Cyanide formation in Zinc-Nickel Electroplating
Galvanotechnik
992
Cyanide formation in Zinc-Nickel Electroplating By Dr. Birgit Sonntag, Dr. Björn Dingwerth, Dr. Roland Vogel and Britta Scheller, Berlin/Germany 1
Introduction
Alkaline zinc-nickel electrolytes are widely used in the electroplating industry to produce highly corrosion resistant zinc-nickel coatings for the automotive industry [1]. These coatings have an important role as they also have high wear resistance, do not lose their corrosion protection when heat is applied (like in high-temperature zones of the car) and can also be used when assembled with aluminum material with regard to contact corrosion. To produce zinc-nickel coatings with a nickel incorporation of 12 to 16 %, all state of the art zinc-nickel electrolytes contain organic amines in the electrolyte composition to stabilize nickel. These complexing agents are necessary to deposit a homogeneous γ-phase zinc-nickel alloy coating. During electrolysis of alkaline zinc-nickel electrolytes breakdown products are formed due to anodic oxidation of electrolyte components, especially the organic amines. These contaminations are increasing during the electrolyte lifetime until a steady state is reached and reduce the process performance of the electrolyte. 2
Formation of cyanide during electrolysis
Cyanide formation during electrolysis was investigated in Reflectalloy® ZNA in a laboratory scale volume. Series of 5 x 5 cm2 mild steel panels were coated on both sides with a zinc-nickel coating using a cathodic current density of 2 A/dm2. On each side of the cathode a nickel anode was installed in a distance of 5 cm. The anode surface area was 1 dm2. The alkaline zinc-nickel electrolyte was made-up using 10 g/l zinc, 120 g/l NaOH, 88 ml/l Reflectalloy ZNA 92 Make Up, 88 ml/l Reflectalloy ZNA 94 Carrier, 1 ml/l Reflectalloy ZNA 95 Brightener, 3 ml/l Reflectalloy ZNA 97 3x Brightener and 1.5 ml/l Reflectalloy ZNA 98. There are different methods available to analyze cyanide. Generally, free cyanide (sodium and potassium cyanide), easy to release cyanide (zinc and nickel cyanide complexes as well as free cyanide) and total cyanide (iron cyanide complexes as well as easy to release and free cyanide) can be analyzed. The analysis of total cyanide was chosen as all counter ions are Galvanotechnik 5/2010
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available in the electrolyte, especially sodium, zinc and nickel as well as traces of iron from impurities. Electrolyte samples have been taken every 2 Ah/l and the cyanide concentration was analyzed for total cyanide according to DIN 38 405 D13-1 (Fig. 1). At new make-up of the zinc-nickel electrolyte no cyanide can be found in the electrolyte. The average cyanide formation rate was determined to be 7 mg/Ah to 10 mg/Ah.
