A drill bit matrix, its preparation method and application

Abstract

The present application provides a drill bit matrix and its preparation method and application. The drill bit matrix of the present application takes a nickel-titanium transition layer as a substrate, and different working layers are sequentially arranged on the surface of the substrate from bottom to top, the working layers including a cobalt-chromium-molybdenum matrix diamond working layer, a Follow100 iron-based matrix diamond working layer and a copper-tin-titanium matrix diamond working layer, which can be designed and adjusted according to the structure of the stratum rock. The nickel-titanium transition layer has excellent deformation performance, which is beneficial to prevent accidents such as sticking during drilling. The working layer lip surface interacts with the matching stratum, the diamond is effectively held, the shedding speed and the matrix wear speed meet the construction requirements, the properties of the excellent matrix material are utilized, and the construction efficiency of the drill bit is improved. At the same time, the diamond abrasive is relatively expensive, and the design of the diamond parameters according to the actual situation of the stratum can make the resources fully utilized and reduce the excessive loss of the diamond caused by the change of the stratum.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of diamond tool advanced manufacturing technology, in particular to a drill bit matrix and a preparation method and application thereof. BACKGROUND

[0002] The diamond drill bit is commonly used in the field of geological drilling, and when manufacturing the working layer thereof, the matrix material should be determined according to the hardness of the rock in the stratum, the development of structural plane and the like, and if the rock properties or the breaking condition of the stratum is different, the composition of the diamond drill bit matrix and the diamond parameters should also be designed differently.

[0003] When drilling in the rock with high drillability level and obvious fracture development and high breaking degree, the drill bit with fine-grained surface inlay or fine-mesh inlay should be selected.

[0004] When drilling in the rock with low drillability level and homogenization and integrity, the drill bit with coarse-grained surface inlay or coarse-mesh inlay should be selected.

[0005] When drilling in the rock with strong abrasiveness, the drill bit with hard matrix should be selected.

[0006] When drilling in the rock with weak abrasiveness, the drill bit with soft matrix should be selected.

[0007] The working layer of the diamond drill bit widely used in the current drilling engineering is composed of single matrix, such as iron-based or copper-based pre-alloy material. With the increase of the stratum depth, the lithology of the stratum rock (such as the rock hardness, the breaking degree of the rock and the like) often changes significantly, and the change of the lithology makes it necessary to frequently change the drill bit matched therewith during the drilling operation, and the drilling engineering project is usually aimed at the deep stratum, and the tripping process is relatively complex, and the frequent change of the drill bit greatly increases the drilling time cost and the labor cost, and meanwhile increases the risks of the collapse of the borehole wall, the falling of the drill bit and the like. When the single matrix material diamond drill bit drills the different strata, the drilling procedure is difficult to change in time, and when the wear speed of the working layer matrix of the drill bit, the falling speed of the diamond and the drilling speed are not matched, the drill bit cannot respond to the adverse effects brought by the change of the stratum, such as the increase of the rock hardness, the decrease of the rock-forming mineral particles and the like, and the downhole accidents such as the sticking of the drill bit, the mud pack drilling and the like are likely to occur, and the mechanical drilling speed of the drill bit will be sharply reduced. Therefore, the innovative design of the working layer of the diamond drill bit suitable for different stratum conditions is urgently needed to be researched. SUMMARY

[0008] The present application aims at the above-mentioned deficiencies of the prior art, and provides a drill bit matrix and a preparation method and application thereof to effectively respond to the change of the stratum during the drilling process. The technical scheme is as follows.

[0009] The first object of the present application provides a drill bit matrix, taking a nickel-titanium transition layer as a substrate, different working layers are sequentially arranged on the surface of the nickel-titanium transition layer from bottom to top, the working layers include a cobalt-chromium-molybdenum matrix diamond working layer, a Follow100 iron-based matrix diamond working layer and a copper-tin-titanium matrix diamond working layer; the thickness of the nickel-titanium transition layer is 5-20 mm, and the thickness of the cobalt-chromium-molybdenum matrix diamond working layer, the Follow100 iron-based matrix diamond working layer and the copper-tin-titanium matrix diamond working layer is 2-30 mm; the nickel-titanium transition layer is made of nickel-titanium alloy, the cobalt-chromium-molybdenum matrix diamond working layer is made of diamond and cobalt-chromium-molybdenum alloy, the Follow100 iron-based matrix diamond working layer is made of diamond and Follow100 pre-alloy, and the copper-tin-titanium matrix diamond working layer is made of diamond and copper-tin-titanium alloy.

[0010] Further, the volume of diamond in the cobalt-chromium-molybdenum matrix diamond working layer is 5%-15%, the volume of cobalt-chromium-molybdenum alloy is 85%-95%, the particle size is 15 μm-53 μm, and the oxygen content is less than 1000 ppm.

[0011] Further, the volume of diamond in the Follow100 iron-based matrix diamond working layer is 10%-25%, the particle size is 38 μm-53 μm, the volume of Follow100 pre-alloy is 75%-90%, the particle size is 20 μm-73 μm, and the oxygen content is less than 1000 ppm.

[0012] Further, the volume of diamond in the cobalt-chromium-molybdenum matrix diamond working layer is 5%-15%, the particle size is 38 μm-53 μm, the volume of cobalt-chromium-molybdenum alloy is 85%-95%, the particle size is 15 μm-53 μm, and the oxygen content is less than 1000 ppm.

