WO2019128210A1

WO2019128210A1 - Method for improving surface abrasion resistance of aluminum alloy under dry friction condition

Info

Publication number: WO2019128210A1
Application number: PCT/CN2018/097265
Authority: WO
Inventors: 王兵; 宋清华; 任小平; 万熠
Original assignee: 山东大学
Priority date: 2017-12-28
Filing date: 2018-07-26
Publication date: 2019-07-04
Also published as: CN107937955A

Abstract

The present invention relates to a method for improving surface abrasion resistance of an aluminum alloy under a dry friction condition. The method comprises the following steps: 1) surface micro-texture; 2) preprocessing before anodic oxidation, comprising: a) ultrasonic cleaning, b) glue coating, c) alkali corrosion, d) washing, e) acid washing, f) washing, g) dedusting, and h) washing; 3) anodic oxidation; 4) ultrasonic deposition of a nano solid lubricant; 5) drying the aluminum alloy subjected to the ultrasonic deposition of the nano solid lubricant in step 4) in a drying oven to improve the adhesion strength of nano solid lubricant particles to a substrate. According to the present invention, the aluminum alloy surface is sequentially subjected to surface micro-texture machining, anodic oxidation preprocessing, anodic oxidation, and ultrasonic deposition of the nano solid lubricant, thereby cooperatively improving the surface corrosion resistance of the aluminum alloy. The method of the present invention is simple, and easy to implement; in addition, surface friction coefficients of the aluminum alloy are decreased, and the surface abrasion resistance of the aluminum alloy is improved.

Description

Method for improving wear resistance of aluminum alloy surface under dry friction condition

Technical field

The invention relates to the technical field of surface treatment, in particular to a method for improving the wear resistance of an aluminum alloy surface under dry friction conditions.

Background technique

Aluminum alloy is widely used in aerospace structural parts, automotive industry and military fields due to its light weight, high strength, good corrosion resistance and low expansion coefficient. However, the tribological properties of aluminum alloys are relatively poor, and the coefficient of friction under dry friction conditions is as high as 0.5-0.8. When contacted with other materials such as cast iron, the aluminum alloy undergoes severe adhesive wear and plastic deformation. Lubrication improvement, mechanical design and surface modification can significantly improve the surface friction properties of aluminum alloys.

Surface microtexture technology is a viable surface modification technology that improves the surface friction properties of aluminum alloys and reduces fuel consumption. With the development of various technologies such as laser processing, machining, ultrasonic vibration and etching processing, surface micro-texturing technology has been successfully applied to mechanical seals, thrust bearings, cylinder liners/piston rings and the like. For example, patent 201410336946.5 discloses a laser processing method and apparatus for improving the wear resistance of an aluminum alloy engine piston; the invention utilizes a high peak short pulse laser beam generated by a laser to focus on a piston skirt of an aluminum alloy engine to be treated by a flowing water constraining layer On the surface, the instantaneously formed high-pressure plasma strikes the surface of the piston skirt, that is, impact treatment, causing compression plastic deformation of the piston skirt surface to form micro-pits, and reciprocating pistons with large-area micro-pits in the engine cylinder When the micro-pits are filled with lubricating fluid to reduce friction, the wear resistance of the aluminum alloy engine piston can be greatly improved. Although a suitable surface microtexture can effectively improve the surface friction properties of an aluminum alloy, the surface microtexture can store wear debris to reduce abrasive wear under dry friction conditions. However, when the aluminum alloy is ground against a relatively hard material, the single surface microtexture technique cannot meet the friction requirements of the aluminum alloy. This is because the hardness of the aluminum alloy is low, and its own friction performance is poor. The surface micro-texture will wear rapidly under relatively strict deformation conditions. At the initial stage of friction, the surface micro-texture can reduce the positive effect of friction and wear. When the surface micro-texture is damaged by wear, the aluminum alloy surface will be exposed directly to the outside and quickly worn (see Houdková

P, Repka M, Martan J, Moskal D. Shifted laser surface texturing for bearings applications. Journal of Physics: Conference Series. 2017, 843, 012076).

