CN1936077A - Two-step electro-zine-plating method on magnesium alloy as chemically nickel-plating intermediate transition layer - Google Patents
Two-step electro-zine-plating method on magnesium alloy as chemically nickel-plating intermediate transition layer Download PDFInfo
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- CN1936077A CN1936077A CN 200610047691 CN200610047691A CN1936077A CN 1936077 A CN1936077 A CN 1936077A CN 200610047691 CN200610047691 CN 200610047691 CN 200610047691 A CN200610047691 A CN 200610047691A CN 1936077 A CN1936077 A CN 1936077A
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Abstract
The invention relates to a two steps electrolytic zinc plating method that coats chemical nickel plating intermediate transition layer on magnesium alloy. The method includes the preprocess technology of taking chemical nickel plating on magnesium alloy. The main feature is that it adopts two steps electrolytic zinc plating technology that are: adopts zinc sulfate as main salt, pyrophosphate as main complex agent to pre-coating a zinc layer on magnesium alloy basal body; dipping into alkaline zinc plating solution of sodium hydroxide and zinc oxide to take further thickening. The zinc plating could be used as bottom of chemical nickel plating and could deposit other protecting decorating metal coating layer on it.
Description
Technical field: the present invention relates on a kind of magnesium alloy to belong to corrosion and protective treatment technical field as the two-step electro-zine method of chemical nickel plating intermediate layer.
Background technology: the chemically reactive of magnesium alloy height is further to enlarge one of its major obstacle of using in automobile and electronic product.The research of Chrome-free chemical conversion film and micro-arc oxidation films is that effective way has been opened up in the corrosion prevention of magnesium alloy.Because the characteristic of semiconductor of chemical conversion film and anode oxide film, and organism application subsequently make it be unsuitable for being applied in the occasion that requires electroconductibility and weldability.Chemical Ni-plating layer can satisfy this specific demand as metal plating.Domestic and international research mainly concentrates on direct chemical nickel plating on the magnesium alloy at present, adopt fluorochemicals to carry out pre-treatment, be pre-formed fluoride film with certain passivation characteristics at Mg alloy surface, adopt the basic nickel carbonate salt of deciding, in the nickel dam deposition process, fluoride films partly comes off and exposes the magnesium alloy substrate, realizes direct chemical nickel plating on the magnesium.
If coating and basal body binding force are poor, thickness of coating is thinner, or exists pin hole and defective, corrosive medium to be easy to penetrate coating arrival magnesium alloy substrate in the coating.In 3.5%NaCl solution, the corrosion potential of magnesium alloy substrate is-1.6V (SCE) about, the corrosion potential of chemical Ni-plating layer is-0.4V (SCE) about.The difference in Electrode Potential that magnesium alloy substrate and chemical nickel plating interlayer are bigger is the powerful impellent of galvanic corrosion between the two, and magnesium alloy substrate will suffer heavy corrosion as anode.Traditional method is to soak zinc to handle before chemical nickel plating, because soaking the zinc process is by the replacement(metathesis)reaction between zinc in zinc dipping solution ion and magnesium alloy substrate, gained zinc layer is very thin and bonding force is poor, and for containing high magnesium alloy of aluminium such as AZ91, second to go up sedimentary zinc layer mutually be no bonding force.Also will carry out cyanide copper plating chemical nickel plating more subsequently, have the cyanide pollution environmental problem, complex process is unsuitable for suitability for industrialized production.
Summary of the invention: the objective of the invention is in order to overcome the defective of prior art, and it is low to have proposed a kind of cost, simple to operate, be easy to realization of industrialization, can reduce simultaneously method for the new electroplating zinc on magnesium alloy of environmental pollution, promptly on the magnesium alloy as the two-step electro-zine method of chemical nickel plating intermediate layer.
The objective of the invention is to realize by following technical proposals: this method adopts a kind of new pretreatment process, in advance magnesium alloy substrate is carried out etch in bimolybdate solution, on magnesium alloy substrate, generate the cream-coloured film of one deck, then, in alkaline molybdate solution, activate, cream-coloured film taken off remove, expose alloy substrate.Use two-step approach electrodepositing zinc coating subsequently on magnesium alloy, (1) adopts zinc sulfate is main salt, and pyrophosphate salt is main complexing agent, and gained electro-galvanized layer and matrix bond are firm, but film is thinner.(2) adopt the alkaline zinc plating liquid of being made up of sodium hydroxide and zinc oxide, further zinc-plated with the film thickening, the coating even compact can be used as bottom electroless plating nickel-phosphorus coating or other metal plating of galvanic deposit thereon.As intermediate layer, reduced the galvanic corrosion tendency between chemical Ni-plating layer and magnesium alloy substrate, for magnesium alloy provides favorable protection.
