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Machinery Industry Standard of the People's Republic of China
JB/T7507-94
General Technical Specification for Brush Plating
1994-10-25 Issued
Ministry of Machinery Industry of the People's Republic of China
1995-10-01 Implementation
Mechanical Industry Standard of the People's Republic of China
General Technical Specification for Brush Plating
1 Subject Content and Scope of Application
This standard specifies the technical requirements for brush plating equipment, materials, processes and brush plating layers. JB/T7507-94
This standard is applicable to brush plating of various metal and alloy coatings on workpieces such as steel, cast iron, iron alloys, aluminum and aluminum alloys, copper and copper alloys, nickel and nickel-chromium alloys.
2 Reference Standards
GB5270 Test Method for Adhesion Strength of Metal Covering Layer (Electrodeposited Layer and Chemical Deposited Layer) on Metal Substrate 3 Terminology
3.1 Brush Plating
The electroplating process completed by wrapping the anode with a layer of insulating material that can absorb the plating solution as a plating brush, and keeping in contact with the workpiece (cathode) and making relative motion under the condition that the plating brush is saturated with the plating solution and keeps in contact with the workpiece (cathode), is called brush plating. 3.2 Power Consumption Coefficient
Indicates the power (Ah) value consumed by a certain plating solution to brush plate a 1μm thick bond layer on an area of 1dm. 4 Equipment and Tooling
Brush Plating Rectifier: Output voltage 18~36V: With positive and negative pole reversing device; With overload protection device; Equipped with ampere-hour meter. 4.2 General machine tool or turntable.
Plating solution circulation device.
4.4 Plating: Mainly composed of anode, sheath and other components. 4.4.1 Anode
The pictographic anode should be designed according to the shape of the workpiece to be plated. 4.4. 1.15
4.4.1.2 Anode materials are divided into two categories: insoluble and soluble. Insoluble anode materials are generally made of high-purity dense stone (purity is 99.99%). Platinum-iridium alloy (containing 90% platinum and 10% iridium) can also be used. Lead-antimony alloy is used for brush plating of hard chrome; soluble anode materials should be the same as brush plating materials. Its purity is not lower than that of electroplating anode materials. 4.4.1.3 The anode and the workpiece should have an optimal contact area. In manual operation, the ratio of this contact area to the total area of the plated workpiece is generally 115~1:2 (except for extra-large areas); in mechanical operation, the contact area can be determined according to the relative movement speed of the anode and cathode. 4.4.2 Package
Usually made of absorbent cotton coated polyester-cotton cloth, preferably acrylic plush or polypropylene fiber. The package thickness is uniform, generally 4 to 15nm.
5 Brush plating solution
The solution should be stable, without turbidity and sediment. The newly prepared solution must undergo strict performance testing, and the test results should meet the requirements of the instruction manual. Approved by the Ministry of Machinery Industry on October 25, 1994
Implementation on October 1, 1995
JB/T7507-94
The plating solutions cannot be mixed with each other during transportation and storage to avoid mutual contamination. Some light-sensitive plating solutions must be stored in colored containers to avoid photodecomposition. The warranty period for plating solution storage should be no less than 6 months. Surface preparation before brush plating
Before brush plating, the workpiece must undergo surface cleaning, degreasing, rust removal, film removal and activation. 6.1 Surface cleaning
Surface cleaning refers to the removal of burrs, fatigue layers, etc. on the surface of the workpiece. The surface roughness R of the substrate after cleaning should be within the range of 3.2 to 0.025 μm. 6.2 Degreasing
The surface of the workpiece to be plated and its adjacent parts should be degreased, and the grease in the loose holes of cast iron parts should also be removed. 6.3 Rust removal
Rust should be removed from the parts to be plated of the workpiece.
6.4 Electrolytic degreasing
The workpiece must be electrolytically degreased, and the specifications for electrolytic degreasing should comply with the requirements of Appendix A (Supplement). The electrolytic degreasing liquid used must meet the requirements of the electrolytic degreasing liquid function in Table A1. The degreasing time is based on the oil removal, generally 0.5 to 1 min, and the relative movement speed of the anode and cathode is 9 to 18 m/min. 6.5 Electrolytic derusting [See Appendix B (Supplement) Table B1 Select hydrochloric acid or sulfuric acid type electrolytic derusting liquid for treatment according to different substrates and surface conditions. 6.6 Electrolytic degreasing [see Appendix B (Supplement) Table B2]. 6.7 Cathodic activation [see Appendix C (Supplement)]. Brush plating process
See Table 1 for the general process flow of brush plating.
