Manufacturing method of lead-tin-copper alloy-steel double-metal plate

Abstract

The invention discloses a manufacturing method of a lead-tin-copper alloy-steel bimetal plate. The manufacturing method comprises the following steps that lead-tin-copper alloy powder is flatly laid on a steel plate; placing the steel plate on which the powder is laid in a mesh belt sintering furnace, raising two ends by using cushion blocks, and carrying out primary sintering; rolling the primary sintered plate, and then carrying out secondary sintering on the primary rolled plate; and the secondarily sintered plate is rolled and then leveled, and a finished plate is obtained. The cushion blocks are adopted in the mesh belt sintering furnace to block up a steel plate, so that fluctuation of a temperature field is accelerated, the temperature field is promoted to keep high uniformity, and the quality of a sintered plate is improved; according to the method, the primary sintering temperature and the secondary sintering temperature are controlled, so that the lead loss is reduced, the quality of a sintered product is ensured, and the sintering efficiency is improved. According to the manufactured lead-tin-copper alloy-steel bimetallic plate copper alloy, the particle size of lead is reduced, distribution is uniform, and the frictional wear performance is improved.

Description

Technical Field

[0001] The invention belongs to the field of copper-steel bimetallic plate manufacturing, and in particular relates to a method for manufacturing a lead-tin-copper alloy-steel bimetallic plate. Background Art

[0002] Copper-steel bimetallic plates for sliding bearings are generally sintered using a mesh belt furnace. The lead particles in the lead-tin-copper alloy-steel bimetallic plates produced using the existing mesh belt furnace sintering method are severely agglomerated and extremely unevenly distributed, resulting in poor friction and wear performance. Summary of the invention

[0003] In order to solve the above problems, the purpose of the present invention is to provide a method for preparing a lead-tin-copper alloy-steel bimetallic plate. The lead particle size in the copper alloy of the lead-tin-copper alloy-steel bimetallic plate prepared by the preparation method of the present invention is reduced and evenly distributed, and the friction and wear performance is improved.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] A method for manufacturing a lead-tin-copper alloy-steel bimetallic plate comprises the following steps:

[0006] a) Use a powder spreading machine to spread the lead-tin-copper alloy powder on the steel plate;

[0007] b) Place the steel plate after powder coating in a mesh belt sintering furnace, raise the two ends with pads by 20mm-40mm, and perform a sintering process at a temperature of 825℃~845℃, a sintering atmosphere of nitrogen-hydrogen mixed gas, in which the proportion of hydrogen is 15%-25%, and a sintering time of 40min-60min;

[0008] c) rolling the primary sintered plate, the size of which after rolling is 0.05mm-0.18mm larger than the finished plate;

[0009] d) placing the first rolled plate in a mesh belt sintering furnace for secondary sintering at a sintering temperature of 815°C to 840°C, a sintering atmosphere of nitrogen-hydrogen mixed gas in which the hydrogen ratio is 15% to 25%, and a sintering time of 20 min to 40 min;

[0010] e) rolling the secondary sintered plate with a rolling amount of 0.05 mm to 0.18 mm;

[0011] f) Use a leveling machine to level the secondary sintered plate to obtain a finished plate.

[0012] As a further solution, when the thickness of the steel plate is 2.5 mm-4.0 mm, the first sintering temperature is 825-835°C; when the thickness of the steel plate is 4.0 mm-7.0 mm, the first sintering temperature is 830-845°C.

[0013] As a further solution, the thickness of the lead-tin-copper alloy layer in the plate after the second rolling is: 0.3mm-0.8mm.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] 1) The air inlet of the mesh belt furnace is set at the top. When the powdered steel plate is directly placed on the mesh belt of the mesh belt sintering furnace for sintering, the hydrogen near the plate is consumed. Since it is far away from the air inlet, the hydrogen cannot be replenished in time, and the densification process is slow, resulting in lead fusion to form large-size lead particles; when the powdered steel plate is placed in the mesh belt sintering furnace and raised at both ends with pads, since it is far away from the air inlet, the hydrogen can be replenished in time. In addition, the raised plate accelerates air fluctuations, promotes the uniform distribution of hydrogen, and the densification process is faster. Lead is not easy to fuse, and the lead particles of the plate produced are smaller.

