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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,171 records · Page 65
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

A New Shape Optimization Approach for Lightweighting Electric Machines Inspired by Additive Manufacturing: Preprint

Minimizing the mass in electric machines while maintaining superior performance is a new requirement for the advancement of drivetrains used in wind energy and electric mobility. Topology optimization (TO) for lightweighting electric machines using traditional approaches typically explores a restricted design space allowed by standard parametrizable geometry and manufacturing, while advanced methods, such as cell-based density approaches, suffer from a lack of robust manufacturability constraints during the optimization process. To overcome these drawbacks, we explore a grid-independent, boundary TO where the outer shape of the magnet is parameterized using Bezier curves. We conduct a design of experiments (DOE) to study the effect of different magnet shapes on machine performance by varying the control points on the Bezier curves. A machine-learning-based surrogate model is constructed using the data from the DOE to quantify the relationship between the control points, air-gap torque, and mass. The control points are then optimized to maximize the torque density. The approach is used for minimizing electrical steel mass in the International Energy Agency (IEA) 15-MW radial flux direct-drive wind turbine generator. The free-form boundary TO resulted in smooth and concise shapes that can be easily additively manufactured with up to a 20-ton reduction in electrical steel mass.

additive manufacturing↗
DOE OSTI2022

Ultrasonic Testing (UT) and Computed Tomography (CT) Comparative Scanning of Proposed Additive Manufacturing Reference Standard

This report presents qualitative results of ultrasonic full matrix capture/total focusing method (FMC/TFM) scanning of two series of blocks, additively manufactured by powder bed fusion, containing a variety of internal features and structures that would not be achievable by conventional manufacturing techniques. The purpose of the first series of additively manufactured (AM) blocks was to explore the possibility of building calibration blocks for FMC/TFM ultrasonic testing (UT). It was confirmed that AM is a suitable candidate for generation of unusual and novel reflector forms, such as rotating slots, purposely embedded voids, and tapering holes, and that FMC/TFM was very capable of characterizing them. The intended use of the second series of AM blocks was as UT reference blocks to characterize the AM process quality or the interrogating UT technique. The larger block in this series was scanned from multiple faces, using multiple UT methods (conventional UT and FMC/TFM) and X-ray computed tomography for comparative purposes. The performance of each method was quantified by a metric corresponding to the detection limit of each feature, and the quantitative results are discussed.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Design and Flow Considerations of Additively Manufactured, Internal Cooling Geometries for Small Industrial Gas Turbines

Additive manufacturing is now a mainstream technology and can be utilized to rapidly develop and test turbine airfoil cooling networks. This paper reports on an ongoing effort to integrate advanced internal cooling architectures in a realistic blade profile for test in a high-speed cascade. Airfoil cooling schemes were developed using reduced order modeling and computer aided design. However, the additive manufacturing impacts on cooling channel flow performance were unknown. Test articles consisting of typical cooling features and networks were derived from the designs and flow proved to identify additive manufacturing impacts on performance and develop guidelines to mitigate these impacts.

additive manufacturing↗
DOE OSTI2022

Effect of humidity of build chamber in hybrid manufacturing systems on part performance

Here hybrid manufacturing combines additive with subtractive machining operations which often require the use of a coolant, that can increase the humidity of the build chamber. The water vapor can be adsorbed on the powder surfaces and subsequently dissociate into hydrogen and oxygen during melting and can be absorbed by part during solidification. Here, we investigated the effect of build chamber humidity during hybrid manufacturing on the part quality on two most common classes of steels i.e., austenitic (316L) and ferritic (grade 91). We report that the humidity increase has a negligible effect on part performance of both classes of steels.