Fig. 1: Cyanide formation in an alkaline zinc-nickel electrolyte (5 l) run with nickel anodes as analysed according to DIN 38405 D13-1
Cyanide generation is also observed in production installations. With anodic cyanide generation on the one hand and drag-out and further oxidation of cyanide on the other, steady-state concentrations of cyanide are reached, which in usual applications range between 250 mg/l and 800 mg/l depending on production line condition. In rack lines with low dragout it may even exceed 1 g/l. As an example at an applicator of a zinc-nickel electrolyte cyanide formation has been investigated with production through put. Figure 2 shows the cyanide concentration in the electrolyte during a one year production period in the electrolyte. Electrolyte samples have been taken from a diversity of applicators and the cyanide content has been analyzed according to DIN 38 405 D13-1. Table 1 shows an overview of analysis results for cyanide contami-
Jahre
Eugen G. Leuze Verlag
Galvanotechnik
Fig. 2: Cyanide in zinc-nickel electrolyte at a Chinese applicator; changing production conditions at a job plater contribute to changing cyanide concentrations
nation. There is a great variation of cyanide contamination in production electrolytes in the field. This is a result of the different operating condition (rack or barrel, drag-out or different anodic current densities for example). Along with cyanides a variety of other breakdown products is formed in the bath, mainly also via anodic oxidation. Presence of cyanide is an easy way to determine symptom for the presence of breakdown products in general. Tab. 1: Examples of analysis results from customer baths operated with nickel anodes Region Eastern Europe Southern Europe Southern Europe
Date Cyanide concentration 10.3.2009 690 mg/l 29.7.2009 491 mg/l 23.2.2010 1170 mg/l
3
Effect of cyanide and other breakdown products in electrolytes Oxidation of amines intermediary yield nitriles [2], which upon nucleophilic substitution with hydroxyl anions produce cyanide. Cyanide itself readily reacts with nickel from the solution to form tetracyano nickel(II) complexes (Fig. 3). The cyanide formed is present as the stable nickel tetracyano complex [Ni(CN)4]2-. Hexacyanoferrat(II) and hexacyanoferrat(III) complexes are the most stable cyanide complexes which can form in the bath. As iron is only present in trace amounts from impurities those complexes do not need to be taken into account Eugen G. Leuze Verlag
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993
and [Ni(CN)4]2- can be considered the dominant cyanide species being present. When nickel is complexed to cyanide it becomes electrochemically inactive in the given matrix and can not any more be deposited cathodically. The tetracyano nickel(II) complex is very stable and avoids further reaction of the nickel. To keep a constant nickel incorporation of 12 % to 16 % in the zinc-nickel layer the nickel concentration has to be increased in the electrolyte. This changes the working window of the electrolyte, making it more difficult to operate. Additionally it increases the operation cost because with a higher nickel concentration in the bath the amount of nickel which is dragged out and wasted also increases. The most important performance parameter for zincnickel application is the overall current efficiency throughout all current densities. High current efficiency electrolytes do not only provide faster deposition in the bulk of the layer but also bear improved seeding capabilities in the very beginning of the deposition process. Hydrogen evolution is always a competing process to metal deposition. Good nucleation capabilities lead to faster overall coverage of the base metal therefore reduced hydrogen evolution and improved overall plating quality. Fast nucleation becomes especially important on hardened steel parts, which often have high carbon concentrations on the steel surface. Carbon facilitates the cathodic generation of hydrogen and interferes with the desired electro deposition. Furthermore, a high current efficiency improves the throughput of the plating line. Parts can be plated at much lower plating time and plating cost. At the same time the burden to the environment is reduced because zinc-nickel electrolytes can be diluted from time to time to improve the plating process performance and to reduce the viscosity of the bath. Cyanide does not have a significant influence on the cathodic current efficiency of the electrolyte. How-
Fig. 3: Mechanism of cyanide formation through anodic oxidation of amines
Jahre
Galvanotechnik 5/2010
Galvanotechnik
994
ever, as discussed above together with cyanide other breakdown products are produced in the electrolyte. As a consequence current efficiency is reduced until a steady state is reached. One other well known breakdown product from zinc-nickel electrolytes next to cyanide is carbonate. Carbonate is also produced on the anode with intermediate formation of oxalate (Fig. 4). Carbonate is additionally produced by reaction of sodium hydroxide with carbon dioxide from the air. In usual practice the carbonate concentration can be kept below 45 g/l by freezing out the carbonate and separate it with a filter material.