[0016] 2) The temperature sensor of the mesh belt furnace is installed at the top. When the steel plate after being coated with powder is directly placed on the mesh belt of the mesh belt sintering furnace for sintering, the heat near the plate is consumed and absorbed first. Since it is too far away from the temperature sensor, the temperature drop cannot be fed back to the temperature control system in time. The temperature control system starts to work only after the temperature drops to a certain level. Therefore, the temperature field near the plate is extremely unstable during sintering, that is, the temperature field where the plate is sintered is unstable, which leads to large differences in the sintering quality of different plates and instability; when the steel plate after being coated with powder is placed in the mesh belt sintering furnace and raised at both ends with pads, the temperature can be detected in time due to its proximity to the temperature sensor and the temperature field can be adjusted through the temperature control system. In addition, the raised plate accelerates the temperature field fluctuation and promotes the temperature field to maintain a high uniformity. Therefore, the quality difference of the sintered plate is small and stable.

[0017] 3) During the first sintering, the copper layer is in a loose state and has poor thermal conductivity. In order to ensure that the copper powder and the steel plate are firmly bonded at the interface, the steel plate needs to be quickly heated to the required temperature. Before raising, the thermal conductivity of the steel plate surface depends on the metal mesh belt. The metal mesh belt has fast thermal conductivity, and the temperature at the interface between the steel plate and the copper powder quickly rises to the required temperature. After raising, the thermal conductivity of the steel plate surface depends on the air. The air has slow thermal conductivity, and the steel plate heats up slowly. It takes a longer time and a higher temperature for the interface between the steel plate and the copper powder to reach the required temperature. In order to ensure that the interface between the steel plate and the copper powder can rise to the required temperature without reducing production efficiency, so that the bonding strength between the copper layer and the steel plate of the prepared bimetallic sheet material meets the requirements, it is necessary to increase the sintering temperature of the first sintering. The time required for the interface between the steel plate and the copper powder to reach the required temperature is the same for steel plates of different thicknesses. The sintering temperature of a slightly thicker steel plate is higher than that of a slightly thicker steel plate.

[0018] 4) During the second firing, the copper layer is in a dense state and has good thermal conductivity. The second firing is mainly to eliminate the internal stress of the copper alloy layer deformed by the first rolling and the cracks caused by the deformation, and to strengthen the bonding strength between the copper layer and the steel plate. Therefore, the second firing temperature can be slightly lower than the first firing temperature. In addition, the lead in the lead-tin-copper alloy exists in a single substance state. When the lead temperature exceeds 400°C, a large amount of lead vapor escapes. Lowering the second firing temperature is beneficial to reducing the loss of lead.

[0019] 5) The lead in the lead-tin-copper alloy exists in a single substance state. When the lead temperature exceeds 400°C, a large amount of lead vapor escapes. Therefore, the overall sintering time cannot be too long when the lead-tin-copper alloy-steel bimetallic plate is produced. The first firing requires more energy to fuse the copper particles together. There are many pores between the copper particles and the thermal conductivity is poor, so the sintering time required is longer. The second firing is to eliminate the internal stress of the copper alloy layer deformed by the first rolling and the cracks caused by the deformation. Less energy is required, so the sintering time required is shorter. If the time is too long, it will cause lead overflow, and the lead content will be reduced and the friction reduction effect will be worse. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 SEM photograph of the plate sintered using Example 1.

[0021] Figure 2 SEM photograph of the plate sintered using Comparative Example 1. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the embodiments.

[0023] Embodiment 1

[0024] A method for manufacturing a lead-tin-copper alloy-steel bimetallic plate comprises the following steps:

[0025] (a) Use a powder spreading machine to spread the CuSn10Pb10 alloy powder on a steel plate with a thickness of 2.5 mm;

[0026] (b) placing the powdered steel plate in a mesh belt sintering furnace, raising the two ends by 20 mm with pads, and performing a sintering operation at a temperature of 825° C. The sintering atmosphere is a nitrogen-hydrogen mixed gas in which the hydrogen ratio is 15%-25%, and the sintering time is 40 min;

[0027] (c) rolling the primary sintered plate, the size of which after rolling is 0.18 mm larger than the finished plate;

[0028] (d) placing the primary rolled plate in a mesh belt sintering furnace for secondary sintering at a sintering temperature of 815° C. in a sintering atmosphere of nitrogen-hydrogen mixed gas in which the hydrogen ratio is 15%-25%; and the sintering time is 20 min;

[0029] (e) rolling the secondary sintered plate with a rolling amount of 0.18 mm;

[0030] (f) The secondary sintered plate is leveled using a leveling machine to obtain a finished plate with a copper layer thickness of 0.3 mm.

