Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “FABRICATION”

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.

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

At least 1,207 records · Page 67

High-Rate Fabrication of a-Si-Based Thin-Film Solar Cells Using Large-Area VHF PECVD Processes

The University of Toledo (UT), working in concert with it’s a-Si-based PV industry partner Xunlight Corporation (Xunlight), has conducted a comprehensive study to develop a large-area (3ft x 3ft) VHF PECVD system for high rate uniform fabrication of silicon absorber layers, and the large-area VHF PECVD processes to achieve high performance a-Si/a-SiGe or a-Si/nc-Si tandem junction solar cells during the period of July 1, 2008 to Dec. 31, 2011, under DOE Award No. DE-FG36-08GO18073. The project had two primary goals: (i) to develop and improve a large area (3 ft × 3 ft) VHF PECVD system for high rate fabrication of > = 8 Å/s a-Si and >= 20 Å/s nc-Si or 4 Å/s a-SiGe absorber layers with high uniformity in film thicknesses and in material structures. (ii) to develop and optimize the large-area VHF PECVD processes to achieve high-performance a-Si/nc-Si or a-Si/a-SiGe tandem-junction solar cells with >= 10% stable efficiency. Our work has met the goals and is summarized in “Accomplishments versus goals and objectives”.

14 SOLAR ENERGY↗

Fabrication and Characterization of a Single Hole Transistor in p-type GaAs/AlGaAs Heterostructures

Most spin qubit research to date has focused on manipulating single electron spins in quantum dots. However, hole spins are predicted to have some advantages over electron spins, such as reduced coupling to host semiconductor nuclear spins and the ability to control hole spins electrically using the large spin-orbit interaction. Building on recent advances in fabricating high-mobility 2D hole systems in GaAs/AlGaAs heterostructures at Sandia, we fabricate and characterize single hole transistors in GaAs. We demonstrate p-type double quantum dot devices with few-hole occupation, which could be used to study the physics of individual hole spins and control over coupling between hole spins, looking towards eventual applications in quantum computing.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

Updated Life-Cycle Assessment of Aluminum Production and Semi-fabrication for the GREET Model

This report serves as an update for the life-cycle analysis (LCA) of aluminum production based on the most recent data representing the state-of-the-art of the industry in North America. The 2013 Aluminum Association (AA) LCA report on the environmental footprint of semifinished aluminum products in North America provides the basis for the update (The Aluminum Association, 2013). The scope of this study covers primary aluminum production, secondary aluminum production, as well as aluminum semi-fabrication processes including hot rolling, cold rolling, extrusion and shape casting. This report focuses on energy consumptions, material inputs and criteria air pollutant emissions for each process from the cradle-to-gate of aluminum, which starts from bauxite extraction, and ends with manufacturing of semi-fabricated aluminum products. The life-cycle inventory (LCI) tables compiled are to be incorporated into the vehicle cycle model of Argonne National Laboratory’s Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) Model for the release of its 2015 version.

Dai, Qiang↗

Validation of cleaning method for various parts fabricated at a Beryllium facility

This study evaluated and documented a cleaning process that is used to clean parts that are fabricated at a beryllium facility at Los Alamos National Laboratory. The purpose of evaluating this cleaning process was to validate and approve it for future use to assure beryllium surface levels are below the Department of Energy’s release limits without the need to sample all parts leaving the facility. Inhaling or coming in contact with beryllium can cause an immune response that can result in an individual becoming sensitized to beryllium, which can then lead to a disease of the lungs called chronic beryllium disease, and possibly lung cancer. Thirty aluminum and thirty stainless steel parts were fabricated on a lathe in the beryllium facility, as well as thirty-two beryllium parts, for the purpose of testing a parts cleaning method that involved the use of ultrasonic cleaners. A cleaning method was created, documented, validated, and approved, to reduce beryllium contamination.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Design and fabrication of a 30 T superconducting solenoid using overpressure processed Bi2212 round wire

