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Evaluation of the use of eddy currents to measure the thickness of nickel plating on carbon steel

Description: The capability of using eddy current techniques to measure the thickness of nickel plating on carbon steel is investigated. Factors examined are the influence of: different plating baths (Watts and Sulfamate), different substrates (A285 and A516 carbon steels), and the effects of using different types of eddy current instrumentation (phase sensitivity versus amplitude sensitivity). The results show that the thickness of nickel plating (for the conditions described) can be measured accurately using eddy current techniques, if proper procedures are followed. These procedures are described along with many other variables that are associated with tests of this type. (auth)
Date: October 17, 1973
Creator: Smith, J.H.
Partner: UNT Libraries Government Documents Department

Investigation of the structure of rhodium films electrodeposited on Au(111) single crystals.

Description: The structure of rhodium films electrodeposited on (111) surfaces of gold was investigated using cyclic voltammetry, x-ray scattering measurements and scanning tunneling microscopy (STM). A better understanding of the rhodium deposition process and film structure was gained. After mechanical polishing the Au(111) crystal was electropolished and annealed in an hydrogen flame. These crystal preparation procedures yielded a gold single crystal with electrochemical characteristics comparable to previously published cyclic voltammagrams. The rhodium film was then deposited electrochemically from a 0.5 mM rhodium chloride and 0.5 M perchloric acid solution at 100 mV versus SCE at 70 C until the desired amount of charge had passed. The deposition of rhodium is a 3 electron process following this electrode reaction, [RhCl{sub 6}]{sup 3{minus}} (aq) + 3 e{sup {minus}} {r_arrow} Rh (s) + 6 Cl{sup {minus}} (aq). X-ray measurements were performed at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory beamlines X10a and X25 using focused, monochromatic radiation ({lambda} = 1.494 and 1.282 angstroms, respectively).
Date: March 29, 1999
Creator: Tanzer, J. A.; You, H.; Chu, Y. S.; Lister, T. E.; Yonco, R.; Wieckowski, A. et al.
Partner: UNT Libraries Government Documents Department

Electrolytic regeneration of acid cupric chloride printed circuit board etchant. Quarterly report No. 1, July 31, 1995--October 30, 1995

Description: During the quarter we ran tests to determine the effects that key plating parameters have on copper deposit quality. Parameters tested include (a) velocity past the plating cathode, (b) copper concentration in the catholyte from which the copper is plated, (c) plating current density, and (d) catholyte cupric content. The most significant effects were obtained for velocity changes. We also tested porous cell separator materials for hydrophilicity, and evaluated graphite felt activation life from 2 preparation methods.
Date: December 1, 1995
Creator: Oxley, J.E. & Smialek, R.J.
Partner: UNT Libraries Government Documents Department

Functionally graded materials for thermal barrier coatings in advanced gas turbine systems research. Semi-annual report, May 1--December 31, 1996

Description: A combination of two new production methods, reaction-bonded metal oxide (RBMO) and electrochemical processing, have been utilized to create a functionally graded thermal barrier coating. Electrochemical processing, which includes both electrodeposition (EDEP) and electrophoretic deposition (EPD), has been used to deposit both the metallic and ceramic layers of the coating. EPD has been used to deposit the RBMO precursor powders, which exhibit the dual properties of both a metal and ceramic due to its composite nature. A summary of the FGM production methods and resulting characterization of the produced coatings for the eleventh and twelfth quarters (5/96--12/96), as well as a project summary, are outlined in this final report.
Date: August 1, 1997
Partner: UNT Libraries Government Documents Department

Underpotential deposition of Ag adlayers on Pt(111): Structures and determination of O{sub 2} adsorption on Pt(111)

