阅读说明：本技术 应用于柱塞泵滑靴基体的超疏油涂层制备方法 (Preparation method of super-oleophobic coating applied to plunger pump sliding shoe substrate ) 是由 王冬云 李飞越 王琳琳 王晓明 于 2020-12-04 设计创作，主要内容包括：本发明涉及金属表面改性技术领域,公开了一种应用于柱塞泵滑靴基体的超疏油涂层制备方法。其制备方法包括：通过浸渍提拉镀膜机将经过表面粗糙度处理的滑靴基体以预定的浸渍速度、浸渍时间和提拉速度放置在制备的勃姆石溶胶中进行浸渍；然后经过干燥、第一次热处理、水浴处理、第二次热处理、在氟硅烷溶液中进行浸渍以及第三次热处理以在滑靴基体表面形成超疏油涂层。通过上述技术方案的设置,以构造超疏油特性,从而通过高接触角和显著滑移效应达到改善磨损、降低摩擦系数的目的,进而提高柱塞泵效率和寿命。(The invention relates to the technical field of metal surface modification, and discloses a preparation method of a super-oleophobic coating applied to a piston shoe substrate of a plunger pump. The preparation method comprises the following steps: dipping the slide shoe substrate subjected to surface roughness treatment in the prepared boehmite sol by a dip coating machine at a preset dipping speed, dipping time and a pulling speed; and then drying, carrying out first heat treatment, carrying out water bath treatment, carrying out second heat treatment, dipping in fluorosilane solution and carrying out third heat treatment to form the super oleophobic coating on the surface of the slipper substrate. Through the setting of above-mentioned technical scheme to construct super oleophobic characteristic, thereby reach the purpose that improves wearing and tearing, reduce coefficient of friction through high contact angle and showing the slippage effect, and then improve plunger pump efficiency and life-span.)

1. A preparation method of a super oleophobic coating applied to piston shoes of a plunger pump is characterized in that a sealing tape is arranged at the bottom of a piston shoe substrate, a friction surface of the sealing tape is impregnated with the super oleophobic coating, and the super oleophobic coating is a nano alumina ceramic coating, and the preparation method comprises the following steps:

s1, dipping the slide shoe substrate subjected to surface roughness treatment in the prepared boehmite sol by a dip coating machine at preset dipping speed, dipping time and pulling speed;

s2, putting the slipper base body into an oven for drying at a preset temperature and time;

s3, putting the sliding shoe substrate into a muffle furnace for first heat treatment at preset temperature and time;

s4, carrying out water bath treatment on the slipper substrate for a preset time;

s5, carrying out secondary heat treatment on the slipper base body at preset temperature and time;

s6, placing the substrate in a fluorosilane solution for dipping at a preset dipping speed, dipping time and pulling speed through a dipping and pulling film coating machine;

s7 subjecting the slipper substrate to a third heat treatment at a predetermined temperature and time.

2. The preparation method of the superoleophobic coating applied to piston shoes of the plunger pump according to claim 1, characterized in that the preparation step of the boehmite sol comprises:

mixing deionized water, ethyl acetoacetate and aluminum sec-butoxide according to the molar ratio of 100:1:1, and stirring at constant speed for 20 minutes;

adding a nitric acid solution to ensure that the molar ratio of nitric acid to sec-butyl aluminum is 1.5-1.7: 1, adjusting the pH of the solution to 3.5-4.1, and then stirring at a constant speed for 30 minutes;

standing at 70 deg.C for 24 hr to form boehmite sol with average particle size of 60-100 nm.

3. The preparation method of the superoleophobic coating applied to the piston shoe of the plunger pump according to claim 1, characterized in that the step of surface roughness treatment of the piston shoe substrate comprises:

treating the sealing tape by sand blasting, polishing to form a roughness of about 4-5 microns on the rubbing surface thereof;

and removing oxides and oil stains on the surface of the slipper substrate by acetone ultrasonic cleaning.

4. The preparation method of the super oleophobic coating applied to piston shoes of the plunger pump according to claim 1,

in said S1, the dipping speed is 2mm/S, the dipping time is: 5s, pull rate: 2 mm/s;

in the above-mentioned S6, the dipping speed was 2mm/S, the dipping time was 2min, and the pulling speed was 2 mm/S.

5. The preparation method of the superoleophobic coating applied to piston shoes of the plunger pump according to claim 4, characterized in that the piston shoe substrate is impregnated along a direction parallel to the sealing belt rubbing surface.

