DOCSLIB.ORG

Cadmium and Hexavalent Chromium Alternatives 5-Year Strategy and Roadmap, Contract # W9128F-12-D-0041

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Cadmium and Hexavalent Chromium Alternatives 5-Year Strategy and Roadmap, Contract # W9128F-12-D-0041 25 May 2016 3150 Fairview Park Drive South Falls Church, Virginia 22042-4519 Cadmium and Hexavalent Chromium Alternatives 5-Year Strategy and Roadmap, Contract #W9128F-12-D-0041 Executive Summary The Strategic Environmental Research and Development Program (SERDP) and Environmental Security Technology Certification Program (ESTCP) Weapons Systems and Platforms Program Area has developed a strategy to reduce use of cadmium (Cd) and hexavalent chromium (Cr6+) by 90% or more at Department of Defense (DoD) maintenance depots over the next five years. The strategy includes objectives, metrics, and actions to demonstrate how this reduction can be achieved. The strategy employs site demonstrations and leverages DoD resources to replicate processes across the DoD depot community. It also includes a recommended future path for success in the advanced coatings area. As part of this effort, installation-specific implementation plans were developed in coordination with Letterkenny Army Depot (LEAD), Fleet Readiness Center Southeast (FRCSE), and Oklahoma City Air Logistics Complex (OC-ALC). These efforts helped inform the strategy. These implementation plans track to the overall Advanced Coating 5-Year Strategy and Roadmap, consist with DoD’s strategic vision as it pertains to Cr6+ and Cd reduction. DoD processes that contribute to current cadmium and hexavalent chromium use and production, and potential alternatives are illustrated in Figure ES-1. DoD Processes Chromate Topcoats and Chromated Cadmium Stainless Steel Adhesives and Cadmium Brush Coatings Stainless Steel Chrome Plating Conversion Chrome Sealers Specialty Primers Plating Passivation Sealants Plating Removal Welding Coatings Coatings Rare Earth and TCP Conversion Zn-Ni Brush TCP Anodize Non-Chrome other Metal HVOF An-NI Plating Citric Acid Laser Removal Coatings Plating Sealers Consumables Primers Mag_Rich Shield Gas nCoPl AlumiPlate Boegel/Sol-Gel Sol-Gel FlashJet Primters Modification Trivalent IVD Aluminum PreKote Other Other Chromium Other DoD Process DoD Alternative Figure ES-1. DoD Cd and Cr6+ Process and Alternatives Cr6+ and Cd-reduction initiatives have been prioritized using a relative scoring methodology. Four metrics were utilized in the prioritization process: 1) Impact to Readiness; 2) Likelihood of Implementation; 3) Return on Investment; and 4) Impact to Goals. Each metric was scored based on qualitative measures. After scoring, reduction initiatives were grouped into tiers based on how essential the alternative process is to achieving the ultimate goal of the strategy. ES-1 Cadmium and Hexavalent Chromium Alternatives 5-Year Strategy and Roadmap, Contract #W9128F-12-D-0041 Tier 1 priority initiatives are critical to achieving Cr6+ and Cd reduction goals. These initiatives must be successfully implemented for reduction goals to be achieved. These initiatives typically impact other depots, and address similar critical usages, emissions, exposures, and/or waste streams at multiple locations. Tier 1 priority initiatives typically have a significant impact to readiness, though this is not always the case. The ten (10) initiatives considered Tier 1 priorities are: • Non-Chromate Primer on Aircraft OML • Non-Chromate Primer on Aircraft non-OML Surfaces • Non-Chromate Primer on Off-Aircraft Components and Commodities • HAP-Free, Non-Cr6+ Wash Primer • Alternative to Chrome Plating • Alternative to Cadmium Plating • Non-Chrome Chemical Conversion Coatings for Aluminum • Alternative to Cadmium Brush Plating • Alternative Coatings Removal Processes to Reduce Cr6+-Containing Waste Streams • Implementation of Engineering Controls for Stainless Steel Welding Operations Tier 2 priority initiatives are not critical to achieving DoD Cr6+ and Cd reduction goals, but these initiatives nevertheless address significant usages, emissions, exposures, and/or waste streams. These initiatives may impact similar processes at other depots, increasing their value and return on investment. Tier 2 initiatives typically have a moderate impact to readiness, and may also exhibit strong ROIs. The four (4) initiatives considered Tier 2 priorities are: • Non-Chrome Stainless Steel Passivation • Alternative to Dichromate Sealers in Anodizing Operations • Non-Chromated Coatings Removal Alternatives • Non-Chrome Consumables for Stainless Steel Welding Tier 3 priority initiatives are not critical to achieving Cr6+ and Cd reduction goals and address usages, emissions, exposures, and/or waste streams to a lesser degree than those identified in Tiers 1 and 2. Tier 3 initiatives have a minor impact, and in fact, may not warrant expending resources to implement