In order to take full advantage of the promise of recent computational efforts, new microstructural models that consider realistic shapes, connectivities, and distributions are required. Characterizing materials in 3D is necessary to reveal the actual distributions of relevant microstructural characteristics and thereby enable development of realistic models to predict the behavior of new materials. This article describes methods to model grain size distributions and presents case studies in cementite precipitation morphology and coarse martensite analysis.

This article describes research at Los Alamos National Laboratory that is aimed at building a coupled experimental and computational methodology that supports the development of predictive damage capabilities by: (1) capturing real distributions of microstructural features from real material and implementing them as digitally generated microstructures in damage model development, and (2) distilling structure-property information to link microstructural details to damage evolution under a multitude of loading states.

This entry won the prestigious Jacquet-Lucas Award for Best in Show in the 2020 International Metallographic Contest. In the research discussed in this article, light microscopy was applied to a Co28Cr6Mo alloy for a biomedical application processed by laser bed powder fusion (LPBF) additive manufacturing.

Structural features, spatial locations, and morphological measures not readily attainable with 2D methods are now accessible using 3D microstructure characterization techniques.

As N95 masks are in short supply and high demand, reusable, sterilizable metal filters for masks built using 3D microstructural characterization and simulation methods are a promising alternative.

A microscale fatigue testing technique for characterizing mechanical response and relating it to microstructure promises to improve fatigue life prediction for turbine engine components.

Boronizing 3D-printed Inconel 718 for improved wear resistance produces results similar to those obtained for wrought 718.

Laser melting of elastocaloric metals can create fatigue-resistant microstructures, which enables solid-state cooling technologies.

3D printing of organic and inorganic materials requires special consideration in both material selection and the process used. This article provides an overview of the the six major processes used for 3D bioprinting: extrusion bioprinting, inkjet printing, selective laser sintering, stereolithography, laser-induced forward transfer bioprinting, and two-photon polymerization.

Two case studies highlight the strengths and weaknesses between traditional metallurgical techniques and 3D micro-computed tomography, as well as the interplay between the two.

A brief literature review and case study explore the effect of particulate reinforcements and processing parameters on the tribological behavior of polymer matrix composites made by 3D printing via fused filament fabrication.

Architected materials are a class of engineered materials carefully designed with an intricate arrangement of their internal structures. These materials leverage specific geometric patterns and configurations to impart tailored mechanical, thermal, or electromagnetic properties, giving rise to emerging functions and characteristics. This article reviews the characteristics and potential benefits of architected materials and describes a case study in which 3d printing was used to create lightweight aircraft runway mats with architected structures.

New electrical, mechanical, and chemical testing capabilities give scanning electron microscopes the feel of a self-contained “nano-laboratory.” Several developments in SEM technology allow new and more flexible approaches to the analysis of novel systems, such as Li battery-related materials, nanostructured and nanoporous materials, and novel approaches to 3D analysis.

The high heating and cooling rates of additive manufacturing make it a good fit for metallic glasses, whose high elasticity, strength, hardness, and corrosion resistance are used in high-performance applications such as aerospace, defense, and biomedical devices.

This article describes the development of applications of phosphate-based materials and characterizes five non-apatite phosphate minerals using 3D optical profilometry. The results reveal the suitability of these materials for new uses in energy storage and conversion as well as medical applications.

Significant advancements in metallurgy were highlighted at a special symposium presented at the Materials Science & Technology 2016 conference in Salt Lake City. This article summarizes the topics presented. All six speakers shared examples of the importance of understanding how the specific manufacturing process affects microstructure development in metals. The fundamental understanding of microstructure allows metallurgists to select manufacturing processes and schedules to tailor the microstructure, and therefore mechanical properties and performance, for a particular component.

Thixomolding is a method of molding semi-solid magnesium alloy pellets using equipment and processing methods similar to injection molding. Its commercial growth has been driven by its technical advantages, including enhanced precision, environmental cleanliness, and the ability to produce complex 3D shapes with high yields and minimal waste.

This article explains how SEM, TEM, and atom probe tomography are being used in the development of additively manufactured high-entropy alloys (HEAs), revealing critical features such as anisotropic microstructure and metallurgical defects. It also discusses ongoing efforts to improve the predictability and analysis of HEA microstructure using data-driven approaches.

Computer modeling is used in the design and development stages of induction hardening to optimize the process and to improve component quality including hardness, beneficial stress distributions, and reduced distortion.

This article reviews additive manufacturing technologies that can be used for manufacturing ceramics and ceramic-based composites. Stereolithography and associated techniques offer the possibility of producing ceramic components with finer resolution. Powder-based techniques like binder jetting and indirect selective laser sintering can be used for designing porous ceramics. Selective laser melting offers practitioners the option of manufacturing ceramics with minimal post-processing requirements, although further research is needed to decrease its cost.