6. The preparation method of the super oleophobic coating applied to piston shoes of the plunger pump according to claim 1,

in the S2, the drying temperature is 100 ℃, and the drying time is 10 min;

in S4, the water bath time is 30 min.

7. The preparation method of the super oleophobic coating applied to piston shoes of the plunger pump according to claim 1,

in the S3, the mixture is treated in a muffle furnace at 400 ℃ for 60 minutes;

in the S5, the mixture is treated in a muffle furnace at 400 ℃ for 10 minutes;

in said S7, the mixture was treated in a muffle furnace at 150 ℃ for 30 minutes.

8. The preparation method of the superoleophobic coating applied to the piston shoe of the plunger pump according to claim 1, characterized in that the thickness of the superoleophobic coating is 1-3 microns.

9. The preparation method of the superoleophobic coating applied to the piston shoe of the plunger pump according to claim 1, characterized in that the roughness of the superoleophobic coating is 1.5-2.5 microns.

10. The preparation method of the superoleophobic coating applied to the piston shoe of the plunger pump according to claim 1, characterized in that the sealing tape material of the bottom of the piston shoe substrate is ZQAl 9-4.

Technical Field

The invention relates to the technical field of metal surface modification, in particular to a preparation method of a super-oleophobic coating applied to a piston shoe substrate of a plunger pump.

Background

The piston shoe pair is used as a key friction pair of the plunger pump, the friction parts of the piston shoe pair are the piston shoe and a swash plate, the motion and stress conditions of the piston shoe pair are complex, the piston shoe uses the swash plate as a support to push the plunger to move axially, and simultaneously slides on the swash plate at a high speed, the piston shoe bears the hydraulic pressure on one side of the plunger, the supporting force of the swash plate, the pressure of a return plate, the self inertia force and the friction force, the piston shoe can overturn under the action of centrifugal force and friction force to cause eccentric wear of the piston shoe, the pressure distribution of an oil film at the bottom of the piston shoe is further damaged, the stress unbalance, the friction coefficient and the local temperature of the piston shoe are increased rapidly, the wear is intensified, the phenomena of 'shoe burning' and 'disc burning' are further caused.

To date, countless hydraulic technologists at home and abroad continuously improve the hydraulic piston pump, but the basic principle and the structure of the hydraulic piston pump still cannot realize major breakthrough, and the problem of wear of a sliding shoe pair is increasingly serious along with the continuous development of the axial piston pump towards high speed, high pressure and large flow.

Disclosure of Invention

The invention aims to provide a preparation method of a super-oleophobic coating applied to a piston shoe substrate of a plunger pump, which can solve the problem that the wear problem of a piston shoe pair in the prior art is increasingly serious.

In order to achieve the purpose, the invention provides a preparation method of a super oleophobic coating applied to a piston shoe of a plunger pump, wherein the bottom of a piston shoe substrate is provided with a sealing belt, the friction surface of the sealing belt is impregnated with the super oleophobic coating, and the super oleophobic coating is a nano alumina ceramic coating, and the preparation method comprises the following steps:

s1, dipping the slide shoe substrate subjected to surface roughness treatment in the prepared boehmite sol by a dip coating machine at preset dipping speed, dipping time and pulling speed;

s2, putting the slipper base body into an oven for drying at a preset temperature and time;

s3, putting the sliding shoe substrate into a muffle furnace for first heat treatment at preset temperature and time;

s4, carrying out water bath treatment on the slipper substrate for a preset time;

s5, carrying out secondary heat treatment on the slipper base body at preset temperature and time;

s6, placing the substrate in a fluorosilane solution for dipping at a preset dipping speed, dipping time and pulling speed through a dipping and pulling film coating machine;

s7 subjecting the slipper substrate to a third heat treatment at a predetermined temperature and time.

Further, the preparation step of the solution comprises:

mixing deionized water, ethyl acetoacetate and aluminum sec-butoxide according to the molar ratio of 100:1:1, and stirring at constant speed for 20 minutes;

adding a nitric acid solution to ensure that the molar ratio of nitric acid to sec-butyl aluminum is 1.5-1.7: 1, adjusting the pH of the solution to 3.5-4.1, and then stirring at a constant speed for 30 minutes;

standing at 70 deg.C for 24 hr to form boehmite sol with average particle size of 60-100 nm.