Concrete preparation method: immerse magnesium alloy workpiece in the degreasing tank earlier, at room temperature, in acetone reagent, after 3～5 minutes, enter in first tank and washed 1～2 minute, enter again and use deionized water wash 1～2 minute in second tank with the mobile tap water in degreasing under the ultrasonic wave effect.At room temperature immerse and soaked in the acid etching liquid 1～2 minute, enter the 3rd tank, enter the 4th tank again and after 1～2 minute, at room temperature enter and soaked in the alkaline activation liquid 3～5 minutes through deionized water wash through tap water washing 1～2 minute.After workpiece takes out, enter the 5th tank, enter the 6th tank again and after 1～2 minute, enter the first electro-galvanizing groove, carried out electro-galvanizing 5～10 minutes through deionized water wash through tap water washing 1～2 minute.Workpiece after the plating enters the 7th tank through tap water washing 1～2 minute, enters the 8th tank again and after 1～2 minute, enters the second electro-galvanizing groove with deionized water wash, carries out electro-galvanizing 20～30 minutes.Enter then in the 9th tank and washed 1～2 minute, enter again and use deionized water wash 1～2 minute in the tenth tank with the mobile tap water.Workpiece enters the chemical nickel plating groove, electroless plating 2～3 hours.Workpiece after the electroless plating enters the 11 tank through tap water washing 1～2 minute, enters the 12 tank again and after 1～2 minute, takes out oven dry through the washing of mobile tap water.
The technical process of adopting is: polishing → oil removing → bimolybdate pickling → alkaline molybdate activation → one step electro-zine → two step electro-zines → chemical nickel plating, each adds washing between the step.Pre-treatment: acetone ultrasonic wave oil removing.It is 30g/L Na that solution is adopted in pickling
2MoO
4With 20ml/L H
3PO
4Handled 0.5～2 minute down at 25 ℃.30g/L Na is adopted in activation
2MoO
4Handled 3～5 minutes down at 25 ℃ with 20g/L NaOH.Electro-galvanizing: (1) ZnSO
410-30g/L, Na
4P
2O
740-120g/L, KF3-15g/L, Na
2CO
32-10g/L, pH 9-12 uses NH
3H
2O 10-20mL/L regulates pH value, cathode current density Dk 0.2-1.8A/dm
2Temperature 40-65 ℃, time 3-20 branch.(2) ZnO, 10-20g/L NaOH 100-120g/L DE additive 3-5mL/L, current density 2-4A/dm
2, ambient operation, time 10-40 minute.Chemical nickel plating: single nickel salt 10-30g/L; Inferior sodium phosphate 18-40g/L; Complexing agent is an amount of; Stablizer is a small amount of; Wetting agent is a small amount of; Ammoniacal liquor (26%～28%) is an amount of; PH6.0-7.0; Temperature 80-85 ℃; Time 2-4 hour.
Compare prior art, the present invention has the following advantages:
1. electro-galvanizing pretreatment technology of the present invention, solution composition is simple, is easy to control, process stabilizing;
2. galvanizing technique of the present invention is simple, combines with magnesium alloy substrate firmly;
3. in whole technological process, do not need to use the chromium element fully, reduce pollution environment;
4. the waste water ratio that produces in handling is easier to handle.
Below in conjunction with embodiment the present invention is further described.
