DOCSLIB.ORG

Electroplating

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Electroplating Pollution Prevention and Abatement Handbook WORLD BANK GROUP Effective July 1998 Electroplating Industry Description and Practices 500 liters per square meter of surface plated) but is usually high in heavy metals, including cad- Electroplating involves the deposition of a thin mium, chrome, lead, copper, zinc, and nickel, and protective layer (usually metallic) onto a pre- in cyanides, fluorides, and oil and grease, all of pared metal surface, using electrochemical pro- which are process dependent. Air emissions may cesses. The process involves pretreatment contain toxic organics such as trichloroethylene (cleaning, degreasing, and other preparation and trichloroethane. steps), plating, rinsing, passivating, and drying. Cleaning or changing of process tanks and The cleaning and pretreatment stages involve a treatment of wastewaters can generate substan- variety of solvents (often chlorinated hydrocar- tial quantities of wet sludges containing high lev- bons, whose use is discouraged) and surface- els of toxic organics or metals. stripping agents, including caustic soda and a range of strong acids, depending on the metal Pollution Prevention and Control surface to be plated. The use of halogenated hy- drocarbons for degreasing is not necessary, as Plating involves different combinations of a wide water-based systems are available. In the plat- variety of processes, and there are many oppor- ing process, the object to be plated is usually used tunities to improve on traditional practices in the as the cathode in an electrolytic bath. Plating so- industry. The improvements listed below should lutions are acid or alkaline and may contain be implemented where possible. complexing agents such as cyanides. Changes in Process Waste Characteristics • Replace cadmium with high-quality, corro- Any or all of the substances used in electroplat- sion-resistant zinc plating. Use cyanide-free ing (such as acidic solutions, toxic metals, sol- systems for zinc plating where appropriate. vents, and cyanides) can be found in the Where cadmium plating is necessary, use wastewater, either via rinsing of the product or bright chloride, high-alkaline baths, or other from spillage and dumping of process baths. The alternatives. Note, however, that use of some solvents and vapors from hot plating baths re- alternatives to cyanides may lead to the release sult in elevated levels of volatile organic com- of heavy metals and cause problems in waste- pounds (VOCs) and, in some cases, volatile metal water treatment. compounds, which may contain chromates. Ap- • Use trivalent chrome instead of hexavalent proximately 30% of the solvents and degreasing chrome; acceptance of the change in finish agents used can be released as VOCs when baths needs to be promoted. are not regenerated. • Give preference to water-based surface-cleaning The mixing of cyanide and acidic wastewaters agents, where feasible, instead of organic clean- can generate lethal hydrogen cyanide gas, and ing agents, some of which are considered toxic. this must be avoided. The overall wastewater • Regenerate acids and other process ingredients stream is typically extremely variable (1 liter to whenever feasible. 307 308 PROJECT GUIDELINES: INDUSTRY SECTOR GUIDELINES Reduction in Dragout and Wastage Target Pollution Loads • Minimize dragout through effective draining A key parameter is the water use in each pro- of bath solutions from the plated part, by, for cess. Systems should be designed to reduce wa- example, making drain holes in bucket-type ter use. Where electroplating is routinely pieces, if necessary. performed on objects with known surface area • Allow dripping time of at least 10 to 20 sec- in a production unit, water consumption of no onds before rinsing. more than 1.3 liters per square meter plated • Use fog spraying of parts while dripping. (l/m2) for rack plating and 10 l/m2 for drum plat- • Maintain the density, viscosity, and tempera- ing should be achieved. The recommended pol- ture of the baths to minimize dragout. lution prevention and control measures can • Place recovery tanks before the rinse tanks achieve the target levels listed below. (also yielding makeup for the process tanks). The recovery tank provides for static rinsing • Cadmium plating should be avoided. Where with high dragout recovery. there are no feasible alternatives, a maximum cadmium load in the waste of 0.3 grams for Minimizing Water Consumption every kilogram of cadmium processed is rec- in Rinsing Systems ommended. • At least 90% of the solvent emissions to air must be recovered by the use of an air It is possible to design rinsing systems to achieve pollution control system such as a carbon 50–99% reduction in traditional water usage. filter. Testing