Fig. 4: Formation of carbonate via intermediate oxalate formation through anodic oxidation of amines
4
Prevention of breakdown product formation
The use of membrane anodes prevents the contact of the alkaline zinc-nickel electrolyte to the anode material. For this reason no breakdown products are produced and the formation of cyanide is completely prevented, which is proven by analysis during production. At the same time the current efficiency is constantly kept on a high level [3]. Also the replenishment cost of the process is reduced as electrolyte ingredients are not destroyed at the anode and the working parameters are kept in the same range which makes it easier to operate. The deposition of high quality zincnickel deposits is achieved on a constant level. Figure 5 shows a membrane anode installation before charging the zinc-nickel electrolyte into the tank. Galvanotechnik 5/2010
108
Fig. 5: Membrane anode installation
Fig. 6: Current efficiency versus throughput of used alkaline zinc-nickel electrolyte operated at 1 A/dm² with (Zinni AL 450 XL) and without (Zinni AL 450) membrane anodes
Figure 6 shows the current efficiency of Zinni AL 450 with and without the use of membrane anodes investigated at an average current density of 1 A/dm². The composition of this alkaline zinc-nickel electrolyte is as follows: 8 g/l zinc, 120 g/l NaOH, 11 ml/l Zinni AL 450 XL Replenisher Ni, 40 ml/l Zinni AL 450 XL Additive and 0.4 ml/l Zinni AL 450 XL Brightener. 5
Reduction of breakdown product contamination
As membrane anodes have to be tailor made for each plating line the investment in this technology is rather high. Another approach has been investigated to take out the cyanide together with other breakdown products from the zinc-nickel plating process by an ion exchange unit with the selective Resin R [4]. This
Jahre
Eugen G. Leuze Verlag
Galvanotechnik
995
Fig. 8: Zinc-nickel electrolyte color at new make-up (a), after high throughput (b) and after regeneration with Recotect (c) Fig. 7: Recotect ion exchange unit installation at plating line
purification technology is easy to install and flexible. Figure 7 illustrates the Recotect® ion exchanger unit. Before an electrolyte regeneration Resin R is conditioned with sodium hydroxide solution. Afterwards the unit is filled with the zinc-nickel electrolyte for purification and after discharge of the electrolyte back into the tank it is rinsed. The Resin R is regenerated by sodium chloride (cyanide and breakdown products taken away from the Resin R) and finally rinsed. This process sequence is fully automatic, takes only a few minutes of operation time and the contact with chemicals is completely avoided. Additionally the regeneration cycle is kept at consistent condition which gives optimum performance. By reducing the breakdown products contamination in the electrolyte the nickel concentration can be kept at constant low level and the current efficiency is at the same level as at new make-up of the process. As a consequence the deposition overall quality is kept on a constant high level. Figure 8 (a, b, c) shows the color of the zinc-nickel electrolyte at new make up, after high throughput and after regeneration with Recotect®. The regeneration of a production zinc-nickel electrolyte Zinni AL 450 R (R stands for the use with Recotect®) has for the first time been investigated at a German applicator. The composition of the electrolyte is as follows: 11 g/l zinc, 120 g/l NaOH, 11 ml/l Zinni AL 451, 60 ml/l Zinni AL 452 and 1 ml/l Zinni AL 453. Figure 9 demonstrates the increase in cyanide content in the electrolyte before the installation of Recotect® until 100 Ah/l (red line). The black line shows the amount of cyanide which is taken out from Eugen G. Leuze Verlag
108
the electrolyte by the Resin R. The increase in cyanide in the electrolyte is much lower than before (red line after 100 Ah/l). 6 Summary Zinc-nickel alloy coatings are increasingly demanded by the automotive industry due to the highly improved corrosion protection compared to pure zinc and other zinc alloy coatings. The alkaline zinc-nickel electrolytes form cyanide during electrolysis as a result of anodic decomposition of the complexing agents used in the electrolyte composition of all state of the art process baths in the market. The formation of cyanide is a high burden for the environment. Cyanide is generated at a rate of about 7 mg/Ah to 10 mg/Ah in the electrolyte. With an average production of 500 kAh per month for an average applicator an amount of about 4 kg cyanide is created. Consequently new plating technologies have been developed. The formation of cyanide can be completely avoided by using membrane anodes which prevents the break-