Embodiment 1
Test materials is the AM60 magnesium alloy
1. degreasing: with acetone solvent washing, remove lubricant that general dirt, sintering adhere to, cutting agent etc. under the ultrasonic wave effect; Service temperature is a room temperature, and the time is 1～2 minute; Washed deionization washing 1～2 minute from the beginning 1～2 fen;
2. acid etching: adopting solution is 30g/L Na
2MoO
4With 20ml/L H
3PO
4Handled 0.5～2 minute down at 25 ℃.Washed deionization washing 1～2 minute from the beginning 1～2 fen;
3. alkaline activation: 30g/L Na is adopted in activation
2MoO
4Handled 3～5 minutes down at 25 ℃ with 20g/L NaOH.Washed deionization washing 1～2 minute from the beginning 1～2 fen;
4. electro-galvanizing: (1) ZnSO
410g/L, Na
4P
2O
740g/L, KF 3g/L, Na
2CO
32 g/L, DE additive 2ml/L, pH 9-10 uses NH
3H
2O 10-20 mL/L regulates pH value, cathode current density Dk 0.2A/dm
2Temperature 50-60 ℃, time 5-10 branch.(2) ZnO 10g/L, NaOH 100g/L, DE additive 2～4ml/L, cathode current density Dk 2A/dm
2, room temperature, time 15-30 minute.Add washing between two steps, washed from the beginning 1～2 fen, deionization washing 1～2 minute.
5. chemical nickel plating: single nickel salt 10g/L; Inferior sodium phosphate 20g/L; Complexing agent is an amount of; Stablizer is a small amount of; Wetting agent is a small amount of; Ammoniacal liquor (26%～28%) is an amount of; PH6.0-7.0; Temperature 80-85 ℃; 2 hours time.
Embodiment 2
Test materials is the AZ31 magnesium alloy
1. degreasing: with acetone solvent washing, remove lubricant that general dirt, sintering adhere to, cutting agent etc. under the ultrasonic wave effect; Service temperature is a room temperature, and the time is 1～2 minute; Washed deionization washing 1～2 minute from the beginning 1～2 fen;
2. acid etching: adopting solution is 20g/L Na
2MoO
4With 10ml/L H
3PO
4Handled 0.5～2 minute down at 25 ℃.Washed deionization washing 1～2 minute from the beginning 1～2 fen;
3. alkaline activation: 20g/L Na is adopted in activation
2MoO
4Handled 3～5 minutes down at 25 ℃ with 10g/L NaOH.Washed deionization washing 1～2 minute from the beginning 1～2 fen;
4. electro-galvanizing: (1) ZnSO
420g/L, Na
4P
2O
780g/L, KF 8g/L, Na
2CO
37g/L, DE additive 2～4ml/L, pH 10-11 uses NH
3H
2O 10-15mL/L regulates pH value, cathode current density Dk1.0A/dm
2Temperature 50-60 ℃, time 5-10 branch.(2) ZnO 15g/L, NaOH 110g/L, DE additive 3～4ml/L, cathode current density Dk3A/dm
2, room temperature, time 15-30 minute.Add washing between two steps, washed from the beginning 1～2 fen, deionization washing 1～2 minute.
5. chemical nickel plating: single nickel salt 20g/L; Inferior sodium phosphate 30g/L; Complexing agent is an amount of; Stablizer is a small amount of; Wetting agent is a small amount of; Ammoniacal liquor (26%～28%) is an amount of; PH6.0-7.0; Temperature 80-83 ℃; 3 hours time.
Embodiment 3
Test materials is the AZ91 magnesium alloy
1. degreasing: with acetone solvent washing, remove lubricant that general dirt, sintering adhere to, cutting agent etc. under the ultrasonic wave effect; Service temperature is a room temperature, and the time is 1～2 minute; Washed deionization washing 1～2 minute from the beginning 1～2 fen;
2. acid etching: adopting solution is 20g/L Na
2MoO
4With 10ml/L H
3PO
4Handled 0.5～2 minute down at 25 ℃.Washed deionization washing 1～2 minute from the beginning 1～2 fen;
3. alkaline activation: 20g/L Na is adopted in activation
2MoO
4Handled 3～5 minutes down at 25 ℃ with 10g/L NaOH.Washed deionization washing 1～2 minute from the beginning 1～2 fen;
4. electro-galvanizing: (1) ZnSO
430g/L, Na
4P
2O
7120g/L, KF 15g/L, Na
2CO
310g/L, DE additive 2～4ml/L, pH 10-11 uses NH
3H
2O 10-15 mL/L regulates pH value, cathode current density Dk 1.5A/dm
2Temperature 50-60 ℃, time 5-10 branch.(2) ZnO 20g/L, NaOH 120g/L, DE additive 3～4ml/L, cathode current density Dk 3A/dm
2, room temperature, time 15-30 minute.Add washing between two steps, washed from the beginning 1～2 fen, deionization washing 1～2 minute.
