Milling and reaming tool and its preparation method

Abstract

This application relates to the field of workover tools, and relates to a milling tool and a preparation method thereof. Ceramic particles are placed in a metal mesh, and the metal mesh containing the ceramic particles is placed on a milling base with a preset shape to obtain a ceramic preform; the ceramic preform is preheated and die-cast and compounded so that the ceramic particles are integrally formed with the milling base to obtain a milling head; the milling head is connected to the milling body; the ceramic preform is subjected to differential pressure casting with a molten Cu-Zn-Ni alloy liquid to compound the ceramic particles with the milling base. The use of the molten Cu-Zn-Ni alloy liquid reduces the temperature difference with the ceramic particles and reduces the damage such as crack generation caused by the thermal shock of the ceramic particles. The obtained milling tool eliminates the porosity and crack defects in the milling head. The ceramic particles are evenly distributed, and the matrix alloy of the milling head is well filled, significantly improving the composite quality and increasing the qualified rate of the milling tool.

Description

Technical Field

[0001] This application relates to the field of workover tools, and more particularly, to a milling and reaming tool and a preparation method thereof. Background Art

[0002] The milling and reaming tool is one of the most common workover tools in workover operations. Super-hard milling materials need to be fixed to the front end of the tool to form a milling head or a reaming head. The reaming head is formed by surfacing hard alloy electrodes, and the reaming body is forged 45# steel.

[0003] Currently, the following steps are generally used to prepare the milling and reaming tool:

[0004] 1. Prepare the reaming head:

[0005] Crush hard alloy particles, select matrix metal materials, such as simple substances of copper, zinc, nickel, manganese, aluminum, etc., and prepare according to the mass ratio.

[0006] Place the crushed hard alloy particles and matrix metals with different ratios in the electrode-shaped mold of a box-type muffle furnace. After the matrix metal melts, the metal melt bonds the hard alloy particles together, and then cools down to form a hard alloy surfacing electrode. Finish machine it into a reaming head.

[0007] 2. Connect the reaming head and the reaming body:

[0008] Prepare a matrix metal transition layer about 5 mm on the reaming body, and then weld the prepared hard alloy surfacing electrode (reaming head) onto the reaming body (usually 45# steel) by oxyacetylene welding process.

[0009] However, the surfacing operation is mainly manual, so the uncertainty is large. Moreover, the reaming head formed by the hard alloy surfacing electrode has visible pores and cracks to the naked eye, and the metal matrix is not fully filled, resulting in a low qualified rate of the milling and reaming tool. Summary of the Invention

[0010] The purpose of the embodiments of this application is to provide a preparation method of a milling and reaming tool.

[0011] In a first aspect, this application provides a preparation method of a milling and reaming tool, and the milling and reaming tool includes a reaming head and a reaming body;

[0012] The preparation method includes:

[0013] Place ceramic particles in a metal mesh, and place the metal mesh containing the ceramic particles on a reaming base with a preset shape to obtain a ceramic preform;

[0014] Preheat and die-cast the ceramic preform to integrally form the ceramic particles and the reaming base to obtain a reaming head;

[0015] Connect the milling head to the milling body;

[0016] Die casting composite includes:

[0017] Perform differential pressure casting on the ceramic preform and the molten Cu-Zn-Ni alloy liquid to composite the ceramic particles with the milling base.

[0018] The method of this application uses the molten Cu-Zn-Ni alloy liquid. This alloy is a low-melting-point non-ferrous copper alloy. Using a low-melting-point metal can reduce the preparation difficulty of the composite material (composite with ceramic particles), reduce the temperature difference with the ceramic particles, and reduce the damage such as cracks caused by the thermal shock of the ceramic particles. Further, the ternary copper-zinc-nickel alloy used in this application has a eutectic alloy composition, good fluidity of the alloy, and is easy to fill the ceramic pores. And the alloy has high tensile strength and good toughness, and is not prone to brittle fracture during service. Therefore, for the sleeve milling tool prepared by the method of this application, the base and the ceramic preform are integrally formed by die casting to form the milling head, and the milling head is then assembled with the milling body, without the need for surfacing. The product quality is not affected by the surfacing technical level of the workers, the production cycle is short, and the quality is high and uniform; and because the base and the ceramic preform are integrally formed by die casting to form the milling head, the pores and crack defects in the milling head are eliminated. The ceramic particles are evenly distributed, and the matrix alloy of the milling head is well filled, significantly improving the composite quality and increasing the qualified rate of the sleeve milling tool. Further, the preset shape of the milling base enables the ceramic particles to be directionally distributed, and the ceramic particles are evenly distributed. Differential pressure die casting improves the wear resistance of the matrix metal and ceramic particles.