Description: The structure of Ag adlayers deposited at underpotentials in sulfuric acid on Pt(111), and the inhibition of O{sub 2} reduction they cause, have been studied using grazing incident angle x-ray diffraction measurements, as well as linear sweep voltammetry and in situ FTIR spectroscopy. Ag forms a hexagonal incommensurate bilayer, with two mutually commensurate monolayers. It is aligned with the Pt(111) substrate, although slightly expanded. The first monolayer has a commensurate (1 x 1) structure. A second layer causes a restructuring of the first monolayer. Deposition of each monolayer is associated with one voltammetry Peak. A complete inhibition of O{sub 2} reduction on Pt(111) has been observed upon deposition of both, Ag monolayer and bilayer. Analysis of the inhibition of O{sub 2} reduction as a function of the Ag coverage shows that during reduction O{sub 2} adsorbs in a bridge configuration on Pt(111).
Date: September 1, 1997
Creator: Marinkovic, N.S.; Wang, J.X. & Adzic, R.R.
Partner: UNT Libraries Government Documents Department

Reaction synthesis of Ni-Al based particle composite coatings

Description: Electrodeposited metal matrix/metal particle composite (EMMC) coatings were produced with a nickel matrix and aluminum particles. By optimizing the process parameters, coatings were deposited with 20 volume percent aluminum particles. Coating morphology and composition were characterized using light optical microscopy (LOM), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA). Differential thermal analysis (DTA) was employed to study reactive phase formation. The effect of heat treatment on coating phase formation was studied in the temperature range 415 to 1,000 C. Long-time exposure at low temperature results in the formation of several intermetallic phases at the Ni matrix/Al particle interfaces and concentrically around the original Al particles. Upon heating to the 500--600 C range, the aluminum particles react with the nickel matrix to form NiAl islands within the Ni matrix. When exposed to higher temperatures (600--1,000 C), diffusional reaction between NiAl and nickel produces ({gamma})Ni{sub 3}Al. The final equilibrium microstructure consists of blocks of ({gamma}{prime})Ni{sub 3}Al in a {gamma}(Ni) solid solution matrix, with small pores also present. Pore formation is explained based on local density changes during intermetallic phase formation and microstructural development is discussed with reference to reaction synthesis of bulk nickel aluminides.
Date: February 11, 2000
Partner: UNT Libraries Government Documents Department

Plasma source ion implantation of ammonia into electroplated chromium

Description: Ammonia gas (NH{sub 3}) has been used as a nitrogen source for plasma source ion implantation processing of electroplated chromium. No evidence was found of increased hydrogen concentrations in the bulk material, implying that ammonia can be used without risking hydrogen embrittlement. The retained nitrogen dose of 2.1 {times} 10{sup 17} N-at/cm{sup 2} is sufficient to increase the surface hardness of electroplated Cr by 24% and decrease the wear rate by a factor of 4.
Date: February 1, 1995
Creator: Scheuer, J.T.; Walter, K.C.; Rej, D.J.; Nastasi, M. & Blanchard, J.P.
Partner: UNT Libraries Government Documents Department

Cermet composite thermal spray coatings for erosion and corrosion protection in combustion environments of advanced coal-fired boilers. Semi-annual technical progress report, February 1996--July 1996

Description: Present coal-fired boiler environments remain hostile to the materials of choice since corrosion and erosion can be a serious problem in certain regions of the boiler. Recently, the Clean Air Act Amendment is requiring electric power plants to reduce NO{sub x}, emissions to the environment. To reduce NO{sub x}, emissions, new low NO{sub x}, combustors are utilized which burn fuel with a substoichiometric amount of oxygen (i.e., low oxygen partial pressure). In these low NO{sub x} environments, H{sub 2}S gas is a major source of sulfur. Due to the sulfidation process, corrosion rates in reducing parts of boilers have increased significantly and existing boiler tube materials do not always provide adequate corrosion resistance. Combined attack due to corrosion and erosion is a concern because of the significantly increased operating costs which result in material failures. One method to combat corrosion and erosion in coal-fired boilers is to apply coatings to the components subjected to aggressive environments. Thermal spray coatings, a cermet composite comprised of hard ceramic phases of oxide and/or carbide in a metal binder, have been used with some success as a solution to the corrosion and erosion problems in boilers. However, little is known on the effect of the volume fraction, size, and shape of the hard ceramic phase on the erosion and corrosion resistance of the thermally sprayed coatings. It is the objective of this research to investigate metal matrix composite (cermet) coatings in order to determine the optimum ceramic/metal combination that will give the best erosion and corrosion resistance in new advanced coal-fired boilers.
Date: August 1, 1996
Creator: Banovic, S.W.; Levin, B.F.; DuPont, J.N. & Marder, A.R.
Partner: UNT Libraries Government Documents Department

