High-temperature-resistant diaphragm pump piston rod coating as well as preparation method and application thereof

Abstract

The invention relates to a high-temperature-resistant diaphragm pump piston rod coating and a preparation method and application thereof, and belongs to the technical field of diaphragm pumps. A polytetrafluoroethylene piston rod is prepared and subjected to roughening treatment; spraying titanium metal powder by a spray gun, wherein the thickness is not less than 1.5 mm; the piston rod is subjected to infiltration treatment, an infiltration treatment agent comprises 20-40 parts of a silane coupling agent and 10-30 parts of hydroxyl cellulose, and the piston rod is dried after being infiltrated for 10-30 min; preparing a high-temperature-resistant coating material comprising 100 parts of polytetrafluoroethylene, 20-30 parts of high-temperature-resistant epoxy glue, 4-10 parts of silane coupling agent modified carbon nanotubes and 3-6 parts of a dispersing agent; the spraying thickness is 3-6 mm, heat preservation is carried out at the temperature of 80-120 DEG C, high-temperature plasticizing is carried out at the temperature of 280-320 DEG C, and after cooling, polishing and flattening are carried out. According to the scheme, the strength and wear resistance of the piston rod at high temperature can be obviously improved, the service life is prolonged, and the operation stability of the diaphragm pump is improved.

Description

Technical Field

[0001] This application relates to a high-temperature resistant diaphragm pump piston rod coating, its preparation method, and its application, belonging to the field of diaphragm pump technology. Background Technology

[0002] A diaphragm pump is a device used to transport liquid media. By receiving signals from a regulator or computer, the flow rate of the controlled medium can be changed. The piston rod drives the piston to reciprocate, thereby pushing the diaphragm to realize the suction and discharge process of the diaphragm pump. It is the main moving part of the diaphragm pump.

[0003] On the one hand, the raw material liquids transported by diaphragm pumps require temperatures of 120°C or even as high as 180°C in some applications. Therefore, the piston rod in the diaphragm pump also needs good high-temperature resistance. On the other hand, since diaphragm pumps are currently small in size, they have high flow rate requirements in some applications. This requires the diaphragm pump to have a very high stroke rate and a very high reciprocating frequency of the piston. This requires the piston rod and piston to reciprocate continuously. During this process, heat is continuously generated, causing the piston rod temperature to rise. This shortens the service life of the piston rod due to the high temperature and makes it prone to deformation or even breakage, thus affecting the operational stability of the diaphragm pump.

[0004] Therefore, it is necessary to propose an improvement measure for the piston rod to solve the problem of poor operational stability of diaphragm pumps caused by its insufficient high-temperature resistance. Summary of the Invention

[0005] To address the aforementioned issues, a high-temperature resistant diaphragm pump piston rod coating, its preparation method, and its application are provided. The built-in titanium layer significantly improves the piston rod's strength, reduces deformation at high temperatures, and minimizes the risk of direct breakage. Furthermore, the outer high-temperature resistant coating material enhances wear resistance at high temperatures and improves overall strength, thereby significantly extending the piston rod's service life at high temperatures and improving the diaphragm pump's operational stability.

[0006] This application provides a method for preparing a high-temperature resistant coating for a diaphragm pump piston rod, characterized by comprising the following steps: S1. Prepare a piston rod made of polytetrafluoroethylene (PTFE), roughen the surface of the piston rod, clean it and dry it for later use. S2. Use a spray gun filled with titanium metal powder to spray the surface of the piston rod, controlling the spray thickness to be no less than 1.5mm, to obtain a titanium layer; S3. Immerse the sprayed piston rod in the wetting agent for wetting treatment. The wetting agent includes 20-40 parts of silane coupling agent and 10-30 parts of hydroxy cellulose by weight. After wetting for 10-30 minutes, remove the piston rod and dry it while keeping it in a rotating state to make the wetting agent evenly adhere to the entire titanium layer. After drying, it is ready for use. S4. Prepare a high-temperature resistant coating material, which includes the following raw materials in parts by weight: 100 parts of polytetrafluoroethylene, 20-30 parts of high-temperature resistant epoxy adhesive, 4-10 parts of silane coupling agent modified carbon nanotubes, and 3-6 parts of dispersant. S5. Load the high-temperature resistant coating material into the spray gun and spray it onto the dried piston rod surface. Control the high-temperature resistant coating material to cover the entire piston rod, and the spray thickness is 3~6mm. After spraying, keep it at 80~120℃, and then put it into a high temperature of 280~320℃ for plasticization. After cooling, grind it smooth to obtain a piston rod containing the high-temperature resistant diaphragm pump piston rod coating.