[0031] Embodiment 2

[0032] A method for manufacturing a lead-tin-copper alloy-steel bimetallic plate comprises the following steps:

[0033] (a) Using a powder spreading machine, CuSn10Pb10 alloy powder is spread on a steel plate with a thickness of 7.0 mm;

[0034] (b) placing the powdered steel plate in a mesh belt sintering furnace, raising the two ends by 40 mm with pads, and performing a sintering operation at a temperature of 845° C. The sintering atmosphere is a nitrogen-hydrogen mixed gas in which the hydrogen ratio is 15%-25%, and the sintering time is 60 min;

[0035] (c) rolling the primary sintered plate, the size of which after rolling is 0.05 mm larger than the finished plate;

[0036] (d) placing the primary rolled plate in a mesh belt sintering furnace for secondary sintering at a sintering temperature of 840° C. in a sintering atmosphere of nitrogen-hydrogen mixed gas in which the hydrogen ratio is 15%-25%; and the sintering time is 40 min;

[0037] (e) rolling the secondary sintered plate with a rolling amount of 0.05 mm;

[0038] (f) The secondary sintered plate is leveled using a leveling machine to obtain a finished plate with a copper layer thickness of 0.8 mm.

[0039] Comparative Example 1

[0040] A method for manufacturing a lead-tin-copper alloy-steel bimetallic plate comprises the following steps:

[0041] (a) Use a powder spreading machine to spread the CuSn10Pb10 alloy powder on a steel plate with a thickness of 2.5 mm;

[0042] (b) placing the powdered steel plate on a mesh belt of a mesh belt sintering furnace for primary sintering at a sintering temperature of 815° C. in a sintering atmosphere of nitrogen-hydrogen mixed gas in which the hydrogen ratio is 15%-25% and the sintering time is 40 min;

[0043] (c) rolling the primary sintered plate, the size of which after rolling is 0.18 mm larger than the finished plate;

[0044] (d) placing the primary rolled plate in a mesh belt sintering furnace for secondary sintering at a sintering temperature of 815° C. in a sintering atmosphere of nitrogen-hydrogen mixed gas in which the hydrogen ratio is 15%-25%; and the sintering time is 20 min;

[0045] (e) rolling the secondary sintered plate with a rolling amount of 0.18 mm;

[0046] (f) The secondary sintered plate is leveled using a leveling machine to obtain a finished plate with a copper layer thickness of 0.3 mm.

[0047] Comparative Example 2

[0048] A method for manufacturing a lead-tin-copper alloy-steel bimetallic plate comprises the following steps:

[0049] (a) Use a powder spreading machine to spread the CuSn10Pb10 alloy powder on a steel plate with a thickness of 2.5 mm;

[0050] (b) placing the powdered steel plate in a mesh belt sintering furnace, raising the two ends by 20 mm with pads, and performing a sintering operation at a temperature of 815°C, a sintering atmosphere of nitrogen-hydrogen mixed gas in which the hydrogen ratio is 15%-25%, and a sintering time of 40 min;

[0051] (c) rolling the primary sintered plate, the size of which after rolling is 0.18 mm larger than the finished plate;

[0052] (d) placing the primary rolled plate in a mesh belt sintering furnace for secondary sintering at a sintering temperature of 815° C. in a sintering atmosphere of nitrogen-hydrogen mixed gas in which the hydrogen ratio is 15%-25%; and the sintering time is 20 min;

[0053] (e) rolling the secondary sintered plate with a rolling amount of 0.18 mm;

[0054] (f) The secondary sintered plate is leveled using a leveling machine to obtain a finished plate with a copper layer thickness of 0.3 mm.

[0055] Comparative Example 3

[0056] A method for manufacturing a lead-tin-copper alloy-steel bimetallic plate comprises the following steps:

[0057] (a) Using a powder spreading machine, CuSn10Pb10 alloy powder is spread on a steel plate with a thickness of 7.0 mm;

[0058] (b) placing the powdered steel plate in a mesh belt sintering furnace, raising the two ends by 40 mm with pads, and performing a sintering operation at a temperature of 840° C. The sintering atmosphere is a nitrogen-hydrogen mixed gas in which the hydrogen ratio is 15%-25%, and the sintering time is 60 min;

[0059] (c) rolling the primary sintered plate, the size of which after rolling is 0.05 mm larger than the finished plate;

[0060] (d) placing the primary rolled plate in a mesh belt sintering furnace for secondary sintering at a sintering temperature of 840° C. in a sintering atmosphere of nitrogen-hydrogen mixed gas in which the hydrogen ratio is 15%-25%; and the sintering time is 40 min;

[0061] (e) rolling the secondary sintered plate with a rolling amount of 0.05 mm;

[0062] (f) The secondary sintered plate is leveled using a leveling machine to obtain a finished plate with a copper layer thickness of 0.8 mm.

[0063] Comparing the particle size and distribution of lead in Example 1 and Comparative Example 1, a scanning electron microscope was used to take a photo of the cross section of the copper layer at 200X. Figure 1 and Figure 2 As can be seen from the figure, the lead particle size of Example 1 is smaller and evenly distributed, while the lead particle size of Comparative Example 1 is larger and unevenly distributed. The metallographic level of Example 1 is higher (QC / T 281 Metallographic standard of automobile engine bearing copper-lead alloy).

