CN105543929A - Novel micro-arc oxidation electrolyte composite nanometer additive and application thereof - Google Patents

Abstract

The invention discloses a novel micro-arc oxidation electrolyte composite nano-additive and its application. The present invention adopts the mixed additive composed of nano-zinc oxide and nano-titanium dioxide, and adds it into the electrolyte solution with silicate as the main film-forming agent: 1. It can generate high-quality ceramic film layer, and can produce micro-arc oxidation ceramic film Under the premise that the layer thickness is not high, the hardness, wear resistance, corrosion resistance and other comprehensive properties of the film layer are significantly improved, the surface of the film layer is smooth, and the porosity and microcracks are less. The film layer mainly contains Al matrix, α- Al ₂ O ₃ phase, γ-Al ₂ O ₃ phase, Al ₃ Ti and titanium zinc (Zn _0.6 Ti _0.4 ) phase; 3. The thickness of the micro-arc oxidation film generated by the present invention is not high, so the film forming time is short, the energy consumption is low, the production cost can be reduced, and it has good economic benefits.

Description

Novel Composite Nano Additives for Micro-arc Oxidation Electrolyte and Its Application

technical field

The invention relates to the field of material science, in particular to a novel micro-arc oxidation electrolyte composite nano-additive and its application.

Background technique

Aluminum and its alloys have become the most widely used metal materials among non-ferrous metals because of their advantages such as high specific strength, excellent electrical conductivity, and easy processing and forming. However, the chemical properties of aluminum are very active, and it will oxidize at room temperature to form a natural oxide film on its surface. Due to the extremely thin film and low hardness, it is not enough to resist corrosion caused by harsh environments and damage caused by external friction. Therefore it must be surface treated. As a new generation of surface treatment technology, micro-arc oxidation can form a dense alumina ceramic layer on the surface of aluminum alloy, thereby greatly improving the comprehensive performance of aluminum alloy surface.

Micro-arc oxidation technology is a new surface treatment technology that directly grows ceramic layers on the metal surface in situ. It has very broad development prospects because of its environmental protection, high efficiency and energy saving. The micro-arc oxidation ceramic film obtained by this technology has the characteristics of high hardness, tight bonding, low wear resistance, corrosion resistance, high temperature impact resistance, etc., and can largely meet the requirements of parts under high temperature or high speed motion conditions, so it is suitable for Used in various fields such as military industry, machinery, electronics, automobile, aerospace, aviation and so on.

The study found that micro-arc oxidation mainly focuses on the optimization of electrical parameters and the adjustment of electrolyte composition, but there are not many studies on adding composite nano-additives to the electrolyte. At present, there are few reports on this aspect at home and abroad. Therefore, it is necessary to develop new nano-nano composite additives in order to further improve the comprehensive performance of aluminum alloy micro-arc oxidation ceramic layer.

Contents of the invention

The purpose of the present invention is to provide a novel micro-arc oxidation electrolyte composite nano-additive and its application, the composite additive can be added to the basic electrolyte, under the condition that the thickness of the micro-arc oxidation ceramic film layer is not high, it can significantly Improve the corrosion resistance and mechanical properties of the micro-arc oxidation ceramic film without polluting the environment.

The present invention is carried out in the following way: the novel micro-arc oxidation electrolyte composite nano-additive, calculated in parts by weight, includes 1-5 parts of nano-zinc oxide and 2-6 parts of nano-titanium dioxide; the composition of the basic electrolyte is 10 parts of sodium silicate , 2 parts of sodium tungstate, 2 parts of sodium hydroxide and 2000 parts of distilled water.

The application of composite nano-additives in the new micro-arc oxidation electrolyte is calculated by weight, adding 2-5 parts of nano-titanium dioxide and 3-6 parts of nano-titanium dioxide into the basic electrolyte, and the composition of the basic electrolyte is 10 parts of silicic acid Sodium, 2 parts sodium tungstate, 2 parts sodium hydroxide and 2000 parts distilled water.

Compared with the prior art, the present invention adopts a mixed additive composed of nano-zinc oxide and nano-titanium dioxide, which is added to the electrolyte solution with silicate as the main film-forming agent: 1. High-quality ceramic film can be generated, which can Under the premise that the thickness of the micro-arc oxidation ceramic film layer is not high, the comprehensive properties of the film layer such as hardness, wear resistance, and corrosion resistance are significantly improved, the surface of the film layer is smooth, and the porosity and microcracks are less. It mainly contains Al matrix, α-Al ₂ O ₃ phase, γ-Al ₂ O ₃ phase, Al ₃ Ti and titanium zinc (Zn _0.6 Ti _0.4 ) phase; 2. The preparation process of the micro-arc oxidation film layer is simple to operate and is a An energy-saving and environmentally-friendly process that neither consumes the cathode nor consumes the electrolyte electrolyte; 3. The thickness of the micro-arc oxidation film generated by the present invention is not high, so the film forming time is short, the energy consumption is low, the production cost can be reduced, and it has good economic efficiency. benefit.

