Manufacturing process of ceramic-metal composite material valve ball body

Abstract

The invention provides a manufacturing process of a ceramic-metal composite material valve ball body, and belongs to the technical field of valve ball body materials. Comprising the following steps that S1, a dry pressing forming method is adopted, and a ceramic blank part of the valve ball body is manufactured; s2, the ceramic ball blank is subjected to shell manufacturing through a precision casting technology; s3, the shell mold with the ceramic balls is put into a furnace to be heated; s4, the metal-ceramic composite blank is taken out and machined by a machining center; and S5, the semi-finished product is subjected to ceramic ball surface treatment, a ceramic-metal complex is obtained, in the step S1, raw materials comprise 8 mol Ge zirconium powder, after sieving and weighing are conducted, molding is conducted through a 315-ton two-way pressing servo press under the pressure of 150 tons, sealing is conducted through a rubber sleeve after molding is conducted, then pressing is conducted again through a static press, and the numerical value of the static press is 160 Mpa. In the normal operation process of the valve, the valve has the abrasion resistance and corrosion resistance of the surface of the ball body and the toughness of the metal ball body, the service life of the valve is prolonged, and the valve meets the use environments with different temperatures and different media.

Description

Technical Field

[0001] The invention relates to the technical field of valve ball materials, and in particular to a manufacturing process of a valve ball made of ceramic-metal composite material. Background Art

[0002] The valve ball is a common valve structure, which is usually used to control the flow of fluid. It consists of a spherical valve body and a rotating valve seat with a hole. The passage and blockage of the fluid are controlled by rotating the valve body. The valve ball has the advantages of simple structure, good sealing performance, and convenient operation. It is widely used in the fields of petroleum, chemical industry, electricity, metallurgy, and pharmaceuticals. It can be used to control various media such as liquids, gases, and solid particles, and plays an important role in industrial production. There are two materials for existing valve balls, one is a metal valve ball and the other is a ceramic valve ball. However, both valve balls have their own advantages and disadvantages. The valve is mainly composed of a valve body, a ball, and a valve stem. For example, a metal valve ball has the problem of easy wear and acid and alkali corrosion resistance. The ceramic ball has the problem of fragmentation of the metal connection part. In particular, the valve ball that rotates frequently or continuously is very easy to be damaged. Therefore, the present application provides a manufacturing process of a ceramic-metal composite valve ball to meet the demand. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a manufacturing process for a ceramic-metal composite valve ball to solve the problem that the existing valve is mainly composed of a valve body, a ball and a valve stem, such as a metal valve ball, which is easy to wear and not resistant to acid and alkali corrosion, and a ceramic ball has a problem of breakage at the connection part with the metal, especially a valve ball that is frequently rotated or continuously rotated, which is extremely easy to be damaged.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] A manufacturing process of a ceramic-metal composite valve ball, comprising the following steps:

[0006] S1. Use dry pressing method to make the ceramic blank part of the valve ball;

[0007] S2, partially processing the high temperature sintered ceramic ball embryo; the ceramic ball embryo is shelled by using a precision casting process;

[0008] S3, placing the shell mold with the ceramic ball into a furnace for heating;

[0009] S4, taking out the metal-ceramic composite blank and processing it in a processing center;

[0010] S5, subjecting the semi-finished product to surface treatment with ceramic balls to obtain a ceramic-metal composite.

[0011] Preferably, in S1, the raw materials include 8 molGe zirconium powder, which is sieved and weighed, and then formed by a 315 ton bidirectional pressing servo press at a pressure of 150 tons.

[0012] Preferably, after forming, a rubber sleeve is used for sealing, and then a static press is used for pressing again, and the static press value is 160Mpa. This is conducive to better uniformity of the sphere, and the green embryo is more dense, which increases the hardness and strength after sintering;

[0013] The sintering process is adjusted according to the size of the sphere. The highest temperature is about 1450℃, and the total time is 81 hours. After sintering, the rough sphere is formed. The finished product density is 6.0g / cm 3 above.

