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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 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Characterization of room temperature recrystallization kinetics in electroplated copper thin films with concurrent x-ray diffraction and electrical resistivity measurements

Concurrent in-situ four-point probe resistivity and high resolution synchrotron x-ray diffraction measurements were used to characterize room temperature recrystallization in electroplated Cu thin films. The x-ray data were used to obtain the variation with time of the integrated intensities and the peak-breadth from the Cu 111 and 200 reflections of the transforming grains. The variation of the integrated intensity and resistivity data with time was analyzed using the Johnson-Mehl-Avrami-Kolmogorov (JMAK) model. For both 111-textured and non-textured electroplated Cu films, four-point probe resistivity measurements yielded shorter transformation times than the values obtained from the integrated intensities of the corresponding Cu 111 reflections. In addition, the JMAK exponents fitted to the resistivity data were significantly smaller. These discrepancies could be explained by considering the different material volumes from which resistivity and diffraction signals originated, and the physical processes which linked these signals to the changes in the evolving microstructure. Based on these issues, calibration of the resistivity analysis with direct structural characterization techniques is recommended.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

In-situ realtime monitoring of nanoscale gold electroplating using micro-electro-mechanical systems liquid cell operating in transmission electron microscopy

The dynamics of nanoscale electroplating between gold electrodes was investigated using a microfabricated liquid cell mounted on a scanning transmission electron microscope. The electroplating was recorded in-situ for 10 min with a spatial resolution higher than 6 nm. At the beginning of the electroplating, gold spike-like structures of about 50 nm in size grew from an electrode, connected gold nanoclusters around them, and form three dimensional nanoscale structures. We visualized the elementary process of the gold electroplating, and believe that the results lead to the deeper understanding of electroplating at the nanoscale.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2017

Electroplating Zr on U-Mo Foils: Process Qualification Report

Fuel Fabrication identified electroplating of zirconium onto the U-Mo fuel low enriched fuel for high performance reactors as an alternative technology. The Process Qualification was performed under the Process Qualification Plan for Fabrication of MP-1 Zirconium Electroplated Foils, Pacific Northwest National Laboratory (PNNL), 67075-PQP-0001. On December 14, 2016 PNNL was authorized to begin qualification plating runs effective January 2017 by the Fuel Fabrication Pillar. PNNL began electroplating of the BWX Technologies Nuclear Operation Group provided qualification bare foils. Receipt inspection of foils identified numerous issues with the surface quality of the foils. Zirconium Electroplating of the 12 thick and 12 thin foils was completed in March 2017. This report summarizes the results of qualification plating runs and provides the documentation necessary to qualify the electroplating process and authorize PNNL to begin plating of the MP-1 foils. Prior to plating of the MP-1 foils, PNNL will be plating demonstration low enriched uranium (LEU).

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2011

Hydration and leaching characteristics of cement pastes made from electroplating sludge

The purpose of this study was to investigate the hydration and leaching characteristics of the pastes of belite-rich cements made from electroplating sludge. The compressive strength of the pastes cured for 1, 3, 7, 28, and 90 days was determined, and the condensation of silicate anions in hydrates was examined with the {sup 29}Si nuclear magnetic resonance (NMR) technology. The leachabilities of the electroplating sludge and the hardened pastes were studied with the multiple toxicity characteristic leaching procedure (MTCLP) and the tank leaching test (NEN 7345), respectively. The results showed that the electroplating sludge continued to leach heavy metals, including nickel, copper, and zinc, and posed a serious threat to the environment. The belite-rich cement made from the electroplating sludge was abundant in hydraulic {beta}-dicalcium silicate, and it performed well with regard to compressive-strength development when properly blended with ordinary Portland cements. The blended cement containing up to 40% the belite-rich cement can still satisfy the compressive-strength requirements of ASTM standards, and the pastes cured for 90 days had comparable compressive strength to an ordinary Portland cement paste. It was also found that the later hydration reaction of the blended cements was relatively more active, and high fractions of belite-rich cement increased the chain length of silicate hydrates. In addition, by converting the sludge into belite-rich cements, the heavy metals became stable in the hardened cement pastes. This study thus indicates a viable alternative approach to dealing with heavy metal bearing wastes, and the resulting products show good compressive strength and heavy-metal stability.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Evaluation of Anodized and Electroplated Radioactive Check Sources for Radiological Monitoring Instruments

