SEARCH · Engineering Papers

Results for “additives”

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.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,351 records · Page 75

All sources NASA NTRS DOE OSTI

DOE OSTI2023

Additively manufactured structure with reinforced access opening

A method and system of additively-manufacturing a structure having a reinforced access opening includes printing, via an additive printing device having at least one printer head, a portion of the structure adjacent to a support surface. The portion of the structure is printed of a cementitious material, and the printed portion of the structure defines an access opening for the structure. Moreover, the method includes providing a void of the cementitious material at a top boundary of the access opening, placing one or more reinforcement members in the void such that the one or more reinforcement members extend across the void, and continuing to print the printed portion of the structure around the void to build up the structure. Thus, the method also includes backfilling the void with a backfill material to incorporate the one or more reinforcement members within the void into the printed portion of the structure.

Li, Xiaopeng↗

DOE OSTI2023

Systems and methods for generating a molecular dynamic graded lattice structure and their application to additive manufacturing

Systems and methods for generating molecular dynamic graded lattice structures that can be used as infill for additively manufactured articles. Molecular dynamically generated lattice infill is based on force balancing a node distribution instead of a circle packing. Field data can be utilized to adjust the spacing of the node distribution according to a force balance equilibrium model that accounts for the field expected to be experienced by the article being additively manufactured. The resultant non-uniform honeycomb structures from force-balancing robustly and efficiently address the connection issues with traditional non-uniform lattice structures.

Kim, Seokpum↗

DOE OSTI2023

Additives for high voltage lithium ion batteries

This invention relates to an electrolyte composition for a lithium ion battery comprising a lithium salt in a non-aqueous solvent containing an additive comprising a compound of formula R 3 SiOP(O) n F 2 ; wherein each R independently is a hydrocarbyl group; and n is 0 or 1; and wherein the additive is substantially free from (R 3 SiO) 3 P(O) n and (R 3 SiO) 2 P(O) n F. Electrochemical cells and batteries also are described.

Peebles, Cameron↗

DOE OSTI2023

Fuel cell cathode and fuel cell system including a polymeric additive

A cathode configured for use within a fuel cell system is provided. The cathode includes a cathode substrate. The cathode further includes a coating disposed upon the cathode substrate and including a fluorocarbon polymer additive configured for sintering at a temperature of less than 200° C. The fluorocarbon polymer additive may be mixed with a catalyst ink coating or may be applied separately as a topcoat layer.

Ramaswamy, Nagappan↗

DOE OSTI2023

System and method for simulation-assisted additive manufacturing involving estimating anisotropic deformation

A simulation-assisted additive manufacturing system and method for generating an anisotropic compensation to account for non-uniform deformation due to additive manufacturing and service loading. The predicted deformation may not be fully defined. The present disclosure provides a system and method for estimating the missing deformation data through regression analysis. The present disclosure also provides an integrated framework where the various simulated-assisted design modules are configured for two-way communication and sharing access to changes to the model.

Kim, Seokpum↗

DOE OSTI2023

Real-time process monitoring for direct ink write additive manufacturing

Direct ink write (DIW) printing of reactive resins presents a unique challenge due to the time-dependent nature of the rheological and chemical properties of the ink. As a result, careful print optimization or process control is important to obtain consistent, high quality prints. The present invention uses a flow-through characterization cell for in situ chemical monitoring of a resin ink during DIW printing. Additionally, in-line extrusion force monitoring can be combined with off-line post inspection using machine vision. By combining in-line spectroscopy and force monitoring, it is possible to follow reaction kinetics (for example, curing of a reactive resin) and viscosity changes during printing, which can be used for a closed-loop process control. Additionally, the capability of machine vision to automatically identify and quantify print artifacts can be incorporated on the printing line to enable real-time, AI-assisted quality control of the printed products. Together, these techniques can form the building blocks of an optimized process control strategy when complex reactive ink must be used to produce printed hardware.

Cook, Adam W.↗

DOE OSTI2023

Additive manufacturing

A nanofluid laser entrainment additive manufacturing apparatus, system and method including a substrate, a dilute nanofluid of inert gas suspended nanoparticles on the substrate, a focused energy beam that irradiates the nanoparticles to selectively melt the nanoparticles, and a raster system that raster scans the focused energy beam across the inert gas suspended nanoparticles to create predetermined shapes by additive manufacturing.

Matthews, Manyalibo Joseph↗

DOE OSTI2024

Characterization of Non-Science Grade DESI CCDs and Creating Additional ICARUS Monitoring Metrics for Data Quality

DESI, otherwise known as the Dark Energy Spectroscopic Instrument, is an astronomical project measuring millions of optical spectra to characterize Dark Energy. The survey has been running for 3 years. My work delves into the data taking/analysis side of the DESI CCDs (Charge-Coupled Devices) which will help in swapping out broken CCDs on the instrument. Additionally, I worked on making new metrics for ICARUS, Imaging Cosmic and Rare Underground Signals for their monitoring of run data. This paper will talk about the types of characterizations done for DESI and additional metrics for data quality and tools used for ICARUS monitoring.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2021