[0019] In other embodiments of this application, the particle size of the above-mentioned ceramic particles is 6 mm to 20 mm;

[0020] The ceramic particles are at least one of tungsten carbide particles or cubic boron nitride particles.

[0021] In other embodiments of this application, the temperature of the above-mentioned preheating is less than or equal to 300 °C.

[0022] In other embodiments of this application, the above-mentioned differential pressure casting includes:

[0023] Place the preheated ceramic preform into the cavity of the metal mold, and evacuate the cavity of the metal mold;

[0024] Place the crucible containing the molten Cu-Zn-Ni alloy liquid in a closed container, introduce dry compressed gas into the closed container, make the molten Cu-Zn-Ni alloy liquid rise along the riser pipe, and enter the cavity of the metal mold through the casting gate;

[0025] Among them, the riser pressure is 0.01 MPa to 0.03 MPa.

[0026] In other embodiments of the present application, evacuating the metal mold cavity includes: controlling the vacuum degree to be below 100 mbar.

[0027] In other embodiments of the present application, holding the pressure to solidify it includes:

[0028] Maintaining the liquid surface pressure on the molten Cu-Zn-Ni alloy entering the metal mold cavity until the casting is completely solidified and then relieving the liquid surface pressure;

[0029] The liquid surface pressure is 0.2 MPa to 0.4 MPa.

[0030] In other embodiments of the present application, before differential pressure casting, it further includes: preparing the molten Cu-Zn-Ni alloy liquid, specifically:

[0031] Placing brass and copper-nickel master alloy in the crucible of the intermediate frequency induction furnace and refining at 950 °C to 1090 °C to obtain a copper alloy melt;

[0032] Putting zinc into the copper alloy melt, heating up to 1100 °C to 1200 °C, and waiting for the "flame spraying" phenomenon to occur to obtain the molten Cu-Zn-Ni alloy liquid.

[0033] In other embodiments of the present application, the above-mentioned milling base has a bottom wall and a peripheral wall, and the bottom wall and the peripheral wall enclose a receiving space with a preset shape;

[0034] Placing the metal mesh containing ceramic particles on the milling base with a preset shape includes:

[0035] Placing the ceramic particles in the receiving space with a preset shape.

[0036] In other embodiments of the present application, connecting the milling head and the milling body together as described above includes:

[0037] Connecting the milling head and the milling body with a connecting piece; or

[0038] Welding the milling head and the milling body.

[0039] In a second aspect, the present application provides a sleeve milling tool prepared by using the preparation method of any one of the foregoing;

[0040] The molten Cu-Zn-Ni alloy liquid forms the matrix metal of the milling head; the ceramic particles are directionally dispersed in the matrix metal according to a preset position. Description of the Drawings

[0041] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0042] Figure 1 Schematic structural diagram of the milling base provided by the embodiment of the present application;

[0043] Figures 2(a) and 2(b) are the macroscopic sectional view and microscopic sectional view of the composite casting milling head provided by Embodiment 1 of the present application. Among them, Figures 2(a) and 2(b) are the macroscopic sectional view and microscopic sectional view of the composite material prepared by the die-casting process (the pictures are grayscale processed);

[0044] Figures 2(c) and 2(d) are the macro-microscopic sectional views of the milling head components prepared by the conventional surfacing technology in the prior art used on-site (the pictures are grayscale processed);

[0045] Figure 3 is the three-dimensional morphology diagram of the matrix metal wear. Among them, Figure 3(a) is the welding process, and Figure 3(b) is the die-casting process (the pictures are grayscale processed);

[0046] Figure 4 is the three-dimensional morphology diagram of the ceramic wear. Among them, Figure 4(a) is the welding process, and Figure 4(b) is the die-casting process (the pictures are grayscale processed);

[0047] Figure 5 is the Vickers hardness value of the matrix metal of the matrix. Among them, Figure 5(a) is the welding process, and Figure 5(b) is the die-casting process (the pictures are grayscale processed). Specific embodiments

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some, rather than all, of the embodiments of the present application.