[0064] Compare the friction and wear performance of Example 1 and Example 2 with Comparative Example 1, Comparative Example 2 and Comparative Example 3, as well as the bonding performance between the steel back and the copper layer. The prepared ball powder plate was tested on an end face friction and wear testing machine, and the test conditions were as follows: load 3.5MPa, linear speed 0.4m / s, test time 3h; take a sample of 15mm×2mm×thickness of the bimetallic plate, use a tool to apply a load to the copper layer, and the bimetallic bonding surface is subjected to shear force, causing the copper layer to displace until the copper layer is separated from the steel back. Calculate the bonding strength based on the load size and force area. The test results are shown in Table 1 below:

[0065] Table 1

[0066] Friction factor Wear amount (mm) Bonding strength (MPa) Embodiment 1 0.051 0.006 202 Embodiment 2 0.056 0.007 208 Comparative Example 1 0.077 0.008 204 Comparative Example 2 0.054 0.006 180 Comparative Example 3 0.055 0.007 160

[0067] The test results show that the friction coefficient of the finished plate in Example 1 is 33.8% lower than that in Comparative Example 1, and the wear amount is 25% lower than that in Comparative Example 1, and the friction and wear performance of the finished plate in Example 1 is more excellent. The bonding strength of the finished plate in Example 1 is not much different from that in Comparative Example 1, but the bonding strength of the finished plate in Comparative Example 2 is 22MPa lower than that in Example 1, and the finished plate in Comparative Example 3 is 48MPa lower than that in Example 2.

[0068] The above description of the embodiments is to facilitate the understanding and application of the present invention by those skilled in the art. It is obvious that those familiar with the art can easily make various modifications to the implementation cases and apply the general principles described herein to other embodiments without creative work. Therefore, this section is not limited to the implementation cases here, and improvements and modifications made by those skilled in the art based on the disclosure of this section without departing from the scope of this section should be within the scope of protection of this section.

Claims

1. A method for manufacturing a lead-tin-copper alloy-steel bimetallic sheet, characterized in that: The steps include: (a) Spreading lead-tin-copper alloy powder on a steel plate; (b) placing the steel plate after powder coating in a mesh belt sintering furnace, raising the two ends with pads, and performing a primary sintering process in a nitrogen-hydrogen mixed gas atmosphere to obtain a primary sintered plate; (c) rolling the primary sintered plate, wherein the size of the plate after rolling is 0.05 mm to 0.18 mm larger than the finished plate; (d) placing the primary rolled plate in a mesh belt sintering furnace for secondary sintering in a nitrogen-hydrogen mixed gas atmosphere to obtain a secondary sintered plate; (e) rolling the secondary sintered plate; (f) Use a leveling machine to level the secondary sintered plate to obtain a finished plate.

2. The method for manufacturing the lead-tin-copper alloy-steel bimetallic sheet according to claim 1, characterized in that: In step (a), the thickness of the steel plate is 2.5-7.0 mm.

3. The method for manufacturing the lead-tin-copper alloy-steel bimetallic sheet according to claim 1, characterized in that: In step (b), the height of the cushion block is 20mm-40mm.

4. The method for manufacturing the lead-tin-copper alloy-steel bimetallic sheet according to claim 1, characterized in that: In step (b), when the thickness of the steel plate is 2.5 mm-4.0 mm, the sintering temperature is 825-835° C.; when the thickness of the steel plate is 4.0 mm-7.0 mm, the sintering temperature is 830-845° C.

5. The method for manufacturing the lead-tin-copper alloy-steel bimetallic sheet according to claim 4, characterized in that: The time of the first sintering is 40min-60min.

6. The method for manufacturing the lead-tin-copper alloy-steel bimetallic sheet according to claim 1, characterized in that: In step (d), the sintering temperature of the secondary sintering is 815° C. to 840° C., and the time of the secondary sintering is 20 min to 40 min.

7. The method for manufacturing the lead-tin-copper alloy-steel bimetallic sheet according to claim 1, characterized in that: In step (e), the rolling amount is 0.05mm-0.18mm.

8. The method for manufacturing the lead-tin-copper alloy-steel bimetallic sheet according to claim 1, characterized in that: In step (f), the thickness of the lead-tin-copper alloy layer in the finished board is 0.3mm-0.8mm.

9. The method for manufacturing the lead-tin-copper alloy-steel bimetallic sheet according to any one of claims 1 to 8, characterized in that: The proportion of hydrogen in the nitrogen-hydrogen mixed gas is 15%-25%.

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