional lattice architectures

“…A large body of theoretical and experimental work has been dedicated to creating new lattice architectures and investigating their properties [1,15,18,19,23,[30][31][32][33][34]. Most analytical models for the mechanical behavior of both 2D and 3D lattices are derived using beam theory, and these models generally predict that strength and modulus follow a power law scaling with relative density as ‫ܧ‬ = ‫ܧܤ‬ ௦ ߩ̅ ,…”

High‐Entropy Alloy (HEA)‐Coated Nanolattice Structures and Their Mechanical Properties

“…[1][2][3][4][5][6][7][8][9] The strength of lattices is determined not only by the order and periodicity of its structure, but also by the constituent materials. [10,11] Recently, numerous engineering materials such as Al 2 O 3, [12][13][14] Ni-P alloy, [4,15] glassy carbon, [16] copper, [17] gold, [18] and metallic glass [19,20] have been employed as constituent materials to significantly enhance the mechanical properties of pristine polymer scaffolds with respect to its strength and stiffness. Nevertheless, exploring a kind of lightweight, low-cost, and easily fabricated material with promising mechanical features that are easily to be coupled with pristine lattice structure is still a challenge.…”