[0007] Optionally, the preparation method of the silane coupling agent modified carbon nanotubes includes the following steps: 1) Prepare a 60-80 vol% ethanol solution, add silane coupling agent and stir for at least 1 hour; 2) Add carbon nanotubes and continue stirring for at least 2 hours; 3) After stopping stirring, let it stand for at least 5 hours; 4) After centrifugation, the precipitate was separated by filtration and dried to obtain silane coupling agent modified carbon nanotube composite powder.

[0008] Optionally, the silane coupling agent used in step S3 is selected from one or more of KH560 and KH570; and / or The silane coupling agent used in the silane coupling agent modified carbon nanotubes is selected from one or more of KH560 and KH570.

[0009] Optionally, the silane coupling agent used in step S3 and the silane coupling agent used in the silane coupling agent modified carbon nanotubes are KH560.

[0010] Optionally, the carbon nanotube is a multi-walled carbon nanotube, with a diameter of 20-30 nm and a length of 80-100 μm.

[0011] Optionally, before immersing the sprayed piston rod in the wetting agent for wetting treatment in step S3, the step further includes a step of heat-treating the dried piston rod at 80~100℃ for at least 1 hour.

[0012] Optionally, in step S1, the surface to be sprayed is roughened by mechanical cutting, and the surface roughness Ra value is controlled to be between 1.2 and 1.6 μm.

[0013] Optionally, the hydroxycellulose used in step S3 is selected from one or more of hydroxyethyl cellulose, hydroxypropyl cellulose, and hydroxypropyl methylcellulose; and / or, The high-temperature resistant epoxy adhesive is high-temperature resistant epoxy adhesive ZS-1071; and / or, The dispersant is perfluorooctanoic acid (PFOA).

[0014] This application provides the application of the above-mentioned method for preparing a high-temperature resistant diaphragm pump piston rod coating in a diaphragm pump piston rod.

[0015] This application provides a diaphragm pump piston rod, the outer side of which includes a protective coating, the protective coating being prepared by the above-described method for preparing a high-temperature resistant diaphragm pump piston rod coating.

[0016] The beneficial effects of this application include, but are not limited to: 1. According to the high-temperature resistant diaphragm pump piston rod coating, its preparation method and application, the piston rod provided by this application can significantly improve the deformation problem of the piston rod at high temperature by incorporating a built-in titanium layer, significantly improve the rigidity of the piston rod, and significantly reduce the occurrence of fracture. In addition, heat can be conducted through the titanium layer, thereby alleviating the situation where the local temperature of the piston rod is too high, which makes the local deformation and wear more likely to occur.

[0017] 2. According to the high-temperature resistant diaphragm pump piston rod coating, its preparation method and application, the outer layer is coated with a high-temperature resistant coating material by spraying, and the carbon nanotubes modified by adding high-temperature resistant epoxy adhesive and silane coupling agent are combined with polytetrafluoroethylene, which can significantly improve the wear resistance of the piston rod at high temperature and make it less prone to oil / liquid leakage due to wear.

[0018] 3. According to the high-temperature resistant diaphragm pump piston rod coating of this application, its preparation method and application, after the titanium layer is impregnated with the aforementioned wetting agent, the high-temperature resistant coating material is then sprayed, which can improve the interfacial bonding performance between the titanium layer and the high-temperature resistant coating material, reduce the porosity between the titanium layer and the high-temperature resistant coating material, and thus facilitate the conduction of heat through the titanium layer.

[0019] 4. According to the high-temperature resistant diaphragm pump piston rod coating, its preparation method and application, the use of multi-walled carbon nanotubes with specific diameters and lengths in the preparation of silane coupling agent modified carbon nanotubes can significantly improve the wear resistance of the piston rod at high temperatures and extend its service life. Detailed Implementation

[0020] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments. Unless otherwise specified, the raw materials and reagents in the embodiments of the present application are all purchased through commercial channels.