[0049] Therefore, the following detailed description of the embodiments of the present application is not intended to limit the scope of the present application claimed, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.

[0050] The embodiment of the present application provides a preparation method for a sleeve milling tool. The sleeve milling tool includes a milling head and a milling body;

[0051] The preparation method includes:

[0052] Place ceramic particles in a metal mesh, and place the metal mesh containing the ceramic particles on a milling base with a preset shape to obtain a ceramic preform.

[0053] Preheat and die-cast the ceramic preform in combination to integrally form the ceramic particles with the milling base to obtain a milling head.

[0054] Connect the milling head to the milling body.

[0055] The die-casting combination includes:

[0056] Perform differential pressure casting on the ceramic preform and a molten Cu-Zn-Ni alloy liquid to combine the ceramic particles with the milling base.

[0057] The sleeve milling tool prepared by this method eliminates the porosity and crack defects in the milling head, the ceramic particles are evenly distributed, the matrix alloy of the milling head is well filled, significantly improves the composite quality, and improves the qualified rate of the sleeve milling tool.

[0058] Further, in some embodiments of the present application, the preparation method of the sleeve milling tool includes the following steps:

[0059] Step S1, prepare a ceramic preform.

[0060] Further, in some embodiments of the present application, the steps of preparing the milling head include:

[0061] Place ceramic particles in a metal mesh, and place the metal mesh containing the ceramic particles on a milling base with a preset shape to obtain a ceramic preform.

[0062] Preheat and die-cast the ceramic preform in combination to integrally form the ceramic particles with the milling base to obtain a milling head.

[0063] Further, in some embodiments of the present application, the above-mentioned ceramic particles are at least one of tungsten carbide particles or cubic boron nitride particles.

[0064] Tungsten carbide particles or cubic boron nitride particles have excellent drilling ability and wear resistance. When combined with the milling base, they can greatly improve the drilling ability and wear resistance of the milling head. And tungsten carbide particles or cubic boron nitride particles have more excellent fracture toughness. Since the use scenario of the sleeve milling tool is that the sleeve milling tool actively drills other workpieces, a higher requirement for fracture toughness is needed. The excellent fracture toughness can prevent the sleeve milling tool from brittle fracture during service. For example, the hardness of tungsten carbide particles is generally above 2000HV, and the fracture toughness is about 4 Mpa, which can effectively improve the milling efficiency of the sleeve milling tool.

[0065] Further, in other alternative embodiments of the present application, the above-mentioned ceramic particles can also be selected as WC-Co cemented carbide particles, etc.

[0066] Further, in some embodiments of the present application, the material of the above-mentioned milling base can be selected to be the same as that of the milling body, such as common 45# steel.

[0067] Further, the milling base has a bottom wall and a peripheral wall, and the bottom wall and the peripheral wall enclose a receiving space with a preset shape;

[0068] Placing the metal mesh containing ceramic particles on the milling base with a preset shape includes:

[0069] Placing the metal mesh containing ceramic particles in the receiving space with a preset shape.

[0070] By placing the ceramic particles in the receiving space with a preset shape, in the milling head obtained by die-casting composite, the Cu-Zn-Ni alloy molten liquid can form the matrix metal of the milling head; the ceramic particles are directionally dispersed in the matrix metal according to a preset position.

[0071] It should be noted that the specific shape of the above-mentioned milling base can be designed directionally according to actual needs.