Electrolytic degreasing
Electrolytic derusting
Brush base layer
Low carbon steel
Ordinary low carbon alloy steel
Medium carbon steel
High carbon steel
Zhehuo steel
Stainless steel
Ultra-high strength steel
Nickel, chromium layer
Anodic degreasing
Rinse with tap water to remove residual degreasing Hydrochloric acid type electrolytic derusting liquid
Sulfuric acid type electrolytic derusting liquid
Rinse with tap water to remove residual derusting Electrolytic degreasing film Liquid
Rinse with tap water to remove residual film removal Ordinary activation liquid
Cathode activation
Chromium activation liquid
Rinse with tap water to remove residual activation liquid Neutral nickel
Quick nickel
Special nickel
Low hydrogen embrittlement pick
Pin and alloy
Cathode degreasing
Sulfuric acid type rust removal
Liquid, anodic corrosion
Drastic working layer
Low carbon steel
Ordinary low carbon alloy steel
JB/T 7507-94
Continued Table 1
Medium Carbon Steel
High Carbon Steel
Ping Huo Steel
Stainless Steel
Nickel, Nickel Layer
Rinse with tap water to remove the residual brush plating solution Select the required metal layer
Rinse with tap water to remove the residual brush plating solution Ultra-high strength steel
Blow dry with compressed air or electric fan and apply anti-rust oil During the entire process of activation and brush plating of metal, the brush plating surface should always be kept moist. When brush plating on high-strength steel, organic solvents should be used for degreasing first and then mechanical rust removal. Copper and Copper Alloys
When brush plating on aluminum and aluminum alloys, anodizing should be used first until the surface is uniformly gray to black. Do not overdo it. After washing with water, use cathode treatment until the surface is uniformly bright. Thickness control of brush-plated coating
The quality of brush-plated coating is closely related to the coating thickness in addition to the brush-plating process. Each metal coating has its own safety thickness (see the instructions of the brush-plating solution manufacturer). Generally, it should not exceed its safety thickness, otherwise it will lead to poor bonding and even rough surface. If the actual coating requirement of the workpiece exceeds the safety thickness, the sandwich layer should be brush-plated. In order to obtain good coating quality, the following requirements must be met. 8.1 Thickness calculation
According to the plated area of the workpiece and the thickness of the coating, the power consumption is calculated using the following formula: Q-cas
Where: C—power consumption coefficient\,Ah/(dm\·μm); 3——required coating thickness, μm;
S—plated area, dm
The coating thickness is controlled by an ampere-hour meter according to the calculated power consumption. Note: 1) Each keying solution has its own calibrated power consumption coefficient. See the instructions of the brush-plating solution manufacturer. 8.2 Combined coating thickness
8.2.1 Bottom layer
The thickness of the bottom layer is usually in the range of 1~3um.
8.2.2 Sandwich coating
According to the use requirements of the coating to be plated, alkaline copper plating solution, low stress nickel plating solution, alkaline nickel plating solution, fast nickel plating solution and other brush plating sandwich coatings should be selected. The sequence thickness is generally not more than 50μm.
