This article reviews the main theoretical and practical aspects of sequence normally followed in digital image-acquisition, processing, analysis, and output for material characterization. It discusses the main methods of digital imaging, image processing, and analysis, as applied to microscopy of materials. The article describes the basic concepts of sampling and resolution and quantization of light microscopy, scanning electron microscopy, and transmission electron microscopy. It discusses the acquisition of a digital image that accurately represents the sample under observation and output of the image to a printer. The methods used to enhance the digital image and to extract quantitative information are also described. Different types of image segmentation, namely, adaptive segmentation and contour-based segmentation, are reviewed. The article also presents case studies on the application of image processing and analysis to materials characterization.

Failure analysis is an investigative process in which the visual observations of features present on a failed component and the surrounding environment are essential in determining the root cause of a failure. This article reviews the basic photographic principles and techniques that are applied to failure analysis, both in the field and in the laboratory. It discusses the processes involved in visual examination, field photographic documentation, and laboratory photographic documentation of failed components. The article describes the operating principles of each part of a professional digital camera. It covers basic photographic principles and manipulation of settings that assist in producing high-quality images. The need for accurate photographic documentation in failure analysis is also presented.

This article presents a basic overview of technology-driven advances in the imaging of primarily metallic fracture surfaces. It describes various types of microscopes, including scanning electron, dual-beam, ion source, and transmission electron microscopes, and their capabilities. It also covers other useful hardware, such as computer-aided tomography (CAT) and micro-computer-aided tomography (micro-CAT) instruments. The article introduces some of the fracture image postprocessing methods and software, including image registration or alignment, focus stacking, Z-stacking, focal plane merging, and image stitching.

This article first describes a typical additive manufacturing (AM) process chain, which involves the transaction of digital information to manufacture physical products. The digitized nature of AM exposes the technology to increased vulnerabilities, posing a hurdle to its mass adoption. The article presents motivation for using blockchain, which is a decentralized, immutable ledger that is shared on a peer-to-peer network. The article presents the advantages of blockchain integration to AM supply chains. These involve aspects of data security, supply chain and logistics, finance, value creation, and scope expansion. The article also presents the opportunities and challenges of blockchain technology.

Data formats play an integral role in leveraging the flexibility of additive manufacturing and achieving consistent part quality. This article compares and contrasts data formats optimized for design, materials, processes, and inspection methods. It also discusses the types of data associated with the six phases of additive manufacturing, namely design, build, design with build plan, design with machine-specific build plan, post-processed part, and qualified part.

Failure analysis is an investigative process that uses visual observations of features present on a failed component fracture surface combined with component and environmental conditions to determine the root cause of a failure. The primary means of recording the conditions and features observed during a failure analysis investigation is photography. Failure analysis photographic imaging is a combination of both science and art; experience and proper imaging techniques are required to produce an accurate and meaningful fracture surface photograph. This article reviews photographic principles and techniques as applied to failure analysis, both in the field and in the laboratory. The discussion covers the processes involved in field and laboratory photographic documentations, provides a description of professional digital cameras, and gives information on photographic lighting and microscopic photography. Special techniques can be employed to deal with highly reflective conditions and are also described in this article.

This article reviews photographic principles, namely, visual examination, field photographic documentation, and laboratory photographic documentation, as applied to failure analysis and the specific techniques employed in both the field and laboratory. It provides information on the photographic equipment used in failure analysis and on film and digital photography. The article describes the basics of photography and the uses of different types of lighting in photography of a fractured surface. The article also addresses the techniques involved in macrophotography and microscopic photography as well as other special techniques.

Additive manufacturing (AM) security is considered an integral part of several broader security fields, including supply chain security and critical infrastructure security. This article presents a general guide to the types of data and locations of data as they may exist in a typical AM-using organization. It discusses the following threat categories: technical data theft, sabotage, illegal part manufacturing, and data infiltration and exfiltration. The article also presents a detailed discussion on countermeasures against threat categories.

This article presents a brief history of additive manufacturing (AM). It begins by describing additive manufacturing prehistory, dating back to 1860, which is characterized by additive part creation without the use of a computer. The article then discusses the development of additive manufacturing processes occurring in the period from 1968 to 1984 and is followed by a section on modern additive manufacturing (1981 to the late 2000s). The article concludes by providing information on the growth of additive manufacturing since 2010 and the development of standards.