[0072] The following exemplarily gives several shape structures of the milling base, and for details, see the attached Figure 1 :

[0073] As shown in the attached Figure 1 Four different shape structures of the milling base shown; in the figure, the area inside the solid line is the receiving space with a preset shape; the solid line is the wall body; ceramic particles are filled inside the solid line, and there are no ceramic particles outside the solid line; thus, the directional filling of ceramics can be realized. So that in the subsequent die-casting composite, the ceramic particles are directionally dispersed in the matrix metal according to a preset position. Thereby greatly ensuring the sufficiency of the matrix metal filling and the uniformity of the separation of the ceramic particles, reducing or even avoiding the appearance of pores and cracks, and improving the wear life of the entire milling head.

[0074] Further, in other alternative embodiments of the present application, the preform formed by the above-mentioned milling base and ceramic particles can be obtained by using 3D printing additive manufacturing technology, so that the directional and uniform arrangement of ceramic particles can be realized more precisely. It should be noted that when using 3D printing additive manufacturing technology, it is preferred to compound cemented carbide ceramics with the milling base; exemplarily, WC-Co cemented carbide ceramics are selected to be compounded with the milling base.

[0075] Further, in some embodiments of the present application, the particle size of the above-mentioned ceramic particles is 6 mm to 20 mm. Further optionally, in some embodiments of the present application, the particle size of the above-mentioned ceramic particles is 6.5 mm to 19.5 mm. Exemplarily, the particle size of the above-mentioned ceramic particles is 8 mm, 10 mm, 12 mm, 14 mm, 15 mm, 17 mm or 18 mm.

[0076] In the preparation method of the present application, since ceramic particles such as tungsten carbide particles or cubic boron nitride particles with excellent drilling ability and wear resistance are used, the particle size of the ceramic particles can be larger (the conventional ceramic particle size in the art is 0.55 mm - 1.70 mm, and large particles cannot ensure the uniform distribution of the composite material and there will be pores in the conventional method); even for larger particle ceramic particles, the uniform distribution of the ceramic particles in the composite material can be ensured and pores can be avoided. And larger particle ceramic particles can reduce the composite process difficulty and energy consumption.

[0077] Further, in some embodiments of the present application, when the ceramic particles are placed in the metal mesh as described above, the metal mesh here can be selected as a copper mesh or the like.

[0078] Step S2: Prepare a milling head.

[0079] Further, in some embodiments of the present application, the ceramic preform prepared in step S1 is preheated and die-cast and compounded to obtain a milling head.

[0080] Further, in some embodiments of the present application, the above-mentioned preheating temperature is less than or equal to 300 °C.

[0081] Further optionally, the above-mentioned preheating temperature is 100 °C to 300 °C; exemplarily, the above-mentioned preheating temperature is 150 °C, 180 °C, 200 °C, 220 °C, 250 °C, 280 °C or 300 °C.

[0082] In some specific embodiments, the preheating of the ceramic preform prepared in step S1 can be achieved by putting the ceramic preform prepared in step S1 into a muffle furnace for preheating.

[0083] In the embodiment of the present application, the preheated ceramic preform is compounded with the molten liquid of the low-melting-point Cu-Zn-Ni alloy, so that preheating can be realized at a very low (less than or equal to 300 °C) preheating temperature (the common preheating temperature in the art is 800 °C - 1000 °C) and the subsequent material compounding requirements can be met; and this low-temperature preheating reduces the requirements for equipment for ceramic preheating, reduces energy consumption and improves production efficiency.

[0084] Further, the die-casting and compounding of the preheated ceramic preform includes:

[0085] The preheated ceramic preform is subjected to differential pressure die casting with a Cu-Zn-Ni alloy molten liquid.

[0086] Further, in some embodiments of the present application, the differential pressure die casting includes:

[0087] Place the aforementioned preheated ceramic preform into the cavity of the metal mold, and evacuate the cavity of the metal mold;

[0088] Then place the crucible containing the Cu-Zn-Ni alloy molten liquid in a closed container, introduce dry compressed gas into the closed container, so that the Cu-Zn-Ni alloy molten liquid rises along the riser pipe, and enters the cavity of the metal mold through the casting gate; and keep the pressure to make it solidify;

[0089] Wherein, the riser pressure is 0.01 MPa to 0.03 MPa.

[0090] Further optionally, the aforementioned riser pressure is 0.015 MPa to 0.025 MPa. Exemplarily, the aforementioned riser pressure is 0.018 MPa, 0.02 MPa, 0.025 MPa or 0.028 MPa.

