CN103938237A - Process for electroplating nickel on surface of magnesium alloy - Google Patents

Abstract

The invention discloses a process for electroplating nickel on the surface of a magnesium alloy, and is characterized in that the process comprises the following steps: alkali washing, pickling, activating, zinc immersion, zinc electroplating, and nickel electroplating. The zinc-immersion and zinc-electroplating secondary zinc plating process is adopted for nickel electroplating pretreatment, moreover, a zinc immersion solution, a zinc electroplating solution and a nickel electroplating solution are adjusted, and a copper plating process is not adopted, so that toxic and high-pollution components brought by cyanide electroplating of copper are avoided, the plating process is environmental friendly and safe, and a prepared plating layer is high in corrosion resistance, beautiful in appearance, and high in binding force of a matrix and the plating layer.

Description

A kind of electroplating nickel on surface of magnesium alloy technique

Technical field

The present invention relates to electroplating technology field, relate in particular to a kind of electroplating nickel on surface of magnesium alloy technique.

Background technology

Magnesium alloy, as a kind of lightweight engineered structured material, has high specific strength, high specific stiffness and superior damping performance, and field has a wide range of applications in fields such as traffic, communication, Aeronautics and Astronautics.But magnesium alloy chemical activity is high, and electropotential is low, surface film oxide is loose, causes barrier propterty low, has restricted the application and development of magnesium alloy.Caused thus the concern of people to magnesium alloy part surface corrosion and protection, at aspects such as Mg alloy surface anodic oxidation, chemical conversion film, organic coating, coating surfaces, carried out a large amount of research, particularly adopt that method for electroplating nickel is low as a kind of cost, technique is simple, the surface coating technique of easy handling, has become the important research direction of people to magnesium alloy surface protective.

At present, the electro-plating method of magnesium alloy could start to electroplate other metal after being mainly zinc-plated, pre-copper facing in advance, and most of for electroplating containing cyanogen.For example, what generally adopt both at home and abroad now is the standard method of the plated metal Ni of U.S. ASTM recommendation, the zinc plating method of soaking of ShiDow company exploitation, and its pre-treatment has adopted soaks zinc and cyanide copper plating technique.Yet, this complex technical process, repeatability is poor, uses prussiate, and plating solution is poisonous, contaminate environment, the bright property of coating and the stability of plating solution also need further improvement.

In order to overcome the shortcoming of complex process, software engineering researchers invent has gone out direct electroless nickel method, as adopted chromic anhydride to carry out etch to magnesium alloy in JP2003073843, after fluorochemical activation, carry out chemical nickel plating, with ammoniacal liquor, regulate chemical nickel-plating liquid to make it be weakly alkaline, once obtained bonding force good, the chemical Ni-plating layer that solidity to corrosion is high, the high employing in patent CN1699634A magnesium alloy plating method of Li De goes wadding → electrochemical deoiling → bright dipping → neutralization → activation → pre-zincincation to obtain reasonable pre-zinc coating, and pre-galvanizing flux is without cyanogen, nontoxic, harmless, the people such as Yang Noboru are in patent CN1737205A, by Direct Electroplating aluminium after the dense hydrofluoric acid of used for magnesium alloy (11%) pickling, obtain reasonable aluminium coat, Chinese patent CN1641075A is to magnesium, the surface of magnesium alloy or activating treatment process and plated surface method were done detailed description, although these techniques have all departed from prussiate plating, but the mostly improvement based on to the technique of DOW for the treatment of process before electroplating.

Summary of the invention

The object of the invention is to propose a kind of electroplating nickel on surface of magnesium alloy technique, this process using is soaked zinc, electro-galvanizing secondary plating zinc technology carries out electronickelling pre-treatment, and by soaking the adjustment of zinc, electro-galvanizing plating solution and electronickelling bath composition, do not adopt poisonous, pollute high component, make plating technic Environmental Safety, and the corrosion-resistant height of coating of preparation, appearance looks elegant, matrix and binding force of cladding material are high.