Fig. 9: Cyanide contamination in Zinni AL 450 R before and after installation of Recotect ion exchanger
Jahre
Galvanotechnik 5/2010
Galvanotechnik
996
down of bath ingredients at the anode and results in higher current efficiency. Another more flexible technology is the use of an ion exchanger called Recotect®, which takes out the cyanide from the zinc-nickel electrolytes. With both technologies the current efficiency of the process can be increased significantly which improves the productivity and throughput of the plating line. Also the seeding capabilities of the zinc-nickel deposit is improved which makes it much easier to use with critical substrate material. The operating window
of the zinc-nickel process is always used as at new make-up which makes it easy to operate for production personal and ensures excellent zinc-nickel coating deposition for the automotive industry. References [1] B. Sonntag, K. Thom, N. Dambrowsky, B. Dingwerth; Galvanotechnik 100 (2009)7, p. 1499 [2] M. Fleischmann, K. Korinek, D. Pletcher; J. Electroanal. Chem., 31 (1971), pp. 39–49 [3] Ernst Walter Hillebrand; WO 00/06807 and corresponding international applications [4] Patent filed by Atotech
UNSERE IDEEN – IHRE VORTEILE Die neue TSH-Serie – „Compact Power“Gleichstromversorgungen in innovativer Schaltnetzteiltechnik: Präzise Mikroprozessortechnik
✘ Effizient, durch hohen Wirkungsgrad, präzise Steuerung und einfache Bedienung.
✘ Zuverlässig, dank umfangreichen Sicherungsund Schutzfunktionen.
✘ Flexibel, mittels anwenderspezifischen Softwarelösungen.
Leistungsstarke TWIN - power MODULE
Innovatives, technisches Design
Weitere Informationen sowie ein ausführliches Datenblatt finden Sie ab sofort im Internet unter: www.tsh-powertower.de Lassen Sie sich begeistern. Besuchen Sie uns auf der O & S in Stuttgart 8. – 10. Juni 2010, Halle 005, Stand C83
Für eine persönliche Beratung erreichen Sie uns unter: Telefon +49 (0) 2385 9355 -14 oder [email protected]
992
Cyanide formation in Zinc-Nickel Electroplating By Dr. Birgit Sonntag, Dr. Björn Dingwerth, Dr. Roland Vogel and Britta Scheller, Berlin/Germany 1
Introduction
Alkaline zinc-nickel electrolytes are widely used in the electroplating industry to produce highly corrosion resistant zinc-nickel coatings for the automotive industry [1]. These coatings have an important role as they also have high wear resistance, do not lose their corrosion protection when heat is applied (like in high-temperature zones of the car) and can also be used when assembled with aluminum material with regard to contact corrosion. To produce zinc-nickel coatings with a nickel incorporation of 12 to 16 %, all state of the art zinc-nickel electrolytes contain organic amines in the electrolyte composition to stabilize nickel. These complexing agents are necessary to deposit a homogeneous γ-phase zinc-nickel alloy coating. During electrolysis of alkaline zinc-nickel electrolytes breakdown products are formed due to anodic oxidation of electrolyte components, especially the organic amines. These contaminations are increasing during the electrolyte lifetime until a steady state is reached and reduce the process performance of the electrolyte. 2
Formation of cyanide during electrolysis
Cyanide formation during electrolysis was investigated in Reflectalloy® ZNA in a laboratory scale volume. Series of 5 x 5 cm2 mild steel panels were coated on both sides with a zinc-nickel coating using a cathodic current density of 2 A/dm2. On each side of the cathode a nickel anode was installed in a distance of 5 cm. The anode surface area was 1 dm2. The alkaline zinc-nickel electrolyte was made-up using 10 g/l zinc, 120 g/l NaOH, 88 ml/l Reflectalloy ZNA 92 Make Up, 88 ml/l Reflectalloy ZNA 94 Carrier, 1 ml/l Reflectalloy ZNA 95 Brightener, 3 ml/l Reflectalloy ZNA 97 3x Brightener and 1.5 ml/l Reflectalloy ZNA 98. There are different methods available to analyze cyanide. Generally, free cyanide (sodium and potassium cyanide), easy to release cyanide (zinc and nickel cyanide complexes as well as free cyanide) and total cyanide (iron cyanide complexes as well as easy to release and free cyanide) can be analyzed. The analysis of total cyanide was chosen as all counter ions are Galvanotechnik 5/2010
108
available in the electrolyte, especially sodium, zinc and nickel as well as traces of iron from impurities. Electrolyte samples have been taken every 2 Ah/l and the cyanide concentration was analyzed for total cyanide according to DIN 38 405 D13-1 (Fig. 1). At new make-up of the zinc-nickel electrolyte no cyanide can be found in the electrolyte. The average cyanide formation rate was determined to be 7 mg/Ah to 10 mg/Ah.