High field superconducting magnets are used in particle colliders, fusion energy devices, and spectrometers for medical imaging and advanced materials research. Magnets capable of generating fields of 20-30 T are needed by future accelerator facilities. A 20-30 T magnet will require the use of high-temperature superconductors (HTS) and therefore the challenges of high field HTS magnet development need to be addressed. Superconducting Bi 2 Sr 2 CaCu 2 O x (Bi2212) conductors fabricated by the oxide-powder-in-tube (OPIT) technique have demonstrated the capability to carry large critical current density of 10 5 A/cm 2 at 4.2 K and in magnetic fields up to 45 T. Available in round wire multi-filamentary form, Bi2212 may allow fabrication of 20-50 T superconducting magnets. Until recently the performance of Bi2212 has been limited by challenges in realizing high current densities (J c ) in long lengths. This problem now is solved by the National High Magnetic Field Lab using an overpressure (OP) processing technique, which uses external pressure to process the conductor. OP processing also helps remove the ceramic leakage that results when Bi-2212 liquid leaks out from the sheath material and reacts with insulation, coil forms, and flanges. Significant advances have also been achieved in developing novel insulation materials (TiO 2 coating) and Ag-Al sheath materials that have higher mechanical strengths than Ag-0.2wt.% Mg, developing heat treatment approaches to broadening the maximum process temperature window, and developing high-strength, mechanical reinforced Bi-2212 cables. In the Phase I work, we leveraged these new opportunities to prototype overpressure processed solenoids and test them in background fields of up to 14 T. Additionally a design of a fully superconducting 30 T solenoid was produced. This work in conjunction with the future path outlined in the Phase II proposal would provide a major step toward qualifying Bi2212 technology for use in high-field accelerator magnets. Additionally, the performance parameters match key requirements of a final muon beam cooling solenoid. This technology will also be of interest to high-field NMR manufacturers.

43 PARTICLE ACCELERATORS↗

Gel Fabrication of Molybdenum “Beads”

Spherical molybdenum particles or “beads” of various diameters are of interest as feedstock materials for the additive manufacture of targets and assemblies used in the production of 99 Mo medical isotopes using accelerator technology. Small metallic beads or ball bearings are typically fabricated from wire; however, small molybdenum spheres cannot readily be produced in this manner. Sol-gel processes are often employed to produce small dense microspheres of metal oxides across a broad diameter range that in the case of molybdenum could be reduced and sintered to produce metallic spheres. These Sol-gel type processes were examined for forming molybdenum oxide beads; however, the molybdenum trioxide was chemically incompatible with commonly used gelation materials. As an alternative, an aqueous alginate process being assessed for the fabrication of oxide spheres for catalyst applications was employed to form molybdenum trioxide beads that were successfully reduced and sintered to produce small molybdenum spheres.

36 MATERIALS SCIENCE↗

MQXFS1 Quadrupole Fabrication Report

This report presents the fabrication and QC data of MQXFS1, the first short model of the low-beta quadrupoles (MQXF) for the LHC High Luminosity Upgrade. It describes the conductor, the coils, and the structure that make the MQXFS1 magnet. Qualification tests and non-conformities are also presented and discussed. The fabrication of MQXFS1 was started before the finalization of conductor and coil design for MQXF magnets. Two strand design were used (RRP 108/127 and RRP 132/169). Cable and coil cross-sections were “first generation”.

43 PARTICLE ACCELERATORS↗

Additive Manufacturing of Molds for Fabrication of Insulated Concrete Block

Oak Ridge National Laboratory (ORNL) worked with concrete block manufacturer, NRG Insulated Block, to demonstrate additive manufacturing of a multi-component block mold for its line of insulated blocks. Solid models of the mold parts were constructed from existing two-dimensional drawings, and the parts were fabricated on a Stratasys Fortus 900 using ULTEM™ 9085. Block mold parts were delivered to NRG and installed on one of their fabrication lines. While form and fit were acceptable, the blocks made from the molds collapsed when extruded from the printed molds during NRG’s testing. However, the project demonstrated significant time and cost reductions and achieving proper functionality through the use of different additive manufacturing techniques.

42 ENGINEERING↗

In-cell Re-fabrication and Loss-of-coolant Accident (LOCA) Testing of High Burnup Commercial Spent Fuel

A high burnup commercial spent fuel segment was re-fabricated into a pressurized test train for fuel safety testing in the Irradiated Fuels and Examination Laboratory (IFEL) hot cell facility at Oak Ridge National Laboratory. Descriptions of the in-cell re-fabrication capabilities and assembly of the loss-of-coolant-accident (LOCA) test train are provided. An in-cell integral LOCA test was performed in the Severe Accident Test Station (SATS) by subjecting the fuel segment to a steam environment, internal pressure, temperatures up to 1200 ºC, and water quench.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Technical Assistance in Fabrication and Testing of MEAs: Cooperative Research and Development Final Report

Altergy's fuel cell cost is highly dependent on expensive purchased membrane electrode assemblies (MEAs), which amount to 42¢/watt in a 5kW system. In order to better compete with other power solutions, the company has identified an MEA breakthrough cost of 20¢/watt to unlock new, major markets for its fuel cell products. Since Altergy presently does not have an accurate cost model for the real costs of these MEAs, it is difficult to know whether the company goal is achievable. Altergy seeks to leverage NREL expertise to reduce cost and improve performance for Altergy's fuel cell products. The objective of this Small Business Voucher (SBV) project therefore will be for NREL and Altergy to work together in three major task areas: 1) demonstrating the fabrication of MEAs at NREL using NREL non-proprietary methods, to the intent of potentially fabricating MEAs at Altergy to reduce product costs; and, 2) creating a cost model to assist Altergy in manufacturing decisions.