them. Tier 3 initiatives are typically localized, impacting only a single location with little impact to readiness. The fourteen (14) initiatives considered Tier 3 priorities are: • Non-Chrome Chemical Conversion Coatings for Magnesium • Non-Chrome Sealants for Aerospace Applications • Non-Chrome Structural Adhesives for Defense Applications • Alternative to Dichromate Sealers for Brush Plating Finishes • Alternative to Dichromate Sealers for Black Oxide and Phosphate Finishes • Non-Chrome Aluminized Coating for Aircraft Engine Applications • Non-Chrome Anodized Dyes • Non-Chrome Conductive EMI Coating • Non-Cadmium Silk Screen Ink ES-2 Cadmium and Hexavalent Chromium Alternatives 5-Year Strategy and Roadmap, Contract #W9128F-12-D-0041 • Non-Cadmium Safety Paint • Non Chrome Desmutting/Deoxidizing Alternatives • Robotic Painting to Reduce Worker Exposure and Increase Maintenance Efficiency • Reducing Emissions and Exposure from Chromated Adhesives and Sealants • Reduction of Emissions, Waste, and Exposures Associated with Cadmium Brush Plating Most of DoD’s Cr6+ and Cd usage, emissions, exposure, and waste stream reduction goals can likely be met by leveraging and expanding ongoing or past initiatives. In fact, 90% reduction in Cr6+ and Cd usage can be achieved through implementation of Tier 1 priority initiatives alone, most leveraging ongoing work either within the DoD or Original Equipment Manufacturers (OEM). ES-3 Cadmium and Hexavalent Chromium Alternatives 5-Year Strategy and Roadmap, Contract #W9128F-12-D-0041 Table of Contents Executive Summary ................................................................................................................ ES-1 List of Acronyms .......................................................................................................................... iii 1. Introduction ............................................................................................................................. 1 1.1. Background ................................................................................................................................... 1 1.2. Regulatory Drivers ....................................................................................................................... 2 2. Problem Definition .................................................................................................................. 2 2.1. Processes ........................................................................................................................................ 2 2.2. Usage/Waste/Emissions/Exposures ............................................................................................. 5 2.3. Weapon Systems and Platforms .................................................................................................. 7 3. Strategy .................................................................................................................................... 7 3.1. Goals .............................................................................................................................................. 7 3.3.1 Goal 1 – Reduce the use of Cd and Cr6+ containing compounds in DoD depots by 90% within 5 years ...................................................................................................... 7 3.3.2 Goal 2 – Reduce Cd and Cr6+ emissions, waste streams, and exposure potential in DoD depots by 90% within 5 years ............................................................................. 7 3.2. Objectives/Success Metrics .......................................................................................................... 7 3.3. Actions ......................................................................................................................................... 16 3.3.3 Tier 1 Priority Actions ..................................................................................................... 16 3.3.4 Tier 2 Priority Actions ..................................................................................................... 23 3.3.5 Tier 3 Priority Actions ..................................................................................................... 24 Appendix A – Processes ............................................................................................................ A-1 Chromated Primers .......................................................................................................................... A-1 Chromated Wash Primers ............................................................................................................... A-1 Chrome Plating ................................................................................................................................. A-2 Cadmium Plating
Recommended publications
  • Methods to Improve the Corrosion Performance of Microporous Nickel Deposits

