A method of manufacturing a hydraulic piston pump cylinder with enhanced interface strength

Abstract

The application belongs to the technical field of industrial product processing and preparation, and particularly relates to a preparation method of a hydraulic plunger pump cylinder body with enhanced interface strength. The preparation method of the hydraulic plunger pump cylinder body with enhanced interface strength is as follows: copper-coated flaky graphite and metal powder are mixed to obtain mixed powder; the mixed powder is formed into a cladding layer on the inner side of a steel hydraulic plunger pump cylinder body through laser cladding, so that copper in the mixed powder and the steel in the inner side form metallurgical bonding, and the hydraulic plunger pump cylinder body is obtained; the laser cladding conditions are as follows: laser power is 3000-5000 W, scanning speed is 50-100 mm / s, spot diameter is 0.5-2 mm, and lap rate is 30%-60%. Through the laser cladding method, copper in the mixed powder and the steel in the steel hydraulic plunger pump cylinder body form metallurgical bonding, the interface bonding strength between copper and steel is effectively improved, and the service life of the hydraulic plunger pump cylinder body is ensured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of industrial product processing and preparation, and particularly relates to a preparation method of a hydraulic plunger pump cylinder body with enhanced interface strength. BACKGROUND

[0002] The hydraulic plunger pump is a typical displacement pump, which converts mechanical energy into pressure energy of liquid and then delivers the pressure and flow to the system. The pump is widely used in various fields of industrial production and daily life due to its ability to deliver liquid at high pressure. The manufacturing process of the traditional hydraulic plunger pump cylinder body is relatively complicated, and a seamless steel pipe or a pipe obtained by casting or forging is usually used. The pipe needs to be processed through multiple processes, including rough boring, semi-fine boring, fine boring, sometimes electroplating, and finally polishing or honing. This manufacturing method not only has low production efficiency, but also has relatively high cost.

[0003] However, the copper-based graphite wear-resistant material is currently used to form a protective layer on the inner wall of the steel hydraulic plunger cylinder body through powder metallurgy process, and a copper-steel bimetallic hydraulic plunger cylinder body is prepared, or a copper-based self-lubricating material is directly used to prepare a copper-based hydraulic plunger pump cylinder body through powder metallurgy sintering, both of which have good wear resistance and corrosion resistance and good mechanical properties. After the graphite is treated by copper plating, a protective layer is formed on the inner wall of the steel hydraulic plunger cylinder body by using the powder metallurgy method. Since the copper and steel are mechanically combined, the bonding strength is weak, so the copper-steel bimetallic interface strength is not high, and the protective layer will fall off from the surface of the cylinder body during use, thereby affecting the service life of the hydraulic plunger pump cylinder body. SUMMARY

[0004] To solve the above technical problems, the application provides a preparation method of a hydraulic plunger pump cylinder body with enhanced interface strength, which effectively improves the interface strength of the copper-steel bimetallic interface.

[0005] To achieve the above purpose, the technical scheme of the application is as follows.

[0006] The first aspect of the application provides a preparation method of a hydraulic plunger pump cylinder body with enhanced interface strength, comprising the following steps:

[0007] Flake graphite is treated by copper plating to obtain copper-plated flake graphite;

[0008] The copper-plated flake graphite and the metal powder are mixed in a mass ratio of 1-2:8-9 to obtain a mixed powder; the metal powder is obtained by mixing copper powder, nickel powder and zinc powder in a mass ratio of 75-85:5-20:5-10;

[0009] The mixed powder is added to the inner wall of the steel hydraulic plunger pump cylinder body, and under laser cladding, the copper element in the mixed powder and the steel element in the inner wall of the steel hydraulic plunger pump cylinder body form a metallurgical bonding cladding layer, so that the interface strength of the hydraulic plunger pump cylinder body is enhanced;

[0010] The laser cladding conditions are as follows: laser power is 3000-5000W, scanning speed is 50-100mm / s, spot diameter is 0.5-2mm, and lap rate is 30-60%.

[0011] The copper element in the mixed powder and the steel element in the inner wall of the steel hydraulic plunger pump cylinder body form a metallurgical bonding, i.e. chemical bonding, under the conditions of laser power of 3000-5000W, scanning speed of 50-100mm / s, spot diameter of 0.5-2mm, and lap rate of 30-60%, so that the interface bonding strength between copper and steel is effectively improved, the cladding layer does not fall off during use, and the service life of the hydraulic plunger pump cylinder body is improved. Moreover, the whole forming process is fast, and the processing efficiency is greatly improved.