For reaching this object, the present invention by the following technical solutions:

An electroplating nickel on surface of magnesium alloy technique, described technique comprises the steps: alkali cleaning → pickling → activate → soak zinc → electro-galvanizing → electronickelling, wherein

Soak zinc: zincate solution consists of: zinc sulfate 32-36g/L, potassium pyrophosphate 200-210g/L, sodium carbonate 8-10g/L, Potassium monofluoride 3-5g/L; Ammonium bifluoride 2-3g/L, surplus is water; Technique is: pH value: 10.5-11.0, temperature: 63-65 ℃, time: 3-5min;

Electro-galvanizing: electro-galvanizing plating solution consists of: ZnSO ₄7H ₂o32-36g/L, K ₄p ₂o ₇3H ₂o164-168g/L, KF18-20g/L, C ₆h ₁₇o ₇n ₃32-36g/L, phytic acid 0.4-0.6g/L, H ₂cSNH ₂: 4-6g/L, surplus is water; Technique is: take pure zinc as anode, electroplating temperature: 35-45 ℃, electroplating time 30-40min, current density: 2-3A/dm ²;

Electronickelling: plating solution consists of: single nickel salt 250-270g/L, nickelous chloride 25-35g/L, boric acid 52-56g/L, potassium sulfate 20-26g/L, sodium laurylsulfonate 0.5-1.5g/L, anhydrous sodium acetate 36-40g/L, ethoxyquin butynediol 30-40mg/L, propionic acid 3-4g/L, surplus is water; Processing condition are: pH value 3.5-4.5; Current density 2.5-3.5A/dm ², temperature 65-75 ℃, time 20-30min.

The present invention has advantages of:

Zinc is soaked in employing, electro-galvanizing secondary plating zinc technology carries out electronickelling pre-treatment, and by soaking the adjustment of zinc, galvanization liquid and electronickelling bath composition, do not adopt copper-plating technique, avoid thus being brought by cyanide electroplating poisonous, pollute high component, make plating technic Environmental Safety, and the corrosion-resistant height of coating of preparation, appearance looks elegant, matrix and binding force of cladding material are high.

Embodiment

Embodiment mono-

An electroplating nickel on surface of magnesium alloy technique, described technique comprises the steps: alkali cleaning → pickling → activate → soak zinc → electro-galvanizing → electronickelling, wherein

Soak zinc: zincate solution consists of: zinc sulfate 32g/L, potassium pyrophosphate 210g/L, sodium carbonate 8g/L, Potassium monofluoride 5g/L; Ammonium bifluoride 2g/L, surplus is water; Technique is: pH value: 10.5-11.0, temperature: 63-65 ℃, time: 3min;

Electro-galvanizing: electro-galvanizing plating solution consists of: ZnSO ₄7H ₂o32g/L, K ₄p ₂o ₇3H ₂o168g/L, KF18g/L, C ₆h ₁₇o ₇n ₃32g/L, phytic acid 0.6g/L, H ₂cSNH ₂: 4g/L, surplus is water; Technique is: take pure zinc as anode, electroplating temperature: 35-45 ℃, electroplating time 30min, current density: 2-3A/dm ²;

Electronickelling: plating solution consists of: single nickel salt 250g/L, nickelous chloride 35g/L, boric acid 52g/L, potassium sulfate 26g/L, sodium laurylsulfonate 0.5g/L, anhydrous sodium acetate 40g/L, ethoxyquin butynediol 30mg/L, propionic acid 4g/L, surplus is water; Processing condition are: pH value 3.5-4.5; Current density 2.5-3.5A/dm ², temperature 65-75 ℃, time 20min.