    Methods to Improve the Corrosion Performance of Microporous Nickel Deposits

    Methods to Improve The Corrosion Performance Of Microporous Nickel Deposits By Robert A. Tremmel During the last several years, nickel, which is essentially sulfur- microporous nickel-chromium free, plus a thinner layer of bright coatings have been critically nickel. Duplex nickel provides scrutinized by the automotive corrosion protection that is far industry. Today these coatings must superior to single layer systems. In be free of all surface defects, even these duplex systems, when corrosion after long-term exposure to acceler- occurs through a pore in the chro- ated tests and in real-life service. mium plate, the bright nickel is While proper control of all the rapidly penetrated until the semi- multi-layer nickel deposits is bright nickel is reached. Because the important, blemish-free surfaces electrochemical potential of the semi- Fig. 1—Corrosion mechanism of decorative nickel- can only be obtained when the chromium deposits. bright deposit is greater than that of microdiscontinuity and the activity the bright nickel deposit, thereby of the post-nickel strike are prop- making it more noble, the bright erly achieved and maintained. This also be free of surface defects1. nickel layer will corrode preferen- edited version of a paper presented Simply meeting porosity specifica- tially to the semi-bright nickel layer. at SUR/FIN® ’96—Cleveland shows tions is not enough. The size of the As the pit widens, however, some that research indicates that the pores is important, as well as the attack will eventually occur in the most important factor is the electrochemical potential of the semi-bright nickel layer and ulti- electrochemical potential of the microporous nickel strike.
  • Analysis of Hard Chromium Coating Defects and Its Prevention Methods

    Analysis of Hard Chromium Coating Defects and Its Prevention Methods

    International Journal of Engineering and Advanced Technology (IJEAT) ISSN: 2249 – 8958, Volume-2, Issue-5, June 2013 Analysis of Hard Chromium Coating Defects and its Prevention Methods L.Maria Irudaya Raj, Sathishkumar.J, B.Kumaragurubaran, P.Gopal Abstract — This paper mainly deals with various Chromium coating defects that occur while electro plating of different II. COATING mechanical components and methodology adopted to prevent it. It also covers suggestions to minimize this problem. This paper Coating may be defined as a coverage that is applied over contains new suggestions to minimize the problems by using the surface of any metal substrate part/object. The purpose of recent technological developments. Since the chemicals used for applying coatings is to improve surface properties of a bulk chromium coating are posing threat to environment it is need of material usually referred to as a substrate. One can improve the hour to minimise the use such chemical consumption. The amongst others appearance, adhesion, wetability, corrosion reduction in defective components will increase productivity as resistance, wear resistance, scratch resistance, etc. well as protect the environment to some extent It also describes the various alternate coating methods for chromium coating through III. HARD CHROME COATING PROCESS which we can achieve the required surface properties. India being a Developing country .for various coating application chromium The coating process consists of Chrome Chemical Bath, is used. Since the process is slow and involves lengthy cycle time Anode, Cathode potentials, part to be coated, Heaters, unless the defects are minimized the products cannot be delivered rectifiers & Electrical control systems. Initially the bath has to in time which will create loss to the Industries.
  • MTI Friction Welding Technology Brochure

    MTI Friction Welding Technology Brochure

    Friction Welding Manufacturing Technology, Inc. All of us at MTI… would like to extend our thanks for your interest in our company. Manufacturing Technology, Inc. has been a leading manufacturer of inertia, direct drive and hybrid friction welders since 1976. We hope that the following pages will further spark your interest by detailing a number of our products, services and capabilities. We at MTI share a common goal…to help you solve your manufacturing problems in the most Table of Contents efficient way possible. Combining friction welding Introduction to Friction Welding 2 with custom designed automation, we have Advantages of MTI’s Process 3 demonstrated dramatic savings in labor and Inertia Friction Welding 4 material with no sacrifice to quality. Contact us Direct Drive & Hybrid Friction Welding 5 today to find out what we can do for you. Machine Monitors & Controllers 6 Safety Features 7 Flash Removal 7 MTI Welding Services 8 Weldable Combinations 9 Applications Aircraft/Aerospace 10 Oil Field Pieces 14 Military 16 Bimetallic & Special 20 Agricultural & Trucking 22 Automotive 28 General 38 Special Welders & Automated Machines 46 Machine Models & Capabilities 48 Friction Welding 4 What It Is Friction welding is a solid-state joining process that produces coalescence in materials, using the heat developed between surfaces through a combination of mechanically induced rubbing motion and Information applied load. The resulting joint is of forged quality. Under normal conditions, the faying surfaces do not melt. Filler metal, flux and shielding gas are not required with this process. Dissimilar Materials Even metal combinations not normally considered compatible can be joined by friction welding, such as aluminum to steel, copper to aluminum, titanium to copper and nickel alloys to steel.
  • Guidelines for the Welded Fabrication of Nickel-Containing Stainless Steels for Corrosion Resistant Services