Fig. 1: Cyanide formation in an alkaline zinc-nickel electrolyte (5 l) run with nickel anodes as analysed according to DIN 38405 D13-1
Cyanide generation is also observed in production installations. With anodic cyanide generation on the one hand and drag-out and further oxidation of cyanide on the other, steady-state concentrations of cyanide are reached, which in usual applications range between 250 mg/l and 800 mg/l depending on production line condition. In rack lines with low dragout it may even exceed 1 g/l. As an example at an applicator of a zinc-nickel electrolyte cyanide formation has been investigated with production through put. Figure 2 shows the cyanide concentration in the electrolyte during a one year production period in the electrolyte. Electrolyte samples have been taken from a diversity of applicators and the cyanide content has been analyzed according to DIN 38 405 D13-1. Table 1 shows an overview of analysis results for cyanide contami-
Jahre
Eugen G. Leuze Verlag
Galvanotechnik
Fig. 2: Cyanide in zinc-nickel electrolyte at a Chinese applicator; changing production conditions at a job plater contribute to changing cyanide concentrations
nation. There is a great variation of cyanide contamination in production electrolytes in the field. This is a result of the different operating condition (rack or barrel, drag-out or different anodic current densities for example). Along with cyanides a variety of other breakdown products is formed in the bath, mainly also via anodic oxidation. Presence of cyanide is an easy way to determine symptom for the presence of breakdown products in general. Tab. 1: Examples of analysis results from customer baths operated with nickel anodes Region Eastern Europe Southern Europe Southern Europe
Date Cyanide concentration 10.3.2009 690 mg/l 29.7.2009 491 mg/l 23.2.2010 1170 mg/l
3
Effect of cyanide and other breakdown products in electrolytes Oxidation of amines intermediary yield nitriles [2], which upon nucleophilic substitution with hydroxyl anions produce cyanide. Cyanide itself readily reacts with nickel from the solution to form tetracyano nickel(II) complexes (Fig. 3). The cyanide formed is present as the stable nickel tetracyano complex [Ni(CN)4]2-. Hexacyanoferrat(II) and hexacyanoferrat(III) complexes are the most stable cyanide complexes which can form in the bath. As iron is only present in trace amounts from impurities those complexes do not need to be taken into account Eugen G. Leuze Verlag
108
993
and [Ni(CN)4]2- can be considered the dominant cyanide species being present. When nickel is complexed to cyanide it becomes electrochemically inactive in the given matrix and can not any more be deposited cathodically. The tetracyano nickel(II) complex is very stable and avoids further reaction of the nickel. To keep a constant nickel incorporation of 12 % to 16 % in the zinc-nickel layer the nickel concentration has to be increased in the electrolyte. This changes the working window of the electrolyte, making it more difficult to operate. Additionally it increases the operation cost because with a higher nickel concentration in the bath the amount of nickel which is dragged out and wasted also increases. The most important performance parameter for zincnickel application is the overall current efficiency throughout all current densities. High current efficiency electrolytes do not only provide faster deposition in the bulk of the layer but also bear improved seeding capabilities in the very beginning of the deposition process. Hydrogen evolution is always a competing process to metal deposition. Good nucleation capabilities lead to faster overall coverage of the base metal therefore reduced hydrogen evolution and improved overall plating quality. Fast nucleation becomes especially important on hardened steel parts, which often have high carbon concentrations on the steel surface. Carbon facilitates the cathodic generation of hydrogen and interferes with the desired electro deposition. Furthermore, a high current efficiency improves the throughput of the plating line. Parts can be plated at much lower plating time and plating cost. At the same time the burden to the environment is reduced because zinc-nickel electrolytes can be diluted from time to time to improve the plating process performance and to reduce the viscosity of the bath. Cyanide does not have a significant influence on the cathodic current efficiency of the electrolyte. How-