is required to determine the optimum • Ozone-depleting solvents such as chlorofluo- method for any specific process, but proven ap- rocarbons and trichloroethane are not to be proaches include: used in the process. • Agitation of rinse water or work pieces to in- crease rinsing efficiency Treatment Technologies • Multiple countercurrent rinses • Spray rinses (especially for barrel loads). Segregation of waste streams is essential because of the dangerous reactions that can occur. Strong Management of Process Solutions acid and caustic reactions can generate boiling and splashing of corrosive liquids; acids can re- • Recycle process baths after concentration and act with cyanides and generate lethal hydrogen filtration. Spent bath solutions should be sent cyanide gas. In addition, segregated streams that for recovery and regeneration of plating are concentrated are easier to treat. chemicals, not discharged into wastewater treatment units. Air Emissions • Recycle rinse waters (after filtration). • Regularly analyze and regenerate process so- Exhaust hoods and good ventilation systems pro- lutions to maximize useful life. tect the working environment, but the exhaust • Clean racks between baths to minimize con- streams should be treated to reduce VOCs and tamination. heavy metals to acceptable levels before venting • Cover degreasing baths containing chlorinated to the atmosphere. Acid mists and vapors should solvents when not in operation to reduce be scrubbed with water before venting. In some losses. Spent solvents should be sent to sol- cases, VOC levels of the vapors are reduced by vent recyclers and the residue from solvent use of carbon filters, which allow the reuse of recovery properly managed (e.g., blended with solvents, or by combustion (and energy recov- fuel and burned in a combustion unit with ery) after scrubbing, adsorption, or other treat- proper controls for toxic metals). ment methods. Electroplating 309 Liquid Effluents of proper sludge disposal are likely to become an increasing incentive for waste minimization. Cyanide destruction, flow equalization and neu- tralization, and metals removal are required, as Emissions Guidelines a minimum, for electroplating plants. Individual design is necessary to address the characteristics Emissions levels for the design and operation of of the specific plant, but there are a number of each project must be established through the en- common treatment steps. For small facilities, the vironmental assessment (EA) process on the ba- possibility of sharing a common wastewater sis of country legislation and the Pollution Prevention treatment plant should be considered. Cyanide and Abatement Handbook, as applied to local con- destruction must be carried out upstream of the ditions. The emissions levels selected must be other treatment processes. If hexavalent chrome justified in the EA and acceptable to the World (Cr+6) occurs in the wastewater, the wastewater Bank Group. is usually pretreated to reduce the chromium to The guidelines given below present emis- a trivalent form using a reducing agent, such as sions levels normally acceptable to the World a sulfide. Bank Group in making decisions regarding The main treatment processes are equalization, provision of World Bank Group assistance. Any pH adjustment for precipitation, flocculation, and deviations from these levels must be described sedimentation/filtration. The optimum pH for in the World Bank Group project documenta- metal precipitation is usually in the range 8.5– tion. The emissions levels given here can be 11, but this depends on the mixture of metals consistently achieved by well-designed, well- present. The presence of significant levels of oil operated, and well-maintained pollution con- and grease may affect the effectiveness of the trol systems. metal precipitation process; hence, the level of The guidelines are expressed as concentrations oil and grease affects the choice of treatment op- to facilitate monitoring. Dilution of air emissions tions and the treatment sequence. It is preferred or effluents to achieve these guidelines is un- that the degreasing baths be treated separately. acceptable. Flocculating agents are sometimes used to facili- All of the maximum levels should be achieved tate the filtration of suspended solids. Pilot test- for at least 95% of the time that the plant or unit ing and treatability studies may be necessary, and is operating, to be calculated as a proportion of final adjustment of pH and further polishing of annual operating hours. the effluent may be required. Modern wastewa- ter treatment systems use ion exchange, mem- Air Emissions brane filtration, and evaporation to reduce the release of toxics and the quantity of effluent A 90% recovery of the quantity of VOCs released that needs to be discharged.