    Guidelines for the Welded Fabrication of Nickel-Containing Stainless Steels for Corrosion Resistant Services

    NiDl Nickel Development Institute Guidelines for the welded fabrication of nickel-containing stainless steels for corrosion resistant services A Nickel Development Institute Reference Book, Series No 11 007 Table of Contents Introduction ........................................................................................................ i PART I – For the welder ...................................................................................... 1 Physical properties of austenitic steels .......................................................... 2 Factors affecting corrosion resistance of stainless steel welds ....................... 2 Full penetration welds .............................................................................. 2 Seal welding crevices .............................................................................. 2 Embedded iron ........................................................................................ 2 Avoid surface oxides from welding ........................................................... 3 Other welding related defects ................................................................... 3 Welding qualifications ................................................................................... 3 Welder training ............................................................................................. 4 Preparation for welding ................................................................................. 4 Cutting and joint preparation ...................................................................
  • Wood Modified by Inorganic Salts: Mechanism and Properties

    Wood Modified by Inorganic Salts: Mechanism and Properties

    WOOD MODIFIED BY INORGANIC SALTS: MECHANISM AND PROPERTIES. I. WEATHERING RATE, WATER REPELLENCY, AND IIIMENSIONAL STABILITY OF WOOD MODIFIEID WITH CHROMIUM (111) NITRATE VERSUS CHROMIC ACID' R. S. Willianzs and W. C. Feisl Research Chemists Forest Products Lab~ratory,~Forest Service U.S. Department of Agriculture Madison, WI 53705 (Received October 1983) ABSTRACT Chromic acid treatment of wood improves surface characteristics. A simple dip or brush application of 5% aqueous chromic acid to a wood surface stops extractive staining, improves dimensional stability, retards weathering of unfinished wood, and prolongs the life of finishes. A better understanding of how chromic acid effects these improvements may facilitate the development of even better treatments. The improvements may be due to a combination offactors: oxidation ofwood by hexavalent chromium compounds, formation of coordination coml~lexeswith trivalent chromium, and the presence of insoluble chromium compounds at the surface. Most trivalent chromium compounds do not become fixed in wood (i.e., do not form water-insolublf: wood-chemical complexes). However, chromium (111) nitrate treatment of western redcedar (Thuja plicata), southern pine (Pinus sp.), and ponderosa pine (Pinus ponderosa) produced modified wood with properties similar to chromic acid-treated wood. Evaluation of the chromium (111) nitrate- and chromic acid-modified wood by leaching, Xenon arc- accelerated weathering, and swellometer experiments clearly demonstrated similar fixation, erosion, and water-repellent properties. Based on the results from chromium (111) nitrate-treated wood, fixation through coordination of trivalent chromium with wood hydroxyls an(5 formation of insoluble chromium appear to be the critical factors in improving the performance of the treated wood.
  • (VI) and Chromium (V) Oxide Fluorides

