CN103668354A - Cyanide-free magnesium alloy electroplating process - Google Patents

Abstract

The invention discloses a cyanide-free magnesium alloy electroplating process. The process comprises the following steps: (1) pretreatment; (2) acidic copper-containing solution treatment, namely soaking the pretreated magnesium alloy in an acidic copper-containing solution for 2-3 minutes, wherein the acidic copper-containing solution is composed of 60-80 g/L of copper salt, 10-16 g/L of acetic acid, 8-12 g/L of citric acid, 20-24 g/L of hydroxy ethidene phosphonic acid (HEDP) and 1-2 g/L of lauryl sodium sulfate, and the temperature of the solution is 66-70 DEG C, and then, washing the magnesium alloy with water; (3) pyrophosphate coppering, namely carrying out pyrophosphate coppering treatment on the magnesium alloy treated in the step (2), wherein the plating solution ingredients and process conditions of the pyrophosphate coppering are as follows: 50-54 g/L of Cu<2+>, 420-460 g/L of P2O7<4+>, 40-50 g/L of potassium citrate, 1.0-1.2 ml/L of ammonia water and a proper amount of mercapto benzimidazole are plating solution ingredients, the temperature is 35-50 DEG C, the pH is 8.5-9.5, the current density is 0.5-2.5 A/dm<2>, and the electroplating time is 6-8 minutes; (4) post treatment.

Description

A kind of magnesium alloy cyanogenless electroplating technology

Technical field

The present invention relates to field of electroplating, particularly a kind of magnesium alloy cyanogenless electroplating technology.

Background technology

Magnesium alloy is lightweight owing to having, high specific tenacity and specific rigidity, good shaping thin wall performance and renewable performance, heat conductivity, and good electromagnetic shielding action, the very high advantages such as anti-electromagnetic interference (EMI) performance, are widely used in fields such as defence and military, communications and transportation, opticinstrument, electronics housing.The maximum purposes of magnesium alloy is the use as die casting on automobile, notebook computer and other miniature electrical equipment, and the damping of automotive industry and light energy conservation impel magnesium alloy constantly to increase in the ratio aspect manufacture automobile component.Also there is the portable electronic equipment of a large amount of use magnesium alloy in communication and electron trade, as products such as Cell phone, portable computer and small-sized Video Cameras.In recent years, the application of magnesium alloy in electronic product, automobile component had the irreplaceable effect of other material, and its consumption with 20% rate increase, is called as " time substituting metal " and " 21 century metal " every year.

Yet the electrode potential of magnesium is low, chemically reactive is high.In malaria, sulfur-bearing atmosphere and marine atmosphere, all can suffer serious galvanic corrosion, this has hindered magnesium-alloy material and in application, has brought into play its advantage, has limited its range of application.For overcoming the above-mentioned defect of magnesium alloy, in many environment, need to use anti-corrosion metal and alloy thereof as the protective layer of protection magnesium alloy, but magnesium alloy is a kind of base material of difficult plating, on its surface, directly electroplate or the suitable difficulty of electroless plating.

Domestic and international report, for magnesium alloy surface protective comparatively proven technique be Dow soak Zn cyaniding plating Cu bottoming and direct electroless plating technique.The technical process of soaking Zn technique of YouDow company exploitation is: surface treatment → activation → soak Zn → cyaniding to plate Cu → chemical Ni-P plating.But contain the prussiates such as a large amount of CuCN, KCN, NaCN in the plating solution in this technique during cyanide electroplating bottoming, toxicity is large, and environmental pollution is serious, aftertreatment trouble; And inapplicable to measuring high alloy containing Al.The method that adopts direct electroless plating Ni-P, its technique is simple, containing prussiate, come into one's own gradually, but that the bonding force of coating and matrix is not so good as the plating piece of cyanide electroplating bottoming is high in plating solution.

Summary of the invention

For the deficiencies in the prior art, one of object of the present invention is to provide a kind of magnesium alloy cyanogenless electroplating technology.This technique can substitute the technique of cyanide electroplating, to solve the environmental pollution causing because of cyanide electroplating, reduces the processing cost of electroplating wastewater, improves economic and social benefit.