Vibrational spectroscopy of buried interfaces using nonlinear optics. Final technical report, July 7, 1986--February 29, 1996

Description: This DOE sponsored program has been dedicated to the understanding, development, and application of nontraditional methods for studying buried interfaces, particularly the electrolyte-solid system. Most of the work has dealt with optical techniques. The early research was directed toward revealing the mechanisms of surface enhanced Raman scattering (SERS). More recently the author has concentrated on surface nonlinear optical effects--second harmonic generation (SHG) and sum-frequency generation (SHG). Both of these techniques have the potential for selective interface sensitivity, and are produced through a higher order susceptibility than that which governs linear optical response. Optical SHG has the potential of providing more information about a buried interface than can be obtained by conventional optical spectroscopy. The author`s experiments have been designed to: (a) extract the second order optical susceptibility tensor associated with the surface of a metal electrode, and (b) discover how the electrochemical environment influences the nonlinear optical measurements. Recent contributions include quantitative comparison of the nonlinear response of single crystal silver to theoretical models for the effect. The author has provided the first detailed test of the time-dependent, local density functional prediction. Optical SHG bears a fundamental connection with the symmetry of the surface atoms. While investigating Ag(111) an anomalous effect was discovered that could not be explained by the known surface structure of Ag. The phenomenon was tentatively assigned to an adsorption induced surface reconstruction, since it behaved like a second order phase transition. In addition to the optical phenomena the author has designed, built, and operated an in situ quartz crystal microbalance (QCM) electrochemical cell.
Date: May 30, 1996
Creator: Furtak, T.E.
Partner: UNT Libraries Government Documents Department

Electroplating fission-recoil barriers onto LEU-metal foils for {sup 99}Mo-production targets

Description: Electroplating experiments on uranium foil have been conducted in order to develop low-enriched uranium composite targets suitable for the production of {sup 99}Mo. Preparation of the foil surface prior to plating was found to play a key role in the quality of the resultant coating. A surface preparation procedure was developed that produces both zinc and nickel coatings with the desired level of coating adherence and coverage. Modifications of the existing plating processes now need investigation to improve to uniformity of the plating thickness, especially at the foil perimeter.
Date: October 1, 1997
Creator: Smaga, J.A.; Sedlet, J.; Conner, C.; Liberatore, M.W.; Walker, D.E.; Wygmans, D.G. et al.
Partner: UNT Libraries Government Documents Department

Improved container electrode coatings for Na/S battery systems. Final report

Description: Current sodium sulfur (Na/S) battery systems utilize the fast ion conducting properties of sodium beta{double_prime}-alumina electrolyte (BASE) to create high energy density sodium-sulfur electrochemical cells which can be used as components of secondary batteries. Since the days when these cells were invented at the Ford Motor Company Scientific Laboratory by J.T. Kummer and N. Weber, problems with container electrode corrosion have troubled the Na/S systems that have been developed in the many laboratories. In an unpublished investigation carried out at the Ford Motor Company laboratory, it was shown that titanium nitride films sputter deposited onto aluminum substrates under the appropriate conditions can exhibit excellent resistance to corrosion by sodium polysulfide melts. In the work carried out here, the corrosion resistant properties of TiN coatings sputter deposited on Al substrates have been investigated. TiN sputter coated aluminum samples were tested under static conditions in sodium sulfide melts and in Na/S cells under the range of electrochemical conditions needed for battery operation. The sputter deposited coatings produced in these experiments exhibited satisfactory corrosion resistance in the static tests but degraded under full cell operation. Tests of TiN coatings deposited by reactive ion-plating (IP), a common commercial process, showed excellent corrosion and electrical performance in both static and complete cell testing. Charge/discharge testing of sulfur core cells with IP coatings for over 350 cycles to 70 % depth of discharge has shown only very minor changes in cell performance and the tests are continuing.
Date: August 1, 1995
Creator: Hunt, T.K.
Partner: UNT Libraries Government Documents Department