Embodiment bis-

An electroplating nickel on surface of magnesium alloy technique, described technique comprises the steps: alkali cleaning → pickling → activate → soak zinc → electro-galvanizing → electronickelling, wherein

Soak zinc: zincate solution consists of: zinc sulfate 36g/L, potassium pyrophosphate 200g/L, sodium carbonate 10g/L, Potassium monofluoride 3g/L; Ammonium bifluoride 3g/L, surplus is water; Technique is: pH value: 10.5-11.0, temperature: 63-65 ℃, time: 3min;

Electro-galvanizing: electro-galvanizing plating solution consists of: ZnSO ₄7H ₂o36g/L, K ₄p ₂o ₇3H ₂o164g/L, KF20g/L, C ₆h ₁₇o ₇n ₃32g/L, phytic acid 0.6g/L, H ₂cSNH ₂: 4g/L, surplus is water; Technique is: take pure zinc as anode, electroplating temperature: 35-45 ℃, electroplating time 40min, current density: 2-3A/dm ²;

Electronickelling: plating solution consists of: single nickel salt 270g/L, nickelous chloride 25g/L, boric acid 56g/L, potassium sulfate 20g/L, sodium laurylsulfonate 1.5g/L, anhydrous sodium acetate 36g/L, ethoxyquin butynediol 40mg/L, propionic acid 3g/L, surplus is water; Processing condition are: pH value 3.5-4.5; Current density 2.5-3.5A/dm ², temperature 65-75 ℃, time 30min.

Embodiment tri-

An electroplating nickel on surface of magnesium alloy technique, described technique comprises the steps: alkali cleaning → pickling → activate → soak zinc → electro-galvanizing → electronickelling, wherein

Soak zinc: zincate solution consists of: zinc sulfate 34g/L, potassium pyrophosphate 205g/L, sodium carbonate 9g/L, Potassium monofluoride 4g/L; Ammonium bifluoride 2.5g/L, surplus is water; Technique is: pH value: 10.5-11.0, temperature: 63-65 ℃, time: 4min;

Electro-galvanizing: electro-galvanizing plating solution consists of: ZnSO ₄7H ₂o34g/L, K ₄p ₂o ₇3H ₂o166g/L, KF19g/L, C ₆h ₁₇o ₇n ₃33g/L, phytic acid 0.5g/L, H ₂cSNH ₂: 5g/L, surplus is water; Technique is: take pure zinc as anode, electroplating temperature: 35-45 ℃, electroplating time 35min, current density: 2-3A/dm ²;

Electronickelling: plating solution consists of: single nickel salt 260g/L, nickelous chloride 30g/L, boric acid 54g/L, potassium sulfate 23g/L, sodium laurylsulfonate 1.0g/L, anhydrous sodium acetate 38g/L, ethoxyquin butynediol 35mg/L, propionic acid 3.5g/L, surplus is water; Processing condition are: pH value 3.5-4.5; Current density 2.5-3.5A/dm ², temperature 65-75 ℃, time 25min.

Claims (1)

1. an electroplating nickel on surface of magnesium alloy technique, is characterized in that, described technique comprises the steps: alkali cleaning → pickling → activate → soak zinc → electro-galvanizing → electronickelling, wherein

Soak zinc: zincate solution consists of: zinc sulfate 32-36g/L, potassium pyrophosphate 200-210g/L, sodium carbonate 8-10g/L, Potassium monofluoride 3-5g/L; Ammonium bifluoride 2-3g/L, surplus is water; Technique is: pH value: 10.5-11.0, temperature: 63-65 ℃, time: 3-5min;

Electro-galvanizing: electro-galvanizing plating solution consists of: ZnSO ₄7H ₂o32-36g/L, K ₄p ₂o ₇3H ₂o164-168g/L, KF18-20g/L, C ₆h ₁₇o ₇n ₃32-36g/L, phytic acid 0.4-0.6g/L, H ₂cSNH ₂: 4-6g/L, surplus is water; Technique is: take pure zinc as anode, electroplating temperature: 35-45 ℃, electroplating time 30-40min, current density: 2-3A/dm ²;

Electronickelling: plating solution consists of: single nickel salt 250-270g/L, nickelous chloride 25-35g/L, boric acid 52-56g/L, potassium sulfate 20-26g/L, sodium laurylsulfonate 0.5-1.5g/L, anhydrous sodium acetate 36-40g/L, ethoxyquin butynediol 30-40mg/L, propionic acid 3-4g/L, surplus is water; Processing condition are: pH value 3.5-4.5; Current density 2.5-3.5A/dm ², temperature 65-75 ℃, time 20-30min.