    (VI) and Chromium (V) Oxide Fluorides

    Portland State University PDXScholar Dissertations and Theses Dissertations and Theses 1976 The chemistry of chromium (VI) and chromium (V) oxide fluorides Patrick Jay Green Portland State University Follow this and additional works at: https://pdxscholar.library.pdx.edu/open_access_etds Part of the Chemistry Commons Let us know how access to this document benefits ou.y Recommended Citation Green, Patrick Jay, "The chemistry of chromium (VI) and chromium (V) oxide fluorides" (1976). Dissertations and Theses. Paper 4039. https://doi.org/10.15760/etd.5923 This Thesis is brought to you for free and open access. It has been accepted for inclusion in Dissertations and Theses by an authorized administrator of PDXScholar. Please contact us if we can make this document more accessible: [email protected]. All ABSTRACT OF THE TllESIS OF Patrick Jay Green for the Master of Science in Chemistry presented April 16, 1976. Title: Chemistry of Chromium(VI) and Chromium(V) Oxide Fluorides. APPROVEO BY MEMBERS OF THE THESIS CO'"o\l TIEE: y . • Ii . ' I : • • • • • New preparative routes to chromyl fluoride were sought. It was found that chlorine ironofluoride reacts with chromium trioxide and chromyl chlo­ ride to produce chromyl fluoride. Attempts were ~ade to define a mechan­ ism for the reaction of ClF and Cr0 in light of by-products observed 3 and previous investigations. Carbonyl fluoride and chromium trioxide react to fom chro·yl fluoride and carbo:i dioxide. A mechanism was also proposed for this react10n. Chromium trioxide 11itl\ l~F6 or WF5 reacts to produce chromyl fluoride and the respective oxide tetrafluoride. 2 Sulfur hexafluoride did not react with Cr03.
  • Chromium Compounds Hazard Summary

    Chromium Compounds Hazard Summary

    Chromium Compounds Hazard Summary Chromium occurs in the environment primarily in two valence states, trivalent chromium (Cr III) and hexavalent chromium (Cr VI). Exposure may occur from natural or industrial sources of chromium. Chromium III is much less toxic than chromium (VI). The respiratory tract is also the major target organ for chromium (III) toxicity, similar to chromium (VI). Chromium (III) is an essential element in humans. The body can detoxify some amount of chromium (VI) to chromium (III). The respiratory tract is the major target organ for chromium (VI) toxicity, for acute (short-term) and chronic (long-term) inhalation exposures. Shortness of breath, coughing, and wheezing were reported from a case of acute exposure to chromium (VI), while perforations and ulcerations of the septum, bronchitis, decreased pulmonary function, pneumonia, and other respiratory effects have been noted from chronic exposure. Human studies have clearly established that inhaled chromium (VI) is a human carcinogen, resulting in an increased risk of lung cancer. Animal studies have shown chromium (VI) to cause lung tumors via inhalation exposure. Please Note: The main sources of information for this fact sheet are EPA's Integrated Risk Information System (IRIS) (7), which contains information on inhalation chronic toxicity and the RfC and oral chronic toxicity and the RfD, and the carcinogenic effects of chromium including the unit cancer risk for inhalation exposure, EPA's Toxicological Review of Trivalent Chromium and Toxicological Review of Hexavalent Chromium (3), and the Agency for Toxic Substances and Disease Registry's (ATSDR's) Toxicological Profile for Chromium. (1) Uses The metal chromium is used mainly for making steel and other alloys.
  • Welding and Joining Guidelines

    Welding and Joining Guidelines

    Welding and Joining Guidelines The HASTELLOY® and HAYNES® alloys are known for their good weldability, which is defined as the ability of a material to be welded and to perform satisfactorily in the imposed service environment. The service performance of the welded component should be given the utmost importance when determining a suitable weld process or procedure. If proper welding techniques and procedures are followed, high-quality welds can be produced with conventional arc welding processes. However, please be aware of the proper techniques for welding these types of alloys and the differences compared to the more common carbon and stainless steels. The following information should provide a basis for properly welding the HASTELLOY® and HAYNES® alloys. For further information, please consult the references listed throughout each section. It is also important to review any alloy- specific welding considerations prior to determining a suitable welding procedure. The most common welding processes used to weld the HASTELLOY® and HAYNES® alloys are the gas tungsten arc welding (GTAW / “TIG”), gas metal arc welding (GMAW / “MIG”), and shielded metal arc welding (SMAW / “Stick”) processes. In addition to these common arc welding processes, other welding processes such plasma arc welding (PAW), resistance spot welding (RSW), laser beam welding (LBW), and electron beam welding (EBW) are used. Submerged arc welding (SAW) is generally discouraged as this process is characterized by high heat input to the base metal, which promotes distortion, hot cracking, and precipitation of secondary phases that can be detrimental to material properties and performance. The introduction of flux elements to the weld also makes it difficult to achieve a proper chemical composition in the weld deposit.
  • Health Hazard Evaluation Report 77-63-449