In this paper, the friction and wear properties of self-lubricating aluminum alloy hard anodized film were studied. The PTFE lubricity particles were introduced into the micropores of hard oxide film, and the composite film with self-lubricating properties was prepared and rubbed with M-2000 type. The test machine studied its friction and wear properties. However, this method requires subsequent heat treatment to obtain a composite film with self-lubricating properties. During the heat treatment process, it is easy to change the microstructure of the aluminum alloy, and the change in the properties of the structure changes the odor. Once the heat treatment conditions are improperly controlled, it is easy. Causes deterioration of the performance of the aluminum alloy.

In summary, the existing methods for improving the surface friction properties of aluminum alloys still have problems such as insufficient friction requirements and poor wear resistance; therefore, it is necessary to further improve a new method for improving the surface friction properties of aluminum alloys.

Summary of the invention

The present invention is directed to a method for improving the wear resistance of an aluminum alloy surface under dry friction conditions, and the present invention is directed to a surface of an aluminum alloy. The method of surface micro-texture processing, anodizing pretreatment, anodizing, ultrasonic deposition of nano-solid lubricant, etc., synergistically improves the surface wear resistance of the aluminum alloy, the method of the invention is simple, easy to implement, and significantly reduces the aluminum alloy The surface friction coefficient greatly improves the surface wear resistance of the aluminum alloy.

One of the objects of the present invention is to provide a method for improving the wear resistance of an aluminum alloy surface under dry friction conditions.

Another object of the present invention is to provide the above-described application of a method for improving the wear resistance of an aluminum alloy surface under dry friction conditions.

In order to achieve the above object, the present invention discloses the following technical solutions:

First, the present invention discloses a method for improving the surface wear resistance of an aluminum alloy under dry friction conditions; specifically, the method includes the following steps:

1) Surface micro-texture: micro-texture is formed on the surface of the aluminum alloy by micro-texturing processing technology.

2) pre-anodizing the surface of the aluminum alloy having the surface micro-texture in the step 1), specifically comprising:

a) ultrasonic cleaning: remove oil stain on the surface of the aluminum alloy to improve the bonding strength of the rubber coating;

b) Gluing: Since it is only necessary to form a porous alumina film on the surface to be microtextured, it is necessary to uniformly coat the other five surfaces of the aluminum alloy with the structural adhesive;

c) alkali etching: completely remove the natural oxide film formed on the surface of the aluminum alloy;

d) Washing: Wash the alkali-etched surface with deionized water to prevent the alkali etching solution from staying on the surface and affect the subsequent pickling process;

e) pickling: remove scratches on the surface;

f) Washing: Wash the pickled surface with deionized water to prevent the pickling solution from staying on the surface, affecting the subsequent ash removal process;

g) ash removal: a surface layer formed by removing various metal compound particles remaining on the surface of the aluminum alloy after the alkali etching is removed;

h) Washing: Wash the ash-removing surface with deionized water to prevent the ash-containing solution from staying on the surface and affect the subsequent anodizing process;

3) Anodizing the surface of the aluminum alloy treated in step 2), including:

The aluminum alloy processed with surface micro-texture is placed in an electrochemical reaction cell for anodization, and a porous alumina film layer having a certain thickness and pore diameter is formed on the surface thereof; the anodization parameter needs to be determined according to the particle size of the deposited nano-solid lubricant. The alumina nanopore diameter is made larger than the particle size diameter of the deposited nanosolid lubricant.

4) Ultrasonic deposition of the nanosolid lubricant for the anodized aluminum alloy in step 3), including:

The nanosolid lubricant is made into a nanoparticle suspension, and the suspension is subjected to ultrasonic vibration treatment. The ultrasonically oscillated nanoparticle suspension is placed in a sonicator tank, and the anodized micro-textured aluminum alloy test piece is immersed in the solution, and then the ultrasonicator is activated to deposit the nano-solid lubricant particles to the porous alumina. in. The reason for using the ultrasonic vibration treatment is to better disperse the solid particles because the agglomeration is liable to occur due to the nanoparticles.