[0091] Further, in some embodiments of the present application, keeping the pressure to make it solidify includes:

[0092] Keep the liquid surface pressure on the Cu-Zn-Ni alloy molten liquid entering the cavity of the metal mold until the casting is completely solidified and then release the liquid surface pressure; the liquid surface pressure is 0.2 MPa to 0.4 MPa.

[0093] Further optionally, the liquid surface pressure is 0.2 MPa, 0.25 MPa, 0.3 MPa, 0.35 MPa or 0.4 MPa.

[0094] Exemplarily, in some specific embodiments of the present application, preheating and die casting of the ceramic preform are combined to obtain a milling head, including:

[0095] First, preheat the ceramic preform, then place it into the cavity of the metal mold, and then quickly evacuate the cavity of the metal mold, and control the vacuum degree below 100 mbar. Synchronously, melt the alloy. After the alloy melting is completed and the mold vacuum degree reaches the requirement, introduce dry compressed air into the closed container equipped with the crucible. The metal melt rises along the riser pipe under the action of the gas pressure, and the riser pressure is 0.02 MPa; the metal melt smoothly enters the casting cavity through the casting gate, and keep the liquid surface pressure of the metal melt (0.3 MPa) until the casting is completely solidified, and then release the pressure on the liquid surface. The remaining metal melt returns to the crucible, and the solidified metal melt forms the required composite material casting with the ceramic preform in the metal mold.

[0096] Further, in some embodiments of the present application, while evacuating the cavity of the metal mold, the molten Cu-Zn-Ni alloy liquid is smelted synchronously.

[0097] Further, in some embodiments of the present application, preparing the molten Cu-Zn-Ni alloy liquid includes:

[0098] Placing brass and copper-nickel master alloy in the crucible of the medium-frequency induction furnace, and refining at 950°C to 1090°C to obtain a copper alloy melt;

[0099] Adding zinc into the copper alloy melt, heating up to 1100°C to 1200°C, and waiting for the "flame spraying" phenomenon to occur to obtain the molten Cu-Zn-Ni alloy liquid.

[0100] Exemplarily, placing brass and copper-nickel master alloy in the crucible of the medium-frequency induction furnace, and refining at 950°C, 960°C, 980°C, 1000°C, 1020°C, 1050°C or 1080°C to obtain a copper alloy melt.

[0101] Exemplarily, adding zinc into the copper alloy melt, heating up to 1100°C, 1150°C, 1180°C or 1200°C, and waiting for the "flame spraying" phenomenon to occur to obtain the molten Cu-Zn-Ni alloy liquid.

[0102] "Flame spraying" is a phenomenon in the smelting process of the copper-zinc-nickel ternary alloy, which is convenient for judging the smelting quality of the alloy melt. During the heating-up process of the copper-zinc-nickel ternary alloy smelting, the saturated vapor pressures of copper, zinc, and nickel elements in the atmospheric environment are different. Among them, the Zn element is the most volatile. When the temperature reaches the boiling point of Zn in the ternary alloy melt, the zinc element volatilizes most violently. At this time, Zn combines with the oxygen element in the melt to form zinc oxide, which is easy to carry away the oxygen element in the melt, playing a role in reducing the gas content. At this time, the temperature of the alloy melt also reaches the requirement, and the gas content in the alloy also decreases, meeting the pouring requirement. If the temperature is further increased and the furnace is not discharged in time, on the one hand, the volatilization of the zinc element will be aggravated, resulting in a sharp decrease in the Zn content in the alloy and causing a large waste of the zinc element; on the other hand, the volatilized Zn makes the cast metal deviate from the target composition, reducing the mechanical properties of the metal matrix.

[0103] Exemplarily, in some specific embodiments of the present application, placing brass and copper-nickel master alloy in the crucible of the medium-frequency induction furnace, heating by electricity, and refining at about 1000°C. Subsequently, a quantitative zinc ingot is added into the copper alloy melt and stirred. After holding for 5 minutes, the temperature is raised to about 1150°C. After the "flame spraying" phenomenon occurs, the furnace is quickly discharged, and the qualified metal melt is poured into the mold cavity.