Load more

Recommended publications
  • Characterization of Copper Electroplating And
    CHARACTERIZATION OF COPPER ELECTROPLATING AND ELECTROPOLISHING PROCESSES FOR SEMICONDUCTOR INTERCONNECT METALLIZATION by JULIE MARIE MENDEZ Submitted in partial fulfillment of the requirements For the degree of Doctor of Philosophy Dissertation Advisor: Dr. Uziel Landau Department of Chemical Engineering CASE WESTERN RESERVE UNIVERSITY August, 2009 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the thesis/dissertation of _____________________________________________________ candidate for the ______________________degree *. (signed)_______________________________________________ (chair of the committee) ________________________________________________ ________________________________________________ ________________________________________________ ________________________________________________ ________________________________________________ (date) _______________________ *We also certify that written approval has been obtained for any proprietary material contained therein. TABLE OF CONTENTS Page Number List of Tables 3 List of Figures 4 Acknowledgements 9 List of Symbols 10 Abstract 13 1. Introduction 15 1.1 Semiconductor Interconnect Metallization – Process Description 15 1.2 Mechanistic Aspects of Bottom-up Fill 20 1.3 Electropolishing 22 1.4 Topics Addressed in the Dissertation 24 2. Experimental Studies of Copper Electropolishing 26 2.1 Experimental Procedure 29 2.2 Polarization Studies 30 2.3 Current Steps 34 2.3.1 Current Stepped to a Level below Limiting Current 34 2.3.2 Current Stepped to the Limiting
    [Show full text]
  • OVERVIEW of FOUNDRY PROCESSES Contents 1
    Cleaner Production Manual for the Queensland Foundry Industry November 1999 PART 5: OVERVIEW OF FOUNDRY PROCESSES Contents 1. Overview of Casting Processes...................................................................... 3 2. Casting Processes.......................................................................................... 6 2.1 Sand Casting ............................................................................................ 6 2.1.1 Pattern Making ................................................................................... 7 2.1.2 Mould Making ..................................................................................... 7 2.1.3 Melting and Pouring ........................................................................... 8 2.1.4 Cooling and Shakeout ........................................................................ 9 2.1.5 Sand Reclamation .............................................................................. 9 2.1.6 Fettling, Cleaning and Finishing....................................................... 10 2.1.7 Advantages of Sand Casting............................................................ 10 2.1.8 Limitations ........................................................................................ 10 2.1.9 By-products Generated .................................................................... 10 2.2 Shell Moulding ........................................................................................ 13 2.2.1 Advantages......................................................................................
    [Show full text]
  • Implementation of Metal Casting Best Practices
    Implementation of Metal Casting Best Practices January 2007 Prepared for ITP Metal Casting Authors: Robert Eppich, Eppich Technologies Robert D. Naranjo, BCS, Incorporated Acknowledgement This project was a collaborative effort by Robert Eppich (Eppich Technologies) and Robert Naranjo (BCS, Incorporated). Mr. Eppich coordinated this project and was the technical lead for this effort. He guided the data collection and analysis. Mr. Naranjo assisted in the data collection and analysis of the results and led the development of the final report. The final report was prepared by Robert Naranjo, Lee Schultz, Rajita Majumdar, Bill Choate, Ellen Glover, and Krista Jones of BCS, Incorporated. The cover was designed by Borys Mararytsya of BCS, Incorporated. We also gratefully acknowledge the support of the U.S. Department of Energy, the Advanced Technology Institute, and the Cast Metals Coalition in conducting this project. Disclaimer This report was prepared as an account of work sponsored by an Agency of the United States Government. Neither the United States Government nor any Agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any Agency thereof. The views and opinions expressed by the authors herein do not necessarily state or reflect those of the United States Government or any Agency thereof.
    [Show full text]
  • The MG Chemicals Professional Prototyping Process
    The MG Chemicals Professional Prototyping Process Introduction ..................................................................................................................................................................3 Before you begin ..........................................................................................................................................................4 Read the instructions in their entirety.......................................................................................................................4 Get everything you need...........................................................................................................................................4 Plan for safety...........................................................................................................................................................5 Plan for disposal .......................................................................................................................................................5 Design your circuit for the MG process ...................................................................................................................6 Step 1: Cutting and Routing .........................................................................................................................................6 Ingredients required..................................................................................................................................................6 Overview:
    [Show full text]
  • Un-Conventional Metal Surfacing with Conductive Coating
    Journal of Material Science and Mechanical Engineering (JMSME) p-ISSN: 2393-9095; e-ISSN: 2393-9109; Volume 5, Issue 2; April-June, 2018 pp. 77-82 © Krishi Sanskriti Publications http://www.krishisanskriti.org/Publication.html Un-conventional Metal Surfacing with Conductive Coating Sulabh Kumar1 and Vaneet Bhardwaj2 1Department of Mechanical Engineering, Sharda University, Greater Noida (UP) India 2Department of Mechanical Engineering, Sharda University, Greater Noida, U.P, India E-mail: [email protected], [email protected] Abstract—As we know that in day-to-day life electricity has become These types of carbon brush holders are being used in basic need of the people. To produce electricity, stress is directly put generator based upon rating of the generator and type of slip over the natural resources like fossil fuels, water, metals by means of ring used because width of rings in the slip ring and diameter either hydraulic power generation or thermal power generation and (outer diameter) of slip ring is the deciding factor for selection in this era, we also generate by nuclear power. To achieve the need of type of carbon brush holder. For example, if the width of of power generation, the setup to produce electricity consists of rotor, stator, different types of windings such as stator winding, rotor ring of slip ring is 10.05 mm then carbon brush of width 10.05 winding, slip rings, carbon brush holder and different types of mm can only be used neither lesser nor bigger. Thus, pocket connections. Several metals and chemicals are used to electroplate size of carbon holder must be of 10.05 mm which means the carbon brush holder such as copper, brass, CuSO4, H2SO4.
