Method for preparing metal plating on magnesium alloy surface

A technology of metal coating and magnesium alloy, applied in metal material coating process, superimposed layer coating, coating and other directions, can solve the problems of large pollution, unstable process, complex process and so on

Inactive Publication Date: 2018-03-09
范晓明
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Using zinc-copper cyanide primer method is the earliest process for magnesium alloy to obtain metal coating, but the process is complicated and seriously polluted; recently, American experts and scholars have proposed that direct copper immersion on magnesium alloy (Luanetal, US Patent, 6669997B2) Or immersion zinc (Pearsonetal, US Patent, 0039829A1) instead of immersion zinc-copper cyanide process, although cyanide is not used, but the bonding force between the copper layer and the substrate obtained is not ideal; and basic nickel carbonate is used as the main salt electroless nickel plating , although avoiding the use of nickel sulfate and nickel chloride salts to bring SO 4 2- , Cl - The disadvantages of accelerated corrosion of the base magnesium alloy, but the use of basic nickel carbonate needs to be dissolved with HF acid, the pollution is large and the cost is high, and the process is not very stable, especially for the treatment of AZ91D magnesium alloy die castings.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0013] Grinding or polishing the surface of magnesium alloy, degreasing with organic solvent, chemical degreasing, pickling and activation, wherein the activation liquid formula used for activation is 5g / L of sodium pyrophosphate or potassium pyrophosphate, and 10g of sodium hypophosphite / L, the activation temperature is 55°C, and the activation time is 10s;

[0014] Carry out pre-electroless nickel plating on the magnesium alloy surface after pretreatment, the composition of pre-electroless nickel plating solution is: nickel hypophosphite 15g / L, sodium hypophosphite 20g / L, organic complexing agent 8g / L, malic acid 50g / L, Glycine 3g / L, Ammonium Hydrogen Fluoride 15g / L, Sodium Acetate 5g / L, Potassium Iodate 5ppm, Sodium Dodecyl Sulfonate 10mg / L; Pre-electroless nickel plating temperature is 70℃, pH=7, The time is 120min;

[0015] Thicken electroless nickel plating or electroplating other metals on the surface of magnesium alloy after pre-electroless nickel plating.

Embodiment 2

[0017] Grinding or polishing, organic solvent degreasing, chemical degreasing, pickling and activation are carried out on the surface of magnesium alloy. The activation liquid formula used for activation is 8g / L of sodium pyrophosphate or potassium pyrophosphate, and 7g of sodium hypophosphite / L, the activation temperature is 58°C, and the activation time is 8s;

[0018] Carry out pre-chemical nickel plating on the magnesium alloy surface after pretreatment, the composition of pre-chemical nickel plating solution is: nickel hypophosphite 20g / L, sodium hypophosphite 10g / L, organic complexing agent 16g / L, malic acid 30g / L, Glycine 4g / L, Ammonium Hydrogen Fluoride 10g / L, Sodium Acetate 8g / L, Potassium Iodate 4ppm, Sodium Dodecyl Sulfonate 20mg / L; Pre-electroless nickel plating temperature is 60℃, pH=8, The time is 60min;

[0019] Thicken electroless nickel plating or electroplating other metals on the surface of magnesium alloy after pre-electroless nickel plating.

Embodiment 3

[0021] Grinding or polishing the surface of magnesium alloy, degreasing with organic solvent, chemical degreasing, pickling and activation, wherein the activation liquid formula used for activation is 10g / L of sodium pyrophosphate or potassium pyrophosphate, and 5g of sodium hypophosphite / L, the activation temperature is 60°C, and the activation time is 5s;

[0022] Carry out pre-chemical nickel plating on the magnesium alloy surface after pretreatment, the composition of pre-chemical nickel plating solution is: nickel hypophosphite 30g / L, sodium hypophosphite 5g / L, organic complexing agent 30g / L, malic acid 10g / L, Glycine 5g / L, Ammonium Hydrogen Fluoride 5g / L, Sodium Acetate 10g / L, Potassium Iodate 3ppm, Sodium Dodecyl Sulfonate 30mg / L; Pre-electroless nickel plating temperature is 50℃, pH=10, The time is 30 minutes;

[0023] Thicken electroless nickel plating or electroplating other metals on the surface of magnesium alloy after pre-electroless nickel plating.

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PUM

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Abstract

A method for preparing a metal coating on the surface of a magnesium alloy, the method comprising the following steps: (1) performing pretreatment on the surface of the magnesium alloy; (2) performing pre-electroless nickel plating on the surface of the pre-treated magnesium alloy; The surface of the magnesium alloy after electroless nickel plating is thickened by electroless nickel plating or electroplated with other metals. The method of the present invention improves the bonding force between the pre-plating layer and the magnesium alloy substrate, and is tested by standard methods, and the bonding force between the pre-plating nickel layer and the substrate is good, reaching the national standard; further thickening the electroless nickel plating or electroplating on the pre-nickel layer For other metals, a metal decorative protective coating with strong bonding force and high corrosion resistance can be obtained.

Description

technical field [0001] The invention belongs to the field of anti-corrosion technology, in particular to a method for preparing a metal coating on the surface of a magnesium alloy. Background technique [0002] The traditional method of metal plating on the surface of magnesium and magnesium alloys is to dip zinc-copper cyanide as a primer, and then conventional electroplating or electroless nickel plating; or to use basic nickel carbonate as the main salt electroless nickel plating as a primer and then conventional electroplating. Using zinc-copper cyanide primer method is the earliest process for magnesium alloy to obtain metal coating, but the process is complicated and seriously polluted; recently, American experts and scholars have proposed that direct copper immersion on magnesium alloy (Luanetal, US Patent, 6669997B2) Or immersion zinc (Pearsonetal, US Patent, 0039829A1) instead of immersion zinc-copper cyanide process, although cyanide is not used, but the bonding fo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C23C28/02C23C18/36
CPCC23C28/023C23C18/36
Inventor 范晓明
Owner 范晓明
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