Geometrical metrology for metal additive manufacturing

Customized manufacturing of a miniaturized device with micro and mesoscale features is a key requirement of mechanical, electrical, electronic and medical devices. Powder-based 3D-printing processes offer a strong candidate for micromanufacturing due to the wide range of materials, fast production and high accuracy. This study presents a comprehensive review of the powder-based three-dimensional (3D)-printing processes and how these processes impact the creation of devices with micro and mesoscale features. This review also focuses on applications of devices with micro and mesoscale size features that are created by powder-based 3D-printing technology.

Powder-Based 3D Printing for the Fabrication of Device with Micro and Mesoscale Features.

Technical advantages of additive manufacturing (AM) have drawn great attention over the past few years. This cost-effective manufacturing process proved its potential applications in a wide range of fields. Although AM techniques (known as 3D printing) are able to fabricate geometrically complex components, it is necessary to evaluate internal and external dimensions of the printed parts. In this context, x-ray computed tomography (CT) as a nondestructive evaluation technique has been utilized. Indeed, CT can be used for geometric analysis, defects detection, quantitative comparison, structural quantification and porosity analysis. In the current study, we present a brief review of 3D printing processes and evolution of CT technology. Moreover, applications of CT in assessment of 3D-printed components are explained in detail. Although CT has been used in academic and industrial researches, abilities of this inspection method are not yet fully documented for precision engineering applications. In this work, usage of this technique in study of printed components are categorized in four subdomains and discussed. The documented data proved that CT is an appropriate non-contact technique for technical evaluation of various printed parts. As usage of CT in assessment of printed parts is still evolving, the limitations, challenges and future perspective are outlined.

https://link.springer.com/content/pdf/10.1007/s10921-020-00721-1.pdf

On the Use of X-ray Computed Tomography in Assessment of 3D-Printed Components

Dimensional artefacts to achieve metrological traceability in advanced manufacturing

Additive manufacturing (AM) is making a big leap in the manufacturing technology world primarily due to its unique capability to produce parts in a layer-by-layer fashion from the digital 3D model with immense versatility in terms of design complexity. In addition, AM does not require any additional tooling and can produce parts with minimal to no material loss. Despite these technological advantages, AM is not making inroads to its potential, mainly due to a lack of fundamental understanding of all the AM processes and cohesive efforts in standardization, metrology (the science of measurement), qualification and certification. As a result, AM produces parts with higher complexity and features yet lacking dimensional accuracy, precision, the required level of tolerances and intended material properties. Particularly, the process-specific standardized metrology and inspection methods for the parts made by AM play a major role in imparting the desired quality and subsequently facilitate the process of certification of the AM part. Considering this, the present article provides (1) a comprehensive review of generic metrology and in-situ, real-time inspection methods that are currently utilized for the parts produced from conventional manufacturing processes in use, as well as (2) a comprehensive review of metrology and in-situ, real-time inspection methods currently and/or may be utilized for the parts produced from AM processes. In addition to these, the appropriate metrology and inspection methods are recommended here for various AM processes. NSWC Corona, the leading agency for the U.S. Navy’s Metrology and Calibration (METCAL) program, is playing an important role towards addressing these AM metrology challenges.

A comprehensive review: metrology in additive manufacturing and 3D printing technology

We present the design and characterisation of a high-speed sintering additive manufacturing benchmarking artefact following a design-for-metrology approach. In an important improvement over conventional approaches, the specifications and operating principles of the instruments that would be used to measure the manufactured artefact were taken into account during its design process. With the design-for-metrology methodology, we aim to improve and facilitate measurements on parts produced using additive manufacturing. The benchmarking artefact has a number of geometrical features, including sphericity, cylindricity, coaxiality and minimum feature size, all of which are measured using contact, optical and X-ray computed tomography coordinate measuring systems. The results highlight the differences between the measuring methods, and the need to establish a specification standards and guidance for the dimensional assessment of additive manufacturing parts.

Vicente M. Rivas Santos

Papers

Design and characterisation of an additive manufacturing benchmarking artefact following a design-for-metrology approach

Benchmarking of an additive manufacturing process