Abstract: Metal ceramic composites, or metallic matrix composites (MMCs), may be formed by additive manufacturing (AM) processing of powder beds including a plurality of metallic particles of one or more metals and a plurality of ceramic particles of one or more ceramic materials. The presence of the ceramic particles during the AM process changes the optical properties and/or thermal conductivity of the powder bed since the ceramic particles have markedly different optical properties and/or thermal conductivity relative to metal particles. These optical properties and/or thermal conductivities of the ceramic particles can be tailored in different areas within a given layer of the powder bed to change energy absorption of an energy beam in the different areas. The resulting MMCs exhibit significantly improved performance characteristics, including increases in strength properties, while maintaining ductility and improvement of resistance to pitting and crevice corrosion, among others characteristics.

Abstract: A system provided herein may be configured to evaluate helmet performance. The system may include an impact assembly that includes a stationary post operably coupled to one or more stationary load cells and a plurality of modular headforms. Each modular headform may include a first side and a second side configured to lock together around the impact assembly and receive a helmet. The modular headform may determine a position of the helmet relative to the one or more stationary load cells. Furthermore, the one or more stationary load cells may be configured to measure impact force at a position where one of the plurality of the modular headforms are operably coupled to the impact assembly. Additionally, each of the plurality of modular headforms correspond to a position in relation to the impact assembly to measure the impact force to the one or more load cells at a predefined number of impact locations on the helmet to evaluate the performance of the helmet.

Abstract: Additive manufacturing processes, systems and three-dimensional articles include the formation of voxels and/or portions of three-dimensional articles with different properties relative to other voxels and/or portions. The processes generally include changing one or more laser beam parameters including power level, exposure time, hatch spacing, point distance, velocity, and energy density during the formation of selected voxels and/or portions of the three-dimensional articles. Also disclosed are processes that include an additive manufacturing process that provides localized secondary heat treatment of certain voxels and/or regions at a temperature below the melting point of the three-dimensional article but high enough to effect a localized property change.

Abstract: Electromagnetic shielding systems, apparatuses, and method are provided. One apparatus is an example free-space absorber metamaterial that includes a first array of patches disposed at a first plane, a conductive backplane disposed at a structural surface plane, and a first dielectric spacer disposed between the first array of patches and the conductive backplane. A first bandwidth of absorption for the free-space absorber metamaterial may be based on the area of a patch in the first array of patches, the first electrical resistance of a patch in the first array of patches, and the first gap distance taken between the first array of patches and the conductive backplane.

Abstract: Electromagnetic shielding systems, apparatuses, and method are provided. One apparatus is an example free-space absorber metamaterial that includes a first array of patches disposed at a first plane, a conductive backplane disposed at a structural surface plane, and a first dielectric spacer disposed between the first array of patches and the conductive backplane. A first bandwidth of absorption for the free-space absorber metamaterial may be based on the area of a patch in the first array of patches, the first electrical resistance of a patch in the first array of patches, and the first gap distance taken between the first array of patches and the conductive backplane.

Abstract: Functionalized metallic feedstock and three-dimensional articles formed therefrom via an additive manufacturing process are provided. The functionalized metallic feedstock includes a plurality of discrete metallic substrates including a first metallic substrate having a first surface area, in which at least a portion of the first surface area comprises a functionalizing agent selected to render the first metallic substrate resistant to corrosion.