Description of drawings

Accompanying drawing 1 is the surface morphology structure of the ceramic film prepared by basic electrolyte;

Accompanying drawing 2 is the surface topography structure of the ceramic film that embodiment 1 prepares;

Accompanying drawing 3 is the surface topography structure of the ceramic film that embodiment 2 prepares;

Accompanying drawing 4 is the relationship diagram of friction coefficient and friction time of ceramic film prepared by different additives.

detailed description

Embodiment 1 of the present invention: new micro-arc oxidation electrolyte composite nano-additive, the basic electrolyte of micro-arc oxidation is sodium silicate electrolyte, including 10g/L sodium silicate, 2g/L sodium tungstate, 2g/L hydroxide Sodium and 2L distilled water; add new micro-arc oxidation electrolyte composite nano-additives to the basic electrolyte, and the concentrations of nano-zinc oxide and nano-titanium dioxide after adding are 2g/L and 4g/L respectively.

Micro-arc oxidation steps:

The micro-arc oxidation process adopts constant voltage mode, the sample is used as the anode, and the stainless steel electrolytic cell is used as the cathode. The sample is drilled and inserted into the aluminum wire connection, and suspended in the prepared electrolyte, the bottom of the sample is not in contact with the oxidation tank. Then turn on the power, set the predetermined process parameters (electrical parameters are set as: time 60min; frequency 400Hz; voltage 600V; duty cycle 30%), press the work button to start the micro-arc oxidation experiment. During the micro-arc oxidation process, the electrolyte is cooled by the circulating water cooling system and the air pump system, and the temperature of the electrolyte is kept at about 35°C. After the reaction of the sample is finished, turn off the power, take out the sample, wash it with distilled water, and dry it.

The thickness, hardness, surface roughness, corrosion resistance and wear resistance test and analysis results of the micro-arc oxidation ceramic film prepared by the above process are shown in Table 1, and its surface morphology is shown in Figure 2.

Embodiment 2 of the present invention: new micro-arc oxidation electrolyte composite nano-additive, the basic electrolyte of micro-arc oxidation is sodium silicate electrolyte, including 10g/L sodium silicate, 2g/L sodium tungstate, 2g/L hydroxide Sodium and 2L of distilled water; add a new type of micro-arc oxidation electrolyte composite nano-additive to the basic electrolyte, and the concentrations of the added nano-zinc oxide and nano-titanium dioxide are 1g/L and 3g/L, respectively.

The micro-arc oxidation step is the same as in Example 1. The thickness, hardness, surface roughness, corrosion resistance and wear resistance test and analysis results of the micro-arc oxidation ceramic film prepared by this process are shown in Table 1, and its surface morphology is shown in Figure 3.

By performing performance detection on the ceramic film layer made by adding new composite nano-additives in Example 1 and Example 2, the experimental effect of the present invention is further verified, and the film layer made from the basic electrolyte without adding any additives For comparison, the results are shown in Table 1:

According to the above experiments, the present invention can significantly improve the hardness, wear resistance and corrosion resistance of the micro-arc oxidation film layer under the condition of using the same equipment and the same basic electrolyte system without reaching a higher film thickness. To a certain extent, the energy consumption in the micro-arc oxidation process can be reduced; by observing and comparing the microscopic morphology of the surface of the film, it can be seen that after adding the composite nano-additive, the film cracks, porosity, and spray-like deposits are all reduced, and the film The surface of the layer is relatively flat.

Claims (2)

1. A novel micro-arc oxidation electrolyte composite nano-additive, characterized in that: calculated in parts by weight, including 1 to 5 parts of nano-zinc oxide and 2 to 6 parts of nano-titanium dioxide; the composition of the basic electrolyte is 10 parts of silicic acid Sodium, 2 parts sodium tungstate, 2 parts sodium hydroxide and 2000 parts distilled water. 2. The application of a novel micro-arc oxidation electrolyte composite nano-additive as claimed in claim 1, characterized in that: by weight parts, 2 to 5 parts of nano titanium dioxide and 3 to 6 parts of nano titanium dioxide are added to the In the basic electrolyte, the composition of the basic electrolyte is 10 parts of sodium silicate, 2 parts of sodium tungstate, 2 parts of sodium hydroxide and 2000 parts of distilled water.