Fig. 3: Mechanism of cyanide formation through anodic oxidation of amines
Jahre
Galvanotechnik 5/2010
Galvanotechnik
994
ever, as discussed above together with cyanide other breakdown products are produced in the electrolyte. As a consequence current efficiency is reduced until a steady state is reached. One other well known breakdown product from zinc-nickel electrolytes next to cyanide is carbonate. Carbonate is also produced on the anode with intermediate formation of oxalate (Fig. 4). Carbonate is additionally produced by reaction of sodium hydroxide with carbon dioxide from the air. In usual practice the carbonate concentration can be kept below 45 g/l by freezing out the carbonate and separate it with a filter material.
Fig. 4: Formation of carbonate via intermediate oxalate formation through anodic oxidation of amines
4
Prevention of breakdown product formation
The use of membrane anodes prevents the contact of the alkaline zinc-nickel electrolyte to the anode material. For this reason no breakdown products are produced and the formation of cyanide is completely prevented, which is proven by analysis during production. At the same time the current efficiency is constantly kept on a high level [3]. Also the replenishment cost of the process is reduced as electrolyte ingredients are not destroyed at the anode and the working parameters are kept in the same range which makes it easier to operate. The deposition of high quality zincnickel deposits is achieved on a constant level. Figure 5 shows a membrane anode installation before charging the zinc-nickel electrolyte into the tank. Galvanotechnik 5/2010
108
Fig. 5: Membrane anode installation
Fig. 6: Current efficiency versus throughput of used alkaline zinc-nickel electrolyte operated at 1 A/dm² with (Zinni AL 450 XL) and without (Zinni AL 450) membrane anodes
Figure 6 shows the current efficiency of Zinni AL 450 with and without the use of membrane anodes investigated at an average current density of 1 A/dm². The composition of this alkaline zinc-nickel electrolyte is as follows: 8 g/l zinc, 120 g/l NaOH, 11 ml/l Zinni AL 450 XL Replenisher Ni, 40 ml/l Zinni AL 450 XL Additive and 0.4 ml/l Zinni AL 450 XL Brightener. 5
Reduction of breakdown product contamination
As membrane anodes have to be tailor made for each plating line the investment in this technology is rather high. Another approach has been investigated to take out the cyanide together with other breakdown products from the zinc-nickel plating process by an ion exchange unit with the selective Resin R [4]. This
Jahre
Eugen G. Leuze Verlag
Galvanotechnik
995
Fig. 8: Zinc-nickel electrolyte color at new make-up (a), after high throughput (b) and after regeneration with Recotect (c) Fig. 7: Recotect ion exchange unit installation at plating line
purification technology is easy to install and flexible. Figure 7 illustrates the Recotect® ion exchanger unit. Before an electrolyte regeneration Resin R is conditioned with sodium hydroxide solution. Afterwards the unit is filled with the zinc-nickel electrolyte for purification and after discharge of the electrolyte back into the tank it is rinsed. The Resin R is regenerated by sodium chloride (cyanide and breakdown products taken away from the Resin R) and finally rinsed. This process sequence is fully automatic, takes only a few minutes of operation time and the contact with chemicals is completely avoided. Additionally the regeneration cycle is