[0104] Further, in other alternative embodiments of the present application, a molten Cu-Zn-Ni alloy liquid can be obtained by pre-melting before evacuating the cavity of the metal mold.

[0105] The embodiment of the present application uses a molten Cu-Zn-Ni alloy liquid. This alloy is a low-melting-point non-ferrous copper alloy. Using a low-melting-point metal can reduce the preparation difficulty of the composite material (composite with ceramic particles), reduce energy consumption, reduce the requirements for mold temperature control and mold material, and improve the service life of the mold. Moreover, the alloy used in the present application has a low melting point, reducing the temperature difference between the molten alloy liquid and the ceramic particles, and reducing the damage such as crack generation caused by the thermal shock of the ceramic particles. Further, the ternary copper-zinc-nickel alloy used in the present application has a eutectic alloy composition, good fluidity of the alloy, and is easy to fill the ceramic pores. And the alloy has high tensile strength and good toughness, and is not prone to brittle fracture during service.

[0106] Currently, the commonly used ferrous metal melt in this field has a high melting point, is prone to cause thermal shock to ceramic particles and lead to crack damage, and has great difficulty in being compounded with ceramic particles, is not easy to fill the pores between ceramic particles, and the obtained composite material has a high risk of porosity.

[0107] The present application uses differential pressure casting to compound the preheated ceramic preform with the molten Cu-Zn-Ni alloy liquid, eliminating porosity and crack defects, with good filling of the matrix alloy, significantly improving the composite quality and the qualified rate of parts; and the proportion of ceramic particles can be custom-designed according to actual needs, and the ceramic particles are evenly distributed.

[0108] Compared with the common squeeze casting in this field, the method of differential pressure casting used in the present application has the following advantages:

[0109] 1. High production efficiency, suitable for mass production;

[0110] 2. High dimensional accuracy of the casting and smooth surface;

[0111] 3. Good dimensional consistency of the casting and high interchangeability;

[0112] 4. Can produce complex thin-walled parts;

[0113] 5. Higher utilization rate of metal;

[0114] 6. Wide application range of alloys, aluminum, zinc, magnesium, copper, lead, tin and even ferrous metals can all be produced by die-casting process;

[0115] 7. Wide application range of die-cast parts.

[0116] Particularly for the second point, the precision of the squeeze casting process in the prior art is low, and subsequent finishing machining of the milling head is required. However, the present application creatively adopts the method of differential pressure casting, which greatly reduces the workload of subsequent finishing machining of the milling head, and its precision level may not even require finishing machining.

[0117] Step S3: Connect the milling head to the milling body.

[0118] In some embodiments of the present application, the above-mentioned milling body adopts the shape of a common milling body in the art, such as a rod shape; further optionally, the material of the milling body is made of a common material in the art; for example: 45# steel.

[0119] Further, in some embodiments of the present application, connecting the milling head obtained in the aforementioned step S2 to the milling body includes:

[0120] Connect the milling head and the milling body with a connecting piece.

[0121] Exemplarily, in some embodiments of the present application, connecting the milling head and the milling body with a connecting piece can be carried out by means of threaded connection. For example, an NC26 threaded interface is provided at the base end of the milling head and connected to the milling body through a connecting piece.

[0122] Further, in some embodiments of the present application, connecting the milling head obtained in the aforementioned step S2 to the milling body includes:

[0123] Weld the milling head and the milling body.

[0124] Exemplarily, bevel the base end of the milling head and perform welding treatment with the milling body.

[0125] When the milling head of the present application is connected to the milling body, it is not necessary to prepare a matrix metal transition layer of about 5 mm on the milling body, and they can be directly connected. This is because the materials of the base of the milling head and the milling body are the same, thus simplifying the preparation process.

[0126] Some embodiments of the present application provide a sleeve milling tool prepared by using the preparation method provided in any of the foregoing embodiments.

[0127] Further, the above-mentioned molten Cu-Zn-Ni alloy forms the matrix metal of the milling head; the ceramic particles are directionally dispersed in the matrix metal according to a preset position.