Radioactive check sources are often used for source checking calibrated instruments to confirm accurate readings are obtained from radiological monitoring instruments. Because of the importance of check sources and their application, PNNL conducted a study to evaluate the effectiveness and accuracy of active sources produced using different construction methods. Eleven, randomly selected check sources of both anodized (five) and electroplated (six) construction were evaluated, along with their calculated decay curves, to determine how well they withstand consistent, multi-year use in the field. Results show that the anodized and electroplated check sources evaluated hold up well enough to continue their use, regardless of wear and tear sustained over years of use. This report provides the source information, empirical data for the 11 anodized and electroplated check sources and their representative decay curves, and it documents the conclusion that anodized and electroplated check sources are reliable for routine use in the field over multiple years.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

Electroplated AU for conformal coating of high aspect ratio silicon structures

A method for electroplating a nonmetallic grating including providing a nonmetallic grating; performing an atomic layer deposition (ALD) reaction to form a seed layer on the nonmetallic grating; and electroplating a metallic layer on the seed layer such that the metallic layer uniformly and conformally coats the nonmetallic grating. An apparatus including a silicon substrate having gratings with an aspect-ratio of at least 20:1; a atomic layer deposition (ALD) seed layer formed on the gratings; and an electroplated metallic layer formed on the seed layer, wherein the electroplated metallic layer uniformly and conformally coats the gratings.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Electroplated Au for conformal coating of high aspect ratio silicon structures

A method for electroplating a nonmetallic grating including providing a nonmetallic grating; performing an atomic layer deposition (ALD) reaction to form a seed layer on the nonmetallic grating; and electroplating a metallic layer on the seed layer such that the metallic layer uniformly and conformally coats the nonmetallic grating. An apparatus including a silicon substrate having gratings with an aspect-ratio of at least 20:1; a atomic layer deposition (ALD) seed layer formed on the gratings; and an electroplated metallic layer formed on the seed layer, wherein the electroplated metallic layer uniformly and conformally coats the gratings.

Rowen, Adam M.↗
DOE OSTI2011

Effects of barrier composition and electroplating chemistry on adhesion and voiding in copper/dielectric diffusion barrier films

The effects of electroplating chemistry and dielectric diffusion barrier composition on copper voiding and barrier adhesion are reported. Adhesion was quantified using the four-point bend thin film adhesion technique, and voiding in the Cu films was quantified using scanning electron microscopy. A total of 12 different film stacks were investigated, including three different Cu electroplating chemistries and four different barrier materials (SiN, N-doped SiC, O-doped SiC, and dual-layer SiC). Both plating chemistry and barrier composition have a large effect on interface adhesion and voiding in the Cu film. X-ray photoelectron spectroscopy was used to investigate the segregation of Cu electroplating impurities, such as S and Cl, to the Cu/barrier interface. Secondary ion mass spectrometry was used to quantify oxygen content at the Cu/barrier interface in a subset of samples. This interface oxygen content is correlated with measured adhesion values.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Devices for Thermal Conductivity Measurements of Electroplated Bi for X-ray TES Absorbers

Electroplated bismuth (Bi) is commonly used in transition-edge sensors (TESs) for X-rays because of its high stopping power and low heat capacity (Collan in Phys Rev B 1:2888, 1970, Yan in Appl Phys Lett 111:192602, 2017). Electroplated Bi is usually grown on top of another metal that acts as seed layer, typically gold (Au), making it challenging to extrapolate its thermoelectric properties. In this work, we present four-wire resistance measurement structures that allow us to measure resistance as a function of temperature of electroplated Bi independently of Au. The results show that the thermal conductivity of the Bi at 3 K is high enough to ensure the correct thermalization of X-ray photons when used as an absorber for TESs.

Bismuth↗
DOE OSTI2010

Thermal stability and adhesion of low-emissivity electroplated Au coatings.