For achieving the above object, the present invention adopts following technical scheme:

A magnesium alloy cyanogenless electroplating technology, this technique comprises the steps:

(1) pre-treatment: by magnesium alloy through electrochemical deoiling 6-10 minute, catholyte oil removing 2-4 minute;

(2) acid copper-containing solution is processed: the magnesium alloy after pre-treatment is put in acid copper-containing solution processing and soaks 2-3 minute, acid copper-containing solution consist of mantoquita 60-80g/L, acetic acid 10-16g/L, citric acid 8-12g/L, hydroxy ethylene diphosphonic acid (HEDP) 20-24g/L, sodium lauryl sulphate 1-2g/L, solution temperature is 66-70 ℃, then washing;

(3) pyrophosphate copper plating: the magnesium alloy after step (2) is processed is carried out to pyrophosphate copper plating processing, and solution composition and the processing condition of pyrophosphate copper plating are: Cu ²⁺50-54g/L, P ₂o ₇ ⁴⁺420-460g/L, Tripotassium Citrate 40-50g/L, ammoniacal liquor 1.0-1.2mL/L, mercaptobenzimidazole is appropriate, and temperature is 35-50 ℃, and pH is 8.5-9.5, and current density is 0.5-2.5A/dm ², electroplating time is 6-8 minute;

(4) then adopt common process to carry out acid copper-plating and bright nickel plating;

(5) in retort furnace, with stove, be warming up to 1 30-140 ℃ and be incubated 15-25min, be cooled to room temperature.

Electroplating technology of the present invention has following beneficial effect:

The invention after pre-treatment, carry out acid copper-containing solution processing, strengthened the bonding force of subsequent plating layer and matrix, and the consequence of having avoided cyanide electroplating bottoming to cause environment to be heavily polluted, be a kind of environment-protective process; After follow-up plating, obtain the metallic coating that bonding force is strong, coating film thickness is even, and solidity to corrosion is high.Metallic coating has good conduction, heat conduction and anti-electromagnetic interference capability; The raw material using in technique of the present invention, low price, low production cost, economic benefit obviously improves; Metallising process of the present invention is simple, and the composition of solution is few, is easy to control process stabilizing.

Embodiment

Embodiment mono-

A magnesium alloy cyanogenless electroplating technology, this technique comprises the steps:

(1) pre-treatment: by magnesium alloy through electrochemical deoiling 6 minutes, catholyte oil removing 4 minutes;

(2) acid copper-containing solution is processed: the magnesium alloy after pre-treatment is put in acid copper-containing solution processing and is soaked 2 minutes, acid copper-containing solution consist of mantoquita 80g/L, acetic acid 10g/L, citric acid 12g/L, hydroxy ethylene diphosphonic acid (HEDP) 20g/L, sodium lauryl sulphate 2g/L, solution temperature is 66 ℃, then washing;

(3) pyrophosphate copper plating: the magnesium alloy after step (2) is processed is carried out to pyrophosphate copper plating processing, and solution composition and the processing condition of pyrophosphate copper plating are: Cu ²⁺50g/L, P ₂o ₇ ⁴⁺460g/L, Tripotassium Citrate 40g/L, ammoniacal liquor 1.2mL/L, mercaptobenzimidazole is appropriate, and temperature is 35 ℃, and pH is 9.5, and current density is 0.5A/dm ², electroplating time is 8 minutes;

(4) then adopt common process to carry out acid copper-plating and bright nickel plating;

(5) in retort furnace, with stove, be warming up to 1 30 ℃ and be incubated 25min, be cooled to room temperature.

