Unlock instant, AI-driven research and patent intelligence for your innovation.

Magnesium alloy micro-arc oxidation low energy consumption black ceramic film and preparation method

A technology of micro-arc oxidation and black ceramics, which is applied in the direction of anodic oxidation, etc., can solve the problems of difficult treatment of electrolyte waste, limited industrialization promotion, poor bonding performance, etc., and achieves small color difference, good corrosion resistance and high casting performance. Effect

Inactive Publication Date: 2016-05-04
SOUTH CHINA UNIV OF TECH
View PDF5 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

There are many technical disadvantages in anodic oxidation coloring: (1) The oxide film formed by anodic oxidation is relatively brittle, has poor bonding performance with the substrate, and is easy to fall off under stress conditions; under many conditions, it must be sealed with resin or coating , making the process more cumbersome; (2) Electrolyte waste liquid is difficult to handle, etc.
However, there are also some problems in micro-arc oxidation, especially the problem of high energy consumption, which has always limited the industrialization of this technology.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Magnesium alloy micro-arc oxidation low energy consumption black ceramic film and preparation method
  • Magnesium alloy micro-arc oxidation low energy consumption black ceramic film and preparation method
  • Magnesium alloy micro-arc oxidation low energy consumption black ceramic film and preparation method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] A method for preparing a magnesium alloy micro-arc oxidation low-energy black film, comprising the following steps:

[0036] (1) Pretreatment: Cut a sample with a thickness of 10mm from a magnesium alloy rod (diameter: 30mm) of model AZ91D, and use 150 # 、400 # 、600 # , 800 # Grind the surface of the magnesium-aluminum alloy until the scratches are in the same direction with SiC sandpaper, and then use acetone, absolute ethanol, and deionized water to clean them in ultrasonic waves for 10 minutes, and then dry them for later use. The purpose of pretreatment of magnesium alloys is to remove oxides and oil stains on the surface of magnesium alloys.

[0037](2) Prepare the electrolyte: weigh 10g of sodium silicate, 10g of sodium hexametaphosphate, 10g of potassium fluoride, 8g of ammonium metavanadate, 1g of sodium hydroxide, 1g of EDTA (ethylenediaminetetraacetic acid) and 1g of phosphorus at room temperature. Dissolve 2 g of sodium citrate in 1 L of deionized water a...

Embodiment 2

[0043] (1) Pretreatment: Same as Example 1.

[0044] (2) Prepare the electrolyte: weigh 30g of sodium silicate, 25g of sodium hexametaphosphate, 15g of potassium fluoride, 12g of ammonium metavanadate, 1g of sodium hydroxide, 4g of EDTA (ethylenediaminetetraacetic acid) and 4g of phosphorus at room temperature. Dissolve 6 g of sodium citrate into 1 L of deionized water, and stir with a magnetic stirrer to fully dissolve it.

[0045] Magnesium Alloy Micro-arc Oxidation Coloring

[0046] The magnesium alloy sample after the above pretreatment is used as the anode, and is completely immersed in the above-mentioned prepared electrolyte, and the stainless steel sheet is used as the cathode, which is fixed at a distance of 5 cm from the anode with a clamp, and the magnesium alloy is subjected to micro-arcing with an AC pulse power supply. Oxidation treatment; the power supply adopts constant current mode, and the electrical parameters are: current density 6.37A / dm2, frequency 600Hz...

Embodiment 3

[0050] (1) Pretreatment: Same as Example 1.

[0051] (2) Prepare the electrolyte: weigh 15g of sodium silicate, 25g of sodium hexametaphosphate, 12g of potassium fluoride, 10g of ammonium metavanadate, and 1g of sodium hydroxide at room temperature, dissolve them in 1L of deionized water, and use a magnetic stirrer Stir to fully dissolve.

[0052] Magnesium Alloy Micro-arc Oxidation Coloring

[0053] The magnesium alloy sample after the above pretreatment is used as the anode, and is completely immersed in the above-mentioned prepared electrolyte, and the stainless steel sheet is used as the cathode, which is fixed at a distance of 5 cm from the anode with a clamp, and the magnesium alloy is subjected to micro-arcing with an AC pulse power supply. Oxidation treatment; the power supply adopts constant current mode, and the electrical parameters are: current density 6.37A / dm2, frequency 600Hz, duty cycle 20%, positive and negative pulse ratio 7:1, oxidation time 8min, after the...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
mean roughnessaaaaaaaaaa
mean roughnessaaaaaaaaaa
mean roughnessaaaaaaaaaa
Login to View More

Abstract

The invention discloses a magnesium alloy microarc oxidation low energy consumption black ceramic coating and a preparation method thereof. The preparation method comprises the following steps of: grinding magnesium alloy by using SiC sand paper, cleaning and drying with hot air, and standing in a drier for later use; and immersing the pre-treated magnesium alloy in electrolyte by using the magnesium alloy as an anode and a stainless steel thin plate as a cathode, and performing a microarc oxidation treatment on the magnesium alloy by adopting an alternating-current constant-current mode, taking out the magnesium alloy and cleaning with deionized water, and drying with hot air to prepare the required microarc oxidation black ceramic coating. Under a condition of lower working voltage (less than or equal to 300V), the black ceramic coating with good corrosion resistance and uniform color can be generated on the surface of magnesium alloy, and is high in efficiency, low in unit energy consumption and small in environmental pollution.

Description

technical field [0001] The invention relates to the field of magnesium alloy surface treatment, in particular to a low-energy micro-arc oxidation black ceramic film of Mg alloy and a preparation method thereof. Background technique [0002] Magnesium alloy is the lightest metal structure material. It has the advantages of light specific gravity, high specific strength, good vibration damping, strong electromagnetic shielding, and easy recycling. It is considered to be the most potential development and application in the 21st century. "Material. However, the standard electrode potential of magnesium is low (-2.36V), and it is easy to lose electrons to cause oxidation reaction, which leads to poor corrosion resistance of magnesium and magnesium alloys, and severe corrosion is easy to occur in corrosive media. As we all know, surface treatment is one of the most effective, reasonable and widely used treatment methods to improve the corrosion resistance of magnesium alloys. A...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C25D11/30
Inventor 李文芳万小芳于非张果戈
Owner SOUTH CHINA UNIV OF TECH