Additive manufacturing (AM) has been a game-changing technology for rapid prototyping and production in many industries, enabling more components to be manufactured domestically. As the Air Force increases its need for producing hard-to-source parts via AM, it is essential to develop quality control processes to validate flight-critical components. To achieve this objective, NCMS has collaborated with the Air Force and Comet Technologies USA for a CTMA project. Titled Computed Tomography for Quality Control for Additive Manufacturing Parts, it began in September 2020 and is scheduled to wrap up later this year. The initiative’s goal is to demonstrate the processes and methodologies needed for on-site quality control of AM components.
Unlike traditional manufacturing, AM components are not cast or forged and therefore have variable properties, including porosity or sometimes foreign material inside the structure. While surface-level inspections can verify components’ form and fit, they cannot verify the functionality of the component without a more detailed look inside the microstructure. To see inside AM components, the team will use a computed tomography (CT) scanner. Originally utilized in the medical world, CT scanners construct 3D images by stacking hundreds of thin 2D images on top of each other.
Using a CT scanner, technicians will inspect AM parts, focusing on their internal geometry, microstructure, porosity, density, quality, accuracy, and tolerance conformance. Ultimately, by using these scanners, technicians will establish best practices to perform on-site quality control of AM polymer and metal components. This process will ensure that AM parts meet Air Force requirements for airworthiness, safety, and readiness, along with reducing component cost and delivery lead-time. Moreover, the project team will advise Air Force Life Cycle Management Center (AFLCMC) on the best available configurations of CT technology, facilitating the Air Force’s shift from using Computed Radiography (CR) to Computed Tomography in its scans of components.
The collaboration will benefit the entire DOD by advancing the goal of manufacturing quality parts on-demand, anytime, anywhere, and on any machine. This initiative will provide new functionality, increase productivity, and establish a streamlined process for all forces. Importantly, this technology will make it possible to create specific components needed during times of emergency and crisis, such as water purification equipment parts. This will have a significant impact on operational readiness and will lessen maintenance downtime caused by a lack of critical part availability. Any new capabilities achieved from this project will be available to multiple DOD organizations.
Furthermore, positive results from this project will assist every industry that prints AM parts by demonstrating a standard methodology, process, and set of tools for quality control. The initiative will provide quality data and procedures for AM of polymers and metals, which will help commercial industry to adopt these AM methods more readily. Additionally, the project will help to advance novel repair applications of metal components. The quality control processes established in this initiative will ensure that parts will perform as intended, which will likely increase confidence in AM and lead to its broader adoption.
When a critical part breaks, and there is not an available replacement, AM can fill that gap by supplying reliable parts quickly and closer to the point of need. This will cut back on equipment downtime, part costs, and supply chain costs for commercial industry. Having the ability to manufacture on-demand parts that meet stringent standards will help industry to attain needed inventory levels, ensure that obsolescence will not derail equipment productivity, and in some cases save natural resources.
As AM becomes a more viable solution to furnish obsolete parts or components, prices for AM equipment will drop. For instance, when AM of polymers was initially developed in the late 1980s, a 3D printer costed approximately $300,000. Today, a 3D printer that delivers the same quality of a part (or better) is less than $3,000. As these equipment prices decrease, the technology will become more widely available, making supplies easier to obtain. This will reduce the overall cost of AM for industry, which will in turn lower costs for consumers.