Embodiment bis-

A magnesium alloy cyanogenless electroplating technology, this technique comprises the steps:

(1) pre-treatment: by magnesium alloy through electrochemical deoiling 10 minutes, catholyte oil removing 2 minutes;

(2) acid copper-containing solution is processed: the magnesium alloy after pre-treatment is put in acid copper-containing solution processing and is soaked 3 minutes, acid copper-containing solution consist of mantoquita 60g/L, acetic acid 16g/L, citric acid 8g/L, hydroxy ethylene diphosphonic acid (HEDP) 24g/L, sodium lauryl sulphate 1g/L, solution temperature is 70 ℃, then washing;

(3) pyrophosphate copper plating: the magnesium alloy after step (2) is processed is carried out to pyrophosphate copper plating processing, and solution composition and the processing condition of pyrophosphate copper plating are: Cu ²⁺54g/L, P ₂o ₇ ⁴⁺420g/L, Tripotassium Citrate 50g/L, ammoniacal liquor 1.0mL/L, mercaptobenzimidazole is appropriate, and temperature is 50 ℃, and pH is 8.5, and current density is 2.5A/dm ², electroplating time is 6 minutes;

(4) then adopt common process to carry out acid copper-plating and bright nickel plating;

(5) in retort furnace, with stove, be warming up to 140 ℃ and be incubated 15min, be cooled to room temperature.

Embodiment tri-

A magnesium alloy cyanogenless electroplating technology, this technique comprises the steps:

(1) pre-treatment: by magnesium alloy through electrochemical deoiling 8 minutes, catholyte oil removing 3 minutes;

(2) acid copper-containing solution is processed: the magnesium alloy after pre-treatment is put in acid copper-containing solution processing and is soaked 2.5 minutes, acid copper-containing solution consist of mantoquita 70g/L, acetic acid 13g/L, citric acid 10g/L, hydroxy ethylene diphosphonic acid (HEDP) 22g/L, sodium lauryl sulphate 1.5g/L, solution temperature is 68 ℃, then washing;

(3) pyrophosphate copper plating: the magnesium alloy after step (2) is processed is carried out to pyrophosphate copper plating processing, and solution composition and the processing condition of pyrophosphate copper plating are: Cu ²⁺52g/L, P ₂o ₇ ⁴⁺440g/L, Tripotassium Citrate 45g/L, ammoniacal liquor 1.1mL/L, mercaptobenzimidazole is appropriate, and temperature is 450 ℃, and pH is 9.0, and current density is 1.5A/dm ², electroplating time is 7 minutes;

(4) then adopt common process to carry out acid copper-plating and bright nickel plating;

(5) in retort furnace, with stove, be warming up to 135 ℃ and be incubated 20min, be cooled to room temperature.

Applicant's statement, the present invention illustrates detailed process equipment and process flow process of the present invention by above-described embodiment, but the present invention is not limited to above-mentioned detailed process equipment and process flow process, do not mean that the present invention must rely on above-mentioned detailed process equipment and process flow process and could implement.Person of ordinary skill in the field should understand, any improvement in the present invention, to the selection of the interpolation of the equivalence replacement of each raw material of product of the present invention and ancillary component, concrete mode etc., within all dropping on protection scope of the present invention and open scope.

Claims (1)

1. a magnesium alloy cyanogenless electroplating technology, this technique comprises the steps:

(1) pre-treatment: by magnesium alloy through electrochemical deoiling 6-10 minute, catholyte oil removing 2-4 minute;

(2) acid copper-containing solution is processed: the magnesium alloy after pre-treatment is put in acid copper-containing solution processing and soaks 2-3 minute, acid copper-containing solution consist of mantoquita 60-80g/L, acetic acid 10-16g/L, citric acid 8-12g/L, hydroxy ethylene diphosphonic acid (HEDP) 20-24g/L, sodium lauryl sulphate 1-2g/L, solution temperature is 66-70 ℃, then washing;

(3) pyrophosphate copper plating: the magnesium alloy after step (2) is processed is carried out to pyrophosphate copper plating processing, and solution composition and the processing condition of pyrophosphate copper plating are: Cu ²⁺50-54g/L, P ₂o ₇ ⁴⁺420-460g/L, Tripotassium Citrate 40-50g/L, ammoniacal liquor 1.0-1.2mL/L, mercaptobenzimidazole is appropriate, and temperature is 35-50 ℃, and pH is 8.5-9.5, and current density is 0.5-2.5A/dm ², electroplating time is 6-8 minute;

(4) then adopt common process to carry out acid copper-plating and bright nickel plating;

(5) in retort furnace, with stove, be warming up to 130-140 ℃ and be incubated 15-25min, be cooled to room temperature.