Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D3/00—Electroplating: Baths therefor
  • C25D3/02—Electroplating: Baths therefor from solutions
  • C25D3/56—Electroplating: Baths therefor from solutions of alloys
  • C25D3/565—Electroplating: Baths therefor from solutions of alloys containing more than 50% by weight of zinc
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C13/00—Alloys based on tin
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C18/00—Alloys based on zinc
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D3/00—Electroplating: Baths therefor
  • C25D3/02—Electroplating: Baths therefor from solutions
  • C25D3/56—Electroplating: Baths therefor from solutions of alloys
  • C25D3/60—Electroplating: Baths therefor from solutions of alloys containing more than 50% by weight of tin

Definitions

• the invention relates to new ternary tin-zinc alloys of a certain composition which contain a metal from the group iron, cobalt, nickel as the third alloy component.
• the invention further relates to galvanic electrolyte baths and a galvanic method for producing such ternary tin-zinc alloy layers and their use as corrosion protection layers or decorative layers.
• N l-i ⁇ ⁇ C ⁇ d t ⁇ iQ
• % By weight of a metal from the group consisting of iron, cobalt and nickel as the third alloy component.
• the ternary tin-zinc alloys according to the invention preferably contain cobalt as the third alloy component.
• Tin-zinc-cobalt alloys according to the invention preferably consist of 40 to 55% by weight of tin, 45 to 55% by weight of zinc and 0.1 to 5% by weight of cobalt.
• Tin-zinc-nickel alloys according to the invention preferably consist of 35 to 50% by weight of tin, 50 to 65% by weight of zinc and 0.1 to 5% by weight of nickel.
• Tin-zinc-iron alloys according to the invention preferably consist of 40 to 55% by weight of tin, 40 to 60% by weight of zinc and 1 to 8% by weight of iron.
• the ternary tin-zinc alloys according to the invention can be produced by melt or powder metallurgy from the individual components.
• tin-zinc alloys can be deposited on substrates from alkaline, neutral or weakly acidic galvanic electrolyte baths.
• An alkaline electrolyte is understood here to mean an electrolyte with a pH greater than 10.
• a neutral electrolyte is an electrolyte with a pH of 6-10.
• a weakly acidic electrolyte is an electrolyte with a pH of 3-6.
• the alloy components are added to the aqueous electrolyte bath in the form of their ionogenic compounds which are soluble in the respective medium.
• Tin is preferably used as a sulfate,
• Zinc is preferably added as a sulfate, chloride, hydroxide, sulfonate 'or oxide.
• DJ 3 ⁇ ⁇ - DJ O ⁇ Q M fl 1 Cfl ⁇ ⁇ DJ 3 * r- J 3 ⁇ o ⁇ ⁇ O CL DJ DJ ⁇ ⁇ ⁇ - ⁇ ⁇
• a temperature of approximately 20-70 ° C. and a current density of approximately 0.1-5 A / dm 2 can be regarded as a framework for the deposition of the ternary tin-zinc alloys from the electrolytes according to the invention, with deposition speeds of approximately 0. 05 - 1 ⁇ m / minute.
• An alkaline electrolyte according to the invention can have the following typical frame composition:
• the alloy is electrodeposited at temperatures between 40 - 70 ° C at current densities of 1 - 5 A / dm 2 with deposition speeds of 0.15 - 0.3 ⁇ m / minute.
• Graphite or platinum-plated titanium can be used as anodes.
• Organic acids and their salts, phosphonic acids, phosphonates, gluconates, glucoheptonic acids, glucoheptonates and ethylenediaminetetraacetic acid can be used as complexing agents.
• Resistant surfactants, polyhydric alcohols and betaines can be used as wetting agents and brighteners in the corresponding media.
• the alloy composition of the layer can be varied by changing the ratio of the individual components in the bath. Thus an increase in the hydroxide content causes a reduction in the tin content and a corresponding increase in the other two metals in the layer.
• a neutral electrolyte according to the invention can have the following typical frame composition:
• the alloy is electroplated at temperatures between 40 - 70 ° C at current densities of 0.5 - 3 A / dm 2 with deposition speeds of 0.05 - 0.3 ⁇ m / minute.
• Graphite or platinized titanium can be used as anodes.
• the use of soluble anodes is also possible.
• the ratio of the alloy composition can be varied by varying the coating parameters.
• a weakly acidic electrolyte according to the invention can have the following typical frame composition:
• the alloy is electroplated at temperatures between 20 - 70 ° C at current densities of 0.5 - 5 A / dm 2 with deposition speeds of 0.1 - 1 ⁇ m / minute.
• Graphite or platinized titanium can be used as anodes.