    [Show full text]
  • Electroplating of Stainless Steel with Gold
    ION SOURCECABLE TO HIGH POWER Fig. 5 Schematic diagram of an SUPPLYVOLTAGE POWER ENCLOSURE SUPPLY_ apparatus which would be suitable for lessing on a ION BEAM FORMING AND laboratory scale the economie ACCELERATINGn SECTION feasibility of gold ion implanta- tion ION CRYOPUMP 'VACUUM LOCK FOR LOADING WORK P1ECES CHAMBER This is not too difficult and sources exist and have References been used to generate gold ions with relatively few 1 E. W. Williams, Gold Bull., 1978, 11, (2), 30-34 2 G. Dearnaley, 'Defects in Crystalline Solids, Vol. 8, Ion Im- problems because the metal is chemically inert and plantation', North Holland Publishing Co., 1973 any alloying effects or reactive effects can be avoided 3 J. Lindhard, M. Scharff and H. E. Schiott, K. Dan. Vidensk. Selsk. Mat.-Fys., 1963, 33, (14), 1-39 by choosing appropriate materials. More recently, the 4 V. 0. Nielson, 'Electromagnetically Enriched Isotopes and liquid field emission sources of Clampitt (13) and Mass Spectrometry', Academie Press, New York, 1956 5 J. F. Gibbons, W. S. Johnson and S. W. Mylroie, 'Projected Swanson (14) have also been used to generate gold Range Statistics', 2nd Edition, Halsted Press, 1975 ions. These are remarkably simple and can operate at 6 H. H. Anderson, 'Seventh Yugoslav Symposium on Physics of Ionized Gases', September 1974 a temperature just above the melting point of gold, 7 0. Almen and G. Bruce, Nucl. lustrum. Methods, 1961, (11), say at 1100°C. Their advantages include long, stable 257-278 8 P. H. Rose, in 'Proceedings of the Symposium on Electron and lifetimes and almost no demand on the vacuum Ion Beam Science & Technology', 1978, pp.
    [Show full text]
  • Electroplating for Decorative Applications: Recent Trends in Research and Development
    coatings Review Electroplating for Decorative Applications: Recent Trends in Research and Development Walter Giurlani 1,2,* ID , Giovanni Zangari 3, Filippo Gambinossi 1 ID , Maurizio Passaponti 1,2, Emanuele Salvietti 1,2, Francesco Di Benedetto 2,4 ID , Stefano Caporali 2,5 ID and Massimo Innocenti 1,2,* ID 1 Dipartimento di Chimica, Università Degli Studi di Firenze, via Della Lastruccia 3, 50019 Sesto Fiorentino, Italy; [email protected] (F.G.); maurizio.passaponti@unifi.it (M.P.); emanuele.salvietti@unifi.it (E.S.) 2 Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, via G. Giusti 9, 50121 Firenze, Italy; francesco.dibenedetto@unifi.it (F.D.B.); stefano.caporali@unifi.it (S.C.) 3 Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA 22904, USA; [email protected] 4 Dipartimento di Scienze Della Terra, Università Degli Studi di Firenze, via La Pira 4, 50121 Firenze, Italy 5 Dipartimento di Ingegneria Industriale, Università Degli Studi di Firenze, via Santa Marta 3, 50139 Firenze, Italy * Correspondence: walter.giurlani@unifi.it (W.G.); m.innocenti@unifi.it (M.I.); Tel.: +39-055-457-3097 (W.G. & M.I.) Received: 25 May 2018; Accepted: 19 July 2018; Published: 25 July 2018 Abstract: Electroplating processes are widely employed in industrial environments for a large variety of metallic coatings, ranging from technological to decorative applications. Even if the galvanic electrodeposition is certainly a mature technology, new concepts, novel applications, environmental legislation and the new material requirements for next-generation devices make the scientific research in this field still very active. This review focuses mostly at the decorative and wearable applications, and aims to create a bridge between the past knowledge and the future direction that this process, i.e., electrodeposition, is taking.