[0014] Preferably, in S2, the process flow comprises:

[0015] a. Mold opening: According to the size of the ball valve and the wax shrinkage ratio of 0.8:1, a mold with a wax model cavity that meets the process requirements is made;

[0016] b. Wax pressing: put the ceramic ball blank into the mold, inject the wax liquid into the mold through the wax injection machine, and make a combination of the ceramic ball blank and wax;

[0017] c. Assembly tree: weld the single ball valve assembly onto a special wax tree;

[0018] d. Shell making: Use a slurry barrel and a floating sand machine to coat the surface of the wax tree with three layers of refractory materials, and quickly air dry it three times through a hanging chain to prepare a mold shell with ceramic balls;

[0019] e. Dewaxing: Place the air-dried mold shell with ceramic balls into a dewaxing kettle, heat it through the dewaxing kettle, drain the wax liquid, and prepare a mold shell with ceramic balls in an empty cavity for use.

[0020] Preferably, the three-layer refractory material includes three surface layers and three back layers.

[0021] Preferably, the air-drying process takes 12 hours each time and requires constant temperature and humidity.

[0022] Preferably, the heating temperature of the dewaxing kettle is a constant temperature of 166° C., and the heating time is 30 minutes.

[0023] Preferably, in S3, the temperature is raised to 1350°C, and the heating rate is not higher than 5°C / min. Molten steel is cast in the furnace, and the temperature of the molten steel is 1580°C. No additives are required at this time, and the temperature is controlled to avoid ceramic cracking. Then the furnace is cooled naturally. During the cooling process, the ceramic and metal are tightly combined together. Due to different shrinkage rates, there is a slight gap in the groove, and high temperature and high pressure resistant sealant is injected to form a sealing ring to prevent fluid leakage.

[0024] Preferably, in S4, the metal part is processed according to a set program, and the processed surface includes the hoop and the inner tube wall.

[0025] Preferably, in S5, the assembled semi-finished product is subjected to fine machining of the outer edge of the ceramic ball, and the concentricity and roundness are accurately determined. After the semi-finished product is machined to a size slightly larger than the required size by 0.01 mm, the surface is polished.

[0026] Compared with the prior art, the present invention has at least the following beneficial effects:

[0027] In the above scheme, during the normal operation of the valve, the wear resistance of the ball surface and the toughness of the metal ball are both achieved, which greatly improves the service life of the valve and can meet the use environment of different temperatures and different media;

[0028] The present invention reduces the difficulty of processing and assembly, improves labor efficiency, and is different from the prior art in that the metal forms a whole, and during the rotation process, especially under high pressure, the stress points of the ceramic part are dispersed, which is not easy to cause the ceramic to break and fail. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, further serve to explain the principles of the invention and to enable those skilled in the relevant art to make and use the invention.

[0030] Figure 1 This is a schematic diagram of the manufacturing process of a ceramic-metal composite valve ball;

[0031] Figure 2 This is a schematic diagram of the process of making a shell from a ceramic ball blank.

[0032] As shown in the figure, in order to clearly implement the structure of the embodiment of the present invention, specific structures and devices are marked in the figure, but this is only for illustrative purposes and is not intended to limit the present invention to the specific structure, device and environment. According to specific needs, ordinary technicians in this field can adjust or modify these devices and environments. DETAILED DESCRIPTION

[0033] The following is a detailed description of the manufacturing process of a ceramic-metal composite valve ball provided by the present invention in combination with the accompanying drawings and specific embodiments. At the same time, it is explained here that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art may also adopt other alternative methods to implement some known technologies; and the accompanying drawings are only for a more specific description of the embodiments, and are not intended to specifically limit the present invention.

[0034] It should be noted that the references to "one embodiment", "an embodiment", "an exemplary embodiment", "some embodiments" and the like in the specification indicate that the embodiments described may include specific features, structures or characteristics, but not every embodiment may include the specific features, structures or characteristics. In addition, when a specific feature, structure or characteristic is described in conjunction with an embodiment, it should be within the knowledge of a person skilled in the art to implement such feature, structure or characteristic in conjunction with other embodiments (whether or not explicitly described).

