Ziniloy Zinc Alloy Plating

Transcription

1 Ziniloy 3028 Zinc Alloy Plating Ziniloy 3028 is an alkaline zinc/nickel alloy plating process offering exceptional corrosion resistance. Ziniloy 3028 produces bright deposits of a zinc/nickel alloy with excellent distribution and covering power. Ziniloy 3028 is suitable for either rack or barrel plating. Ziniloy 3028 deposits easily accept clear, yellow or black passivates. Passivated deposits retain excellent corrosion resistance, even after 24 hours of a 250 F (120 C) temper. 1,000+ hours to red rust in salt spray Nickel alloy between 12-15% across all current density ranges Readily accepts passivates and conversion coatings Bright zinc nickel deposits Suitable for rack and barrel PAVCO, Inc John Crosland Jr Drive Charlotte, NC Phone: Toll-free: or PAVCO INC ( ) Fax: Order Fax (for orders only)

2 2 Operating Parameters (12-15% Nickel Alloy): Zinc Nickel Sodium hydroxide Range oz/gal g/l oz/gal g/l oz/gal g/l Ziniloy 3028 Base 4% - 8% 5% Optimum 0.9 oz/gal 6.8 g/l 0.14 oz/gal 1.1 g/l 15 oz/gal 110 g/l 3028 BRT X % 0.06% Ziniloy 3028 Stabilizer 5-7% 6% Ziniloy Additive B % 0.5% Ziniloy 3028 NIC % 1.3% Ziniloy 3028 Wetter % 0.2% Current Density Rack amps/ft amps/dm 2 20 amps/ft 2 2 amps/dm 2 Current Density Barrel 2-10 amps/ft amps/dm 2 5 amps/ft amps/dm 2 Zinc to Nickel Ratio 6-8 Total Complexing Value 8-14 RACK & BARREL Temperature: F C 72 F 22 C Anode to Cathode ratio 1:3-1:5 1:3 Anode Current Density ASF 30 ASF SOLUTION MAINTENANCE: 3028 BRT X ml/1,000 Amp-hrs. Brightener consumption will increase as bath ages. Initial feed rate is typically 200 ml/kah. Adjust based on brightness requirement. Complexor Maintenance Mix In order to maintain the complexors in the bath, it is recommended to make a mixture as follows: Ziniloy 3028 Stabilizer 50% Ziniloy 3028 Base 40% Ziniloy Additive B 10% Add at 1L/2,500 Amp-hrs for barrel or 1L/3,750 Amp-hrs for rack. Adjust based on analysis of Total Complexing Value. Ziniloy 3028 NIC - By nickel analysis approximately 0.6 2L per 1,000 Amp-hrs. Feed rate will decrease as efficiency decreases. Initial feed rate is typically 1L/kAh. Zinc, Caustic - by analysis.

3 3 Equipment: Tank: Generator tank: Anodes: Anode Connections: Anode Bars: Filtration: Agitation: Rectifier: Temperature Control: Ventilation: Polypropylene, polyethylene, PVC, or alkaline resistant rubber lined steel. Do not use fiberglass. Plumbing connections must be welded or threaded. A steel tank is preferred, sized at 10-20% of bath volume. Consult Pavco for design parameters. Thin nickel anodes, 4-6 inches (10-15 cm) width and inch (0.64 cm) thick are recommended. Nickel plated steel anodes with 2 mils (51 microns) of sulfur-free nickel are also acceptable. Anodes should be bolted to the anode rail with stainless steel bolts, nuts and washers. Use square or rectangular copper anode bars, preferably shielded with plastic. Use 5-15 micron polypropylene disks or cartridges. Filtration rate should be 1-2 tank turnovers per hour. Critical to uniform operation. Cathode rod agitation in a direction parallel to anode rails is recommended at a linear speed of ft/min. ( m/min). Additional circulation using eductor systems is recommended. Uniformity of agitation is important. Do not use air agitation. Up to 12 volts A cooling/heating system is required to maintain a constant bath temperature between 68-85ºF. A range of +/- 2º F is necessary in order to maintain a consistent alloy co-deposition. Titanium or PTFE coils are recommended. Recommended, comply with local regulations. Ziniloy 3028 Bath Makeup per 1,000 gallons (3,785 L): 1. Prepare a tank by leaching it with 1% sodium hydroxide for hours. 2. Rinse the tank. 3. Fill the lined tank with 500 gallons (2,000 L) of water. 4. Add 100 gallons (378 L) of 50% sodium hydroxide (Lead Free) or 624 pounds (284 kg) solid sodium hydroxide and mix well. 5. Add 45 gallons (170 L) of Pavco Zincate and mix well. Allow solution to cool to 90 F (32 C) before making further additions. 6. Add 50 gallons (189 L) of Ziniloy 3028 Base and mix well. 7. Add 13 gallons (49 L) of Ziniloy 3028 NIC and mix well. 8. Add 60 gallons (225 L) of Ziniloy 3028 Stabilizer and mix well. 9. Add 5 gallons (19 L) of Ziniloy Additive B and mix well. 10. Add water to the 1,000 gallon (3,785 L) level. 11. Allow solution to sit for 8-24 hours before production. 12. Electrolyze at 5ASF (0.5 ASD) for 2 Ah/L. 13. Add 0.6 gallon (2.3 L) of 3028 BRT X. 14. Add 2 gallons (7 L) of Ziniloy 3028 Wetter. IMPORTANT NOTE: New solutions must sit idle for 8-24 hours for the bath to equilibrate and form the proper complexes. Function of Additives: Ziniloy 3028 Base Operates as a nickel complexing agent and stabilizes the nickel ions in the zinc nickel bath. It also assures a uniform nickel co-deposition over the entire current density. Ziniloy 3028 Stabilizer Operates first as a nickel and zinc complexing agent, but also as a low current density brightener and a high current density anti-burn agent.