Further, the step of surface roughness treatment of the slipper substrate comprises:

the bottom of the slipper base body is provided with a sealing belt, and the sealing belt is processed by sand blasting and polishing to form roughness of about 4-5 microns on the surface of the sealing belt;

and removing oxides and oil stains on the surface of the slipper substrate by acetone ultrasonic cleaning.

Further, in said S1, the dipping speed is 2mm/S, the dipping time: 5s, pull rate: 2 mm/s;

in the above-mentioned S6, the dipping speed was 2mm/S, the dipping time was 2min, and the pulling speed was 2 mm/S.

Further, the slipper substrate is impregnated in a direction parallel to the sealing strip of the bottom of the slipper substrate.

Further, in the step S2, the drying temperature is 100 ℃, and the drying time is 10 min;

in S4, the water bath time is 30 min.

Further, in the S3, the mixture is processed in a muffle furnace at 400 ℃ for 60 minutes;

in the S5, the mixture is treated in a muffle furnace at 400 ℃ for 10 minutes;

in said S7, the mixture was treated in a muffle furnace at 150 ℃ for 30 minutes.

Further, the thickness of the super oleophobic coating is 1-3 microns.

Further, the roughness of the super oleophobic coating is 1.5-2.5 microns.

Furthermore, the sealing tape material of the bottom of the slipper base body is ZQAl 9-4.

According to the invention, the super oleophobic coating of the alumina ceramic with a specific nanoscale rough structure and lower surface free energy is formed on the friction surface of the sliding shoe by a sol-gel method to construct the super oleophobic characteristic, so that the purposes of improving abrasion and reducing friction coefficient are achieved by high contact angle and obvious slip effect, and further the efficiency and the service life of the plunger pump are improved.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

FIG. 1 is a schematic view of the construction of a slipper base.

Description of the reference numerals

1 sliding shoe substrate 2 superoleophobic coating

Detailed Description

The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

In order to solve the problem that the wear problem of the sliding shoe pair in the prior art is increasingly serious, the embodiment of the invention is further described with reference to the attached drawings:

as shown in figure 1, the preparation method of the super oleophobic coating applied to the piston shoe of the plunger pump comprises a piston shoe substrate 1, wherein a sealing strip at the bottom of the piston shoe substrate 1 is provided with a super oleophobic coating 2, in particular to a nano alumina ceramic coating. The specific preparation method comprises the following steps:

a sol preparation step, mixing deionized water, ethyl acetoacetate and aluminum sec-butoxide according to a molar ratio of 100:1:1, stirring at a constant speed for 20 minutes, obtaining small-particle boehmite precipitate after hydrolysis reaction, and then addingThe method comprises the following steps of (1) preparing a nitric acid solution, adjusting the molar ratio of nitric acid to aluminum sec-butoxide to 1.5-1.7: 1, adjusting the pH of the solution to 3.5-4.1 to control the reaction process, enabling colloidal particles to carry positive charges to avoid aggregation of nanoparticles, and stirring at a constant speed for 30 minutes to form a suspension; finally, standing for 24 hours at 70 ℃ to form stable and transparent boehmite sol with the average particle size of 60-100 nm; preferably, to mitigate the rate of aluminum sec-butoxide dissolution in water, the production of Al (OH) is avoided₃Precipitation, firstly adding ethyl acetoacetate into water; secondly, aluminum sec-butoxide is added to the water.

The method comprises the following steps of (1) carrying out surface roughness treatment on a sealing belt at the bottom of a sliding shoe substrate 1, forming microscale roughness of about 4-5 microns by carrying out sand blasting treatment and polishing treatment on the sealing belt at the bottom of the sliding shoe substrate 1, and then carrying out ultrasonic cleaning on the sliding shoe substrate 1 by acetone to remove oxides and oil stains on the surface of the sliding shoe substrate 1 so as to improve the surface coating adhesive force of the sliding shoe substrate 1;

a dipping and coating step, namely placing the slipper substrate 1 subjected to surface roughness treatment in the prepared boehmite sol through a dipping and pulling coating machine, and dipping in a direction parallel to the sealing tape at the bottom of the slipper as shown in figure 1, wherein the dipping conditions are as follows: dipping speed 2mm/s, dipping time: 5s, pull rate: 2 mm/s;

the following treatment is then required for the shoe substrate 1 impregnated in the above process:

