CN102400203B - Chromium plating anode of trivalent chromium chloride system - Google Patents

Abstract

The invention discloses a chromium plating anode of a trivalent chromium chloride system and provides a chromium plating anode of a trivalent chromium chloride system. The chromium plating anode contains ruthenium, iridium and titanium, has certain mechanical strength, and can be used for overcoming the defect that the chromium plating graphite anode of the traditional trivalent chromium chloride system is easy to fracture and cannot be processed and molded into the anode of complex shape easily. The chromium plating anode disclosed by the invention further has the advantages of strong dispersive power and covering power and corrosion resistance, and can be widely applied to the electroplating process for the trivalent chromium chloride system.

Description

A kind of trivalent chromium chloride system chromium plating anode

technical field

The invention relates to the field of electroplating, in particular to a trivalent chromium chloride system chromium plating anode.

Background technique

Chromium has excellent decorative and functional properties. The most common industrial process currently used is hexavalent chromium plating, but hexavalent chromium is extremely harmful. The World Health Organization, Europe and the United States are paying more and more attention to the hazards of hexavalent chromium, and continue to reduce the discharge standards of hexavalent chromium wastewater. Trivalent chromium electroplating, as the most important, direct and effective alternative to hexavalent chromium electroplating, has incomparable advantages over hexavalent chromium electroplating in terms of process performance and environmental protection. For example, the pollution of trivalent chromium plating solution is relatively small, its toxicity is only 1% of hexavalent chromium, no harmful chromic acid mist is produced during electroplating, and the concentration of the plating solution is low, and the sewage treatment is simple. As long as the pH of the wastewater is adjusted to above 8, That is, Cr(OH) ₃ is precipitated; theoretically, under the same current density, the electrodeposition speed of trivalent chromium can reach twice that of hexavalent chromium, and its plating solution dispersion and coverage are better than chromic acid plating solution , the bright current density range is relatively wide, suitable for chrome plating of parts with more complex shapes; the current efficiency of trivalent chromium is higher than that of hexavalent chromium plating, which can reach 25%; the trivalent chromium process can be used on zinc, zinc die-casting parts or titanium. Direct chrome plating, barrel chrome plating is also available; trivalent chromium plating solution can work at room temperature, saving energy; trivalent chromium plating is a continuous micro-cracked chromium, the corrosion resistance is higher than that of chromic acid chromium plating, and the hardness is not lower than that of chromic acid chromium plating ; Wide range of current density, 015 ~ 100A/dm ² ; Not affected by current interruption.

However, the trivalent chromium chloride system chrome-plated anode is usually made of graphite material, because graphite is brittle and easy to break, it is not easy to process into an anode with complex shape.

Therefore, it is of great significance to develop a trivalent chromium chloride system chromium plating anode that is easy to form and has certain mechanical strength.

Contents of the invention

In view of the above problems, the object of the present invention is to provide a trivalent chromium chloride system chromium-plated anode, which is easy to form and has a certain mechanical strength, which can overcome the existing trivalent chromium chloride system chromium-plated graphite anode which is easy to break and is not easy to process into complex shapes. Disadvantages of anodes.

The invention is realized through the following technical means: a trivalent chromium chloride system chromium-plated anode, the anode core is graphite, and the surface of the anode is covered with ruthenium, iridium and titanium metals.

The present invention can also do following improvement:

The content of the metal ruthenium is 5-150 grams/square meter; the metal iridium content is 5-150 grams/square meter; the metal titanium content is 5-150 grams/square meter.

The content of the metal ruthenium is 30-110 grams/square meter; the metal iridium content is 30-110 grams/square meter; the metal titanium content is 30-110 grams/square meter.

The trivalent chromium chloride system chromium plating, in addition to using the anode of the present invention, other can be various trivalent chromium chloride system chromium plating electroplating solutions and process conditions conventionally used in this field.

Compared with the prior art, the beneficial effects of the present invention are: 1) It has certain mechanical strength and is not easy to break. Tensile strength ≥ 420MPa; Yield strength: ≥ 355Mpa.

2) The trivalent chromium chloride system chromium-plated anode used in the present invention has little pollution and low toxicity.