    [Show full text]
  • Classification 1
    ME477 Fall 2004 NonTraditional Processes (NTP) NONTRADITIONAL • Conventional Machining Processes (cutting, milling, MACHINING AND THERMAL drilling & grinding) use a sharp cutting tool • NTP - A group of processes that remove excess CUTTING PROCESSES material without a sharp cutting tool by various techniques involving mechanical, thermal, electrical, or chemical energy (or combinations) developed since 1. Mechanical Energy Processes World War II (1940’s). 2. Electrochemical Machining Processes • Motivations in Aerospace and Electronics Industries – to machine new (harder, stronger & tougher) materials difficult 3. Thermal Energy Processes or impossible to machine conventionally – for unusual & complex geometries that cannot easily 4. Chemical Machining machined conventionally – to achieve stringent surface (finish & texture) requirements not possible with conventional machining 1 2 Classification 1. Mechanical Energy Processes • Ultrasonic Machining (USM) • Mechanical - Erosion of work material by a high – Abrasives (20-60 volume %) in a slurry are driven High-frequency oscillation velocity stream of abrasives and/or fluid at high velocity by the tool vibrating at low Flow – Ultrasonic machining, Water jet cutting (WJC), Abrasive water amplitude (0.05-0.125mm) and high frequency Flow jet cutting (AWJC) and Abrasive jet machining (AJM) (20kHz). • Electrical - Electrochemical energy to remove material – Tool oscillation is perpendicular to work surface – Electrochemical machining (ECM), Electrochemical deburring – Tool: soft and stainless steels fed slowly into work. (ECD) and Electrochemical grinding (ECG) – Abrasives (Grit size 100 (rough) to 2000(fine)) – BN, BC, Al O , SiC & Diamond • Thermal - Thermal energy applied to small portion of 2 3 – The vibration amplitude equals to grit size, which work surface, removing by fusion and/or vaporization also determines the resulting surface finish.
    [Show full text]
  • Electrodeposition Research
    NAT'L INST OF STANDARDS & TECH R.I.C. All 101 888778 /National Bureau of Standards circular QC100 .U555 V529;1953 C.1 NBS-PUB-R 1947 •'>1 A 1 .. _ 1- • .. yil Ur U . ^ 4 1 'U tt mm, Co mm ere ureat) ;o UNITED STATES DEPARTMENT OF COMMERCE • Sinclair Weeks, Secretary NATIONAL BUREAU OF STANDARDS • A. V. Astin, Director Electrodeposition Research Proceedings of the NBS Semicentennial Symposium on Electrodeposition Research Held at the NBS on December 4-6, 1951 National Bureau of Standards Circular 529 Issued May 22, 1953 For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price 31-50 Buckram National Bureau of Standards AUG 2 8 1953 Sli5£ QC 100 0555 Foreword Electrodeposition processes have become an integral and important part of many industries—for example, the printing, metal refining, extractive metallurgy, hardware, automobile, and electronic indus- tries. This has come about largely as a result of extensive research in the field of electrodeposition, especially during the past 25 years. To encourage further research in this field, to present current re- search results and problems, and to facilitate the exchange of informa- tion, the National Bureau of Standards held the Symposium on Electrodeposition Research as the last of a series of twelve symposia conducted during the Bureau’s semicentennial in 1951. The papers presented at the Symposium are published in this volume. These papers represent a cross section of research currently being conducted in electrodeposition by industrial, university, and government labora- tories in Europe and the United States.