5) Drying the aluminum alloy of the nano-solid lubricant in the step 4) in an oven to improve the adhesion strength of the nano-solid lubricant particles to the substrate, that is, obtained.

In the step 1), the micro-texturing processing technology includes laser processing, mechanical processing, shot peening, etching processing technology, and the like.

Preferably, in step 1), the PMMA colloid may be uniformly coated on the surface of the aluminum alloy to be processed to reduce the burrs generated on the cutting surface, and then the micro-texture is formed on the surface of the aluminum alloy by micro-texturing processing technology. Coating PMMA colloids can reduce burrs when microfabrication is achieved using machining techniques.

Preferably, in step 1), the micro-pit texture is processed on the surface of the aluminum-silicon alloy by using a micro-milling technique, and the micro-texture parameters are processed by the micro-milling technique: using KERN2522 five-axis micro-milling, cutting speed It is 20000 r/min, the axial cutting depth is 10 μm, and the feed speed is 60 mm/min.

Preferably, in step 1), the micro-texture is a rectangular micro-pit containing two arcs, the length, the width, the spacing, and the depth are 600, 200, 1000, and 50 μm, respectively, and the surface micro-texture area density is It is 15% and the distribution angle is 60°.

Preferably, in step 1), the processed aluminum alloy is placed in an acetone solution and placed in an ultrasonic cleaner for 5 minutes to remove PMMA.

Preferably, in step 1), the deburring brush can be used to remove the burrs generated on the surface of the processed aluminum alloy, so as to further reduce the influence of the micro-textured burrs on the anodizing experiment, resulting in uneven discharge.

In step 2), the ultrasonic cleaning refers to ultrasonic cleaning of the micro-texture of the aluminum alloy surface with acetone, alcohol and deionized water for 5-10 min each.

In step 2), the coating means that the structural adhesive is uniformly applied to the surface of the aluminum alloy and fully cured.

Preferably, the structural adhesive is AB type glue; wherein the main component of the agent A is acrylate, the main component of the agent B is a curing agent, and the agent A and the agent B are mixed in a ratio of 1:1, and are applied to the aluminum to be processed. The surface of the alloy can be cured for 24 hours.

Further preferably, the structural adhesive is a good glue for the two brothers.

In the step 2), the alkali corrosion refers to: at room temperature, in 5g / L NaOH, 20g / L Na ₃ PO ₄ , 20g / L NaCO ₃ solution, soak for 2-3min;

In step 2), the water washing refers to: cleaning the surface of the aluminum alloy with deionized water for 30-40 s.

In step 2), the pickling means: immersing in a volume concentration of 60% H ₃ PO ₄ , 40% H ₂ SO ₄ , and an appropriate amount of Na ₂ CO ₃ for 2-3 minutes at 50-60 ° C, respectively. .

In step 2), the ash removal means: immersing in a volume concentration of 50% HNO ₃ and 5% HF for 1-2 min at room temperature.

In step 3), the parameter of the anodization is: 4 wt% phosphoric acid solution, using a two-electrode configuration, the aluminum sheet is used as the anode, the lead sheet is used as the cathode, the distance between the two electrodes is 10 mm, and the constant DC current density is 0.025 A. /cm ² , time is 30-35 min, and the electrolyte temperature is maintained at 20 ± 1 °C. The use of a phosphoric acid solution can achieve a larger alumina pore size, which is more conducive to the deposition of nanosolid lubricants.

In the step 3), the porous alumina film layer has a thickness of 3-5 mm.

In the step 3), the porous alumina film layer has a pore diameter of 200 to 220 nm.

In step 4), the ultrasonic frequency of the oscillating process is 20 kHz, and the time is 1 h.

In step 4), the time for ultrasonic deposition of the nanosolid lubricant is 20-25 min.