4 BRT X Operates as a brightener in the mid to high current density and improves the metal distribution at low current densities. Ziniloy Additive B Operates as a brightener in the mid to high current density, a nickel and zinc complexing agent, and improves the covering power. It also helps lower the amount of nickel needed in the bath to get the same alloy, but should not exceed more than 1.0% in the bath for better nickel alloy control. Ziniloy 3028 NIC Used for makeup and to maintain the nickel content of bath. Ziniloy 3028 Wetter Prevents pitting in rack applications, however does not reduce surface tension. Alkaline Zinc Wetter Not normally needed, but can be used in cases of excess fuming in plating bath or zinc generator. Add is 0.01% increments. Dilute before adding. UltraPure Used to precipitate metallic contaminants. Operating Tips: A small amount of cyanide may be generated during the operation of this system. Appropriate precautions to the management of cyanide bearing materials should be taken. The zinc concentration must be tightly controlled within recommended parameters. A zinc generator is necessary. Large variations of zinc concentration are not acceptable. The plating bath must be analyzed daily. The concentration of nickel is adjusted using Ziniloy 3028 NIC, which contains 66 g/l nickel (8.8 oz/gal). An addition of 1.5% Ziniloy 3028 NIC (15 ml/l) will raise nickel 1 g/l (0.13 oz/gal). All additives should be maintained by a metering pump. Carbonates and sulfates will build up in alkaline zinc nickel solutions. The accumulation of carbonates decreases the efficiency of the working solution. If the combined sodium carbonate and sodium sulfate concentration reaches 11 oz/gal (83 g/l), the nickel salts can precipitate. To minimize efficiency loss, keep carbonate and sulfate totals below 10 oz/gal (75 g/l) by freeze out procedures or equipment. As carbonate/sulfate increase, caustic levels should be reduced to help maintain efficiency. Baths high in carbonate/sulfate should run at oz/gal ( g/l) of caustic. An X Ray Fluorescence unit is mandatory to monitor alloy composition. Numerous operating parameters can impact the alloy %, so this must be monitored regularly. Uniform temperature and adequate cooling capacity are critical to maintaining consistent alloy composition. Increase zinc concentration to maintain efficiency at higher carbonate/sulfate levels. Maintain zinc nickel ratio to ensure proper alloy.