30 DIRECT ENERGY CONVERSION↗

Fabrication and Mechanical Testing of Block Shear Joints to Measure Ultimate Shear Strength in Adhesive-Bonded High Explosive (HE) Joints (Progress Summary)

Small-scale adhesive-bonded HE joints were designed, using roughly 4% of the HE mass required by fixtures described in the ASTM D905 standard. Custom 3D-printed bonding fixtures were designed, fabricated, and used to generate reproducible joints with programmable bondline thickness. A custom 3D-printed block shear testing fixture was designed, fabricated, and employed to measure the shear strength of test joints.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

AGR-5/6/7 Fuel Fabrication Feedstock Chemical Purity Specifications

This specification has been prepared to provide fuel fabricators with minimum chemical purity specifications intended to ensure that fuel components have consistent properties and that impurity levels in the as-fabricated fuel is sufficiently low to minimize in-pile TRISO particle failures and to enhance fission product retention. Process chemical purity specifications are given for the following processes: • Kernel forming and sintering • TRISO particle coating • Matrix preparation • TRISO overcoating • Compact carbonization and heat treatment

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Dissolution Flowsheet for U-10Mo Scrap Generated from the Fabrication of High Performance Research Reactor Fuel

The Savannah River National Laboratory was requested to develop dissolution flowsheets for low enriched uranium scrap streams generated during the fabrication of high performance research reactor (HPRR)fuel. The scrap streams include U-10Mo-Zr foil and rejected Al-clad plates. Co-rolled U-10Mo-Zr foils and Alclad U-10Mo-Zr mini-plates which have been through the hot isostatic pressing process were obtained from BWX Technologies, Inc. for use in this work. Small-scale dissolution experiments were performed to identify the flowsheet conditions required to safely and efficiently dissolve the fuel fabrication scrap for subsequent U recovery. Experiments were performed to demonstrate the dissolution of the U-10Mo-Zr foil, removal of the Al cladding from the mini-plates, and the dissolution of the mini-plates following cladding removal.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Documentation Package Supporting Fabrication of Doped UO 2 Samples for MiniFuel Irradiation and Fission Gas Release Benchmarking

The Oak Ridge National Laboratory (ORNL) is looking into the fabrication of high performance UO 2 fuel candidates via the addition of dopants to the UO 2 . The addition of dopants is proposed to cause enlarged grains that will slow down fission gas release from the irradiated fuel pellet candidates. The Cr-doped UO 2 pellets were fabricated from a microspherical feedstock, and enlarged grains were observed during the microstructural characterization. Irradiation under the Miniature Fuel program in the High Flux Isotope Reactor at ORNL will enable the study of irradiation response of such potential fuel candidates and will allow fission gas release benchmarking for these fuel candidates.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Documenting Development of Processing Parameters for Fabrication of Doped and Undoped Fuel Pellets (Summary Report)

Early FY20 restructuring of the TREAT work package FT-20LA02020608 Enriched Fuel Fabrication for Safety Testing, and associated deliverables necessitated the rescoping of existing LANL deliverables. This rescoped carryover report summarizes work to date on doped and undpoped fuel pellet fabrication development of proceeding parameters. This summary also includes a status update of intended research activities that fall under the activity associated with this work package.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Self-Disinfecting PPE Fabric [Factsheet]

Green Theme Technologies Inc. developed a chemical finishing technology that uses a high pressure, water-free, thermally triggered polymerization process to produce a thin conformal polymer coating around fabric fibers. This process can be used to embed selective, disinfectant chemicals to provide an anti-microbial, anti-viral finish to fabrics. In the face of COVID-19, the company hopes this process produces a permanent, laundry-durable, anti-pathogenic finish. Essentially, creating regenerative and reusable PPE.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Vessel Fabrication Overview

LANL utilizes spherical vessels for numerous basic science, materials, and system performance experiments. These pressure vessels are designed and fabricated to meet the intent of ASME B&PV Section VIII, Division 3 and Code Case 2564. LANL has successfully contracted vessel construction in the past, utilizing HSLA-100 steel. As current vessel inventories approach design life, we are once again embarking upon a series of fabrication contracts to produce replacement components and vessel assemblies to support continued experiment cadence at LANL. LANL’s intent is to ramp up a continuous vessel supply chain for the DOE Complex.

42 ENGINEERING↗