3) It can be seen from the comparative examples that the trivalent chromium chloride system chromium-plated anode of the present invention has the advantages of strong dispersion ability and strong covering ability.

4) It can be seen from the comparative examples that a trivalent chromium chloride system chromium-plated anode of the present invention has the advantage of corrosion resistance.

Detailed ways

The present invention will be further described in detail below in conjunction with the examples, but it does not constitute any limitation to the present invention.

Example 1

A kind of trivalent chromium chloride system chromium-plated anode of the present invention, take graphite anode, specification is: length 12 centimeters, width 5 centimeters, thickness 0.2 centimeters, surface covering metal ruthenium content is 30 grams/square meter, metal iridium content is 30 grams/square meter, the metal titanium content is 30 grams/square meter, and the anode A1 is obtained.

Example 2

A kind of trivalent chromium chloride system chromium-plated anode of the present invention, take graphite anode, specification is: length 12 centimeters, width 5 centimeters, thickness 0.2 centimeters, surface covering metal ruthenium content is 70 grams/square meter, metal iridium content is 70 grams/square meter, the metal titanium content is 70 grams/square meter, and the anode A2 is obtained.

Example 3

A kind of trivalent chromium chloride system chromium-plated anode of the present invention, take graphite anode, specification is: length 12 centimeters, width 5 centimeters, thickness 0.2 centimeters, surface covering metal ruthenium content is 110 grams/square meter, metal iridium content is 110 grams/square meter, the metal titanium content is 110 grams/square meter, and the anode A3 is obtained.

Example 4

A kind of trivalent chromium chloride system chromium-plated anode of the present invention, take graphite anode, specification is: length 12 centimeters, width 5 centimeters, thickness 0.2 centimeters, surface covering metal ruthenium content is 30 grams/square meter, metal iridium content is 110 grams/square meter, the metal titanium content is 110 grams/square meter, and the anode A4 is obtained.

Example 5

A kind of trivalent chromium chloride system chromium-plated anode of the present invention, take graphite anode, specification is: length 12 centimeters, width 5 centimeters, thickness 0.2 centimeters, surface covering metal ruthenium content is 30 grams/square meter, metal iridium content is 110 grams/square meter, the metal titanium content is 30 grams/square meter, and the anode A5 is obtained.

Example 6

A kind of trivalent chromium chloride system chromium-plated anode of the present invention, take graphite anode, specification is: length 12 centimeters, width 5 centimeters, thickness 0.2 centimeters, surface covering metal ruthenium content is 30 grams/square meter, metal iridium content is 70 grams/square meter, the metal titanium content is 30 grams/square meter, and the anode A6 is obtained.

Example 7

A kind of trivalent chromium chloride system chromium-plated anode of the present invention, take graphite anode, specification is: length 12 centimeters, width 5 centimeters, thickness 0.2 centimeters, surface covering metal ruthenium content is 30 grams/square meter, metal iridium content is 70 grams/square meter, the metal titanium content is 70 grams/square meter, and the anode A7 is obtained.

Example 8

A kind of trivalent chromium chloride system chromium-plated anode of the present invention, take graphite anode, specification is: length 12 centimeters, width 5 centimeters, thickness 0.2 centimeters, surface covering metal ruthenium content is 70 grams/square meter, metal iridium content is 30 grams/square meter, the metal titanium content is 110 grams/square meter, and the anode A8 is obtained.

Example 9

A kind of trivalent chromium chloride system chromium-plated anode of the present invention, take graphite anode, specification is: length 12 centimeters, width 5 centimeters, thickness 0.2 centimeters, surface covering metal ruthenium content is 70 grams/square meter, metal iridium content is 70 grams/square meter, the metal titanium content is 110 grams/square meter, and the anode A9 is obtained.

Example 10

A kind of trivalent chromium chloride system chromium-plated anode of the present invention, take graphite anode, specification is: length 12 centimeters, width 5 centimeters, thickness 0.2 centimeters, surface covering metal ruthenium content is 5 grams/square meter, metal iridium content is 5 grams/square meter, the metal titanium content is 150 grams/square meter, and the anode A10 is obtained.