    Health Hazard Evaluation Report 77-63-449

    \ U.S. DEPARTMENT OF HE1\LTH, EDUCATI0f1, AND WELFARE CENTER FOR DISEASE COllTROL I NATIONAL INSTITUTE FOR OCCUPATIOfU\L SAFETY AND HEALTH i CINCINNATI, OHIO 45226 HEALTH HAZARD EVALUATIOf~ DETERMINATION l REPORT NO. 77-63-449 McDONNELL AIRCRAFT COMPANY ST. LOUIS, MISSOURI DECEMBER 1977 I. TOXICITY DETERMINATION A health hazard evaluation was conducted by the National Institute for Occupational Safety and Health on July 11-14, 1977, at the McDonnell Aircraft Company in St. Louis, Missouri. Based on the medical evaluation of employees in Department 151 and the industrial hygiene survey, it is determined that employees were not exposed to toxic concentrations of contaminants during this evaluatton. Potential contaminants studied included: iron oxide, nickel, chromium, sulfuric acid, sodium hydroxide, hydrochloric acid, hydrofluoric acid, nitric acid, hydrogen sulfide, sulfur dioxide, nitrogen dioxide, nitric oxide, toluene, xylene, benzene, refined petroleum solvents, tetrachloroethylene, acetone, and styrene. It is our opinion that workers in the masking operations may occasionally be exposed to concentrations of organic solvents, and workers involved in the etching operations may occasionally be exposed to concentrations of acids and/or associated emissions such as nitric acid, nitrogen dioxide and nitric oxide which have produced medical symptoms among the employees. These substances are known to produce nose, throat and skin irritation, dizziness and headaches - symptoms which were reported by workers in private interviews during the survey and are important indications of excessive exposure. From this limited evaluation, the authors feel that no definitive statement can be made concerning the workers in Department 151 having an increased incidence of deaths which could be directly attributed to occupational exposure.
  • Chromic Acid Chromium Trioxide Flake

    Chromic Acid Chromium Trioxide Flake

    CHROMIC ACID CHROMIUM TRIOXIDE FLAKE PROPERTIES: Chemical Formula: Stability in Air: CrO3 Deliquesces at humidity above 30% CAS Number: 1333-82-0 Solubility in Water: Highly soluble: 62.5% w/w at 20 ºC ( 68 ºF) 67.5% w/w at 100 ºC (212 ºF) Molecular Weight: 99.99 Bulk Density Loose 75 - 82 lbs. per cubic foot Appearance: Dark Red Flakes Heat of Solution Exothermic (24.7 cal./g.; 44.5 BTU/lb.) ThroughApplied Innovation Specific Gravity: 2.7 at 20 °C (68 °F) Behavior on Heating Melts at 197 ºC (387 ºF) - starts to decompose to intermediate chromium oxides at slightly higher temperatures. Chemical Characteristics: Performance d Chromic acid is a strong acid and oxidizing agent. When neutralized with alkalis, chromic acid forms dichromate or chromate compounds. In oxidation reactions, the chromium atom is reduced from the hexavalent to trivalent Enhance state. continued… www.elementis.com CHROMIC ACID CHROMIUM TRIOXIDE FLAKE TYPICAL ANALYSIS: * Specification Typical Analysis CrO3 99.85 % Min. 99.9 % Sulfate as SO4 0.10 % Max. 0.07 % Chloride as Cl 0.005 % Max. <0.005 % Insoluble Matter 0.005 % Max. 0.002 % Sodium as Na2O 0.020 % Max. 0.014 % pH of 1% Aqueous Solution NA 1.0 Meets GSA Commercial Item Description A-A-55827D, 20 April 2015 GENERAL APPLICATIONS: ThroughApplied Innovation The major uses of chromic acid are in wood preservation, metal finishing and plating. Secondary applications include catalyst manufacture and as an oxidizing agent. Chromic acid is used to produce salt-free CCA type wood preservatives. These preservatives are combinations of chromium, copper and arsenic.
  • Plating on Aluminum

