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Interlocking metasurfaces

Journal of Materials Science

Bolmin, Ophelia M.E.; Young, Benjamin; Leathe, Nicholas S.; Noell, Philip J.; Boyce, Brad L.

Interlocking metasurfaces (ILMs) are architected arrays of mating features that enable joining of two bodies. Complementary to traditional joining technologies such as bolts, adhesives, and welds, ILMs combine ease of assembly, removal, and reassembly with robust mechanical properties. Structural in nature, they act in a quasi-continuous manner across a surface and enable joining of complex surfaces, e.g., lattices. In this perspective, we define an ILM, begin exploring the design domain and illustrate its breath, and pragmatically evaluate mechanical performance and manufacturability. ILMs will find applications in various fields from aerospace to micro-robotics, civil engineering, and prosthetics.

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TYPE Journal Article YEAR 2023
DOIOSTIScopus

Super-Resolution Approaches in Three-Dimensions for Classification and Screening of Commercial-Off-The-Shelf Components

Polonsky, Andrew; Martinez, Carianne; Appleby, Catherine; Bernard, Sylvain R.; Griego, James G.; Noell, Philip J.; Pathare, Priya R.

X-ray computed tomography is generally a primary step in characterization of defective electronic components, but is generally too slow to screen large lots of components. Super-resolution imaging approaches, in which higher-resolution data is inferred from lower-resolution images, have the potential to substantially reduce collection times for data volumes accessible via x-ray computed tomography. Here we seek to advance existing two-dimensional super-resolution approaches directly to three-dimensional computed tomography data. Multiple scan resolutions over a half order of magnitude of resolution were collected for four classes of commercial electronic components to serve as training data for a deep-learning, super-resolution network. A modular python framework for three-dimensional super-resolution of computed tomography data has been developed and trained over multiple classes of electronic components. Initial training and testing demonstrate the vast promise for these approaches, which have the potential for more than an order of magnitude reduction in collection time for electronic component screening.

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TYPE SAND Report YEAR 2022
DOIOSTI

Identifying the microstructural features associated with void nucleation during elevated-temperature deformation of copper

Fatigue and Fracture of Engineering Materials and Structures

Noell, Philip J.; Deka, Nipal; Sills, Ryan B.; Boyce, Brad L.

The microstructural-scale mechanisms that produce cracks in metals during deformation at elevated temperatures are relevant to applications that involve thermal exposure. Prior studies of cavitation during high-temperature deformation, for example, creep, suffered from an inability to directly observe the microstructural evolution that occurs during deformation and leads to void nucleation. The current study takes advantage of modern high-speed electron backscatter diffraction (EBSD) detectors to observe cavitation in oxygen-free, high-conductivity copper in situ during deformation at 300°C. Most voids formed at the triple junction between a twin boundary and a high-angle grain boundary (HAGB). This finding does not contradict previous studies that suggested that twins are resistant to cracking—it reveals that cracks in HAGBs originate at twin/HAGB triple junctions and that cracks preferentially grow along HAGBs rather than the accompanying twins. Atomistic simulations explored the origins of this observation and suggest that twin/HAGB triple junctions are microstructural weak points.

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TYPE Journal Article YEAR 2022
DOIOSTIScopus

Measuring the Residual Stress and Stress Corrosion Cracking Susceptibility of Additively Manufactured 316L by ASTM G36-94

Corrosion

Karasz, Erin K.; Taylor, Jason M.; Autenrieth, David; Reu, P.L.; Johnson, Kyle L.; Melia, Michael A.; Noell, Philip J.

Residual stress is a contributor to stress corrosion cracking (SCC) and a common byproduct of additive manufacturing (AM). Here the relationship between residual stress and SCC susceptibility in laser powder bed fusion AM 316L stainless steel was studied through immersion in saturated boiling magnesium chloride per ASTM G36-94. The residual stress was varied by changing the sample height for the as-built condition and additionally by heat treatments at 600°C, 800°C, and 1,200°C to control, and in some cases reduce, residual stress. In general, all samples in the as-built condition showed susceptibility to SCC with the thinner, lower residual stress samples showing shallower cracks and crack propagation occurring perpendicular to melt tracks due to local residual stress fields. The heat-treated samples showed a reduction in residual stress for the 800°C and 1,200°C samples. Both were free of cracks after >300 h of immersion in MgCl2, while the 600°C sample showed similar cracking to their as-built counterpart. Geometrically necessary dislocation (GND) density analysis indicates that the dislocation density may play a major role in the SCC susceptibility.

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TYPE Journal Article YEAR 2022
DOIDOIOSTIOSTIScopusScopus
Results 26–50 of 94
Results 26–50 of 94
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