[0021] Example 1 1) Prepare a PTFE piston rod and roughen the surface of the piston rod to be coated by mechanical cutting so that the roughness Ra value reaches 1.4μm. Then, use acetone ultrasonic cleaning for 4 minutes to clean the impurities on the surface of the workpiece. After cleaning, dry it for later use. 2) The piston rod surface was coated with titanium powder using a spray gun, with the coating thickness controlled at 1.5 mm to obtain a titanium layer. Specifically, titanium powder precursors with a particle size of 57 μm were loaded into the spray gun, and supersonic flame spraying was performed on the central columnar region of the piston rod. The combustion chamber pressure of the spray gun containing the titanium powder was 7.2 MPa, the powder feeding rate was 53 g / min, and the spraying distance was 300 mm.

[0022] 3) Prepare the impregnation treatment agent, which includes, by weight, 30 parts of KH560 silane coupling agent and 20 parts of hydroxyethyl cellulose. Add the hydroxyethyl cellulose to the silane coupling agent, heat to 130°C and stir for 1 hour. 4) Heat-treat the dried piston rod at 90℃ for 1 hour, then immerse the sprayed piston rod in the wetting agent for wetting treatment. After wetting for 20 minutes, remove it and dry it while keeping it in a rotating state to make the wetting agent evenly adhere to the entire titanium layer. Heat and dry at 75℃ and set aside for later use. 5) Prepare a high-temperature resistant coating material, which includes the following raw materials in parts by weight: 100 parts polytetrafluoroethylene, 25 parts high-temperature resistant epoxy adhesive ZS-1071, 8 parts silane coupling agent modified carbon nanotubes, and 5 parts perfluorooctanoic acid amine dispersant; add 0.1μm polytetrafluoroethylene resin particles and dispersant to water to form a dispersion, add high-temperature resistant epoxy adhesive and silane coupling agent modified carbon nanotubes while stirring continuously, stir for 3 hours, and filter to obtain the high-temperature resistant coating material; The preparation method of silane coupling agent modified carbon nanotubes includes the following steps: prepare a 70 vol% ethanol solution, add KH560 silane coupling agent and stir for 1 h; add multi-walled carbon nanotubes (diameter 20~30 nm, length 80~100 μm) and continue stirring for 2 h; after stopping stirring, let stand for 5 h; after centrifugation, filter to separate the precipitate, and dry to obtain silane coupling agent modified carbon nanotube composite powder; 6) Load the high-temperature resistant coating material into the spray gun hopper, and atomize the coating with 0.8MPa compressed air. Keep the spray gun perpendicular to the surface of the piston rod, and move the spray gun parallel in one direction. Keep the piston rod rotating slowly along its axial direction. The spray gun moving speed is 10m / min, and the distance between the spray gun and the surface of the rod is 300mm. Spray repeatedly to control the high-temperature resistant coating material to cover the entire piston rod without exposing the titanium layer, and the coating thickness is 5mm. After spraying, place the piston rod in a 100℃ constant temperature drying oven for 45min, and then place it in a 300℃ resistance furnace for 30min to plasticize. After cooling, grind it smooth to obtain the piston rod.

[0023] Example 2 1) Prepare a PTFE piston rod. Roughen the surface of the piston rod to be coated by mechanical cutting so that the roughness Ra value reaches 1.2μm. Then clean the impurities on the workpiece surface with acetone ultrasonic cleaning for 3 minutes. After cleaning, dry it for later use. 2) The piston rod surface was coated with titanium powder using a spray gun, with the coating thickness controlled at 1.5 mm to obtain a titanium layer. Specifically, titanium powder precursors with a particle size of 57 μm were loaded into the spray gun, and supersonic flame spraying was performed on the central columnar region of the piston rod. The combustion chamber pressure of the spray gun containing the titanium powder was 7.2 MPa, the powder feeding rate was 53 g / min, and the spraying distance was 300 mm.