• the use of soluble anodes is also possible.
• Boric acid for example, can be used as the buffer substance.
• the ratio of the alloy composition can be adjusted by changing the coating parameters (amount of components, working parameters). For example, an increase in the current density causes an increase in the proportion of alloys in zinc and nickel, cobalt or iron and a decrease in the proportion of tin. The variation of the temperature in the specified range only results in insignificant changes in the alloy composition of the layer.
• the ternary tin-zinc alloys according to the invention have very advantageous material properties, on the basis of which they can be used in different ways both as an independent material and in particular in the form of coatings on substrates.
• the ternary tin-zinc alloys have a particularly high level of corrosion resistance, which is most pronounced in the SnZnNi and SnZnCo systems. These alloys are therefore particularly suitable as corrosion protection layers on ferrous materials.
• the corresponding galvanic electrolytes can therefore preferably be used to produce corrosion protection layers on ferrous materials. In this way, coated iron sheets in combination with the usual passivation by chromating or chromitizing easily achieve a resistance to the appearance of red rust of over 3000 hours.
• the SnZnFe and SnZnCo alloy layers achieve the highest hardness values.
• the greatest abrasion resistance is shown by SnZnNi layers.
• Such alloy layers can therefore advantageously be used as wear protection layers in the event of mechanical stress.
• SnZnFe and SnZnCo layers can be soldered particularly well and are therefore particularly suitable in electronics as solderable layers and as contact surfaces. Table 2 shows the corresponding data for selected alloy systems.
• the ternary tin-zinc alloys according to the invention can also be used as decorative end layers.
• the three alloy systems have interesting and appealing colors in the blue range. example 1
• An alkaline electrolyte for the deposition of an alloy consisting of 45% by weight Sn, 52% by weight Zn and 3% by weight cobalt has the following composition:
• a pH of 11 is established.
• the above-mentioned layer composition can be achieved with this electrolyte at a temperature of 60 ° C. and current densities of 1-2 A / dm 2 . In this case, about 0.2 ⁇ m alloy layer is built up per minute. The density of the alloy layer is 7.27 g / cm 3 .
• a neutral electrolyte for the deposition of an alloy consisting of 48% by weight Sn, 49% by weight Zn and 3% by weight cobalt has the following composition:
• a pH of 8.5 is established.
• the above-mentioned layer composition can be achieved with this electrolyte at a temperature of 60 ° C. and current densities of 0.5-1 A / dm 2 .
• a 0.15 ⁇ m layer is built up per minute.
• the density of the alloy layer is 7.27 g / cm 3 .
• a weakly acidic electrolyte for the deposition of an alloy consisting of 49.2% by weight of Sn, 50.5% by weight of Zn and 0.3% by weight of nickel has the following composition:
• a pH of 4.5 is established.
• the above-mentioned layer composition can be achieved with this electrolyte at a temperature of 40 ° C. and current densities of 1.5 A / dm 2 .
• about 0.4 ⁇ m alloy layer is built up per minute.
• the density of the alloy layer is 7.2 g / cm 3 .
• a weakly acidic electrolyte for the deposition of an alloy consisting of 52% by weight of Sn, 44% by weight of Zn and 4% by weight of iron has the following composition:
• a pH of 4.4 is established.
• the above-mentioned layer composition can be achieved with this electrolyte at a temperature of 40 ° C. and current densities of 1.5 A / dm 2 .
• about 0.4 ⁇ m alloy layer is built up per minute.
• the density of the alloy layer is 7.25 g / cm 3 .

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Mechanical Engineering (AREA)
• Electroplating And Plating Baths Therefor (AREA)
• Electroplating Methods And Accessories (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (2)

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• 2000
  • 2000-09-16 DE DE10045991A patent/DE10045991A1/de not_active Ceased
• 2001
  • 2001-08-16 US US10/380,212 patent/US20040091385A1/en not_active Abandoned
  • 2001-08-16 DE DE50114623T patent/DE50114623D1/de not_active Expired - Lifetime
  • 2001-08-16 CN CN01816986.4A patent/CN1239751C/zh not_active Expired - Fee Related
  • 2001-08-16 WO PCT/EP2001/009452 patent/WO2002022913A2/de not_active Ceased
  • 2001-08-16 JP JP2002527347A patent/JP4817352B2/ja not_active Expired - Fee Related
  • 2001-08-16 EP EP01969597A patent/EP1319093B1/de not_active Expired - Lifetime

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