8.2.3 Working coating
The corresponding coating should be selected according to the requirements of the workpiece, and the thickness should be guaranteed to meet the use requirements. Adhesion strength test
Perform according to 1.5, 1.9, 1.11 and 1.12 of GB5270. 3
JB/T750794
Appendix A
Electrolytic degreasing
(Supplement)
The purpose, equipment and process of electrolytic degreasing are shown in Table A1. Table Al
Electrolytic degreasing liquid
Working conditions
Main ingredientsbZxz.net
Catheter phosphate (industrial grade)
Sodium hydroxide (industrial grade)
Catheter carbonate (industrial grade)
Sodium fluoride (industrial grade)
Mainly remove oil stains and impurities on the metal surface Brush plating Rectifier: The workpiece is connected to the cathode and powered on Turntable: The anode and the workpiece are required to move relative to each other Concentration g/L
Graphite (purity is 99.99%), platinum-iridium alloy (containing 90% platinum and 10%) stainless steel can also be used
Cathode current density
Note: Table A1 is suitable for electrolytic degreasing of common metal materials. Electro
Room temperature ~ 70
JB/T 750794
Appendix B
Electrolytic derusting and electrolytic defilming
(Supplement)
The purpose, equipment and process of electrolytic derusting and electrolytic defilming are shown in Table B1 and Table B2. B1
Table B1 Electrolytic rust removal
Electrolytic rust removal liquid
Working conditions
Scope of application
Defilming liquid
Working conditions
Hydrochloric acid type electrolytic rust removal liquid has a strong ability to remove rust and oxides on the metal surface, exposing fresh metal on the plated surface. It is convenient for the metal atoms after discharge reduction to combine well with the surface of the base metal. Plating rectifier: the workpiece is connected to the anode and powered on. Turntable: the workpiece and the cathode are required to move relative to each other. Ingredients
Hydrochloric acid solution
Sulfuric acid solution
Hydrochloric acid (industrial grade
Sodium oxide (industrial grade)
Acid (industrial grade)
Sodium sulfate (industrial grade)
Concentration g/L
120~140
100~110
Graphite (purity is 99.99%), platinum-Iron alloy (containing 90% platinum and 10% titanium). Stainless steel solution can also be selected
Hydrochloric acid type
Sulfuric acid type
Hydrochloric acid type
Sulfuric acid type
Current density
Carbon steel, Zehuo steel, aluminum alloy, stainless steel, nickel-chromium steel, etc. Cast iron, steel, various alloy steels, etc.
Table B2 Electrolytic de-filming
Remove the carbon black remaining on the metal surface after electrolytic derusting Power supply: The workpiece is connected to the anode and powered on Turntable: The anode and the workpiece are required to move relative to each other Main ingredients
Sodium citrate (industrial grade)
Citric acid (industrial grade)
90～100
Graphite (purity is 99.99%), platinum-iridium alloy (containing 90% platinum and 10%), stainless steel current density
Room temperature～60
Room humidity～60
Workpiece connected to anode
Workpiece connected to anode
Room temperature~60
All workpieces with carbon black impurities on the surface after electrolytic derusting must be treated with electrolytic de-filming liquid to remove carbon black. Metal materials without carbon Materials such as copper, aluminum, stainless steel, etc. do not need to be electroplated. When using electroplating liquid to remove carbon black, the metal surface must be grayish white before brush plating. This is the key to ensure good adhesion strength of the coating.
JB/T750794
After electroplating, it should be immediately rinsed with water, and then brush-plated with the base or working layer. The faster this step is connected, the better. The metal surface must be kept moist between processes to prevent the newly exposed metal from coming into contact with the air and generating Oxide film. Appendix C
Cathode Activation
(Supplement)
The purpose, equipment and process of cathode activation are shown in Table C1. C1
Scope of Application
According to the principle of cathode reduction, the passivation effect caused by anode polarization in the anode process is eliminated. The metal atoms on the surface of the base metal are activated
Brush plating rectifier: the workpiece is connected to the cathode and powered on for processing Turntable: the workpiece and the cathode are required to move relative to each other Ordinary activation liquid
Nickel-chromium activation liquid| |tt||Ammonium sulfate
H.S0,(industrial grade)80~100g/L
(NH)SO (industrial grade>80~100g/L
H,SOg chemically pure)80100g/L
H,POa chemically pure>30~40g/L
Fluorosilicic acid H,SiF (chemically pure)5~10g/L
Ammonium sulfate
(NH)SO (chemically pure)80~100g/L||t t||Graphite (purity 99.99%), platinum-iridium alloy (90% platinum + 10% iridium), stainless steel solution selection