5. chemical nickel plating: single nickel salt 30g/L; Inferior sodium phosphate 40g/L; Complexing agent is an amount of; Stablizer is a small amount of; Wetting agent is a small amount of; Ammoniacal liquor (26%～28%) is an amount of; PH 6.0-7.0; Temperature 80-83 ℃; 3 hours time.
Claims (8)
1, on a kind of magnesium alloy as the two-step electro-zine method of chemical nickel plating intermediate layer, it is characterized in that: this method comprises the pretreatment process and the two-step electro-zine method of electro-galvanizing, and the pretreatment process of described electro-galvanizing comprises acid etching and two steps of alkaline activation; Described two-step electro-zine method is main salt at zinc sulfate earlier, and pyrophosphate salt is to electroplate skim zinc in the plating bath of main complexing agent, adopts the alkaline zinc plating liquid of being made up of sodium hydroxide and zinc oxide subsequently, further zinc-plated film is thickeied.
2, on the magnesium alloy as claimed in claim 1 as the two-step electro-zine method of chemical nickel plating intermediate layer, it is characterized in that: contain molybdate and phosphoric acid in the described acid etching solution formula; Contain molybdate and alkali in the described alkaline activation liquid, treatment temp is a room temperature.
3, on the magnesium alloy as claimed in claim 1 as the two-step electro-zine method of chemical nickel plating intermediate layer, it is characterized in that: it is inhibiter that the first step in the two-step electro-zine method also can add carbonate, fluorochemical is a stablizer.
4, as on claim 1 or the 3 described magnesium alloy as the two-step electro-zine method of chemical nickel plating intermediate layer, it is characterized in that: sulfur acid zinc 10～30g/L in the described electroplating zinc on magnesium alloy solution, pyrophosphate salt 40～120g/L, carbonate 2～10g/L, fluorochemical 3～15g/L.
5, on the magnesium alloy as claimed in claim 4 as the two-step electro-zine method of chemical nickel plating intermediate layer, it is characterized in that: the pH value of described electroplating zinc on magnesium alloy solution is 9～12, temperature 40-65 ℃, 3～20 minutes treatment times, current density 0.2～1.8A/dm
2
6, on the magnesium alloy as claimed in claim 1 as the two-step electro-zine method of chemical nickel plating intermediate layer, it is characterized in that: the used electro-galvanizing solution ZnO 10-20g/L of second step in the two-step electro-zine method, NaOH 100-120g/L, DE additive 3～5ml/L, cathode current density Dk 2-4A/dm
2, ambient operation, time 10-40 minute, add washing between two steps, washed deionization washing 1～2 minute from the beginning 1～2 fen.
7, on the magnesium alloy as claimed in claim 1 as the two-step electro-zine method of chemical nickel plating intermediate layer, it is characterized in that: with the two-step electro-zine layer is bottom, carries out chemical nickel plating thereon, used solution is as follows: single nickel salt 10-30g/L; Inferior sodium phosphate 20-40g/L; Complexing agent is an amount of; Stablizer is a small amount of; Wetting agent is a small amount of; Ammoniacal liquor 26%～28% is an amount of, its pH 6.0-7.0, temperature 80-85 ℃, 2～4 hours treatment times.
8, on the magnesium alloy as claimed in claim 1 as the two-step electro-zine method of chemical nickel plating intermediate layer, it is characterized in that: its treatment process comprises degreasing process, at least one washing step, the acid etching operation, at least one washing step, alkaline activation operation, at least one washing step, a step electro-zine operation, at least one washing step, two step electro-zines, at least one washing step, chemical nickel plating, at least one washing step, baking operation, degreasing process adopts ultrasonication.