Additive Manufacturing of Lightweight Structures: Microfibrillated Cellulose – PLA Biofoams

Extrusion-based polymer additive manufacturing (AM) technology is growing rapidly. The introduction of fiber reinforced feedstock materials and recent developments in the manufacturing systems have promulgated large scale AM of composites to create new industries and applications. Synthetic fibers such as carbon and glass fibers are commonly used to reinforce polymer composites. However, increasing environmental and long-term sustainability concerns are leading to new materials using cellulose fiber reinforcement in bio-derived polymers. These materials offer new property sets, new supply chains and have the potential to provide economical solutions leading to new applications. Large scale AM can be attractive for many different applications because of its ability to freeform manufacture complex geometries; each application may require different material properties. One of the novel application areas for large scale AM is 3D printing of lightweight materials via foaming. Although achieving low density is the key in light weighting via foaming, mechanical performance is also important for many applications. In this study the impact of micro-cellulose fibers (MFC) on foaming behavior and the mechanical properties of additively manufactured parts is investigated. MFC-polylactic acid (PLA) feedstock pellets were prepared at varying MFC content (5, 10, 15 and 20 wt.%) to understand the impact of cellulose fiber content on density and mechanical properties of the AM biocomposites. Also, the impact of extrusion speed and foaming agent content on the AM biocomposites is investigated. Although achieving uniform printed foam structure is challenging with the presence of cellulose fibers, promising results were accomplished with density values below 0.5g/cm3.

Tekinalp, Halil↗

DOE OSTI2024

Flashback characterization of additively manufactured swirl-stabilized fuel injector with varying surface roughness

This work investigates the effects of as-built surface roughness on the flashback propensity in additively manufactured (AM) swirl-stabilized lean premixed (LPM) fuel injectors. Adoption of AM for rapid prototyping and fabrication of complex fuel-flexible injector designs requires investigating surface roughness effects on the flow and flame stability characteristics of the combustor. Wall roughness increases the near-wall shear, which could alter the boundary layer structure and change the propensity for flame flashback. Accounting for the realistic as-built surface roughness is crucial in carrying out computational modeling and experimental analysis to establish a feedback loop for the precision designing of fuel-flexible injectors. The presented numerical analysis of as-built AM injector is an essential consideration to optimize injector design for aerodynamics and additive manufacturability.

Mohanty, Pratikshya↗

DOE OSTI2024

Advanced Instrumentation for Metal Additive Manufacturing

Laser powder bed fusion (LPBF) is the most widely used process for metal additive manufacturing (AM), particularly where complex geometries provide performance advantages unattainable with traditional manufacturing techniques. However, LPBF is highly sensitive to innate variability in both the powder spreading and fusion steps, often leading to defects such as pores that are difficult to detect yet significantly impair component mechanical properties and fatigue life. This thesis presents a range of novel instruments enabling both precise assessment of powder layer characteristics and in-situ thermal metrology of metal AM to advance the quality control of LPBF. First, leveraging a custom X-ray microscope and a radiation-transport model developed through this work, transmission X-ray imaging is used to study spreading of thin metal powder layers. Effective layer depth is directly mapped at a process-relevant size scale, surpassing optical techniques that can only estimate local deposition from layer surface topography. Layer packing density and quality are shown to be influenced by powder flowability and particle size relative to nominal powder layer thickness. Layer quality is additionally connected to the geometry of the spreading implement and its velocity. This technique and its presented findings enable pairing feedstocks with spreading strategies that create layers with consistent packing density and uniformity. Second, a twofold approach is employed to optically interrogate the laser fusion step of LPBF for observing signatures of defect formation. Aperture division multiplexing is conceptualized, providing for simultaneous laser delivery and high-fidelity infrared (IR) process monitoring through a common optic. In-situ microscopy at 50 μm spatial resolution and at mid-wave IR wavelengths is proven readily achievable with the first purpose-built optic of this type. Next, a bespoke imaging spectrometer, along with a temperature-emissivity separation technique, is used to retrieve accurate process temperatures over a 1000 K range. Data from these instruments are correlated to porosity as fine as 4.3 μm in two LPBF test artifacts, as verified using computed tomography (CT), establishing the viability of robust optically-based component qualification.

Penny, Ryan↗

DOE OSTI2025

Fundamental Path Optimization Strategies for Extrusion-based Additive Manufacturing

Extrusion-based additive manufacturing processes begin with a software program, called a slicer, that generates layer geometry and fits toolpaths to each layer to define where material is to be extruded or deposited. Before the toolpaths are output as g-code for the additive manufacturing system to execute, the toolpaths should be optimized. Many complex optimization approaches using graph theory, Chinese postman problem, and other complex mathematical models exist, but these approaches are rarely used in daily printing operations and are not available through common slicing programs such as Cura and PrusaSlicer. Instead, path planning and optimization typically revolves around simpler, fully automated approaches such as inside out and next closest. This paper will explore the fundamental optimization strategies for toolpath planning and document a new implementation, available via open-source slicing software, that allows for greater control of the path planning process.

