Method for electrodepositing chromium and chromium alloy composite coating through ultrasound-pulse for trivalent chromium plating liquid system

A pulse electrodeposition and composite coating technology, which is applied in coatings, electrolytic coatings, etc., can solve the problems of high pollution, high toxicity, and high energy consumption in the hexavalent chromium electroplating process, and achieve strong bonding, reduce environmental pollution, and bright coatings Dense and smooth effect

Inactive Publication Date: 2009-03-25
CENT SOUTH UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] In order to solve the problems of high pollution, high toxicity and high energy consumption in the electroplating process of hexavalent chromium, the present invention makes full use of the characteristics of ultrasonic-pulse electrodeposition technology and trivalent chromium plating solution system to provide a metal or metal alloy surface ultrasonic-pulse A method for electrodepositing chromium and chromium alloy composite coating, which has the characteristics of economical practicability and low toxicity

Method used

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  • Method for electrodepositing chromium and chromium alloy composite coating through ultrasound-pulse for trivalent chromium plating liquid system
  • Method for electrodepositing chromium and chromium alloy composite coating through ultrasound-pulse for trivalent chromium plating liquid system
  • Method for electrodepositing chromium and chromium alloy composite coating through ultrasound-pulse for trivalent chromium plating liquid system

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] 1) Take an ordinary brass sample with a size of 40mm×20mm×2mm, using 2 # 、4 # 、6 # Metallographic sandpaper was polished in turn, washed with tap water; then washed with alcohol and acetone solution, and then washed in H 2 SO 4 40-100ml / l, HCl 40-70g / l activation solution, temperature 20-40°C, activate for 2-3 minutes, and the pretreated sample to be plated can be obtained.

[0028] 2) Take the pretreated sample to be plated as the cathode and the insoluble anode (graphite) as the anode. Under the condition of stirring, directly insert the 3 ·6H 2 O 0.6mol L -1 , SiC 30g·L -1 , trisodium citrate 0.6mol L -1 , sodium oxalate 0.3mol L -1 , CH 3 COONa0.1mol L -1 , CO(NH 2 ) 2 2.0mol·L -1 , Cr 2 (SO 4 ) 3 ·6H 2 O0.1mol L -1 , H 3 BO 3 0.72mol·L -1 , NaCl 2.0mol·L -1 In the plating solution, the temperature of the plating solution is 35°C, and the current density is 8A·dm -2 , the pH of the plating solution is 2.0, the pulse working ratio is 0.8, the...

Embodiment 2

[0030] 1) The pretreatment of the plated part is the same as "Example 1".

[0031] 2) Take the pretreated sample to be plated as the cathode and the insoluble anode (graphite) as the anode. Under the condition of stirring, directly insert the 3 ·6H 2 O 0.6mol L -1 , NiSO 4 ·6H 2 O 0.075mol L -1 , SiC 50g·L -1 , trisodium citrate 0.5mol L -1 , sodium oxalate 0.4mol L -1 , CH 3 COONa 0.1mol L -1 , CH 3 CH(OH) COOH 0.1mol L -1 , CO(NH 2 ) 2 2.0mol·L -1 , Cr 2 (SO 4 ) 3 ·6H 2 O 0.1mol L -1 , H 3 BO 3 0.72mol·L -1 , NaCl 2.0mol·L -1 In the plating solution, the temperature of the plating solution is 35°C, and the current density is 8A·dm -2 , the pH of the plating solution is 2.0, the pulse working ratio is 0.7, the reversing time is 2ms, the pulse frequency is 50Hz, the ultrasonic power is 45W, the ultrasonic frequency is 80KHz, and the pulse electrodeposition time is 70min, the Cr-Ni / SiC composite Coating sample, the thickness of the coating is about 15....

Embodiment 3

[0033] 1) The pretreatment of the plated part is the same as "Example 1".

[0034] 2) Take the pretreated sample to be plated as the cathode and the insoluble anode (graphite) as the anode. Under the condition of stirring, directly insert the 3 ·6H 2 O 0.6mol L -1 , FeSO 4 ·7H 2 O 0.05mol L -1 , SiO 2 40g·L -1 , trisodium citrate 0.5mol L -1 , sodium oxalate 0.4mol L -1 , CH 3 COONa 0.1mol L -1 , CO(NH 2 ) 2 2.0mol·L -1 , Cr 2 (SO 4 ) 3 ·6H 2 O 0.1mol L -1 , H 3 BO 3 0.72mol·L -1 , NaCl 2.0mol·L -1 In the plating solution, the temperature of the plating solution is 35°C, and the current density is 8A·dm -2 , the pH of the plating solution is 1.5, the pulse working ratio is 0.3, the reversing time is 2ms, the pulse frequency is 50Hz, the ultrasonic power is 100W, and the ultrasonic frequency is 60KHz. The pulse electrodeposition time is 40min, and the Cr-Fe / SiO 2 Composite coating sample, the thickness of the coating is about 13.81 μm, and the SiO in th...

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Abstract

The invention relates to a method for ultrasound-pulse electrodepositing of chromium and chromium alloy composite plating layer in a tervalent chromium plating bath system, pertaining to the technology of surface engineering and surface processing. The method comprises the pretreatment of to be plated articles and the ultrasound-pulse electrodepositing. By using the method, a Cr/SiC or Cr/SiO2 composite plating layer with 0 to 5.5 percent of composite particles, a Cr-Ni/SiC or Cr-Ni/SiO2 alloy composite plating layer with 0 to 3.9 percent of composite particles, and a Cr-Ni-Fe/SiC or Cr-Ni-Fe/SiO2 composite plating layer with 0 to 4.4 percent of composite particles can be obtained. The thickness of the composite plating layer can be thickened with the electrodepositing time, with the largest thickness of 18.26Mum. The composite plating layer is compact and smooth and can be well combined with the substrate, and has good wearing resistance and corrosion resistance.

Description

technical field [0001] The invention relates to surface engineering and surface treatment technology, in particular to the technology of preparing chromium and chromium alloy composite coating by ultrasonic-pulse electrodeposition. Background technique [0002] Since 1982, Raj Narayan et al first used hexavalent chromium plating solution system to prepare Cr / Al 2 o 3 Since the composite coating, the research on chromium and chromium alloy composite coating has attracted widespread attention at home and abroad. For example, in 1996, SunKe-Ning et al. prepared Cr / Al with excellent wear resistance by using a hexavalent chromium plating solution system. 2 o 3 Composite coating, but its Al 2 o 3 The particle content is less than 1%; in 2001, S. Survilienea et al. successfully obtained Cr / MoO with high hardness 2 and Cr / TiO 2 Composite coating, but the thickness of the coating is only 3.3 microns. However, the hexavalent chromium electrodeposition process has attracted wide...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C25D3/06C25D5/18C25D5/20C25D15/00
Inventor 何新快
Owner CENT SOUTH UNIV
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