[0128] The features and performance of the present application are further described in detail below in conjunction with embodiments:

[0129] Example 1

[0130] Provide a reaming and milling tool, which is prepared according to the following steps:

[0131] Use forged 45# steel and machine it according to the drawing to obtain the corresponding reaming and milling base as Figure 1 . Place ceramic particles on the 45# steel reaming and milling base through a copper mesh. The combination is called a ceramic preform, and then corresponding preheating and die-casting composite processes are carried out for preparation.

[0132] First, preheat the ceramic preform at 200°C, then place it in the cavity of the metal mold. After that, quickly evacuate the cavity of the metal mold, and control the vacuum degree below 100 mbar. Synchronously, melt the alloy. Melting steps: Place brass and copper-nickel master alloy in the crucible of the intermediate frequency induction furnace, energize and heat, and refine at about 1000°C. Subsequently, put a certain amount of zinc ingots into the copper alloy melt and stir. After holding for 5 minutes, raise the temperature to about 1150°C. After the "flaming" phenomenon appears, quickly take out of the furnace, and the Cu-Zn-Ni alloy molten liquid is qualified for melting.

[0133] After the alloy melting is completed and the mold vacuum degree reaches the requirement, introduce dry compressed air into the closed container equipped with the crucible. The molten metal rises along the riser pipe under the action of gas pressure, and the riser pressure is 0.02 MPa; it smoothly enters the casting cavity through the casting gate, and maintain the liquid surface pressure of the molten metal (0.3 MPa) until the casting is completely solidified. Then relieve the pressure on the liquid surface, and the remaining molten metal returns to the crucible. The solidified molten metal forms the required composite material casting with the ceramic preform in the metal mold. The part blank after demolding and cooling is machined according to the required dimensional requirements. Because the ceramic preform can be designed directionally, there are no ceramic particles at the positions that need to be machined, only copper alloy. Obtain the reaming and milling head, and connect the reaming and milling head with the reaming and milling body.

[0134] Detect the composite material casting prepared above:

[0135] 1. Detect the macroscopic and microscopic structures of the composite material casting.

[0136] Figure 2(a) and Figure 2(b) show the macroscopic sectional view and microscopic sectional view of the reaming and milling head of the composite material casting prepared in the above-mentioned Example 1.

[0137] Among them, Figure 2(a) and Figure 2(b) are the macroscopic sectional view and microscopic sectional view of the composite material prepared by the die-casting process.

[0138] Figure 2(c) and Figure 2(d) provide the macro-microscopic sectional views of the reaming and milling head components prepared by the conventional surfacing technology in the prior art used on site.

[0139] As can be seen from FIGS. 2(a) and 2(b), at both the millimeter scale and the micron scale, the interface between the metal melt and the ceramic particles in the composite material prepared in this application is completely compounded, the filling is complete, and there are no obvious defects such as pores, micropores, and cracks.

[0140] As can be seen from FIGS. 2(c) and 2(d), there are a large number of pores, shrinkage cavities on the millimeter scale, cracks in the component, and the filling is incomplete. At the micron scale, there are a large number of micropores on the surface of the metal melt and the ceramic particles, and the filling is incomplete, reducing the interfacial bonding strength between the metal melt and the ceramic particles.

[0141] 2. Use the RTEC-MFT5000 multi-functional friction and wear testing machine to detect the wear performance of the matrix metal of the composite material casting; the results are shown in FIGS. 3-5.

[0142] FIG. 3 is a three-dimensional morphology diagram of the wear of the matrix metal, (a) is the welding process, and (b) is the die-casting process;

[0143] FIG. 4 is a three-dimensional morphology diagram of the wear of the ceramic, (a) is the welding process, and (b) is the die-casting process;

[0144] FIG. 5 is the Vickers hardness value of the matrix metal of the matrix; (a) is the welding process, and (b) is the die-casting process.

[0145] In FIGS. 3-5, (a) are the test results of the existing welding process, which are the wear depth of the matrix metal, the wear depth of the original ceramic, and the hardness of the matrix metal respectively. (b) are the corresponding results of the die-casting process. From the hardness and wear depth of the matrix metal, the sample data prepared by the die-casting process are better than the original welding process. The hardness has increased by about 100 HV, and the wear depth has decreased by about 18% compared with the original welding process. The weight loss of the ceramic particles used is 1 / 5 of the original welding process.