Preferably, in step 4), the surface of the anodized micro-textured aluminum alloy is irradiated toward the ultrasonic wave propagation direction to obtain a good deposition effect on the surface of the aluminum alloy.

Preferably, in step 4), the nanosolid lubricant is a suspension prepared from nano MoS ₂ particles, and the preparation method thereof is: ammonium sulfate 50 g/L, Triton (polyethylene glycol to isooctylphenyl ether) 20 wt%, nano MoS ₂ particles 14 g / L, pH 10.5, temperature 25 ° C; wherein Triton is a dispersant of MoS ₂ particle suspension; PH value is adjusted with ammonia water.

In step 5), the drying temperature is 120-150 ° C and the time is 1-3 h.

Secondly, the present invention discloses the above-mentioned method for improving the surface abrasion resistance of an aluminum alloy under dry friction conditions in the surface abrasion resistance treatment of a metal material.

The invention is characterized in that: firstly, the surface micro-texture processing technology is applied to form a certain distributed micro-texture on the surface of the aluminum alloy; then an anodized film is formed on the micro-textured surface by anodizing treatment; Porous alumina has high porosity and high activity, and has excellent adsorption capacity and large specific surface area. At the same time, the present invention obtains a self-lubricating functional film by depositing a nano-solid lubricant inside a porous alumina film by means of ultrasonic deposition technology. Under dry friction conditions, when the aluminum alloy is reciprocating, the micro-texture can store wear debris and reduce abrasive wear; the high surface hardness anodized film can effectively improve the wear resistance life of the surface micro-texture; nano-solid The lubricant can form a self-lubricating functional film with excellent anti-wear and anti-friction properties; the synergistic effect of the three can effectively reduce the friction coefficient and significantly improve the wear resistance of the aluminum alloy surface. It should be noted that the deposited nano-solid lubricant used in the present invention can not only exert self-lubricating effect under dry friction conditions, but also can be effective because of the excellent chemical stability and thermal stability of the nano-solid lubricant. It resists the aging and decomposition of itself (nano-solid lubricant) by the frictional heat generated under dry friction conditions, thereby effectively prolonging the duration of the self-lubricating effect.

Compared with the prior art, the present invention achieves the following beneficial effects:

(1) The preparation process of the invention is simple and easy to implement, and the method of the invention significantly reduces the surface friction coefficient of the aluminum alloy, improves the surface wear resistance, compensates for the defects of the single micro-texture technology, and does not perform surface treatment and only Compared with the aluminum alloy subjected to the surface microtexture treatment, the wear resistance coefficient of the present invention was reduced by 22.6% and 21.3%, respectively.

(2) The surface micro-texture can store the wear debris; the anodizing can improve the surface hardness of the aluminum alloy; the nano-solid lubricant combines the excellent anti-wear and anti-friction properties, and the synergistic effect of the three can effectively improve the tribological properties of the aluminum alloy surface. .

(3) The technical solution of the invention has wide application range, and is applicable not only to the treatment of the wear resistance of the surface of the aluminum alloy, but also to the treatment of the surface wear resistance of other metal materials such as magnesium alloys and titanium alloys.

DRAWINGS

The accompanying drawings, which are incorporated in the claims of the claims

Figure 1 is a process flow diagram of the present invention.

2 is a schematic view of the surface of the rubberized coating of the present invention; wherein 1 is an anodized surface and 23456 is a rubberized surface.

Figure 3 is a schematic illustration of a rectangular microtexture of the present invention.

4 is a graph showing the friction coefficient and the slip time of an aluminum alloy; wherein curve 1 is an untreated ZL109 aluminum alloy, curve 2 is a ZL109 aluminum alloy having only a surface microtexture treatment, and curve 3 is the first embodiment of the present invention. Prepared ZL109 aluminum alloy.

5 is a wear morphology of an untreated, only surface microtexture treatment and an aluminum alloy prepared in Example 1 of the present invention under a scanning electron microscope; wherein FIG. 5(a) is an untreated ZL109 aluminum-silicon alloy, 5(b) is a ZL109 aluminum-silicon alloy which has only been subjected to surface microtexture treatment, and FIG. 5(c) is a ZL109 aluminum-silicon alloy for depositing a nano-MoS ₂ solid lubricant according to Example 1 of the present invention.