[0035] In general, a term can be understood, at least in part, from its use in context. For example, depending, at least in part, on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in the singular sense, or can be used to describe a combination of features, structures, or characteristics in the plural sense. Additionally, the term "based on" can be understood as not necessarily intended to convey an exclusive set of factors, but can instead, depending, at least in part, on the context, allow for the presence of other factors that are not necessarily explicitly described.

[0036] It will be understood that the meanings of “on,” “over,” and “above” in the present invention should be interpreted in the broadest manner, so that “on” not only means “directly on” something, but also includes the meaning of being “on” something with intervening features or layers therebetween, and “on” or “over” not only means “on” or “above” something, but also includes the meaning of being “on” or “above” something with no intervening features or layers therebetween.

[0037] Additionally, spatially relative terms such as "under," "beneath," "lower," "above," "upper," and the like may be used herein for descriptive convenience to describe the relationship of one element or feature to another element or features, as shown in the accompanying drawings. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. The device may be oriented in other ways, and the spatially relative descriptors used herein may be similarly interpreted accordingly.

[0038] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a process for manufacturing a ceramic-metal composite valve ball, comprising the following steps:

[0039] S1. Use dry pressing method to make the ceramic blank part of the valve ball;

[0040] S2, partially processing the high temperature sintered ceramic ball embryo; the ceramic ball embryo is shelled by using a precision casting process;

[0041] S3, placing the shell mold with the ceramic ball into a furnace and heating it;

[0042] S4, taking out the metal-ceramic composite blank and processing it in a processing center;

[0043] S5, subjecting the semi-finished product to surface treatment with ceramic balls to obtain a ceramic-metal composite.

[0044] In S1, the raw materials include 8molGe zirconium powder, which is sieved and weighed, and then formed using a 315-ton bidirectional pressing servo press at a pressure of 150 tons.

[0045] After forming, a rubber sleeve is used for sealing, and then a static press is used to press again. The static press value is 160Mpa. This is conducive to better uniformity of the sphere, more compact green embryos, and increased hardness and strength after sintering.

[0046] The sintering process is adjusted according to the size of the sphere. The highest temperature is about 1450℃, and the total time is 81 hours. After sintering, the rough sphere is formed. The finished product density is 6.0g / cm 3 above.

[0047] In S2, the process includes:

[0048] a. Mold opening: According to the size of the ball valve and the wax shrinkage ratio of 0.8:1, a mold with a wax model cavity that meets the process requirements is made;

[0049] b. Wax pressing: put the ceramic ball blank into the mold, inject the wax liquid into the mold through the wax injection machine, and make a combination of the ceramic ball blank and wax;

[0050] c. Assembly tree: weld the single ball valve assembly onto a special wax tree;

[0051] d. Shell making: Use a slurry barrel and a floating sand machine to coat the surface of the wax tree with three layers of refractory materials, and quickly air dry it three times through a hanging chain to prepare a mold shell with ceramic balls;

[0052] e. Dewaxing: put the air-dried mold shell with ceramic balls into the dewaxing kettle, heat it through the dewaxing kettle, discharge the wax liquid, and prepare the mold shell with ceramic balls in the empty cavity for use. The three-layer refractory material includes three surface layers and three back layers. The air-drying process is 12 hours each time, and constant temperature and humidity are required. The heating temperature of the dewaxing kettle is a constant 166°C, and the heating time is 30 minutes.

[0053] In S3, the temperature is raised to 1350°C, and the heating rate is no higher than 5°C / min. Molten steel is cast in the furnace, and the temperature of the molten steel is 1580°C. No additives are needed at this time, and the temperature is controlled to avoid ceramic cracking. Then the furnace is cooled naturally. During the cooling process, the ceramic and metal are tightly combined together. Due to different shrinkage rates, there is a slight gap in the groove, and high temperature and high pressure resistant sealant is injected to form a sealing ring to prevent fluid seepage.

[0054] In S4, the metal part is processed according to the set program, and the processed surface includes the hoop and the inner pipe wall.