    [Show full text]
  • Considerations in the Use of Pulsed Water Jet Techniques for The
    2007 American WJTA Conference and Expo August 19-21, 2007 ● Houston, Texas Paper CONSIDERATIONS IN THE USE OF PULSED WATER JET TECHNIQUES FOR THE REMOVAL OF HVOF COATINGS Andrew Tieu, Wenzhuo Yan and Mohan Vijay VLN Advanced Technologies Ottawa, Ontario, Canada ABSTRACT Thermal spray coatings are becoming increasingly common in a wide variety of industrial applications. Specifically, Tungsten Carbide - High Velocity Oxygen Fuel (HVOF) coating, which is a derivation of thermal spray technology, is currently being tested on landing gear components. The authors have conducted extensive laboratory work on the removal of HVOF coatings from landing gear pins and other aircraft/aerospace components using forced-pulsed waterjet (FPWJ). These tests were conducted at pressures ≤ 104 MPa (15 kpsi) using only pure (tap) water. Several measurements were taken to assess the performance, and to ensure that the process meets the criteria specified by the aircraft/aerospace industry. Surface roughness measurements, taken by one of the aerospace companies, indicated no significant difference between the measurements taken before and after the removal process, indicating the substrate experienced minimal to no surface damage. Post stress analysis of the substrate, using x-ray diffraction technique, showed compressive stresses initially induced by peening to improve fatigue life, was not relieved by the removal method. Organized and Sponsored by the WaterJet Technology Association 1 INTRODUCTION Thermal-spray coatings are becoming increasingly common for coating in a wide variety of industrial applications. Specifically, Tungsten Carbide - High Velocity Oxygen Fuel (HVOF) coating, which is a derivation of thermal-spray technology, is currently being tested on landing gear components. HVOF coatings can be easily applied and are highly resistant to abrasion wear.
    [Show full text]
  • Inst-109 Electroless Nickel
    SELECTION. SERVICE. SATISFACTION.™ 200 S. Front St. Montezuma, IA 50171 800-741-0015 or 641-623-4000 • www.brownells.com ELECTROLESS NICKEL PLATING INSTRUCTIONS & EQUIPMENT by Ralph Walker and the Crew at Brownells, Inc. cally rough. Often pieces have to be pulled out, wire brushed to “reactivate” the surface and put back into the plating bath. An easily applied, beautiful, durable, attractive, long-wear- Then, the final finish is so rough that extensive polishing has ing and non-rusting finish for metal gun parts has long been to be done to bring the gun up to the expected “bright stan- sought by the firearms industry. Nickel plating has been one dards of nickel plating”. of the favorite plated finishes, meeting all of these require- ments except the first one - “easily applied” - until now. Finally, Fortunately, about 1945 a method of depositing nickel on the we can offer you a simple to do, easy to apply, absolutely fool- surface of the steel was discovered that did not require elec- proof, nickel plating system for the individual gun shop that tricity, but used chemical action to do the work of the anode, will give you a beautiful, uniform, evenly-plated, ready-for- cathode and cyanide salts solutions. Because of intense indus- assembly finish of the exact thickness you want each time you trial interest in the success of the process, it has been devel- use it. And, you can do it yourself in your own shop using safe- oped to the point now that almost universally perfect results to-handle chemicals with a minimum of extra equipment.
    [Show full text]
  • Special Aspects of Electrodeposition on Zinc Die Castings
    NASF SURFACE TECHNOLOGY WHITE PAPERS 82 (8), 1-9 (May 2018) Special Aspects of Electrodeposition on Zinc Die Castings by Valeriia Reveko1,2* and Per Møller2* 1Collini GmbH, Hohenems, Austria 2Technical University of Denmark, Lyngby, Denmark ABSTRACT Metal die casting has become a popular choice for the manufacturing of different consumer goods. Among the various engineering alloys and other metals, zinc alloys have often been preferred by manufacturers due to their qualities such as castability, dimensional stability and moderate solidification temperature, which provides energy and cost savings. Electroplating is a frequent choice to give zinc die cast components a high quality protective and decorative surface finish. However, applying this kind of treatment for die cast zinc components presents hidden challenges. In order to overcome these issues, a thorough morphology and composition analysis of die cast items was conducted. Special aspects of zinc die cast as a plating substrate are described and linked to the die casting process. Keywords: electrodeposition, zinc die cast, surface finishing, electroplating defects Introduction: why do we need to improve zinc die cast parts? Currently, metal die casting has become a popular choice for the manufacturing of finished products. An increasing number of industrial producers are attracted by this highly economical and efficient process capable of providing near-net shaped components that fully satisfy the geometrical requirements. Zinc, as a basis material, offers a broad range of desirable properties, beginning with hardness, ductility, impact strength, self- lubricating characteristics,1 and exhibits excellent thermal and heat conductivity. Among the various engineering alloys and other metals, zinc alloys have often been preferred by manufacturers because of their castability, dimensional stability and moderate solidification temperatures, which provide significant energy and cost savings.
    [Show full text]