Detailed ways

It should be noted that the following detailed description is illustrative and is intended to provide a further description of the application. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise indicated.

It is to be noted that the terminology used herein is for the purpose of describing particular embodiments, and is not intended to limit the exemplary embodiments. As used herein, the singular " " " " " " There are features, steps, operations, devices, components, and/or combinations thereof.

As described in the background art, the prior art single surface abrasion resistance treatment technology still has a problem that the friction requirement cannot be satisfied; therefore, the present invention provides a method for improving the surface abrasion resistance of an aluminum alloy under dry friction conditions. The invention will now be further described in conjunction with the drawings and specific embodiments.

Example 1:

A method for improving the wear resistance of an aluminum alloy surface under dry friction conditions, comprising the following steps:

1) Surface micro-texture: In order to reduce the burrs generated on the cutting surface, the prepared PMMA colloid is uniformly coated on the surface of the ZL109 aluminum-silicon alloy to be processed, and the micro-pits are processed on the surface of the aluminum-silicon alloy by micro-milling technology. The texture and processing micro-texture parameters are: KERN2522 five-axis micro-milling, cutting speed is 20000r/min, axial cutting depth is 10μm, feed rate is 60mm/min, and the micro-texture after processing contains two sides. The rectangular micro-pits of the arc have length, width, spacing, and depth of 600, 200, 1000, and 50 μm, respectively, and the surface micro-texture area density is 15%, and the distribution angle is 60°.

2) Removal of PMMA: The processed aluminum alloy was placed in an acetone solution and placed in an ultrasonic cleaner for 5 minutes to remove PMMA to obtain a machined part.

3) Deburring: The deburring brush is used to remove the burrs generated on the machined surface to further reduce the influence of the micro-textured burrs on the micro-machining surface on the anodizing experiment, resulting in uneven discharge.

4) pre-anodizing the surface of the aluminum alloy having the surface micro-texture in the step 3), specifically comprising:

a) Ultrasonic cleaning: in order to remove the oil stain on the surface of the aluminum alloy which has been subjected to surface microtexture processing in step 3), improve the bonding strength of the rubber coating, and ultrasonically clean the surface of the aluminum alloy with acetone, alcohol and deionized water respectively. The texture is 5-10 min each.

b) Gluing: Since it is only necessary to form a porous alumina film on the surface to be microtextured, it is necessary to uniformly coat the other five surfaces of the aluminum alloy with a structural adhesive, which means: The adhesive is uniformly applied to the surface of the aluminum alloy and fully cured. The structural adhesive is good for the brothers, which is an AB type glue; wherein the main component of the agent A is acrylate, and the main component of the agent B is a curing agent. After mixing the agent A and the agent B, it is applied to the surface of the aluminum alloy to be processed within 3 minutes and cured for 24 hours.

c) alkali etching: at room temperature, soaked in 5g / L NaOH, 20g / L Na ₃ PO ₄ , 20g / LNaCO ₃ solution, 2-3min; to completely remove the natural oxidation formed on the surface of aluminum alloy membrane;

d) washing with water; cleaning the surface of the alkali etching with deionized water for 30 s to prevent the alkali etching solution from staying on the surface, affecting the subsequent pickling process;

e) pickling: at 60 ° C, soaked in a volume concentration of 60% H ₃ PO ₄ , 40% H ₂ SO ₄ , an appropriate amount of Na ₂ CO ₃ for 3 min; to remove surface scratches;

f) Washing: Wash the surface with deionized water for 40s to prevent the pickling solution from staying on the surface, affecting the subsequent ash removal process;

g) ash removal: immersed in HNO ₃ with a volume concentration of 50%, 5% HF for 2 min, respectively; to remove the surface layer formed by various metal compound particles remaining on the surface of the aluminum alloy after alkali etching;

h) Washing: Wash the ash removal surface with deionized water for 25 s to avoid the ash removal solution staying on the surface and affect the subsequent anodization process;