Laser-assisted electrochemistry

Description: The effect of laser irradiation on electrodeposition processes has been investigated. These studies demonstrated that the addition of laser irradiation to an electroplating process can dramatically enhance plating rates and current efficiencies, as well as improve the morphology of the resultant electrodeposit. During the course of these investigations, the mechanism for the laser enhancement of electrodeposition processes was determined. Experimental evidence was obtained to show that laser irradiation of the substrate results in increased metal ion concentrations at the surface of the electrode due to a laser-induced Soret effect. The laser-induced Soret effect has important implications for laser-assisted electrochemical processing. The increase in the surface concentration of ions allows efficient electrodeposition from dilute solutions. As such, laser- assisted electrodeposition may develop into an environmentally conscious manufacturing process by reducing waste and limiting worker exposure to toxic chemicals.
Date: May 1, 1995
Creator: Glenn, D. F.
Partner: UNT Libraries Government Documents Department

Environmental research brief: Pollution prevention assessment for a manufacturer of locking devices

Description: The US Environmental Protection Agency (EPA) has funded a pilot project to assist small and medium-size manufacturers who want to minimize their generation of waste but who lack the expertise to do so. In an effort to assist these manufacturers Waste Minimization Assessment Centers (WMACs) were established at selected universities and procedures were adapted from the EPA Waste Minimization Opportunity Assessment Manual (EPA/625/7-88/003, July 1988). That document has been superseded by the Facility Pollution Prevention Guide (EPA/600/R-92/088). The WMAC team at the University of Tennessee performed an assessment at a plant that fabricates and finishes metal components that are assembled into several types of locking devices. Raw materials are machined and then shipped offsite for heat-treating, stored until needed, or buffed and cleaned. Then, all parts other than those made of stainless steel are electroplated, electrostatically powder coated, or lacquer coated. The various component parts are then assembled into the locking devices. The assessment team`s report, detailing findings and recommendations, indicated that the vapor degreasers generate a significant amount of waste and that vapor degreasing could be replaced with an aqueous cleaning system for intermediate cleaning. This Research Brief was developed by the principal investigators and EPA`s National Risk Management Research Laboratory, Cincinnati, OH, to announce key findings of an ongoing research project that is fully documented in a separate report of the same title available from University City Science Center.
Date: August 1, 1995
Creator: Jendrucko, R.J.; Hurst, B.T. & Looby, G.P.
Partner: UNT Libraries Government Documents Department

Potentiometric determination of percent porosity in nickel electroplates on uranium metal

Description: A potentiometric procedure has been developed to determine the percent porosity of nickel electroplates on uranium metal. In this case, percent porosity is defined as the ratio of the exposed uranium surface to the nickel electroplate surface times 100. Basically, this procedure exploits the high chemical reactivity between uranium metal and chloride ions in aqueous solution. It involves the potentiometric measurement of the corrosion potentials of coupled uranium/nickel metal electrodes in 0.01 molar potassium chloride solution versus a double-junctioned calomel electrode. A mathematical treatment of observed potentiometric measurements from a two-point calibration technique permits a best-fit calibration for a particular porosity determination on the same nickel-plated sample.
Date: January 1, 1982
Creator: Dietrich, W.C. & Johnson, E.E.
Partner: UNT Libraries Government Documents Department

Mechanical properties of electroplated nickel rings for bath aging study

Description: Hydraulic burst tests were performed on electroplated nickel rings as part of a bath aging study. Ring tensile properties were measured. An invalid failure mechanism was observed for rings having a significant gradient in wall thickness over the height. Finite element method (FEM) stress analysis models established the probable cause and helped set limits for future specimen dimension tolerances.
Date: November 1, 1979
Creator: Heffley, P.M.
Partner: UNT Libraries Government Documents Department

