Beyond near-net shape manufacturing of parts with complex geometry, additive manufacturing (AM) makes it possible to fabricate materials with distinct, site-specific microstructures. This ability is unique to AM and enables the design of architected materials that were previously unattainable. Here, we leverage this strategy to encode data into metal parts using the microstructure as the medium to store information. We use a novel laser scanning technique to control the local solidification conditions during laser powder bed fusion and embed a linear barcode and Quick Response (QR) code into stainless steel 316 L. The codes use blocks of different crystallographic texture–i.e., regions in which the crystal lattice of most grains is aligned towards a preferred orientation–as the data “bits”. The data may be retrieved by analytical techniques that are sensitive to local microstructure variations. As a demonstration, we decode the barcodes by measuring the scattering of optical light from their etched surface using a technique called directional reflectance microscopy. The resulting texture maps are readable by conventional barcode scanners, such as those found on mobile phones. The ability to embed data has significant potential in fields such as law enforcement, biomedicine, and transportation, where permanent, damage-resistant tracking is essential. 

Encoding Data into Metal Alloys Using Laser Powder Bed Fusion

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Measurement of the single crystal elasticity matrix of polycrystalline materials

Inversion methodology for ultrasonic characterization of polycrystals with clusters of preferentially oriented grains.

The use of resonators, filters, interdigital transducers (IDT) and stable sources in electronic industry is widespread today. One of the most used filters are the surface acoustic wave (SAW) type, which is mostly based on Rayleigh waves propagation on the surface. On the other hand, the use of Phase change materials (PCMs) is considered as a heat sink method in the field of thermal cooling of electronic circuits. Recent development in heat transfer is obtained by nanoparticle-enhanced PCM (NEPCM), which is a result of combining nanoparticles with PCMs. Increase of thermal conductivity of NEPCM in comparison with common PCM enhances the heat transfer rate. The aim of the current study is thermal management of SAW for the application of high frequency heating by phase change material. Melting of NEPCMs inside a rectangular cavity next to the SAW cell is used for the cooling purpose. Free convection heat transfer of a NEPCMs in an square cavity is modeled throughout the mass and momentum. Energy governing equations are solved by using the finite element method. Electrohydrodynamic (EHD) forces exist in natural convection heat transfer within the fluid part of the enclosure. The results also show that the NEPCM causes heat transfer improvement up to 10%.

https://www.mdpi.com/2311-5521/6/1/31/pdf

Paul Marrow

Papers

Determining the crystallographic orientation of hexagonal crystal structure materials with surface acoustic wave velocity measurements.