4) Anodizing the surface of the aluminum alloy treated in step 3), including:

The aluminum alloy processed with surface micro-texture is placed in an electrochemical reaction cell for anodization, and the parameters for adjusting the anodization are: 4 wt% phosphoric acid solution, using a two-electrode configuration, an aluminum sheet as an anode, a lead sheet as a cathode, and two electrodes. The distance between the electrodes was 10 mm, the constant DC current density was 0.025 A/cm ² , the time was 35 min, and the electrolyte temperature was maintained at 20 ± 1 ° C.

A uniform porous alumina mold having a diameter of 220 nm and a diameter of 220 nm may be formed on the surface of the aluminum alloy;

5) Ultrasonic deposition of the nanosolid lubricant for the aluminum alloy treated in step 4), including:

The nanosolid lubricant is made into a nanoparticle suspension, and the suspension is subjected to ultrasonic vibration treatment. The ultrasonically oscillated nanoparticle suspension is placed in a sonicator tank, and the anodized micro-textured aluminum alloy test piece is immersed in the solution, and then the ultrasonicator is activated to deposit the nano-solid lubricant particles to the porous alumina. in.

In step 5), the ultrasonic frequency of the oscillating process is 20 kHz, and the time is 1 h.

In step 5), the time for ultrasonic deposition of the nanosolid lubricant is 25 min.

In step 5), the surface of the anodized micro-textured aluminum alloy is irradiated toward the ultrasonic wave propagation direction, so that the surface of the aluminum alloy has a good deposition effect.

In the step 5), the nano solid lubricant is a suspension prepared from nano MoS ₂ particles, and the preparation method thereof is: ammonium sulfate 50 g/L, Triton (polyethylene glycol to isooctylphenyl ether) 20 wt% , nano MoS ₂ particles 14g / L, pH value 10.5, temperature 25 ° C; wherein Triton is a dispersant of MoS ₂ particle suspension; PH value is adjusted with ammonia water.

6) The ZL109 silicon aluminum alloy of the nano-solid lubricant in the step 5) was ultrasonically dried in an oven at 120 ° C for 3 h to improve the adhesion strength of the nano MoS ₂ particles to the substrate.

The ZL109 silicon aluminum alloy prepared in this example, the untreated ZL109 aluminum silicon alloy, and the ZL109 aluminum silicon alloy which was only subjected to surface microtexture treatment were subjected to friction and wear performance tests, and the results are shown in FIG. 4 . The test conditions were as follows: surface contact pin-disc reciprocating friction wear, friction speed of 0.05 m/s, load of 10 N, and running time of 15 min, and a friction coefficient curve was obtained. As can be seen from FIG. 4, the friction coefficient of the ZL109 silicon aluminum alloy prepared in this embodiment, the untreated ZL109 aluminum silicon alloy, and the ZL109 aluminum silicon alloy which was only subjected to the surface microtexture treatment was reduced by 22.6% and 21.3%. In addition, the wear scars of the above three ZL109 silicon aluminum alloys were observed under the scanning electron microscope under the scanning electron microscope. The results are shown in Fig. 5. It can be seen from Fig. 5 that the ZL109 regular alloy surface deposited with the nano MoS ₂ solid lubricant The micro-texture and its micro-texture have almost no wear, while the untreated ZL109 aluminum-silicon alloy and the surface micro-texture-treated ZL109 aluminum-silicon alloy have severe surface and micro-texture wear.