316L stainless steel↗
DOE OSTI2023

Comparative Life Cycle Assessment of Injection Molded and Big Area Additive Manufactured NdFeB Bonded Permanent Magnets

Permanent magnets are expected to play a crucial role in the realization of the clean economy. In particular, the neodymium-iron-boron (Nd2Fe14B or NdFeB) magnets, which have the highest energy density among rare earth permanent magnets, are needed for building more efficient windmill generators, electric vehicle motors, etc. Currently, near-net shape magnets can be either made through sintering and compression molding with extensive post machining or directly through injection molding. However, injection molding has a loading volume fraction limitation of 0.65 for nylon binders. A novel method of manufacturing bonded permanent magnets with loading fraction greater than 0.65 has been demonstrated using Big Area Additive Manufacturing (BAAM) printers. As energy density is directly proportional to the square of the magnet loading fraction, magnets produced using BAAM printers require less volume and magnetic material compared to that of injection molded magnets on average. A comparative LCA shows that this difference in magnetic powder consumption nearly constitutes the difference in the environmental impact categories. Even after assuming recycled magnetic input, the BAAM magnets perform better environmentally than injection molded magnets, especially in the ozone depletion category. Since BAAM printers can accommodate even higher loading fractions, at scale, BAAM printers possibly can bring about a significant decrease in rare earth mineral consumption and environmental emissions. So furthermore, single screw extrusion enables BAAM printers to have high print speeds and allow them to be economically competitive against injection molding. Therefore, BAAM printed magnets show promise in transitioning towards the clean economy.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Potential Impacts of the Inflation Reduction Act on Domestic Manufacturing and Deployment for Land-Based Wind Turbines

The land-based wind energy industry in the United States has matured over the past several decades, representing 10% of the country's total electricity generation in 2022. It has experienced periods of rapid growth and decline in recent years, in large part because of supply chain disruptions at a global and domestic level. With the recent passing of the 2022 Inflation Reduction Act, the industry faces unprecedented opportunities to strengthen domestic manufacturing and enable greater deployment over the next decade. To better understand the opportunities and challenges, the authors explore the value of relevant IRA provisions and provide a set of scenarios evaluating impacts on domestic component demand and manufacturing.

17 WIND ENERGY↗
NASA NTRSDate not supplied

Advanced and Additive Manufacturing Technologies for Liquid Rocket Engine Components

Overview of advanced manufacturing and additive manufacturing development at NASA for liquid rocket engines. Presentation includes various material, process, design, and hot-fire testing developments demonstrating the use of advanced components for liquid rocket engines on launch vehicles and in-space systems.

Additive Manufacturing↗
NASA NTRSDate not supplied

Cold Metal Transfer (CMT) Wire-Arc Additive Manufacturing (WAAM)

Aluminum has been identified as a compound within regolith and is likely to become a core component of our infrastructure on the lunar surface as in-situ resource utilization (ISRU) capabilities are advanced Large-scale components, outfitting, and repairs of aluminum materials can be fabricated with robotic wire arc additive manufacturing (WAAM) in order to inhabit the moon’s surface long term WAAM is a high value process for lunar advanced manufacturing as it does not require special containment to reduce explosion hazards such as powder-based additive processes and feedstock The welding process of cold metal transfer (CMT) is a relatively new variation of gas metal arc welding (GMAW, also known as MIG) that relies on the detection of a short circuit in the welding process to control the deposition droplet action, resulting in lower heat input and splatter compared to conventional MIG welding The past year was spent developing the CMT-WAAM process for aluminum materials, tested specialty feedstock, tested within the high vacuum environment, and advanced the MSFC capability to perform complex toolpathing from solid models Upcoming and future work includes large depositions working towards material certification for multiple feedstocks, in-situ monitoring, work to use recycled materials for the AM feedstock, and the design and fabrication of a parabolic flight experiment payload.

cold metal transfer↗
DOE OSTI2023

Infusible Thermoplastic Composites for Wind Turbine Blade Manufacturing: Fatigue Life of Thermoplastic Laminates under Ambient and Low-Temperature Conditions

