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Results for “Metallization process”

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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1998

Plasma Processing of Metallic and Semiconductor Thin Films in the Fisk Plasma Source

The use of plasmas to process materials has become widespread throughout the semiconductor industry. Plasmas are used to modify the morphology and chemistry of surfaces. We report on initial plasma processing experiments using the Fisk Plasma Source. Metallic and semiconductor thin films deposited on a silicon substrate have been exposed to argon plasmas. Results of microscopy and chemical analyses of processed materials are presented.

Lampkin, Gregory↗
NASA NTRS1981

Analysis and evaluation in the production process and equipment area of the low-cost solar array project

The attributes of the various metallization processes were investigated. It is shown that several metallization process sequences will lead to adequate metallization for large area, high performance solar cells at a metallization add on price in the range of $6. to 12. m squared, or 4 to $.8/W(peak), assuming 15% efficiency. Conduction layer formation by thick film silver or by tin or tin/lead solder leads to metallization add-on prices significantly above the $6. to 12/m squared range c.) The wet chemical processes of electroless and electrolytic plating for strike/barrier layer and conduction layer formation, respectively, seem to be most cost effective.

Wolf, M.↗
NASA NTRS2011

Modeling and Characterization of Damage Processes in Metallic Materials

This paper describes a broad effort that is aimed at understanding the fundamental mechanisms of crack growth and using that understanding as a basis for designing materials and enabling predictions of fracture in materials and structures that have small characteristic dimensions. This area of research, herein referred to as Damage Science, emphasizes the length scale regimes of the nanoscale and the microscale for which analysis and characterization tools are being developed to predict the formation, propagation, and interaction of fundamental damage mechanisms. Examination of nanoscale processes requires atomistic and discrete dislocation plasticity simulations, while microscale processes can be examined using strain gradient plasticity, crystal plasticity and microstructure modeling methods. Concurrent and sequential multiscale modeling methods are being developed to analytically bridge between these length scales. Experimental methods for characterization and quantification of near-crack tip damage are also being developed. This paper focuses on several new methodologies in these areas and their application to understanding damage processes in polycrystalline metals. On-going and potential applications are also discussed.

Glaessgen, E. H.↗
DOE OSTI2023

Defect‐Free Sound Insulator Using Single Metal‐Based Friction Stir Process Array

Metals are excellent conductors for phonon transportation such as vibration, sound, and heat. Generally, metal sound insulators require multimaterial structure or defects and unimetal sound insulators are challenging. Therefore, a design of a defect-free sound insulator made by single alloys with multiple friction stir processes (FSPs) is proposed. Periodic friction stir processing can induce superlattice-like local mechanical properties’ modifications. By experimental acoustic characterization, it is observed that FSP can introduce clear acoustic–elastic property contrast on an aluminum plate by the presence of stir zone and heat-affected zones. In numerical simulations, the signature FSP-induced property profile is periodically and parallelly arranged on a long aluminum plate. The transmission gap frequencies are present on the frequency spectrum with the sound propagation direction perpendicular to the FSP paths. Disorder offsets on FSP periodicity are further introduced. Anderson localization is found on a resonance frequency, which provides −11 dB sound reduction by an exponential decay. Due to the finite design length, the slight disorder can also enhance sound insulation in the periodic transmission gap frequency. In conclusion, with analysis and comparison with different configurations, the best performance in the models can achieve −30 dB sound insulation in the 350 mm-long aluminum alloy plate with 14 parallel FSPs.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Sustainable bioleaching of lithium-ion batteries for critical metal recovery: Process optimization through design of experiments and thermodynamic modeling

Recycling spent lithium-ion batteries (LIBs) could alleviate supply risks for critical metals and be less harmful to the environment compared to new production of metals from mining. Developing a cost-effective LIB bioleaching process could be a promising alternative to traditional energy-intensive recycling technologies. Here, this study aimed to optimize bioleaching conditions for maximum economic competitiveness through design of experiments using iterative response surface methodology (RSM), assisted by thermodynamic modeling. The optimal condition was identified as 2.5% pulp density in 75 mM gluconic acid biolixiviant at 55°C for 30 h which could recover 57%–84% of nickel, 71%–86% of cobalt, and 100% of lithium and manganese, yielding a 17%–26% net profit margin. The recommended pulp density and acid concentrations, together with the observed metal solubilization, were supported by thermodynamic modeling predictions. Our study demonstrated that combining RSM with thermodynamic simulations could be a powerful tool for optimizing bioleaching conditions.