[0024] 3) Prepare the impregnation treatment agent, which includes, by weight, 20 parts of KH570 silane coupling agent and 10 parts of hydroxyethyl cellulose. Add the hydroxyethyl cellulose to the silane coupling agent, heat to 120°C and stir for at least 1 hour. 4) Heat-treat the dried piston rod at 80℃ for 1 hour, then immerse the sprayed piston rod in the wetting agent for wetting treatment. After wetting for 10 minutes, remove it and dry it while keeping it in a rotating state to make the wetting agent evenly adhere to the entire titanium layer. Heat and dry at 50℃ and set aside for later use. 5) Prepare a high-temperature resistant coating material, which includes the following raw materials in parts by weight: 100 parts polytetrafluoroethylene, 20 parts high-temperature resistant epoxy adhesive ZS-1071, 4 parts silane coupling agent modified carbon nanotubes, and 3 parts perfluorooctanoic acid amine dispersant; add 0.1μm polytetrafluoroethylene resin particles and dispersant to water to form a dispersion, add high-temperature resistant epoxy adhesive and silane coupling agent modified carbon nanotubes while stirring continuously, stir for 3 hours, and filter to obtain the high-temperature resistant coating material; The preparation method of silane coupling agent modified carbon nanotubes includes the following steps: prepare a 60 vol% ethanol solution, add KH570 silane coupling agent and stir for 1 h; add multi-walled carbon nanotubes (diameter 20~30 nm, length 80~100 μm) and continue stirring for 2 h; after stopping stirring, let stand for 5 h; after centrifugation, filter to separate the precipitate, and dry to obtain silane coupling agent modified carbon nanotube composite powder; 6) Load the high-temperature resistant coating material into the spray gun hopper, and atomize the coating with 0.8MPa compressed air. Keep the spray gun perpendicular to the surface of the piston rod, and move the spray gun parallel in one direction. The piston rod rotates slowly along its axial direction. The spray gun moves at a speed of 10m / min, and the distance between the spray gun and the surface of the rod is 300mm. Spray repeatedly to ensure that the high-temperature resistant coating material covers the entire piston rod without exposing the titanium layer, and the coating thickness is 3mm. After spraying, place the piston rod in an 80℃ constant temperature drying oven for 30 minutes, and then place it in a 280~320℃ resistance furnace for 20 minutes to plasticize. After cooling, grind it smooth to obtain the piston rod.

[0025] Example 3 1) Prepare a PTFE piston rod and roughen the surface of the piston rod to be coated by mechanical cutting so that the roughness Ra value reaches 1.6μm. Then, use acetone ultrasonic cleaning for 5 minutes to clean the impurities on the surface of the workpiece. After cleaning, dry it for later use. 2) The piston rod surface is sprayed with titanium powder using a spray gun, with the spray thickness controlled to be no less than 1.5 mm, to obtain a titanium layer. Specifically, titanium powder precursors with a particle size of 57 μm are loaded into the spray gun, and supersonic flame spraying is performed on the central columnar region of the piston rod. The combustion chamber pressure of the spray gun containing titanium powder is 7.2 MPa, the powder feeding rate is 53 g / min, and the spraying distance is 300 mm.

[0026] 3) Prepare the impregnation treatment agent, which includes, by weight, 40 parts of KH560 silane coupling agent and 30 parts of hydroxypropyl cellulose. Add the hydroxypropyl cellulose to the silane coupling agent, heat to 150°C and stir for 1 hour. 4) Heat-treat the dried piston rod at 100℃ for 1 hour, then immerse the sprayed piston rod in the wetting agent for wetting treatment. After wetting for 10~30 minutes, take it out and dry it while keeping it in a rotating state so that the wetting agent can be evenly attached to the entire titanium layer. Heat and dry at 80℃ and set aside for later use. 5) Prepare a high-temperature resistant coating material, which includes the following raw materials in parts by weight: 100 parts polytetrafluoroethylene, 30 parts high-temperature resistant epoxy adhesive ZS-1071, 10 parts silane coupling agent modified carbon nanotubes, and 6 parts perfluorooctanoic acid amine dispersant; add 0.1 μm polytetrafluoroethylene resin particles and dispersant to water to form a dispersion, add high-temperature resistant epoxy adhesive and silane coupling agent modified carbon nanotubes while stirring continuously, stir for 3 hours, and filter to obtain the high-temperature resistant coating material; The preparation method of silane coupling agent modified carbon nanotubes includes the following steps: prepare an 80 vol% ethanol solution, add KH560 silane coupling agent and stir for 1 h; add multi-walled carbon nanotubes (diameter 20~30 nm, length 80~100 μm) and continue stirring for 2 h; after stopping stirring, let stand for 5 h; after centrifugation, filter to separate the precipitate, and dry to obtain silane coupling agent modified carbon nanotube composite powder; 6) Load the high-temperature resistant coating material into the spray gun hopper, and atomize the coating with 0.8MPa compressed air. Keep the spray gun perpendicular to the surface of the piston rod, and move the spray gun parallel in one direction. The piston rod rotates slowly along its axial direction. The spray gun moving speed is 10m / min, and the distance between the spray gun and the surface of the rod is 300mm. Spray repeatedly to control the high-temperature resistant coating material to cover the entire piston rod without exposing the titanium layer, and the coating thickness is 6mm. After spraying, place the piston rod in a 120℃ constant temperature drying oven for 60min, and then place it in a 320℃ resistance furnace for 40min to plasticize. After cooling, grind it smooth to obtain the piston rod.