drying, namely drying in an oven at 100 ℃ for 10min to obtain dry gel;

a first heat treatment step, namely treating the film in a muffle furnace at 400 ℃ for 60 minutes to obtain a gamma-alumina nano film;

a water bath treatment step, namely performing water bath for 30 minutes to form a flower-shaped nano-structure film;

a second heat treatment step, namely treating the gamma-alumina nano film in a muffle furnace at the temperature of 400 ℃ for 10 minutes to reinforce the gamma-alumina nano film;

a low surface energy modification step, wherein in order to reduce the surface free energy, the substrate is placed in a fluorosilane solution for dipping by a dipping and pulling coating machine, and the specific dipping conditions are as follows: the dipping speed is 2mm/s, the dipping time is 2min, and the pulling speed is 2 mm/s;

and a third heat treatment step, namely treating the film in a muffle furnace at 150 ℃ for 30 minutes to crosslink the gamma-alumina nano film and the fluoride layer so as to reinforce the coating.

The super oleophobic coating 2 adopts a sol-gel method as a coating preparation method, the prepared coating has the advantages of low temperature in the reaction process, high chemical uniformity, easy control of the reaction process, adjustable gel microstructure, low cost, simple equipment and the like, and the super oleophobic coating 2 which is specifically a nano alumina ceramic coating can be obtained by controlling the proportion of aluminum sec-butoxide, deionized water, ethyl acetoacetate and nitric acid solution and subsequent treatment conditions.

The oleophobic property of the super oleophobic coating 2 can increase the contact angle, reduce the wettability of the surface of the sliding shoe and oil, and reduce the friction between the surface of the sliding shoe and the oil, thereby reducing the surface heating of the sliding shoe and reducing the adhesion abrasion; the specific micro-nano composite rough structure of the super oleophobic coating 2 can enhance the phenomenon of interface slippage and reduce the interaction of flow and solid phases, thereby reducing the friction force; the super oleophobic coating 2 on the surface of the sliding shoe substrate 1 maintains the reduction rate of the friction coefficient at 20% -30% under the complete machine replacement test under different pressure and rotating speed working conditions.

The superoleophobic coating 2 is further formed to a thickness of 1-3 microns.

The further superoleophobic coating 2 is formed with a roughness of 1.5-2.5 microns.

Preferably, the material of the sealing tape friction surface is ZQAl 9-4.

Example 1

The superoleophobic coating 2 was prepared according to the method described above, in which, in the solution preparation step, the molar ratio of nitric acid to aluminum sec-butoxide was 1.6, and the solution pH was adjusted to 3.64.

Example 2

And (3) preparing a super oleophobic coating 2 based on the preparation method of the example 1, and removing the surface roughness treatment of the sealing tape at the bottom of the sliding shoe substrate 1.

Example 3

The superoleophobic coating 2 was produced on the basis of the production method of example 1, in which only the dipping speed and the pull-up speed in the dipping coating step and the low surface energy modification step were replaced with 3 mm/s.

Example 4

A superoleophobic coating 2 was produced based on the production method of example 1, in which only the temperatures in the first heat treatment step and in the second heat treatment step were replaced with 450 ℃.

Example 5

A superoleophobic coating 2 was prepared based on the preparation method of example 1, in which only the temperature in the third heat treatment step was replaced with 100 ℃.

Comparative example

The standard sample was the slipper substrate 1 without any treatment.

To further explore the performance of this superoleophobic coating, the surface performance characterization parameters (water contact angle, surface free energy, and oil contact angle) of the shoe bottom sealing strips of examples 1-5 and comparative example were compared, for the following table:

	water contact Angle (°)	Surface free energy (mN/m)	Oil contact Angle (°)
				Comparative example	74.7±1.1	38.67±1.00	16.8±2.2
Example 1	157.8±2.5	0.48±0.05	122.8±11.9
				Example 2	110.8±5.6	15.6±1.19	98.7±7.6
Example 3	136.1±3.0	12.7±0.13	120.7±6.3
				Example 4	141.5±3.2	2.02±0.57	112.7±11.6
Example 5	130.5±4.6	1.83±0.69	113.6±12.4

It should be noted that the comparative parameters of the comparative example and examples 1 to 5 are the average values of five sets of the samples of the shoe base 1. The oil liquid used for measuring the oil contact angle is No. 46 antiwear hydraulic oil.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.