[0012] In another preferred embodiment, the thickness of the cladding layer is 1-5mm.

[0013] In another preferred embodiment, the specific process of the copper plating treatment is as follows:

[0014] The flaky graphite is placed in the plating solution A, the plating solution B is added and stirred uniformly, and then the reaction is carried out at 30-50℃ for 20-40min, and then the flaky graphite is obtained by washing and filtration.

[0015] In the plating solution A, the mass ratio of C4H4KNa, HCHO and water is 4.5-5.5:2.5-3.5:100.

[0016] In the plating solution B, the mass ratio of NaOH, CuSO4 and water is 0.5-1:8-12:100.

[0017] In another preferred embodiment, the mass-volume ratio of the flaky graphite, the plating solution A and the plating solution B is 1kg:4-5L:4-5L.

[0018] In another preferred embodiment, the particle size of the flaky graphite is 100-200mesh.

[0019] In another preferred embodiment, the rotating speed of the mixing and stirring is 30-100rpm / min.

[0020] In another preferred embodiment, the mesh number of the copper powder, the nickel powder and the zinc powder is 100-200mesh.

[0021] The second aspect of the present application provides the interface strength enhanced hydraulic plunger pump cylinder.

[0022] Compared with the prior art, the present application has at least the following beneficial effects:

[0023] By adopting the method of laser cladding, the copper element in the mixed powder can form metallurgical bonding with the steel element in the inner wall of the steel hydraulic plunger pump cylinder, thereby effectively improving the interface bonding strength between copper and steel, and solving the problem that in the traditional powder metallurgy or casting forming process, the mechanical bonding between copper and steel makes the interface strength of copper-steel bimetal not high, and the protective layer can fall off from the surface of the cylinder during use.

[0024] The present application controls the laser cladding conditions, and under the cooperation of various parameters, the copper and steel are directly formed into metallurgical bonding, and the obtained cladding layer can better protect the hydraulic plunger pump cylinder, effectively improve the performance of the hydraulic plunger pump cylinder, and meet the service requirements of future high-performance hydraulic plunger pump cylinders. Compared with the traditional powder metallurgy preparation method, the copper-steel bimetal interface bonding strength is better, the mechanical, corrosion resistance and wear resistance are higher, the preparation process is simpler, and the cost is lower. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 Figure 1 is a morphology diagram of the cladding layer in the embodiment 1 of the present application.

[0026] Figure 2 Figure 2 is a structure distribution diagram of the cladding layer in the embodiment 1 of the present application; in the figure, 1 is the cladding layer, and 2 is the inner wall. DETAILED DESCRIPTION

[0027] The technical solutions in the present application will be described clearly and completely in combination with the specific embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0028] The methods described in the embodiments of the present application are all conventional methods unless otherwise specified. The materials, reagents, etc. used are all available from commercial channels unless otherwise specified.

[0029] At present, after copper plating treatment of graphite, powder metallurgy sintering is adopted to form on the inner layer side of the steel hydraulic plunger cylinder for improving the wear resistance and corrosion resistance of the inner wall of the steel hydraulic plunger cylinder. However, in the powder metallurgy sintering mode, the copper in the copper-plated graphite is mechanically combined with the steel interface, so that in the use process, the problem of protective layer falling off easily occurs, thereby seriously affecting the performance and service life of the steel hydraulic plunger cylinder.

[0030] The application can make the copper in the copper-plated graphite and the steel component of the inner wall of the steel hydraulic plunger cylinder directly form metallurgical combination, that is, the copper and the steel produce metallurgical chemical reaction and form tight combination, thereby effectively improving the interface combination strength, effectively preventing the problem of peeling of the cladding layer from the inner wall of the steel hydraulic plunger cylinder, guaranteeing the performance of the hydraulic plunger pump cylinder and improving the service life of the hydraulic plunger pump cylinder.

[0031] The following will specifically describe a hydraulic plunger pump cylinder with enhanced interface strength and a preparation method thereof. The application is not limited to the type and shape of the steel hydraulic plunger pump cylinder. The purity of the pure copper powder, the pure nickel powder and the pure zinc powder in the following examples is all above 99%.