Traditionally, thermoset resins such as polyesters (PE) and epoxies are used as the polymer matrix for construction of wind turbine blades. However, concern about their end-of-life treatment garners interest to use thermoplastics for increased recyclability. However, the high viscosity of molten thermoplastics inhibits their use in manufacturing wind turbine blades with injection or compression molding. A recently developed, infusible, reactive thermoplastic resin overcomes this technological barrier. Toward verifying that this recyclable resin is suitable for use in wind turbine blades, a dataset of R?=?0.1 and R?=?10 fatigue data for glass fiber-reinforced acrylic composites is provided and equal fatigue life to industry standard epoxy and unsaturated PE resin systems is demonstrated. Specifically, R?=?0.1 fatigue data for acrylic composites at room temperature and -30?degrees C for verification of low-temperature performance are tabulated. To elucidate failure mechanisms, in situ mechanical testing with X-ray computed tomography demonstrates that damage accumulation occurs by crack propagation along the fiber-matrix interface under cyclic loading. Infrared (IR) thermography predicts failure points in composites specimens with porosity defects introduced from nonideal manufacturing processes. Furthermore, these manufacturing defects are shown to compromise the fatigue life of the acrylic laminates by an order of magnitude.

effect of defects↗
DOE OSTI2022

Grid‐responsive smart manufacturing: A perspective for an interconnected energy future in the industrial sector

Abstract With the growing amount of renewable energy sources, the grid has become responsible for accounting for intermittency and the flexibility needed to utilize dynamic sources. Expensive peaking plants and energy storage systems have been proposed as ways to mitigate those problems. There is a large group of energy consumers that can respond to grid conditions. Historically, these consumers have been residential and commercial users, but with modern innovations and practices, industrial consumers have the potential to become a major player in this space. Grid‐responsive smart manufacturing can be used to utilize modern tools in manufacturing innovation as enablers for grid response. These modern tools already exist but are not widely used for industrial grid‐side energy management. This article defines grid‐responsive smart manufacturing, identifies five major barriers to its widespread implementation, and portrays the path to getting industrial users to be key players in grid stability and flexibility.

Billings, Blake W.↗
DOE OSTI2024

Development of transparent, particle‐loaded photoresins for volumetric additive manufacturing of silica glass

Abstract Additive manufacturing of glass aims to change the paradigm of glass manufacturing by allowing for improved customization coupled with lower energy and post‐processing needs. Fabrication of glass via volumetric additive manufacturing (VAM) involves printing in a silica‐loaded photopolymer resin with subsequent thermal processing and adds additional advantages by allowing for rapid printing of parts with smooth surfaces and no supports. Previous work in glass VAM has demonstrated fabrication of optical quality microoptics with overall dimensions on the scale of tens of cubic millimeters. For applications requiring glass printed on the scale of cubic centimeters the rheology, scattering, and green part strength must be controlled via resin formulation. Here, we present insight into a novel glass photopolymer resin suitable for VAM and in the effect of tuning formulation on the ability to produce dense glass parts with volumes on the scale of cubic centimeters.

Myers, Luke A.↗
DOE OSTI2018

Additive Manufacturing – A New Challenge for Automation and Robotics

Additive manufacturing (AM) is a rapidly growing technology descended from the first stereolithography systems. AM describes a variety of material deposition technologies for forming objects in a digital manner layer-by-layer under computer control. Now commonly known as 3D printing, AM quickly branched out into several key directions – material extrusion, sheet lamination, direct energy deposition, vat polymerization, powder bed fusion, binder jetting, and material jetting. The common factor in all AM branches is a foundation in robotics and automation. While most of the mechanical 3D printing structures are based on simple gantry systems, there are Gough-Stewart platforms and, more recently, six or more DoF manipulator-based systems that have been developed. Currently available commercial systems are based on open-loop control with minimum sensing capabilities; the latest systems in development are starting to take advantage of complex feedback loops and layers of advanced sensing and data logging. The Manufacturing Demonstration Facility of Oak Ridge National Laboratory is leading the efforts in applying advanced robotics in the creation of large-scale 3D printers. The recent demonstration of an additively manufactured excavator at the CONEXPO 2017 exhibition in Las Vegas showed that the use of cutting edge robotics and automation is essential for the next generation of additive systems. The future of AM will heavily rely on advanced robotics, machine learning, and the internet of things. This paper summarizes progress in AM; presents the practical aspects, challenges, and lessons learned in developing robotic-based AM systems; and outlines the needs and future directions of robotics for AM.