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| CN101748354B (en) * | 2008-12-16 | 2011-08-31 | 上海宝钢设备检修有限公司 | Spray method of composite coating resisting corrosive wear of zinc solution |
| CN103706315A (en) * | 2013-12-24 | 2014-04-09 | 苏州纳微生物科技有限公司 | Preparation method of conductive micro-sphere applicable to conductive material |
| CN103882492A (en) * | 2014-02-24 | 2014-06-25 | 哈尔滨工程大学 | Chemical plating posttreatment method of metallic matrix |
| CN103898587A (en) * | 2013-06-04 | 2014-07-02 | 无锡市锡山区鹅湖镇荡口青荡金属制品厂 | Secondary galvanizing pretreatment process for electroplating nickel on surface of magnesium alloy |
| CN105463414A (en) * | 2015-11-25 | 2016-04-06 | 天津东义镁制品股份有限公司 | Fluoride-free chromium-free pretreatment method for magnesium alloy chemical plating |
| CN107513739A (en) * | 2017-07-26 | 2017-12-26 | 张家港市亚亨金属制品有限公司 | A kind of Nickel Pretreatment of magnesium alloy |
| CN109023460A (en) * | 2018-08-22 | 2018-12-18 | 哈尔滨工程大学 | A kind of method of magnesium lithium alloy electroplating surface zinc |
| CN109056016A (en) * | 2018-09-11 | 2018-12-21 | 乐清市正鑫金属件有限公司 | Electroplating double-layer zinc technology |
| CN110644016A (en) * | 2019-09-16 | 2020-01-03 | 燕山大学 | Preparation method of nickel phosphide-carbon cloth self-supporting electrode for hydrogen evolution by water and electricity dissociation |
| CN111603615A (en) * | 2020-06-08 | 2020-09-01 | 郑州大学 | Controllable degradable high-strength magnesium-based composite stent composite coating and preparation method thereof |
| CN117448741A (en) * | 2023-12-26 | 2024-01-26 | 泓欣科创生物科技(北京)有限公司 | Preparation method of coating for controlling degradation rate of biomedical material magnesium alloy and biomedical material magnesium alloy |
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- 2006-09-08 CN CNB2006100476916A patent/CN100485088C/en not_active Expired - Fee Related
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101748354B (en) * | 2008-12-16 | 2011-08-31 | 上海宝钢设备检修有限公司 | Spray method of composite coating resisting corrosive wear of zinc solution |
| CN103898587A (en) * | 2013-06-04 | 2014-07-02 | 无锡市锡山区鹅湖镇荡口青荡金属制品厂 | Secondary galvanizing pretreatment process for electroplating nickel on surface of magnesium alloy |
| CN103706315A (en) * | 2013-12-24 | 2014-04-09 | 苏州纳微生物科技有限公司 | Preparation method of conductive micro-sphere applicable to conductive material |
| CN103882492A (en) * | 2014-02-24 | 2014-06-25 | 哈尔滨工程大学 | Chemical plating posttreatment method of metallic matrix |
| CN103882492B (en) * | 2014-02-24 | 2016-08-24 | 哈尔滨工程大学 | Metallic matrix chemical plating pre-treating method |
| CN105463414A (en) * | 2015-11-25 | 2016-04-06 | 天津东义镁制品股份有限公司 | Fluoride-free chromium-free pretreatment method for magnesium alloy chemical plating |
| CN107513739A (en) * | 2017-07-26 | 2017-12-26 | 张家港市亚亨金属制品有限公司 | A kind of Nickel Pretreatment of magnesium alloy |
| CN109023460A (en) * | 2018-08-22 | 2018-12-18 | 哈尔滨工程大学 | A kind of method of magnesium lithium alloy electroplating surface zinc |
| CN109056016A (en) * | 2018-09-11 | 2018-12-21 | 乐清市正鑫金属件有限公司 | Electroplating double-layer zinc technology |
| CN110644016A (en) * | 2019-09-16 | 2020-01-03 | 燕山大学 | Preparation method of nickel phosphide-carbon cloth self-supporting electrode for hydrogen evolution by water and electricity dissociation |
| CN111603615A (en) * | 2020-06-08 | 2020-09-01 | 郑州大学 | Controllable degradable high-strength magnesium-based composite stent composite coating and preparation method thereof |
| CN117448741A (en) * | 2023-12-26 | 2024-01-26 | 泓欣科创生物科技(北京)有限公司 | Preparation method of coating for controlling degradation rate of biomedical material magnesium alloy and biomedical material magnesium alloy |
| CN117448741B (en) * | 2023-12-26 | 2024-03-22 | 泓欣科创生物科技(北京)有限公司 | Preparation method of coating for controlling degradation rate of biomedical material magnesium alloy and biomedical material magnesium alloy |
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