[0027] Comparative Example 1 This comparative example uses a piston rod made of polytetrafluoroethylene, without titanium spraying or high-temperature coating.

[0028] Comparative Example 2 This comparative example is basically the same as Example 1, except that it does not include the step of treatment with a wetting agent.

[0029] Comparative Example 3 This comparative example is basically the same as Example 1, except that it does not include the steps of titanium spraying and wetting agent treatment, and the piston rod is directly sprayed with high temperature resistant coating material.

[0030] Comparative Example 4 This comparative example is basically the same as Example 1, except that the high-temperature resistant coating material does not contain silane coupling agent modified carbon nanotubes.

[0031] Comparative Example 5 This comparative example is basically the same as Example 1, except that the silane coupling agent modified carbon nanotubes in the high-temperature resistant coating material are ordinary carbon nanotubes, not multi-walled carbon nanotubes.

[0032] Test Example 1 The performance of the piston rods obtained in Examples 1-3 and Comparative Examples 1-5 was tested, and the results are shown in Table 1 below.

[0033] The specimens were prepared in accordance with ISO 178 standard, and the bending strength was measured using a KZ-DSC-20 universal testing machine at an ambient temperature of 120℃.

[0034] Wear was tested according to GB / T 3960-2016 standard, with an ambient temperature of 120℃.

[0035] The corrosion rate was tested according to GB / T 10125 standard, and the test environment temperature was 120℃.

[0036] The compressive strength was tested according to ISO 604 standard at an ambient temperature of 120°C.

[0037] Table 1 Piston rod performance test results

[0038] As shown in Table 1, the present application solution, by spraying a titanium layer and a high-temperature resistant coating material onto the PTFE piston rod and treating the titanium layer with an impregnation agent, can significantly improve the wear resistance of the piston rod at 120℃, and also significantly improve the compressive strength and bending strength. This can extend the service life of the piston rod, reduce the frequency of oil / liquid leakage, deformation, bending, or even breakage and replacement due to piston rod wear, and thus improve the operational stability of the diaphragm pump.

[0039] As can be seen from the results of Comparative Example 1, the piston rod provided in this application has significant wear resistance and deformation resistance at high temperatures, which is of great significance for improving the operational stability of diaphragm pumps.

[0040] According to the results of Comparative Example 2, the wetting agent treatment can effectively improve the interfacial bonding between the titanium layer and the high-temperature resistant coating material, which helps to reduce porosity during the preparation process.

[0041] According to the results of Comparative Example 3, the introduction of the titanium spray layer can significantly improve the compressive strength and flexural strength. In addition, it also improves the wear resistance at high temperatures. It can be seen that the titanium layer has a certain effect on heat conduction and avoids increased wear due to local overheating. Furthermore, the experimenters found that the introduction of the titanium layer did not make the piston rod more prone to breakage and delamination. This is because the potential impact was taken into account during the preparation process. Therefore, the titanium spraying was mainly concentrated on the columnar surface of the piston rod, and the high-temperature resistant coating material completely covered the piston rod. Afterwards, it was plasticized at a high temperature of 280~320℃. Moreover, the titanium layer itself has excellent high-temperature resistance, and the piston rod can be used stably for a long time.

[0042] According to the results of Comparative Examples 4 and 5, the addition of silane coupling agent to modify multi-walled carbon nanotubes in this application plays an important role in improving the wear resistance, compressive strength, and flexural strength of piston rods at high temperatures.

[0043] The above description is merely an embodiment of this application, and the scope of protection of this application is not limited to these specific embodiments, but is determined by the claims of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the technical concept and principles of this application should be included within the scope of protection of this application.