Roschli, Alex [ORNL] (ORCID:0000000213084632)↗

DOE OSTI2024

7 Innovations in high-rate composite manufacturing: integrating additive manufacturing with compression molding process

Advanced composites play a pivotal role in modern engineering, offering exceptional strength-to-weight ratios and tailored properties, essential for various industries. High-rate composite manufacturing techniques have rapid production capabilities, which are essential for meeting the demands of industries requiring cost-saving, efficiency, and quick turnaround times. This chapter explores the Additive Manufacturing- Compression Molding (AM-CM) system developed by Oak Ridge National Laboratory (ORNL) for advanced composites manufacturing. The AM-CM system integrates additive manufacturing with compression molding, facilitating the production of polymer composite parts with superior mechanical properties and meticulously controlled microstructures. This innovative system not only ensures precise material deposition but also operates as a fast composite manufacturing process, enhancing productivity and performance, which are needed attributes across industrial applications. Through comprehensive mechanical testing and microstructural analysis, AM-CM promotes remarkable fiber alignment and reduced porosity in composite parts compared to alternative thermoplastic high-rate composite manufacturing methods. Furthermore, AM-CM enables overmolding reinforcement using continuous carbon fiber and supports selective reinforcement through customizable toolpaths. It also facilitates the production of hybrid materials to achieve tailored mechanical properties. Future advancements in AM-CM technology aim to enhance process efficiency, broaden material versatility, and improve part performance. This involves exploring novel materials, advancing process monitoring, implementing automation technologies, and integrating artificial intelligence (AI) and machine learning (ML) for predictive modeling and real-time optimization in composite manufacturing. These developments will establish the AM-CM system as a transformative technology in composite manufacturing, driving innovation across industries.

Hassen, Ahmed [ORNL] (ORCID:0000000328521222)↗

DOE OSTI2024

System and method for in situ inspection of defects in additively manufactured parts using high speed melt pool pyrometry

A system and method is disclosed for detecting anomalies in an additively manufactured part. An energy source generates a signal forming an optical beam for creating a melt pool in a layer of feedstock material being selectively fused to make a part in an additive manufacturing operation. A sensor is configured to receive a signal reflected from the melt pool. The reflected signal forms a thermal signal indicative of a temperature of the feedstock material at a known location on a layer of the feedstock material while the feedstock material is being fused at the known location. A controller receives and analyzes data relating to the received signal to determine if an anomaly exists at the known location.

Forien, Jean-Baptiste↗

DOE OSTI2024

Systems and methods for abrasive oxide removal in additive manufacturing processes

Systems and methods for removing an oxide layer in an additive manufacturing process are provided. A direct write machine may be used to create wire bonds for semiconductors. The direct write machine may deposit a conductive print material between bond pads to create interconnections. The bond pads may comprise aluminum and an aluminum oxide layer on an outer surface. The presence of an aluminum oxide layer may decrease the electrical connection between the wire bond and the aluminum substrate. To remove the aluminum oxide layer, an abrasive tool is provided to ultrasonically abrade the aluminum oxide layer while the conductive print material is being deposited. The conductive print material may include abrasive additives materials to further aid in abrading the aluminum oxide layer.

Young, Barbara D.↗

DOE OSTI2024

Additive manufacturing process for producing aluminum-boron carbide metal matrix composites

A method for additive manufacturing of a composite object containing a bonded network of boron carbide particles and aluminum occupying spaces between boron carbide particles, the method comprising: (i) producing a porous preform constructed of boron carbide by an additive manufacturing process in which particles of boron carbide are bonded together; and (ii) infiltrating molten aluminum, at a temperature of 1000-1400° C., into pores of said porous preform to produce said composite object constructed of boron carbide particles within an aluminum matrix, wherein the boron carbide is present in the composite object in an amount of 30-70 wt. %. The resulting composite material is also herein described.

Cramer, Corson L.↗

DOE OSTI2024

Systems and methods for automated depowdering and transfer of additively manufactured objects

Systems and methods for additive manufacturing of objects are disclosed. The system includes an object builder subsystem configured to additively manufacture an object in a powder bed, an object extraction subsystem configured to extract the object from the powder bed, and a depowdering subsystem configured to remove powder from the object while the object is gripped by the gripper assembly. The object extraction subsystem includes a gripper assembly comprising two or more gripper members that each include a perforated mesh structure.

Elliott, Amelia M.↗

DOE OSTI2025

Overall Cooling Effectiveness of Internally Cooled Additively Manufactured Blades

Power generation gas turbine blades must utilize highly effective cooling schemes to withstand moderate heat loads for long operating times. Prior work indicates that gas turbines in the 5-10 MW range primarily utilize internal cooling to prevent further increase of aerodynamic losses that result from film cooling, but few studies focus solely on internal cooling. In this study, three additively manufactured internal cooling designs were tested in the 50 percent span section of the National Experimental Turbine (NExT) blade: a baseline cooling design with pin-fin arrays and rib turbulators, a double wall design with impingement jets and serpentine channels, and an incremental impingement design. The designs were tested in a high-speed linear cascade at exit Reynolds numbers ranging from 700,000 to 1,400,000 at an exit Mach of 0.8. In addition, freestream turbulence and build angle effects on cooling performance were studied.

gas turbine blades↗