We are developing a low-emissivity thermal management coating system to minimize radiative heat losses under a high-vacuum environment. Good adhesion, low outgassing, and good thermal stability of the coating material are essential elements for a long-life, reliable thermal management device. The system of electroplated Au coating on the adhesion-enhancing Wood's Ni strike and 304L substrate was selected due to its low emissivity and low surface chemical reactivity. The physical and chemical properties, interface bonding, thermal aging, and compatibility of the above Au/Ni/304L system were examined extensively. The study shows that the as-plated electroplated Au and Ni samples contain submicron columnar grains, stringers of nanopores, and/or H{sub 2} gas bubbles, as expected. The grain structure of Au and Ni are thermally stable up to 250 C for 63 days. The interface bonding is strong, which can be attributed to good mechanical locking among the Au, the 304L, and the porous Ni strike. However, thermal instability of the nanopore structure (i.e., pore coalescence and coarsening due to vacancy and/or entrapped gaseous phase diffusion) and Ni diffusion were observed. In addition, the study also found that prebaking 304L in the furnace at {ge} 1 x 10{sup -4} Torr promotes surface Cr-oxides on the 304L surface, which reduces the effectiveness of the intended H-removal. The extent of the pore coalescence and coarsening and their effect on the long-term system integrity and outgassing are yet to be understood. Mitigating system outgassing and improving Au adhesion require a further understanding of the process-structure-system performance relationships within the electroplated Au/Ni/304L system.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Concept Feasibility Report for Electroplating Zirconium onto Uranium Foil - Year 2

The Fuel Fabrication Capability within the U.S. High Performance Research Reactor Conversion Program is funded through the National Nuclear Security Administration (NNSA) NA-26 (Office of Material Management and Minimization). An investigation was commissioned to determine the feasibility of using electroplating techniques to apply a coating of zirconium onto depleted uranium/molybdenum alloy (U-10Mo). Electroplating would provide an alternative method to the existing process of hot roll-bonding zirconium foil onto the U-10Mo fuel foil during the fabrication of fuel elements for high-performance research reactors. The objective of this research was to develop a reproducible and scalable plating process that will produce a uniform, 25 μm thick zirconium metal coating on U-10Mo foil. In previous work, Pacific Northwest National Laboratory (PNNL) established a molten salt electroplating apparatus and protocol to plate zirconium metal onto molybdenum foil (Coffey 2015). During this second year of the research, PNNL furthered this work by moving to the U-10Mo alloy system (90 percent uranium:10 percent molybdenum). The original plating apparatus was disassembled and re-assembled in a laboratory capable of handling low-level radioactive materials. Initially, the work followed the previous year’s approach, and the salt bath composition was targeted at the eutectic composition (LiF:NaF:ZrF4 = 26:37:37 mol%). Early results indicated that the formation of uranium fluoride compounds would be problematic. Other salt bath compositions were investigated in order to eliminate the uranium fluoride production (LiF:NaF = 61:39 mol% and LiF:NaF:KF = 46.5:11.5:42 mol% ). Zirconium metal was used as the crucible for the molten salt. Three plating methods were used—isopotential, galvano static, and pulsed plating. The molten salt method for zirconium metal application provided high-quality plating on molybdenum in PNNL’s previous work. A key advantage of this approach is that plating can be performed under conditions that would greatly reduce the quantity of intermetallics that form at the interface between the zirconium and U-10Mo; unlike roll bonding, the molten salt plating approach would allow for complete coverage of the U-10Mo foil with zirconium. When utilizing the experimental parameters developed for zirconium plating onto molybdenum, a uranium fluoride reaction product was formed at the Zr/U-10Mo interface. By controlling the initial plating potential, the uranium fluoride could be prevented; however, the targeted zirconium thickness (25 ±12.5 μm) could not be achieved while maintaining 100% coverage.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Copper-nickel electroplating of 3D-printed acrylonitrile butadiene styrene for interference and radiation shielding applications