5 5 Analytical Procedures: Zinc Reagents Acetate Buffer Dissolve 180 grams of sodium acetate into 500 ml of deionized water. Add 30 ml of acetic acid and dilute to 1 liter with deionized water. Xylenol Orange Indicator - Dissolve 1 gram of Xylenol Orange in 1 liter of deionized water. 0.1 M EDTA Solution Equipment 5 ml pipette 400 ml beaker Procedure 1. Pipette a 5 ml bath sample into a 400 ml beaker. 2. Add 150 ml deionized water and 5 ml 50% v/v HCl. 3. Add 50 ml acetate buffer. 4. Add 1 ml of indicator. 5. Titrate with 0.1 M EDTA until the color changes from red to yellow. Calculation: ml of titration = zinc in oz/gal ml of titration 1.32 = zinc in g/l Sodium hydroxide, Sodium Carbonate and Sodium Sulfate: Reagents Indigo Carmine Indicator Phenolphthalein indicator 1N acid Equipment 5 ml pipette 125 ml Erlenmeyer flask Procedure for Sodium Hydroxide 1. Pipette a 5 ml bath sample into a 125 ml Erlenmeyer flask. 2. Add 10 ml of deionized water. 3. Add 5 drops of Indigo Carmine indicator. 4. Titrate with 1N acid until the color changes from yellow to blue. Calculation: ml of titration + oz/gal zinc = sodium hydroxide in oz/gal Procedure for Sodium Carbonate 1. Pipette a 5 ml bath sample into a 125 ml Erlenmeyer flask. 2. Add 10 ml deionized water. 3. Add 5 drops of phenolphthalein indicator. 4. Titrate with 1N acid until the color changes from pink to colorless. Calculation: (ml of titration for sodium carbonate ml of titration for sodium hydroxide) x 2.65 = sodium carbonate in oz/gal Sodium Sulfate analysis (Kocour method) Reagents Concentrate HCl solution 25% BaCl2 solution Equipment Centrifuge Kocour tubes 10 ml pipette 200 ml beaker

6 6 Procedure 1. Pipette 10 ml of Ziniloy bath into a 200 ml beaker. 2. Add concentrated HCl to beaker until foaming stops, then dilute to 200 ml. 3. Pipette 20 ml of the above solution into a Kocour sulfate tube. 4. Add 5 ml of 25% BaCl2 solution. 5. Cap the tube and shake it vigorously for 1 minute. 6. Centrifuge the tube for 10 minutes. 7. Take a reading and centrifuge for another 1 minute to check that all the sulfate has settled. Calculation: each graduation mark on the Kocour tube equals 0.59 oz/gal sodium sulfate (Anhydrous) Nickel: Measure nickel using atomic absorption (AA) % Ziniloy 3028 NIC = ppm nickel/670 Determination of total complexing value by titration: Reagents 30% Potassium Iodide Solution 10% Sulfuric Acid Copper Sulfate 5-hydrate solution (50 g/l) 0.1N Sodium Thiosulfate Starch Solution Equipment 5 ml pipette 100 ml beaker Glass or plastic funnel #41 filter paper Procedure 1. Pipette 5 ml bath sample into a 100 ml beaker. 2. With agitation, add 20 ml of the copper sulfate 5-hydrate solution. 3. After 5~10min, filter the solution through # 41 filter paper into a 500 ml Erlenmeyer flask and rinse the filter paper thoroughly (until you have 200 ml in the flask). 4. Add 10 ml 10% sulfuric acid and 20 ml 30% potassium iodide solution. 5. Add 1 ml starch indicator. Titrate with 0.1N sodium thiosulfate to a milky-white endpoint. Calculation: Total complexing value = ml 0.1N sodium thiosulfate titrated This method determines the combined complexing value of Ziniloy 3028 Base, Ziniloy 3028 Stabilizer and Ziniloy Additive B.

7 7 Troubleshooting Chart: Problem Cause Solution High current density burn Low nickel level Low Brightener Low Total Complexing Value High Caustic coupled with high carbonate/sulfate High Carbonate/Sulfate Rapid increase of zinc metal Excessively high current Check and adjust zinc and nickel levels Add increments of 0.02% 3028 BRT X Add 1.0% increments of complexor Reduce caustic level Freeze out Carbonate/Sulfate Improve Zn generator control in order to avoid spikes in zinc. Allow for time for zinc to complex. Reduce current Pitting in Deposit Low Ziniloy 3028 Wetter Add increments of 0.05% Ziniloy 3028 Wetter Low 3028 BRT X Organic contaminants Low Total Complexing Value Add increments of 0.02% 3028 BRT X Carbon filter with g/l activated carbon Add 1.0% increments of complexor Slow Plating Rate Low Zinc Analyze and adjust to proper range High Nickel alloy High Carbonates and/or sulfates Adjust alloy to proper range Freeze out carbonates and sulfates Total Complexing value is too high Temporarily raise metal levels by 10-15% and/or reduce or stop additions of complexor Incorrect alloy Metals are out of range Check and adjust zinc and nickel content Incorrect Total Complexing Value Check total complexing value analysis, and make necessary adjustments Overall dullness Low Nickel alloy Adjust alloy to proper range Low Total Complexing Value High temperature Low Brightener Poor contact Add 1.0% increments of complexor Lower temperature Add increments of 0.02% 3028 BRT X Check part contact Poor LCD coverage High Carbonate/Sulfate Freeze out Carbonate/Sulfate Wide alloy range (>2%) High temperature Low caustic Metallic contamination Rapid increase of zinc metal Low Total Complexing Value Lower temperature Add sodium hydroxide Add UltraPure in 0.1% increments Improve Zn generator control in order to avoid spikes in zinc. Allow time for zinc to complex. Add 1% increments of complexor