Example 11

A kind of trivalent chromium chloride system chromium-plated anode of the present invention, take graphite anode, specification is: length 12 centimeters, width 5 centimeters, thickness 0.2 centimeters, surface covering metal ruthenium content is 150 grams/square meter, metal iridium content is 150 grams/square meter, the metal titanium content is 5 grams/square meter, and the anode A11 is obtained.

Example 12

A kind of trivalent chromium chloride system chromium-plated anode of the present invention, take graphite anode, specification is: length 12 centimeters, width 5 centimeters, thickness 0.2 centimeters, surface covering metal ruthenium content is 150 grams/square meter, metal iridium content is 150 grams/square meter, the metal titanium content is 150 grams/square meter, and the anode A12 is obtained.

Example 13

A kind of trivalent chromium chloride system chromium-plated anode of the present invention, take graphite anode, specification is: length 12 centimeters, width 5 centimeters, thickness 0.2 centimeters, surface covering metal ruthenium content is 5 grams/square meter, metal iridium content is 5 grams/square meter, the content of metal titanium is 5 grams/square meter, and the anode A13 is obtained.

comparative example

A trivalent chromium chloride system chrome-plated graphite anode routinely used in the field is used, and the specifications are: length 12 cm, width 5 cm, and thickness 0.2 cm, to obtain anode B1.

The composition of the electroplating solution used is: chromium sulfate 120 g/L, potassium bromide 15 g/L, potassium chloride 200 g/L, boric acid 55 g/L, sodium formate 8 g/L, ammonium acetic acid 10 g/L, sulfur Base succinate 0.2 g/L, polyol surfactant 0.6 g/L. The direct current is 8 amps, the pH is 2.8, and the temperature is under the condition of 35 ° C. The anodes of Examples 1-13 and Comparative Examples are respectively carried out in a Hall cell with a volume of 267 milliliters for 2 minutes. , the cathode is a standard bronze sheet (10 cm * 7 cm) plated with bright nickel. The performance of the anode is evaluated from three indicators: the appearance of the coating, the bright range of the coating, and the appearance of the anode. The test results are shown in Table 1.

Table 1 Performance evaluation table of different anodes

Example number Anode No. Plating Appearance Coating brightness range Anode Appearance Example 1 A1 bright white 8.2 cm No corrosion defects Example 2 A2 bright white 8.5 cm No corrosion defects Example 3 A3 bright white 8.4 cm No corrosion defects Example 4 A4 bright white 8.6 cm No corrosion defects

Example 5 A5 bright white 8.5 cm No corrosion defects Example 6 A6 bright white 8.3 cm No corrosion defects Example 7 A7 bright white 8.1 cm No corrosion defects Example 8 A8 bright white 8.7 cm No corrosion defects Example 9 A9 bright white 8.3 cm No corrosion defects Example 10 A10 bright white 8.4 cm No corrosion defects Example 11 A11 bright white 8.2 cm No corrosion defects Example 12 A12 bright white 8.5 cm No corrosion defects Example 13 A13 bright white 8.0 cm No corrosion defects comparative example B bright white 7.8 cm There is a small amount of graphite hanging ash

As can be seen from the test results shown in Table 1, compared with the anode of the comparative example, the bright coating of the embodiment 1-13 anode reaches more than 8 centimeters, and the highest reaches 8.7 centimeters, which is greater than the 7.8 centimeters of the comparative example. centimeter. And there is no corrosion defect in the appearance of Examples 1-13, and a small amount of graphite ash on the appearance of the comparative example, indicating that the anode used in the present invention is suitable for the anode of trivalent chromium chloride system and has the advantages of large bright coating range and corrosion resistance.

The above-mentioned embodiments are only preferred embodiments of the present invention, and cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the patent scope of the present invention still fall within the scope of the present invention.

Claims (2)

1. a chromium plating anode of trivalent chromium chloride system, described anode core is graphite, it is characterized in that: described anode surface is coated with ruthenium, iridium, titanium metal; Described metal Ru content is 5-150 gram/m; Metal iridium content is 5-150 gram/m; Metal titanium content is 5-150 gram/m.

2. a kind of chromium plating anode of trivalent chromium chloride system according to claim 1, is characterized in that: described metal Ru content is 30-110 gram/m; Metal iridium content is 30-110 gram/m; Metal titanium content is 30-110 gram/m.