[0032] Example 1

[0033] A preparation method of a hydraulic plunger pump cylinder with enhanced interface strength, comprising the following steps:

[0034] S1, placing 100 mesh flake graphite in plating liquid A and stirring uniformly, then pouring into plating liquid B and stirring uniformly, reacting at 30°C for 20 min, then washing, filtering and drying to obtain copper-plated flake graphite;

[0035] The mass-volume ratio of the flake graphite, the plating liquid A and the plating liquid B is 1 kg:4 L:4 L;

[0036] In the plating liquid A, the mass ratio of C4H4KNa, HCHO and water is 4.5:2.5:100; in the plating liquid B, the mass ratio of NaOH, CuSO4 and water is 0.5:8:100.

[0037] S2, mixing the pure copper powder, the pure nickel powder and the pure titanium powder according to a mass ratio of 75:20:5 to obtain metal powder; mixing the nickel-plated flake graphite and the metal powder according to a mass ratio of 1:8 and stirring at 30 rpm / min for 5 h to obtain mixed powder; the particle size of the pure copper powder, the pure nickel powder and the pure zinc powder is all 100 mesh.

[0038] S3, under the parameters of laser power 3000 W, scanning speed 50 mm / s, spot diameter 0.5 mm and overlap rate 30%, using the powder feeding mode, cladding the mixed powder on the inner wall of the steel hydraulic plunger pump cylinder under laser cladding, measuring the thickness of the cladding layer during the powder feeding process, stopping cladding when the thickness of the cladding layer is 1 mm, to obtain the hydraulic plunger pump cylinder with enhanced interface strength.

[0039] Example 2

[0040] A method for preparing a hydraulic plunger pump cylinder with enhanced interface strength, comprising the following steps:

[0041] S1, the 150 mesh flake graphite is stirred uniformly in plating solution A, then poured into plating solution B and stirred uniformly, reacted at 40℃ for 30 min, then washed, filtered and dried to obtain copper-plated flake graphite;

[0042] The mass-volume ratio of flake graphite, plating solution A and plating solution B is 1 kg:5 L:4 L;

[0043] In the plating solution A, the mass ratio of C4H4KNa, HCHO and water is 4:3:100.

[0044] In the plating solution B, the mass ratio of NaOH, CuSO4 and water is 0.75:10:100.

[0045] S2, pure copper powder, pure nickel powder and pure titanium powder are mixed according to a mass ratio of 80:12.5:7.5 to obtain metal powder; the nickel-plated flake graphite and the metal powder are mixed according to a mass ratio of 1.5:8.5, mixed and stirred at 65 rpm / min for 7.5 h to obtain mixed powder; the pure copper powder, the pure nickel powder and the pure zinc powder all have a particle size of 150 mesh.

[0046] S3, under the conditions of laser power 4000 W, scanning speed 75 mm / s, spot diameter 1 mm and overlap rate 45%, the mixed powder is cladded on the inner wall of the steel hydraulic plunger pump cylinder by laser cladding in a powder feeding mode, the thickness of the cladding layer is measured during the powder feeding process, and when the thickness of the cladding layer is 3 mm, the cladding is stopped to obtain the hydraulic plunger pump cylinder with enhanced interface strength.

[0047] Example 3

[0048] A method for preparing a hydraulic plunger pump cylinder with enhanced interface strength, comprising the following steps:

[0049] S1, the 200 mesh flake graphite is stirred uniformly in plating solution A, then poured into plating solution B and stirred uniformly, reacted at 50℃ for 40 min, then washed, filtered and dried to obtain copper-plated flake graphite;

[0050] The mass-volume ratio of flake graphite, plating solution A and plating solution B is 1 kg:5 L:5 L;

[0051] In the plating solution A, the mass ratio of C4H4KNa, HCHO and water is 5.5:3.5:100; in the plating solution B, the mass ratio of NaOH, CuSO4 and water is 1:12:100.

[0052] S2, pure copper powder, pure nickel powder, pure titanium powder are mixed according to a mass ratio of 85:5:10 to obtain metal powder; the plated nickel flaky graphite and the metal powder are mixed according to a mass ratio of 2:9, and are mixed and stirred at 100 rpm / min for 10 h to obtain mixed powder; the pure copper powder, the pure nickel powder and the pure zinc powder all have a particle size of 200 meshes.

[0053] S3, under the parameters of a laser power of 5000 W, a scanning speed of 100 mm / s, a spot diameter of 2 mm and an overlapping rate of 60%, the mixed powder is cladded on the inner wall of the steel hydraulic ram cylinder by laser cladding in a powder feeding mode, the thickness of the cladding layer is measured during the powder feeding process, and when the thickness of the cladding layer is 5 mm, the cladding is stopped, and the interface strength enhanced hydraulic ram cylinder is obtained.