[0055] In S5, the assembled semi-finished product is finely processed on the outer edge of the ceramic ball to find the concentricity and roundness. After processing to a size slightly larger than the required size by 0.01 mm, the surface is polished.

[0056] The present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention. In order to make the public have a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without the description of these details. In addition, in order to avoid unnecessary confusion about the essence of the present invention, well-known methods, processes, procedures, components and circuits are not described in detail.

[0057] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A process for manufacturing a ceramic-metal composite valve ball, characterized in that: The following steps are involved: S1. Use dry pressing method to make the ceramic blank part of the valve ball; S2, partially processing the high temperature sintered ceramic ball embryo; the ceramic ball embryo is shelled by using a precision casting process; S3, placing the shell mold with the ceramic ball into a furnace and heating it; S4, processing the metal-ceramic composite blank by a processing center; S5, subjecting the semi-finished product to surface treatment with ceramic balls to obtain a ceramic-metal composite.

2. The manufacturing process of a ceramic-metal composite valve ball according to claim 1, characterized in that: In S1, the raw materials include 8molGe zirconium powder, which is sieved and weighed, and then formed under a pressure of 150 tons using a 315-ton bidirectional pressing servo press.

3. The manufacturing process of a ceramic-metal composite valve ball according to claim 2, characterized in that: After forming, it is sealed with a rubber sleeve and then pressed again with a static press, the value of which is 160Mpa; The sintering process is adjusted according to the size of the sphere. The highest temperature is about 1450℃, and the total time is 81 hours. After sintering, the rough sphere is formed. The finished product density is 6.0g / cm 3 above.

4. The manufacturing process of a ceramic-metal composite valve ball according to claim 1, characterized in that: In S2, the shell making process includes: a. Mold opening: According to the size of the ball valve and the wax shrinkage ratio of 0.8:1, a mold with a wax model cavity that meets the process requirements is made; b. Wax pressing: put the ceramic ball blank into the mold, inject the wax liquid into the mold through the wax injection machine, and make a combination of the ceramic ball blank and wax; c. Assembly tree: weld the single ball valve assembly onto a special wax tree; d. Shell making: Use a slurry barrel and a floating sand machine to coat the surface of the wax tree with three layers of refractory materials, and quickly air dry it three times through a hanging chain to prepare a mold shell with ceramic balls; e. Dewaxing: Place the air-dried mold shell with ceramic balls into a dewaxing kettle, heat it through the dewaxing kettle, drain the wax liquid, and prepare a mold shell with ceramic balls in an empty cavity for use.

5. The manufacturing process of a ceramic-metal composite valve ball according to claim 4, characterized in that: The three-layer refractory material includes three surface layers and three back layers.

6. The manufacturing process of a ceramic-metal composite valve ball according to claim 4, characterized in that: The air drying process takes 12 hours each time and requires constant temperature and humidity.

7. The manufacturing process of a ceramic-metal composite valve ball according to claim 4, characterized in that: The heating temperature of the dewaxing kettle is a constant 166°C, and the heating time is 30 minutes.

8. The manufacturing process of a ceramic-metal composite valve ball according to claim 1, characterized in that: In S3, the temperature is raised to 1350°C, and the heating rate is no higher than 5°C / min. Molten steel is cast in the furnace, and the temperature of the molten steel is 1580°C. No additives are needed at this time, and the temperature is controlled to avoid ceramic cracking. Then the furnace is cooled naturally. During the cooling process, the ceramic and metal are tightly combined together. Due to different shrinkage rates, there is a slight gap in the groove, and high temperature and high pressure resistant sealant is injected to form a sealing ring to prevent fluid seepage.

9. The manufacturing process of a ceramic-metal composite valve ball according to claim 1, characterized in that: In S4, the metal part is processed according to the set program, and the processed surface includes the hoop and the inner pipe wall.

10. The manufacturing process of a ceramic-metal composite valve ball according to claim 1, characterized in that: In S5, the assembled semi-finished product is finely processed on the outer edge of the ceramic ball to find the concentricity and roundness. After processing to a size slightly larger than the required size by 0.01 mm, the surface is polished.

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