kept at consistent condition which gives optimum performance. By reducing the breakdown products contamination in the electrolyte the nickel concentration can be kept at constant low level and the current efficiency is at the same level as at new make-up of the process. As a consequence the deposition overall quality is kept on a constant high level. Figure 8 (a, b, c) shows the color of the zinc-nickel electrolyte at new make up, after high throughput and after regeneration with Recotect®. The regeneration of a production zinc-nickel electrolyte Zinni AL 450 R (R stands for the use with Recotect®) has for the first time been investigated at a German applicator. The composition of the electrolyte is as follows: 11 g/l zinc, 120 g/l NaOH, 11 ml/l Zinni AL 451, 60 ml/l Zinni AL 452 and 1 ml/l Zinni AL 453. Figure 9 demonstrates the increase in cyanide content in the electrolyte before the installation of Recotect® until 100 Ah/l (red line). The black line shows the amount of cyanide which is taken out from Eugen G. Leuze Verlag
108
the electrolyte by the Resin R. The increase in cyanide in the electrolyte is much lower than before (red line after 100 Ah/l). 6 Summary Zinc-nickel alloy coatings are increasingly demanded by the automotive industry due to the highly improved corrosion protection compared to pure zinc and other zinc alloy coatings. The alkaline zinc-nickel electrolytes form cyanide during electrolysis as a result of anodic decomposition of the complexing agents used in the electrolyte composition of all state of the art process baths in the market. The formation of cyanide is a high burden for the environment. Cyanide is generated at a rate of about 7 mg/Ah to 10 mg/Ah in the electrolyte. With an average production of 500 kAh per month for an average applicator an amount of about 4 kg cyanide is created. Consequently new plating technologies have been developed. The formation of cyanide can be completely avoided by using membrane anodes which prevents the break-
Fig. 9: Cyanide contamination in Zinni AL 450 R before and after installation of Recotect ion exchanger
Jahre
Galvanotechnik 5/2010
Galvanotechnik
996
down of bath ingredients at the anode and results in higher current efficiency. Another more flexible technology is the use of an ion exchanger called Recotect®, which takes out the cyanide from the zinc-nickel electrolytes. With both technologies the current efficiency of the process can be increased significantly which improves the productivity and throughput of the plating line. Also the seeding capabilities of the zinc-nickel deposit is improved which makes it much easier to use with critical substrate material. The operating window
of the zinc-nickel process is always used as at new make-up which makes it easy to operate for production personal and ensures excellent zinc-nickel coating deposition for the automotive industry. References [1] B. Sonntag, K. Thom, N. Dambrowsky, B. Dingwerth; Galvanotechnik 100 (2009)7, p. 1499 [2] M. Fleischmann, K. Korinek, D. Pletcher; J. Electroanal. Chem., 31 (1971), pp. 39–49 [3] Ernst Walter Hillebrand; WO 00/06807 and corresponding international applications [4] Patent filed by Atotech
UNSERE IDEEN – IHRE VORTEILE Die neue TSH-Serie – „Compact Power“Gleichstromversorgungen in innovativer Schaltnetzteiltechnik: Präzise Mikroprozessortechnik
✘ Effizient, durch hohen Wirkungsgrad, präzise Steuerung und einfache Bedienung.
✘ Zuverlässig, dank umfangreichen Sicherungsund Schutzfunktionen.
✘ Flexibel, mittels anwenderspezifischen Softwarelösungen.
Leistungsstarke TWIN - power MODULE
Innovatives, technisches Design
Weitere Informationen sowie ein ausführliches Datenblatt finden Sie ab sofort im Internet unter: www.tsh-powertower.de Lassen Sie sich begeistern. Besuchen Sie uns auf der O & S in Stuttgart 8. – 10. Juni 2010, Halle 005, Stand C83
Für eine persönliche Beratung erreichen Sie uns unter: Telefon +49 (0) 2385 9355 -14 oder [email protected]