Here, in this study, electromagnetic and radiation shielding structures were fabricated by 3D printing acrylonitrile butadiene styrene (ABS) structures via fused filament fabrication and electroplating with copper (Cu) and nickel (Ni) metals. Prior to electroplating, the printed ABS materials were made conductive by surface electrodeposition of polypyrrole (PPy). ABS adsorbs the pyrrole monomer, which subsequently polymerizes via oxidation forming conductive PPy layer on the printed structures. The successful anchoring of PPy layer can be attributed to its hydrogen bonding and electrostatic interactions with ABS. Thermal analysis, optical, and electron microscopy equipped with energy dispersive X-ray were employed to characterize the printed shielding structures, while the interference and radiation shielding effectiveness were evaluated using a spectrum analyzer and dosimeter, respectively. The interference shielding was found to be effective at 60 ± 5 dB over relatively small frequency range. Shielding was also apparent against gamma and X-ray ionizing rays, but more significantly effective against beta rays. Furthermore, the Cu/Ni coating was able to reduce any heat-induced dimensional changes for the 3D printed ABS substrate without compromising the mechanical integrity.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2017

Electroplating lithium transition metal oxides

Materials synthesis often provides opportunities for innovation. We demonstrate a general low-temperature (260°C) molten salt electrodeposition approach to directly electroplate the important lithium-ion (Li-ion) battery cathode materials LiCoO 2 , LiMn 2 O 4 , and Al-doped LiCoO 2 . The crystallinities and electrochemical capacities of the electroplated oxides are comparable to those of the powders synthesized at much higher temperatures (700° to 1000°C). In conclusion, this new growth method significantly broadens the scope of battery form factors and functionalities, enabling a variety of highly desirable battery properties, including high energy, high power, and unprecedented electrode flexibility.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Brazing of Martensitic Stainless Steel to Copper Using Electroplated Copper and Silver Coatings

Brazing of 3 mm thick sheets of low-carbon martensitic stainless steel and Cu-Cr-Zr-Ti alloy was attempted using electroplated coatings of Cu and Ag. Ni coating of 5 µm thick was provided on the MSS base metal to enhance the wettability. Brazing experiments were carried out at 985 °C for a holding of 15 min. Detailed microstructural studies, hardness, lap-shear, tensile, and pressure tests were carried out on the brazed joints. The reaction between the Cu and Ag coatings lead to the formation of in situ braze metal. The microstructure of the braze metal was found to consist of Cu-rich primary alpha (α{sub P}) and Ag-rich eutectic mixture (β + α{sub E}). In lap-shear tests, the brazed joints produced with an overlap of 9 and 6 mm were found to fail in copper base metal, while the joints produced with an overlap of 3 mm failed in the braze metal exhibiting a lap-shear strength of 147 MPa. In tensile tests, the butt brazed joints were found to fail in copper base metal as well with an average tensile strength of 213 MPa. The braze metal hardness was found to be higher than the hardness of the copper base metal. In pressure tests, the brazed panels were found to survive a pressure of 750 bar without undergoing any damage. These results show that electroplated coatings of Cu and Ag can be advantageously utilized for brazing of large, complex-shaped parts such as thrust chambers in space industry.

36 MATERIALS SCIENCE↗
DOE OSTI2025

In-situ synchrotron X-ray study on microstructure and stress evolutions of electroplated copper upon self-annealing

Background: The self-annealing behavior of electroplated copper (Cu) at room temperature is gaining attention in the microelectronics industry due to its significant impact on reliability issues such as substrate warpage and electrical resistivity. Methods: In this study, in-situ analysis of the microstructure transition and stress relaxation of the electroplated copper upon self-annealing was conducted via synchrotron white X-ray nanodiffraction (beamline 21A, Taiwan Photon Source) and grazing-incidence X-ray diffraction (beamline 17B1, Taiwan Light Source). Significant Findings: Remarkable relaxations of deviatoric stress and absolute strain component along the [002] direction were closely related to the Cu grain growth and crystallographic reorientation at the early stage of selfannealing, and a complete stress/strain relaxation can be achieved with the cessation of microstructure transition. In conclusion, the in-situ synchrotron X-ray studies provided an insight into Cu self-annealing mechanism, offering valuable information for improving Cu interconnect reliability.

Cu Self-annealing↗