[0146] 3. Detect the hardness performance of the matrix metal of the composite material casting.

[0147] The hardness value is obtained by a Vickers microhardness tester (model XHV-1000T-CCD, Shanghai Jujing). The wear analysis of the GCr15 grinding ball is obtained by the RTEC-MFT5000 multi-functional friction and wear testing machine. The results are shown in Tables 1 and 2.

[0148] Table 1

[0149] Hardness value HV Standard deviation HV Welded process metal matrix 108 3 Die-cast metal matrix 187 8

[0150] Table 2 Comparison of Wear Failure of GCr15 Grinding Balls

[0151]

[0152] As can be seen from the above table, the hardness of the matrix metal produced by the die-casting process has been improved, increasing by 73% compared to the original welding process; for the matrix metal produced by the die-casting process, under the laboratory wear condition, its wear depth has decreased by 17.8%, indicating that the die-casting process helps to improve the wear resistance of the matrix metal.

[0153] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A preparation method of a reaming and milling tool, characterized in that, The reaming and milling tool includes a milling head and a milling body; The preparation method includes: Placing ceramic particles in a metal mesh, and placing the metal mesh containing the ceramic particles in the accommodation space of a milling base to obtain a ceramic preform; the milling base has a bottom wall and a peripheral wall, and the bottom wall and the peripheral wall enclose the accommodation space of a preset shape; the particle size of the ceramic particles is 6 mm to 20 mm; the ceramic particles are at least one of tungsten carbide particles or cubic boron nitride particles; Preheating and die-casting composite the ceramic preform so that the ceramic particles are integrally formed with the milling base to obtain the milling head; Connecting the milling head and the milling body together; The die-casting composite includes: Performing differential pressure casting on the ceramic preform and a Cu-Zn-Ni alloy molten liquid to composite the ceramic particles and the milling base; The differential pressure casting includes: Placing the preheated ceramic preform into a metal mold cavity, and evacuating the metal mold cavity; Placing a crucible containing the Cu-Zn-Ni alloy molten liquid in a closed container, introducing dry compressed gas into the closed container, causing the Cu-Zn-Ni alloy molten liquid to rise along a riser pipe, and entering the metal mold cavity through a casting gate; and maintaining pressure until it solidifies; Wherein, the riser pressure is 0.01 MPa to 0.03 MPa.

2. The preparation method of the reaming and milling tool according to claim 1, wherein The temperature of the preheating is less than or equal to 300 °C.

3. The preparation method of the reaming and milling tool according to claim 1, wherein The evacuating the metal mold cavity includes: controlling the vacuum degree to be below 100 mbar.

4. The preparation method of the reaming and milling tool according to claim 1, wherein The maintaining pressure until it solidifies includes: Maintaining the liquid surface pressure on the Cu-Zn-Ni alloy molten liquid entering the metal mold cavity until the casting is completely solidified, and then releasing the liquid surface pressure; The liquid surface pressure is 0.2 MPa to 0.4 MPa.

5. The preparation method of the reaming and milling tool according to claim 1, wherein Before the differential pressure casting, it further includes the step of preparing the Cu-Zn-Ni alloy molten liquid: Placing brass and a copper-nickel master alloy in a crucible of an intermediate frequency induction furnace, and refining at 950 °C to 1090 °C to obtain a copper alloy melt; Putting zinc into the copper alloy melt, heating up to 1100 °C to 1200 °C, and waiting for the "flame spraying" phenomenon to obtain the Cu-Zn-Ni alloy molten liquid.

6. The preparation method of the reaming and milling tool according to claim 1, wherein The connecting the milling head and the milling body together includes: Connecting the milling head and the milling body with a connecting piece; or Welding the milling head and the milling body.

7. A reaming and milling tool, characterized in that, Prepared by using the preparation method according to any one of claims 1-6; The Cu-Zn-Ni alloy molten liquid forms the matrix metal of the milling head; the ceramic particles are directionally dispersed in the matrix metal according to a preset position.

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