Nycz, Andrzej↗
DOE OSTI2019

Opportunities for Lighter Weight and Lower Total Cost Component Manufacturing

This paper describes how a relatively new manufacturing technology known as additive manufacturing (AM) can enable creation of more mass efficient components when compared to those created by conventional or subtractive manufacturing (SM). An important element in the use of AM is re-thinking the design approach when completely new shape possibilities are enabled. Similarly, creative use of AM also can enable significant part count reduction. In order to make the case for the potential of AM, the more common AM processes are described and illustrated. As with any new technology, there come challenges during the reduction to practice phase of AM. Some of these challenges have been addressed and solved. Others are a work in progress and the approach to possible solutions to some of these is described.

Williams, James C.↗
DOE OSTI2023

Reinforcement learning for real-time process control in high-temperature superconductor manufacturing

With high efficiency and low energy loss, high-temperature superconductors (HTS) have demonstrated their profound applications in various fields, such as medical imaging, transportation, accelerators, microwave devices, and power systems. The high-field applications of HTS tapes have raised the demand for producing cost-effective tapes with long lengths in superconductor manufacturing. However, achieving the uniform and enhanced performance of a long HTS tape is challenging due to the unstable growth conditions in the manufacturing process. Although it is confirmed that the process parameters during the advanced metal organic chemical vapor deposition (A-MOCVD) process influence the uniformity of the produced HTS tapes, the high-dimensional process parameter signals and their complicated interactions make it difficult to develop an effective control policy. In this paper, we propose a local measure for the uniformity of HTS tapes to provide instant feedback for our control policy. Then, we model the manufacturing of HTS tapes as a Markov decision process (MDP) with continuous state and action spaces to assess the instant reward in real time in our feedback control model. As our MDP involves continuous and high-dimensional state and action spaces, a neural fitted Q-iteration (NFQ) algorithm is adopted to solve the MDP with artificial neural network (ANN) function approximation. The collinearity of process parameters can restrict our capability of adjusting the process parameters, which is addressed by the principal component analysis (PCA) in our method. The control policy adjusts the PCA of process parameters using the NFQ algorithm. In conclusion, based on our case studies on real A-MOCVD dataset, the obtained control policy increases the average uniformity of tapes by 5.6% and performs especially well on sample HTS tapes with a low uniformity.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2019

On the potential mechanisms of β to α' + β decomposition in two phase titanium alloys during additive manufacturing: a combined transmission Kikuchi diffraction and 3D atom probe study

In this paper, we focus on the mechanisms of phase transformations in additively manufactured Ti–6Al–4V during cooling. In particular, the goal is to understand if the imposed thermal cycles during fabrication results in the complete transformation of the α' to the β phase or the sub-transus decomposition of α' (martensite) to α + β. To this effect, samples fabricated using electron beam melting and laser-directed energy deposition techniques were analyzed using atom probe tomography (APT) in conjunction with correlative transmission Kikuchi diffraction (TKD). While the composition measurement using APT shows partitioning of vanadium into the β phase, the crystallographic analysis suggests evidence of a shear-induced transformation. Despite the pronounced differences in the processing conditions, both of the additive manufacturing techniques lead to similar partitioning of vanadium to the β phase. Finally, calculations using THERMOCALC and DICTRA show that under the time and temperature regimes of additive manufacturing the microstructure could develop by the decomposition reaction of α' → α+β.

36 MATERIALS SCIENCE↗