Structure of as-deposited and heat-treated iron-zinc coatings from chloride bath

Description: The iron content, phase constitution, and microstructure of electrodeposited iron-zinc alloy (EZA) coatings, deposited from chloride baths, is described for as-deposited and heat-treated conditions of coatings containing bulk iron contents of 6, 8, 10, and 13 w/o. The observed influence of current density upon iron content, which in turn influences the phase constitution and microstructure of the coatings, is reported. The microstructure, composed of non-equilibrium phases that have nanometer grain sizes, is illustrated and described with respect to iron content, crystallography, and morphology. As-deposited {eta} phase coatings undergo transformations through a sequence of metastable phases when heated. The sequence of phase transformations varies with iron content, but the mechanisms of phase transformation from the as-deposited eta phase to the metastable G phase was found to be similar in 6, 8, and 10 w/o Fe coatings. Microstructural, compositional, and crystallographic changes associated with this phase transformation are discussed.
Date: September 1, 1993
Creator: Drewien, C. A.; Goldstein, J. I. & Marder, A. R.
Partner: UNT Libraries Government Documents Department

Polycrystalline thin-film cadmium telluride solar cells fabricated by electrodeposition. Annual subcontract report, 20 March 1992--19 March 1993

Description: This report describes progress during the first year of a 3-year program at Colorado School of Mines, based upon earlier studies performed by Ametek Corporation, to develop specific layers of the Ametek n-i-p structure as well as additional studies of several transparent conducting oxides. Thin films of ZnO and ZnO:Al were deposited under various conditions. For the n-layer of the Ametek structure, a dip-coating method was developed for the deposition of CdS films. The authors also present data on the characterization of these films by X-ray diffraction, Raman spectroscopy, scanning tunneling microscopy, small-angle X-ray scattering, and other techniques. They made progress in the electrodeposition of the CdTe i-layer of the Ametek structure. They developed appropriate electrochemical baths and are beginning to understand the role of the many experimental parameters that must be controlled to obtain high-quality films of this material. They explored the possibility of using an electrochemical process for fabricating the ZnTe p-layer. Some preliminary success was achieved, and this step will be pursued in the next phase. Finally, they fabricated a number of ``dot`` solar cells with the structure glass/SnO{sub 2}/CdS/CdTe/Au. Several cells with efficiencies in the range of 5%-6% were obtained, and they are confident, given recent progress, that cells with efficiencies in excess of 10% will be achieved in the near future.
Date: August 1, 1993
Creator: Trefny, J. U.; Furtak, T. E.; Wada, N.; Williamson, D. L. & Kim, D.
Partner: UNT Libraries Government Documents Department

1.06 μm 150 psec laser damage study of diamond turned, diamond turned/ polished and polished metal mirrors

Description: Using a well characterized 1.06 μm 150 ps glass laser pulse the damage characteristics for diamond turned, diamond turned/ polished, and polished copper and silver mirrors less than 5 cm diameter were studied. Although most samples were tested with a normal angle of incidence, some were tested at 45$sup 0$ with different linear polarization showing an increase in damage threshold for S polarization. Different damage mechanisms observed will be discussed. Laser damage is related to residual surface influences of the fabrication process. First attempts to polish diamond turned surfaces resulted in a significant decrease in laser damage threshold. The importance of including the heat of fusion in the one dimensional heat analysis of the theoretical damage threshold and how close the samples came to the theoretical damage threshold is discussed. (auth)
Date: July 24, 1975
Creator: Saito, T. T.; Milam, D.; Baker, P. & Murphy, G.
Partner: UNT Libraries Government Documents Department

Plating on stainless steel alloys

Description: Quantitative adhesion data are presented for a variety of electroplated stainless steel type alloys. Results show that excellent adhesion can be obtained by using a Wood's nickel strike or a sulfamate nickel strike prior to final plating. Specimens plated after Wood's nickel striking failed in the deposit rather than at the interface between the substrate and the coating. Flyer plate quantitative tests showed that use of anodic treatment in sulfuric acid prior to Wood's nickel striking even further improved adhesion. In contrast activation of stainless steels by immersion or cathodic treatment in hydrochloric acid resulted in very reduced bond strengths with failure always occurring at the interface between the coating and substrate.
Date: September 11, 1981
Creator: Dini, J.W. & Johnson, H.R.
Partner: UNT Libraries Government Documents Department

Surface scanning techniques to locate and study defects in painted zinc and zinc alloy coated steels