8 8 Problem Cause Solution Dull or iridescent dull deposit that doesn t respond to brightener adds Low nickel alloy Organic impurities Raise alloy to 14% nickel Treat with 0.2% hydrogen peroxide and/or carbon filter with 0.5-1g/L activated carbon. Pink precipitate High carbonate/sulfate/caustic Freeze out carbonate/sulfate. Reduce the level of caustic to opg ( g/l). Waste Treatment: Dispose of the concentrate or solutions thereof according to local waste treatment regulations. Safety: Handling Pavco mandates that the following safety equipment be used when handling chemicals in an electroplating environment: safety glasses, face shield, plastic or rubber apron, rubber gloves and safety shoes. Chemicals should only be handled by trained and experienced personnel. Storage Store Pavco products in a clean, well ventilated room which temperature remains above 45 F (7 C). Pavco products should remain in their original container with the lid or cap tightened. Drum pumps or pails must be clean prior to dispensing Pavco products to prevent contamination. If any Ziniloy 3028 product freezes during shipment or storage, warm the product to and mix it well before use. Emergency Procedures Refer to the MSDS for detailed emergency procedures. Eye Contact Seek immediate medical attention. Flush the eyes with water for 15 minutes. Skin Contact Remove all contaminated clothing. Wash the skin with soap and water. Seek medical attention. Inhalation Remove the person to an area with fresh air. Seek medical attention if necessary. Ingestion Seek immediate medical attention. Spill Dike the area to contain the spill. Refer to the MSDS for clean-up. Notify the proper authorities if required. *NOTE: Refer to the MSDS for detailed emergency medical procedures.

9 9 Product Description & Shipping: Ziniloy 3028 Base (ZNA200) is a clear, colorless to slight yellow liquid with a specific gravity of and a ph >11. Ziniloy 3028 NIC (ZNA222) is a dark green blue liquid with a specific gravity of and a ph of BRT X (ZNA206) is a light amber liquid with a specific gravity of and a ph < 7.5. Ziniloy 3028 Stabilizer (ZNA215) is a clear pale yellow liquid with a specific gravity of with a ph > 9. Ziniloy 3028 Wetter (ZNA223) is a clear liquid with a specific gravity of and a ph <8. Ziniloy Additive B (ZN210) is a pale yellow liquid with a specific gravity of with a ph > 9.5. Ziniloy 3028 products are available in 5-gallon containers or 55-gallon drums except for Ziniloy 3028 Wetter which is available in 5-gallon containers only. UltraPure (ZB1630) is a yellow to colorless opaque liquid with a specific gravity of with a ph > UltraPure is available in 5-gallon pails, 55-gallon drums and 275-gallon totes. Alkaline Zinc Wetter (ZB270) is a clear colorless to pale yellow liquid with a specific gravity of and a ph > 9.5. Alkaline Zinc Wetter is available in 5 gallon pails and 55 gallon drums. Revision Date: 8/6/18 WARRANTY AND DISCLAIMER Technical information and recommendations contained herein are believed to be reliable, however, the accuracy or completeness thereof is not guaranteed. No statement or recommendation shall constitute a representation unless set forth in an agreement in writing by the seller and manufacturer. NO WARRANTY OR MERCHANTABILITY OR WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE IS MADE. The following warranty is made in lieu of any other warranties, express, implied, or statutory. Products are warranted to be free from defects on material and workmanship at the time sold. The sole obligation of the seller and manufacturer under this warranty shall be to replace any product defective at the time sold. Under no circumstances shall the manufacturer or seller be liable for any loss, damage, expense, direct or consequential, arising out of the use of or inability to use the product. Materials shall not be returned to the seller or manufacturer without express written permission. No information or suggestions given by us shall be deemed to be a recommendation to use any product in conflict with any existing patent rights.