[0054] The mechanical property indexes of the inner walls of the interface strength enhanced hydraulic ram cylinders obtained in Examples 1-3 are determined, the same raw materials are used, the hydraulic ram cylinders prepared by a conventional powder metallurgy method are used as a control group, the mechanical property indexes of the inner walls are determined, and the results are shown in Table 1.

[0055] Table 1: Mechanical property indexes of inner walls of different hydraulic ram cylinders

[0056] Group Tensile properties Hardness Friction coefficient Wear rate Example 1 ≥ 230 MPa ≥ 65 HV ≤0.25 ≤ 2.0 g / m 3 ]] Example 2 ≥ 215 MPa ≥ 60 HV ≤0.22 ≤ 1.8 g / m 3 ]] Example 3 ≥ 200 MPa ≥ 55 HV ≤0.20 ≤ 1.5 g / m 3 ]] Control > 160 MPa > 30 HV ＜0.25 <5 g / m 3 ]]

[0057] As can be seen from the results in Table 1, the tensile property and hardness of the inner walls of the interface strength enhanced hydraulic ram cylinders in Examples 1-3 are obviously higher than those of the control group, and the wear rate is lower than that of the control group. It is shown that the interface bonding strength of copper and steel can be effectively improved by the method of laser cladding, and then the peeling of the cladding layer is prevented, and the performance and service life of the interface strength enhanced hydraulic ram cylinder are improved.

[0058] The appearance and organization of the cladding layer of the interface strength enhanced hydraulic ram cylinder in Example 1 are analyzed, and the results are shown in Figure 1 and Figure 2 As can be seen from Figure 1 , the cladding layer organization is dense and has no defects. As can be seen from Figure 2 , the interface between the cladding layer and the inner wall of the interface strength enhanced hydraulic ram cylinder is well bonded, the transition zone of copper phase and steel phase is small, and the dilution rate is low. It can be seen that the interface strength of copper phase and steel phase can be effectively improved by laser cladding.

[0059] The above are only the preferred embodiments of the present application, and are not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method of making a hydraulic piston pump cylinder with enhanced interface strength, characterized in that, The method comprises the following steps: The flaky graphite is subjected to copper plating treatment to obtain copper-plated flaky graphite; the specific process of the copper plating treatment is as follows: the flaky graphite is placed in plating solution A, plating solution B is added and stirred uniformly, and then the mixture is reacted at 30-50 DEG C for 20-40 min, washed, and filtered to obtain the copper-plated flaky graphite; in the plating solution A, the mass ratio of C4H4KNa, HCHO and water is 4.5-5.5:2.5-3.5:100; in the plating solution B, the mass ratio of NaOH, CuSO4 and water is 0.5-1:8-12:100; the particle size of the flaky graphite is 100-200 mesh; The copper-plated flaky graphite and metal powder are mixed in a mass ratio of 1-2:8-9 to obtain a mixed powder; the metal powder is obtained by mixing copper powder, nickel powder and zinc powder in a mass ratio of 75-85:5-20:5-10; the stirring speed of the mixing is 30-100 rpm, and the mixing time is 5-10 h; The mixed powder is added to the inner wall of a steel hydraulic plunger pump cylinder, and under laser cladding, the copper element in the mixed powder and the steel element in the steel hydraulic plunger pump cylinder form a metallurgical bonding cladding layer to obtain a hydraulic plunger pump cylinder with enhanced interface strength; The laser cladding conditions are as follows: laser power is 3000-5000 W, scanning speed is 50-100 mm / s, spot diameter is 0.5-2 mm, and overlap rate is 30-60%.

2. The method of making an interface strength enhanced hydraulic piston pump cylinder as set forth in claim 1, wherein, The thickness of the cladding layer is 1-5 mm.

3. The method of making an interface strength enhanced hydraulic piston pump cylinder as set forth in claim 1, wherein, The mass-volume ratio of the flaky graphite, plating solution A and plating solution B is 1 kg:4-5 L:4-5 L.

4. The method of making an interface strength enhanced hydraulic piston pump cylinder as defined in claim 1, wherein, The mesh number of the copper powder, nickel powder and zinc powder is 100-200 mesh. 5.A hydraulic plunger pump cylinder with enhanced interface strength prepared by the method of any one of claims 1-4.

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