    Plating on Aluminum

    JJW o NBSiR 80-2142 (Aluminum Association) on Aluminum AUG 5 1981 D. S. Lashmore Corrosion and Electrodeposition Group Chemical Stability and Corrosion Division National Measurement Laboratory U.S. Department of Commence National Bureau of Standards Washington, DC 20234 November 1980 Final Report Prepared for The Aiuminum Association The American Electropiaters Society 818 Connecticut Avenue, N.W. 1201 Louisiana Ave. Washington, DC 20006 Winter Park, FL 32789 NBSIR 80-2142 (Aluminum Association) PLATING ON ALUMINUM D. S. Lashmore Corrosion and Electrodeposition Group Chemical Stability and Corrosion Division National Measurement Laboratory U.S. Department of Commerce National Bureau of Standards Washington, DC 20234 November 1980 Final Report Prepared for The Aluminum Association The American Electroplaters Society 818 Connecticut Avenue, N.W. 1201 Louisiana Ave. Washington, DC 20006 Winter Park, FL 32789 U.S. DEPARTMENT OF COMMERCE, Philip M. Klutznick, Secretary Jordan J. Baruch, Assistant Secretary for Productivity, Technoiogy, and Innovation NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director Table of Contents Page 1. Introduction 1 2. Program Summary 2 3. Phosphoric Acid Anodizing Prior to Plating 10 3.1. Adhesion Data 10 3.2. Microstructure of the Anodic Film 17 3.2.1. Microstructure of nickel plated onto the anodic 19 film 3.2.2. Initial Stages of Oxidation 25 3.3. Electrochemical Measurements 32 3.3.1. Current Density versus Applied Potential 32 3.3.2. Scanning Voltammetry 33 4. Immersion Deposition 37 4.1. Scanning Voltammetry 37 4.2. Dissolution Data 41 4.3. Discussion 44 5. Adhesion Theory 45 5.1. Adhesion of Metallic Coatings 45 5.2. Pre-existing Crack--Griffith Criterion 52 5.3.
  • Laser Beams a Novel Tool for Welding: a Review

    Laser Beams a Novel Tool for Welding: a Review

    IOSR Journal of Applied Physics (IOSR-JAP) e-ISSN: 2278-4861.Volume 8, Issue 6 Ver. III (Nov. - Dec. 2016), PP 08-26 www.iosrjournals.org Laser Beams A Novel Tool for Welding: A Review A Jayanthia,B, Kvenkataramananc, Ksuresh Kumard Aresearch Scholar, SCSVMV University, Kanchipuram, India Bdepartment Of Physics, Jeppiaar Institute Of Technology, Chennai, India Cdepartment Of Physics, SCSVMV University, Kanchipuram, India Ddepartment Of Physics, P.T. Lee CNCET, Kanchipuram, India Abstract: Welding is an important joining process of industrial fabrication and manufacturing. This review article briefs the materials processing and welding by laser beam with its special characteristics nature. Laser augmented welding process offers main atvantages such as autogenous welding, welding of high thickness, dissimilar welding, hybrid laser welding, optical fibre delivery, remote laser welding, eco-friendly, variety of sources and their wide range of applications are highlighted. Significance of Nd: YAG laser welding and pulsed wave over continuous wave pattern on laser material processesare discussed. Influence of operating parameter of the laser beam for the welding process are briefed including optical fibre delivery and shielding gas during laser welding. Some insight gained in the study of optimization techniques of laser welding parameters to achieve good weld bead geometry and mechanical properties. Significance of laser welding on stainless steels and other materials such as Aluminium, Titanium, Magnesium, copper, etc…are discussed. I. INTRODUCTION Welding is the principal industrial process used for joining metals. As materials continue to be highly engineered in terms of metallic and metallurgical continuity, structural integrity and microstructure, hence, welding processes will become more important and more prominent.