Example 2:

e) pickling: soaking in a volume concentration of 60% H ₃ PO ₄ , 40% H ₂ SO ₄ , an appropriate amount of Na ₂ CO ₃ for 2 min at 50 ° C; to remove scratches on the surface;

f) Washing: Wash the surface with deionized water for 40s to avoid the pickling solution staying on the surface, affecting the subsequent ash removal process;

g) ash removal: immersed in HNO ₃ with a volume concentration of 50%, 5% HF for 1 min, respectively; to remove the surface layer formed by various metal compound particles remaining on the surface of the aluminum alloy after alkali etching;

4) Anodizing the surface of the aluminum alloy treated in step 3), including:

The aluminum alloy processed with surface micro-texture is placed in an electrochemical reaction cell for anodization, and the parameters for adjusting the anodization are: 4 wt% phosphoric acid solution, using a two-electrode configuration, an aluminum sheet as an anode, a lead sheet as a cathode, and two electrodes. The distance between the electrodes was 10 mm, the constant DC current density was 0.025 A/cm ² , the time was 30 min, and the electrolyte temperature was maintained at 20 ± 1 ° C.

A uniform porous alumina mold having a diameter of 200 nm and a pore diameter of 200 nm may be formed on the surface of the aluminum alloy;

The nanosolid lubricant is suspended into a nanoparticle suspension, and the suspension is subjected to ultrasonic vibration treatment. The ultrasonically oscillated nanoparticle suspension is placed in a sonicator tank, and the anodized micro-textured aluminum alloy test piece is immersed in the solution, and then the ultrasonicator is activated to deposit the nano-solid lubricant particles to the porous alumina. in. The reason for using the ultrasonic vibration treatment is to better disperse the solid particles because the agglomeration is liable to occur due to the nanoparticles.

In step 5), the time for ultrasonic deposition of the nanosolid lubricant is 20 min.

6) The ZL109 silicon aluminum alloy in which the nanosolid lubricant was ultrasonically deposited in the step 5) was dried in an oven at 150 ° C for 1 h to improve the adhesion strength of the nano MoS ₂ particles to the substrate.

The above description is only a preferred embodiment of the present application, and is not intended to limit the present application, and various changes and modifications may be made by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application are intended to be included within the scope of the present application.

Claims

A method for improving wear resistance of an aluminum alloy surface under dry friction; characterized in that the method comprises the following steps:

1) Surface micro-texture: micro-texture is formed on the surface of the aluminum alloy by micro-texturing processing technology;

2) pre-anodizing the surface of the aluminum alloy having surface microtexture in step 1), including: a) ultrasonic cleaning; b) gluing; c) alkali etching; d) water washing; e) pickling; Water washing; g) ash removal; h) water washing;

3) Anodizing the surface of the aluminum alloy treated in the step 2), comprising: placing the surface-treated micro-alloyed aluminum alloy in an electrochemical reaction cell for anodization, and forming porous oxidation having a certain thickness and pore diameter on the surface thereof. Aluminum film layer;

4) Ultrasonic deposition of the nano-solid lubricant for the aluminum alloy of the anodizing step in the step 3), comprising: preparing the nano-solid lubricant into a nanoparticle suspension, and performing ultrasonic vibration treatment on the suspension; and ultrasonically oscillating the nanometer The particle suspension is placed in a sonicator tank, and the anodized micro-textured aluminum alloy test piece is immersed in the solution, and then the ultrasonic meter is activated;

5) Drying the aluminum alloy of the nano-solid lubricant by ultrasonic deposition in step 4) in an oven.
The method for improving the surface wear resistance of an aluminum alloy under dry friction conditions according to claim 1, wherein in the step 1), the micro-texturing processing technology comprises laser processing, mechanical processing, shot peening, etching Processing Technology;

Preferably, in step 1), the micro-pit texture is processed on the surface of the aluminum-silicon alloy by using a micro-milling technique, and the micro-texture parameters are processed by the micro-milling technique: using KERN2522 five-axis micro-milling, cutting speed It is 20000r/min, the axial cutting depth is 10μm, and the feed speed is 60mm/min;

Preferably, in step 1), the micro-texture is a rectangular micro-pit containing two arcs, the length, the width, the spacing, and the depth are 600, 200, 1000, and 50 μm, respectively, and the surface micro-texture area density is 15%, the distribution angle is 60°;