60 APPLIED LIFE SCIENCES↗
NASA NTRS1976

Development of techniques for processing metal-metal oxide systems

Techniques for producing model metal-metal oxide systems for the purpose of evaluating the results of processing such systems in the low-gravity environment afforded by a drop tower facility are described. Because of the lack of success in producing suitable materials samples and techniques for processing in the 3.5 seconds available, the program was discontinued.

Johnson, P. C.↗
NASA NTRS2002

Preliminary Thermal-Mechanical Sizing of Metallic TPS: Process Development and Sensitivity Studies

The purpose of this research was to perform sensitivity studies and develop a process to perform thermal and structural analysis and sizing of the latest Metallic Thermal Protection System (TPS) developed at NASA LaRC (Langley Research Center). Metallic TPS is a key technology for reducing the cost of reusable launch vehicles (RLV), offering the combination of increased durability and competitive weights when compared to other systems. Accurate sizing of metallic TPS requires combined thermal and structural analysis. Initial sensitivity studies were conducted using transient one-dimensional finite element thermal analysis to determine the influence of various TPS and analysis parameters on TPS weight. The thermal analysis model was then used in combination with static deflection and failure mode analysis of the sandwich panel outer surface of the TPS to obtain minimum weight TPS configurations at three vehicle stations on the windward centerline of a representative RLV. The coupled nature of the analysis requires an iterative analysis process, which will be described herein. Findings from the sensitivity analysis are reported, along with TPS designs at the three RLV vehicle stations considered.

Poteet, Carl C.↗
DOE OSTI2023

Uncertainty Quantification of Metal Additive Manufacturing Processing Conditions Through the use of Exascale Computing

Metal additive manufacturing (AM) is a disruptive manufacturing technology that opens the design space for parts outside those possible from traditional manufacturing methods. In order to accelerate industry and R&D needs to certify AM parts, the Exascale Additive Manufacturing project (ExaAM) has developed a suite of exascale-ready computational tools to model the process-to-structure-to-properties (PSP) relationship for additively manufactured metal components. One such tool is an uncertainty quantification (UQ) pipeline to quantify the effect that uncertainty in processing conditions has on local mechanical responses. We present an overview of this pipeline and its required simulation and workflow codes. Using the Oak Ridge National Laboratory’s (ORNL) exascale computer, Frontier, we utilize this pipeline to cross multiple length and time scales to predict the local mechanical response of a location within a complex AM bridge part, AMB2018-01 produced by the National Institute of Standards and Technology (NIST) as part of their 2018 AM-Bench test series. Our results are then compared to experimental mechanical tests of parts from the NIST build to quantify the error in the ExaAM UQ workflow.

Carson, Robert↗
NASA NTRS1986

A mesh re-zoning technique for finite element simulations of metal forming processes

Based on some fundamental properties of finite element approximations, a mesh re-zoning scheme is proposed for finite element simulations of metal forming problems. It is demonstrated that this technique is indispensable in analyzing many difficult forming processes, especially when there exist corners or very irregular shapes on the boundaries. The algorithm is tested by a backward extrusion process and direct extrusion through a square die.

Cheng, J.-C.↗
NASA NTRS1979

A new method of metallization for silicon solar cells

The new metallization process based on Mo-Sn system was studied. The reaction mechanism of MoO3 and its mixture with Sn was examined. The basic ink composition was modified in order to obtain a low ohmic contact to the cell. The electrical characteristics of the cells were comparable with the existing metallization processes. However, in comparison with the standard processes using silver as the contacting metal, the saving obtained by the use of the new process was substantial.

Macha, M.↗
NASA NTRS1991

Considerations of metal joining processes for space fabrication, construction and repair

A comprehensive evaluation is conducted of candidate processes for metalworking in orbital (vacuum-microgravity) conditions. Attention is given to electron-beam welding, brazing, gas-tungsten arc welding, laser welding, plasma arc welding, and gas-metal arc welding. It is established that several of these processes will be required to cover all foreseeable requirements. Microgravity effects are considered minor, and efforts are being concentrated on problems associated with vacuum conditions and with process-operator safety.