Description: Current density and impedance mapping measurements have been used to locate and monitor corrosion and defects on painted surfaces in solution. Measurements are reported for painted zinc and aluminum-zinc alloy coated steel surfaces. When scratched, current density mapping showed corrosion of the metal coating started at localized sites in both dilute chloride and sulfate solutions. Different scribing techniques were tested exposing only the metal coating and both the coating and the underlying steel. Effect of roll forming was investigated. Current density mapping located corrosion susceptible defects on painted roll formed materials that were not readily discernible optically. Scanning ac mapping showed that artificially formed defects were readily observed. Local impedance variations with frequency were measured for simulated defects and defect free areas of painted surfaces. Variations in paint thickness and the presence of defects were detected using the ac techniques.
Date: February 1, 1995
Creator: Isaacs, H.S.; Aldykiewicz, A.J. Jr.; Thierry, D. & Simpson, T.C.
Partner: UNT Libraries Government Documents Department

Industry participation workshop: Chromium electroplating of superconductor strand. Proceedings

Description: The primary objective of the workshop was to inform US plating vendors about the opportunity to participate in the effort on Cr plating of large quantities of superconducting wires required for the ITER and the TPX projects and DOE`s interest in developing several reliable and high quality suppliers of Chromium plating services for the superconducting strand industry. The objective was also to inform plating vendors about the Cr plating technology developed in LLNL and invite interested plating vendors to get the technology. Finally the workshop was intended to inform the plating vendors about the plan to get verification of capability of two to four vendors for Cr plating of superconducting strands.
Date: December 13, 1994
Partner: UNT Libraries Government Documents Department

Functionally gradient materials for thermal barrier coatings in advanced gas turbine systems

Description: New designs for advanced gas turbine engines for power production are required to have higher operating temperatures in order to increase efficiency. However, elevated temperatures will increase the magnitude and severity of environmental degradation of critical turbine components (e.g. combustor parts, turbine blades, etc.). To offset this problem, the usage of thermal barrier coatings (TBCs) has become popular by allowing an increase in maximum inlet temperatures for an operating engine. Although thermal barrier technology is over thirty years old, the principle failure mechanism is the spallation of the ceramic coating at or near the ceramic/bond coat interface. Therefore, it is desirable to develop a coating that combines the thermal barrier qualities of the ceramic layer and the corrosion protection by the metallic bond coat without the detrimental effects associated with the localization of the ceramic/metal interface to a single plane.
Date: December 31, 1995
Creator: Banovic, S.W.; Chan, H.M. & Marder, A.R.
Partner: UNT Libraries Government Documents Department

Separation of hydrogen using thin film palladium-ceramic composite membrane

Description: The primary objective of this study was to prepare and characterize a hydrogen permselective palladium-ceramic composite membrane for high temperature gas separations and catalytic membrane reactors. Electroless plating method was used as a potential route to deposit a thin palladium film on microporous ceramic substrate. The objectives of the work presented here were to characterize the new Pd-ceramic composite membrane by SEM and EDX analysis and to carry out fundamental permeability measurements of the membrane at elevated temperatures and pressures. The potential application of membranes in high temperature gas separation and reactor technology have been recognized by many investigators. In the coal gasification process, the exit gases are normally hydrogen, carbon monoxide, carbon dioxide, hydrogen sulfide, and water vapor. The objective is to obtain hydrogen from this gas mixture.
Date: November 1, 1995
Creator: Ilias, S.; King, F.G.; Su, N. & Udo-Aka, U.I.
Partner: UNT Libraries Government Documents Department

Effects of deburring contaminants on electroplating adhesion. Final report

Description: Vibratory deburring and centrifugal barrel finishing can result in inadequate adhesion of electroplated metals. Fine particles of the abrasive metals and compounds used in these processes impregnate the exposed surfaces of the workpieces. If too many of these particles are in the workpiece surfaces, electroplated coatings fail to adhere properly. Ceramic bonded aluminum oxide media causes fewer adhesion problems than fused aluminum oxide media. The implications of impregnated material in other processes were also explored. 7 figures, 10 tables.
Date: February 1, 1978
Creator: Gillespie, L.K.
Partner: UNT Libraries Government Documents Department