Preferably, in step 1), the PMMA colloid is uniformly coated on the surface of the aluminum alloy to be processed, and then the micro-texture is formed on the surface of the aluminum alloy by micro-texturing processing technology.
The method for improving the surface wear resistance of an aluminum alloy under dry friction conditions according to claim 2, wherein in the step 1), the processed aluminum alloy is placed in an acetone solution and placed in an ultrasonic cleaner for 5 minutes. Remove the PMMA colloid.
The method for improving the surface wear resistance of an aluminum alloy under dry friction conditions according to claim 1, wherein in the step 1), after the aluminum alloy is processed, the burr generated by the surface of the aluminum alloy is removed by a deburring brush.
The method for improving the surface wear resistance of an aluminum alloy under dry friction conditions according to claim 1, wherein in the step 2), the ultrasonic cleaning means: ultrasonically cleaning the surface of the aluminum alloy with acetone, alcohol and deionized water respectively. Micro-texture each 5-10min;

In step 2), the coating means that the structural adhesive is uniformly applied to the surface of the aluminum alloy and is sufficiently cured; preferably, the structural adhesive is AB type glue; wherein the main component of the agent A is acrylate, B agent The main component is a curing agent, and the A agent and the B agent are mixed in a ratio of 1:1, coated on the surface of the aluminum alloy to be processed, and cured for 24 hours; further preferably, the structural adhesive is a good glue for the two brothers;

The alkali etching refers to: immersing in a solution of 5 g / L of NaOH, 20 g / L of Na 3 PO 4 , 20 g / L of NaCO 3 at room temperature for 2-3 min;

The water washing refers to: cleaning the surface of the aluminum alloy with deionized water for 30-40 s;

The pickling means: immersing in a volume concentration of 60% H 3 PO 4 , 40% H 2 SO 4 , an appropriate amount of Na 2 CO 3 for 2-3 minutes at 50-60 ° C;

The ash removal means: immersing in a volume concentration of 50% HNO 3 and 5% HF for 1-2 min at room temperature.
The method for improving the surface wear resistance of an aluminum alloy under dry friction conditions according to claim 1, wherein in the step 3), the parameter of the anodization is: 4 wt% phosphoric acid solution, using a two-electrode configuration, aluminum The sheet was used as the anode and the lead sheet was used as the cathode. The distance between the two electrodes was 10 mm, the constant DC current density was 0.025 A/cm 2 , the time was 30-35 min, and the electrolyte temperature was maintained at 20 ± 1 ° C.
The method for improving the surface wear resistance of an aluminum alloy under dry friction conditions according to claim 1, wherein in the step 3), the porous alumina film layer has a thickness of 3-5 mm, and the porous alumina film layer The diameter of the aperture is 200-220 nm;

In step 4), the ultrasonic frequency of the oscillating process is 20 kHz, and the time is 1 h;

In step 4), the time for ultrasonic deposition of the nanosolid lubricant is 20-25 min.
The method for improving the surface wear resistance of an aluminum alloy under dry friction conditions according to any one of claims 1 to 7, characterized in that in step 4), the surface of the anodized micro-textured aluminum alloy is irradiated to the ultrasonic wave. Direction, so that the aluminum alloy surface has a good deposition effect.
The method for improving the surface wear resistance of an aluminum alloy under dry friction conditions according to claim 8, wherein in the step 4), the nano solid lubricant is a suspension prepared from nano MoS 2 particles, and the preparation method thereof is : ammonium sulfate 50g / L, polyethylene glycol to isooctyl phenyl ether 20wt%, nano MoS 2 particles 14g / L, pH 10.5, temperature 25 ° C; wherein polyethylene glycol to isooctyl phenyl ether a dispersing agent for the MoS 2 particle suspension; the pH is adjusted with aqueous ammonia;

In step 5), the drying temperature is 120-150 ° C and the time is 1-3 h.
The method for improving the surface abrasion resistance of an aluminum alloy under dry friction conditions according to any one of claims 1 to 9 for use in the surface abrasion resistance treatment of a metal material.