Russell, C.↗
DOE OSTI2023

In vitro maturation of NiSOD reveals a role for cytoplasmic histidine in processing and metalation

The importance of cellular low molecular weight (LMW) ligands in metalloenzyme maturation is largely unexplored. Maturation of NiSOD requires post-translational N-terminal processing of the proenzyme, SodN, by its cognate protease, SodX. Here we provide evidence for the participation of L-histidine in the protease-dependent maturation of Nickel-dependent Superoxide Dismutase (NiSOD) from Streptomyces coelicolor. Furthermore, in vitro studies using purified proteins cloned from S. coelicolor and overexpressed in E. coli support a model where a ternary complex formed between the substrate (SodN), the protease (SodX) and L-Histidine creates a novel Ni-binding site that is capable of the N-terminal processing of SodN and specifically incorporates Ni into the apo-NiSOD product. Thus, L-Histidine serves many of the functions associated with a metallochaperone or, conversely, eliminates the need for a metallochaperone in NiSOD maturation.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2023

High Performing Inverted Flexible Perovskite Solar Cells via Solution Phase Deposition of Yttrium-Doped SnO 2 Directly on Perovskite

Solution processing of flexible perovskite solar cells (f-PSCs) provides an avenue for scalable, high-throughput printing of lightweight, scalable, and cost-effective flexible solar cells. However, the deposition of fully solution-processed metal oxide charge transport layers on perovskites has been limited by solvent incompatibilities and high processing temperatures for metal oxide nanoparticles. In this study, we present high-performance, inverted f-PSCs from the direct deposition of yttrium doped SnO 2 nanoparticles functionalized with acetate on top of perovskite as an ink in anhydrous ethanol via blade coating. Yttrium doping improved device performance by improving the charge extraction leading with a decreased series resistance leading to improvements in the open-circuit voltage and fill factor. Furthermore, the champion power conversion efficiency for 0.1 cm 2 devices increased from 14.3% for undoped SnO 2 to 18.2% with 2% Y:SnO 2 doping, which is unprecedented for f-PSCs on ITO-PET substrate employing SnO 2 as an ETL.

14 SOLAR ENERGY↗
DOE OSTI2024

Scalable and Quench-Free Processing of Metal Halide Perovskites in Ambient Conditions

With the rise of global warming and the growing energy crisis, scientists have pivoted from typical resources to look for new materials and technologies. Perovskite materials hold the potential for making high-efficiency, low-cost solar cells through solution processing of Earth-abundant materials; however, scalability, stability, and durability remain key challenges. In order to transition from small-scale processing in inert environments to higher throughput processing in ambient conditions, the fundamentals of perovskite crystallization must be understood. Classical nucleation theory, the LaMer relation, and nonclassical crystallization considerations are discussed to provide a mechanism by which a gellan gum (GG) additive—a nontoxic polymeric saccharide—has enabled researchers to produce quality halide perovskite thin-film blade coated in ambient conditions without a quench step. Furthermore, we report on the improved stability and durability properties inherent to these films, which feature improved morphologies and optoelectronic properties compared to films spin-coated in a glovebox with antisolvent. We tune the amount of GG in the perovskite precursor and study the interplay between GG concentration and processability, morphological control, and increased stability under humidity, heat, and mechanical testing. The simplicity of this approach and insensitivity to environmental conditions enable a wide process window for the production of low-defect, mechanically robust, and operationally stable perovskites with fracture energies among the highest obtained for perovskites.

14 SOLAR ENERGY↗
NASA NTRS1997

Effects of Gravity on Processing Heavy Metal Fluoride Fibers

The effects of gravity on the crystal nucleation of heavy metal fluoride fibers have been studied in preliminary experiments utilizing NASA's KC-135 reduced gravity aircraft and a microgravity sounding rocket flight. Commercially produced fibers were heated to the crystallization temperature in normal and reduced gravity. The fibers processed in normal gravity showed complete crystallization while the fibers processed in reduced gravity did not show signs of crystallization.

Tucker, Dennis S.↗