Claims

1. A method of making a high temperature resistant diaphragm pump piston rod coating, characterized by, It comprises the following steps: S1, preparing a piston rod made of polytetrafluoroethylene, roughening the surface of the piston rod, and drying after cleaning for standby; S2, using a spray gun filled with titanium metal powder to spray the surface of the piston rod, controlling the spraying thickness to be not less than 1.5 mm, and obtaining a titanium layer; S3, immersing the sprayed piston rod into the infiltration treatment agent for infiltration treatment, the infiltration treatment agent comprises, by weight fraction: 20-40 parts of silane coupling agent, 10-30 parts of hydroxy cellulose, after 10-30 min of immersion, taking out and keeping in a rotating state for drying, so that the infiltration treatment agent is evenly attached to the entire titanium layer, and after drying, it is ready for use; S4, preparing a high-temperature-resistant coating material, the high-temperature-resistant coating material comprises the following raw materials by weight: 100 parts of polytetrafluoroethylene, 20-30 parts of high-temperature-resistant epoxy adhesive, 4-10 parts of silane coupling agent modified carbon nanotube, and 3-6 parts of dispersing agent; S5, loading the high-temperature-resistant coating material into the spray gun, spraying it on the surface of the dried piston rod, controlling the high-temperature-resistant coating material to wrap the entire piston rod, and the spraying thickness is 3-6 mm, after spraying, keeping it at 80-120℃, then putting it into high temperature plasticization at 280-320℃, and after cooling, polishing it to obtain a piston rod containing the high-temperature-resistant diaphragm pump piston rod coating.

2. The method of claim 1, wherein the coating is applied by a process selected from the group consisting of: physical vapor deposition, chemical vapor deposition, thermal spraying, and combinations thereof. The preparation method of the silane coupling agent modified carbon nanotube comprises the following steps: 1) preparing 60-80 vol% ethanol solution, adding silane coupling agent and stirring for at least 1 h; 2) adding carbon nanotube and continuing to stir for at least 2 h; 3) stopping stirring and standing for at least 5 h; 4) obtaining precipitate after centrifugation and filtration separation, and obtaining silane coupling agent modified carbon nanotube composite powder after drying.

3. The method of making a high temperature resistant diaphragm pump piston rod coating of claim 2, wherein, The silane coupling agent used in step S3 is selected from one or more of KH560 and KH570; and / or The silane coupling agent used in the silane coupling agent modified carbon nanotube is selected from one or more of KH560 and KH570.

4. The method of making a high temperature resistant diaphragm pump piston rod coating of claim 3, wherein, The silane coupling agent used in step S3 and the silane coupling agent used in the silane coupling agent modified carbon nanotube are KH560.

5. The method of making a high temperature resistant diaphragm pump piston rod coating of claim 3, wherein, The carbon nanotube is a multi-walled carbon nanotube, the diameter of the multi-walled carbon nanotube is 20-30 nm, and the length is 80-100 μm.

6. The method of making a high temperature resistant diaphragm pump piston rod coating of claim 1, wherein, Before immersing the sprayed piston rod into the infiltration treatment agent for infiltration treatment in step S3, it further comprises the step of heat treating the dried piston rod at 80-100℃ for at least 1 h.

7. The method of making a high temperature resistant diaphragm pump piston rod coating of claim 1, wherein, In step S1, the surface to be sprayed is roughened by mechanical cutting, and the surface roughness Ra value is controlled to be 1.2-1.6 μm.

8. The method of making a high temperature resistant diaphragm pump piston rod coating of claim 1, wherein, The hydroxy cellulose used in step S3 is selected from one or more of hydroxyethyl cellulose, hydroxypropyl cellulose, and hydroxypropyl methyl cellulose; and / or, The high-temperature-resistant epoxy adhesive is high-temperature-resistant epoxy adhesive ZS-1071; and / or, The dispersing agent is perfluorooctanoic acid amine.

9. The application of the preparation method of the high-temperature-resistant diaphragm pump piston rod coating in a diaphragm pump piston rod according to any one of claims 1-8.

10. A diaphragm pump piston rod, characterized by The outer side of the diaphragm pump piston rod comprises a protective coating, which is obtained by the method for preparing a high-temperature-resistant diaphragm pump piston rod coating according to any one of claims 1 to 8.

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