Design and analysis of electrical/electronic systems and components tends to be different from the corresponding process for most mechanical and hydraulic systems. This article provides an overview of three overlapping phases followed in electrical design: functional, electrical, and physical. It also presents information on the simulation and testing carried out to evaluate the design behavior.

Bridging the gap between education and medical practice, centralized hospital-based 3D printing, or what is termed point-of-care (POC) manufacturing, has been rapidly growing in the United States as well as internationally. This article provides insights into the considerations and the current workflow of creating 3D-printed anatomical models at the POC. Case studies are introduced to show the complex range of anatomical models that can be produced while also exploring how patient care benefits. It describes the advanced form of communication in medicine. The advantages as well as pitfalls of using the patient-specific 3D-printed models at the POC are addressed, demonstrating the fundamental knowledge needed to create 3D-printed anatomical models through POC manufacturing.

Miscellaneous hardness tests encompass a number of test methods that have been developed for specific applications. These include dynamic, or "rebound," hardness tests using a Leeb tester or a Scleroscope; static indentation tests on rubber or plastic products using the durometer or IRHD testers; scratch hardness tests; and ultrasonic microindentation testing. This article reviews the procedures, equipment, and applications associated with these alternate hardness test methods.

This article surveys common additive manufacturing (AM) data-acquisition methods, covering preprocess materials characterization in the lab, machine calibration in the field, in-process monitoring during a build, and the postprocess part inspections and tests. The focus is to identify acquisition-related metadata for AM data sets to improve data usability and reusability. Also included in the article are exemplar metadata definitions for a data set acquired from light-scattering-based particle size analysis.

This article describes the basic functions that should be included when considering the relationship of computer-aided design (CAD)/computer-aided manufacturing (CAM) and machining. These include design, analysis, drafting, process planning, part programming, program verification, part machining, and inspection. The article provides information on hardware, data base, interfaces, and benefits of integrating machining with the CAD/CAM system of a manufacturing plant. It also provides an overview of direct, computer and, distributed numerical control, which are devoid of a number of problems inherent in conventional numerical control.

Additive manufacturing (AM) creates parts layer by layer directly from three-dimensional computer-aided design data. This article discusses systematic ways to address the challenges in AM data integration by exploring various AM-specific data-integration scenarios that can improve the current AM ecosystem. Representative AM data sources are also described. A reference framework that captures the heterogenous AM data sources and existing data-integration mechanisms are used. General data-integration practices—based on existing manufacturing data and lab information system integration experiences—are recommended to automate AM data flow, operations, and development. Lastly, the article discusses the seven steps in the big-data-integration workflow.

Efforts in improving the efficiency of automated equipment lead to combining automatic joining equipment with a modem computer technique eventually known as artificial intelligence (intelligent automation) that usually includes an off-line planning system and a real-time adaptive control system connected through a computer communications interface. This article focuses on the application of intelligent automation system to arc welding, called WELDEXCELL, and other joining processes. An outline of the interface between off-line planners and real-time control systems is also provided.

Part quality in additive manufacturing (AM) is highly dependent on process control, but there is a lack of adequate AM control methods and standards. Laser powder-bed fusion (L-PBF) is one of the most-used metal AM techniques. This article focuses on the following laser control parameters: laser focus, laser power, laser position, and laser power-position synchronization. It then provides a discussion on laser scan strategies. The article also provides an overview of the AM control framework, the two major sections of which are software and hardware.

X-ray powder diffraction (XRPD) techniques are used to characterize samples in the form of loose powders or aggregates of finely divided material that readily diffract x-rays in specified patterns. This article provides an introduction to XRPD, beginning with a review of sensing devices, including pinhole/Laue cameras, Debye-Scherrer/Gandolfi cameras, Guinier cameras, glancing angle cameras, conventional diffractometers, thin film diffractometers, Guinier diffractometers, and micro diffractometers. The article then describes several quantitative measurement methods, such as lattice parameter, absorption diffraction, spiking, and direct comparison, explaining where each may be used. It also identifies potential sources of error in XRPD measurements.