Ordinary activation solution
Nickel-chromium activation solution
Current density
Shantong activation solution: cast iron, steel, ordinary alloy steelNickel-chromium activation solution: nickel-chromium alloy steel, nickel-chromium platingAdditional instructions:
Workpiece polarity
This standard was proposed by the Brush Plating Professional Committee of the Electroplating Branch of the China Surface Engineering Association and is under the jurisdiction of the Wuhan Institute of Materials Protection. This standard was drafted by the Brush Plating Professional Committee of the Electroplating Branch of the China Surface Engineering Association, the Wuhan Institute of Materials Protection, the Armored Forces Engineering Academy, and the Highway Science Research Institute of the Ministry of Communications. The main drafters of this standard are Qian Youyu, Yang Mingan, Zhang Shaoxian, and Liang Zhaowei. 6
People's Republic of China
Mechanical Industry Standard
General Technical Specification for Brush Plating
JB.T 750794
Published by the Mechanical Standardization Research Institute of the Ministry of Machinery Industry Printed by the Mechanical Standardization Research Institute of the Ministry of Machinery Industry Zip Code 100681)
(P.O. Box 8144, Beijing
Copyright reserved. No reproduction allowed
Format 880×12301.15
6 sheets 5/8 Number of words 120GO
October 1995 First edition October 1995 First printing Number of copies 60.001-500
Price 6.00 Yuan
No. 94-284SiF (chemically pure) 5~10g/L
Ammonium sulfate
(NH)SO (chemically pure) 80~100g/L
Graphite (purity 99.99%), platinum-iridium alloy (90% platinum + 10% iridium), stainless steel solution selection
Ordinary activation solution
Nickel-chromium activation solution
Current density
Shantong activation solution: cast iron, steel, ordinary alloy steelNickel-chromium activation solution: nickel-chromium alloy steel, nickel-chromium platingAdditional instructions:
Workpiece polarity
This standard was proposed by the Brush Plating Professional Committee of the Electroplating Branch of the China Surface Engineering Association and is under the jurisdiction of the Wuhan Institute of Materials Protection. This standard was drafted by the Brush Plating Professional Committee of the Electroplating Branch of the China Surface Engineering Association, the Wuhan Institute of Materials Protection, the Armored Forces Engineering Academy, and the Highway Science Research Institute of the Ministry of Communications. The main drafters of this standard are Qian Youyu, Yang Mingan, Zhang Shaoxian, and Liang Zhaowei. 6
People's Republic of China
Mechanical Industry Standard
General Technical Specification for Brush Plating
JB.T 750794
Published by the Mechanical Standardization Research Institute of the Ministry of Machinery Industry Printed by the Mechanical Standardization Research Institute of the Ministry of Machinery Industry Postal Code 100681)
(Box 8144, Beijing
Copyright reserved. No reproduction allowed
Format 880×12301.15
6 sheets 5/8 Number of words 120GO
October 1995 First edition First printing in October 1995 Number of copies 60.001-500
Price 6.00 Yuan
No. 94-284SiF (chemically pure) 5~10g/L
Ammonium sulfate
(NH)SO (chemically pure) 80~100g/L
Graphite (purity 99.99%), platinum-iridium alloy (90% platinum + 10% iridium), stainless steel solution selection
Ordinary activation solution
Nickel-chromium activation solution
Current density
Shantong activation solution: cast iron, steel, ordinary alloy steelNickel-chromium activation solution: nickel-chromium alloy steel, nickel-chromium platingAdditional instructions:
Workpiece polarity
This standard was proposed by the Brush Plating Professional Committee of the Electroplating Branch of the China Surface Engineering Association and is under the jurisdiction of the Wuhan Institute of Materials Protection. This standard was drafted by the Brush Plating Professional Committee of the Electroplating Branch of the China Surface Engineering Association, the Wuhan Institute of Materials Protection, the Armored Forces Engineering Academy, and the Highway Science Research Institute of the Ministry of Communications. The main drafters of this standard are Qian Youyu, Yang Mingan, Zhang Shaoxian, and Liang Zhaowei. 6
People's Republic of China
Mechanical Industry Standard
General Technical Specification for Brush Plating
JB.T 750794
Published by the Mechanical Standardization Research Institute of the Ministry of Machinery Industry Printed by the Mechanical Standardization Research Institute of the Ministry of Machinery Industry Postal Code 100681)
(Box 8144, Beijing
Copyright reserved. No reproduction allowed
Format 880×12301.15
6 sheets 5/8 Number of words 120GO
October 1995 First edition First printing in October 1995 Number of copies 60.001-500
Price 6.00 Yuan
No. 94-284
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