[0013] The second object of the present application provides a preparation method of the above-mentioned drill bit matrix, which specifically includes the following steps:

[0014] Step S1, batching: preparing the powder of the nickel-titanium transition layer, the cobalt-chromium-molybdenum matrix diamond working layer, the Follow100 iron-based matrix diamond working layer and the copper-tin-titanium matrix diamond working layer;

[0015] Step S2, modeling: modeling the multi-material model for 3D printing forming by using a three-dimensional modeling software, and saving as an STL format input into a laser selective melting forming device;

[0016] Step S3, printing the drill bit matrix:

[0017] Step S31, a powder with a thickness of not less than 50 μm is laid on the substrate of the nickel-titanium alloy material, and the nickel-titanium alloy particles on the printing platform are scanned by using a high-energy laser to make them melt and then solidify on the surface of the printing platform to obtain a nickel-titanium transition layer;

[0018] Step S32, the powder particles of the first working layer are laid on the surface of the nickel-titanium transition layer, the laser selective melting process parameters are set, and the powder particles on the printing platform are scanned by using a high-energy laser or an electron beam to complete the solidification of the first layer of powder particles to obtain the first working layer;

[0019] Step S33, the powder particles of the second working layer are laid on the surface of the first working layer, the laser selective melting process parameters are set, and the powder particles on the printing platform are scanned by using a high-energy laser or an electron beam to complete the solidification of the second layer of powder particles to obtain the second working layer;

[0020] Step S34, according to the model of the drill bit matrix, the solidification of all working layers is completed layer by layer in sequence;

[0021] Step S35, after the formation of all working layers is completed, the formed object is cooled to 40℃, and then taken out for cutting to obtain the drill bit matrix.

[0022] Further, the particle size of the nickel-titanium alloy particles is 15 μm to 53 μm, and the oxygen content is less than 1000 ppm; the laser selective melting process parameters of the nickel-titanium transition layer are: the laser power is 100 W to 200 W, the scanning speed is 900 mm / s to 1000 mm / s, the laying thickness is 50 μm, and the scanning interval is 120 μm.

[0023] Further, the powder particles of the cobalt-chromium-molybdenum matrix diamond working layer include diamond particles and cobalt-chromium-molybdenum alloy particles, the particle size of the diamond particles is 38 μm to 53 μm, the particle size of the cobalt-chromium-molybdenum alloy particles is 15 μm to 53 μm, and the oxygen content is less than 1000 ppm; the laser selective melting process parameters of the cobalt-chromium-molybdenum matrix diamond working layer are: the laser power is 200 W to 300 W, the scanning speed is 500 mm / s to 800 mm / s, the laying thickness is 50 μm, and the scanning interval is 120 μm.

[0024] Further, the powder particles of the Follow100 iron-based matrix diamond working layer include diamond particles and iron-based Follow100 pre-alloy particles, the particle size of the diamond particles is 38-53 mu m, the particle size of the iron-based Follow100 pre-alloy particles is 20-74 mu m, and the oxygen content is less than 1000 ppm; the laser selective melting process parameters of the Follow100 iron-based matrix diamond working layer are as follows: the laser power is 300-400 W, the scanning speed is 600-700 mm / s, the laying thickness is 70 mu m, and the scanning interval is 120 mu m.

[0025] Further, the powder particles of the copper-tin-titanium matrix diamond working layer include diamond particles and copper-tin-titanium alloy particles, the particle size of the diamond particles is 38-53 mu m, the particle size of the copper-tin-titanium particles is 15-53 mu m, and the oxygen content is less than 1000 ppm; the laser selective melting process parameters of the copper-tin-titanium matrix diamond working layer are as follows: the laser power is 300-400 W, the scanning speed is 500-600 mm / s, the laying thickness is 50 mu m, and the scanning interval is 120 mu m.

[0026] The third object of the present application provides a drill bit, which comprises a drill bit rigid body and the drill bit matrix as described above, and the drill bit matrix is fixedly arranged on the drill bit rigid body through the nickel-titanium transition layer.

[0027] The present application has the following beneficial effects:

[0028] (1) The drill bit matrix of the present application adopts 3D printing advanced manufacturing technology, first laser melting forms a nickel-titanium transition layer, and then forms different working layers on the surface of the nickel-titanium transition layer, including a cobalt-chromium-molybdenum matrix diamond working layer, a Follow100 iron-based matrix diamond working layer, and a copper-tin-titanium matrix diamond working layer. The shape memory effect of the nickel-titanium alloy is very sensitive to changes in temperature, gravity, etc. With the change of environmental temperature or external force, the nickel-titanium alloy base layer will undergo a recoverable deformation. In the drilling process, once the phenomena such as sticking or mud ball drilling occur, the temperature at the downhole drill bit is easy to rise sharply, the stress state of the drill bit working layer is redistributed, and the nickel-titanium alloy base layer is elastically contracted, the drill bit working layer is lifted to a certain extent, which is beneficial to prevent the continuous impact of downhole accidents on the drill bit and avoid burning the drill. The materials such as cobalt-chromium-molybdenum, iron-based Follow100, and copper-tin-titanium alloy are tightly combined to realize the integrated forming of the multifunctional component with multiple drill bit working layers and shape memory performance. The multifunctional component formed by the present application can prevent sticking accidents in the drilling process based on the excellent deformation performance of the nickel-titanium shape memory alloy.

[0029] (2) The drill bit matrix of the present application comprises a plurality of metal-based matrix working layers, which can be designed according to the actual situation of the stratum. During drilling operation, the working layer lip surface interacts with the matching stratum, the diamond is effectively held, the shedding speed and the matrix wear speed meet the construction requirements, the properties of the excellent matrix material are utilized, and the construction efficiency of the diamond drill bit is improved. At the same time, the price of diamond abrasive is relatively high, and the design of diamond parameters (such as particle size, concentration, grade, etc.) according to the actual situation of the stratum can make full use of resources and reduce the excessive loss of diamond caused by changes in stratum conditions.

[0030] (3) The 3D printing technology realizes the integrated forming of multifunctional and multi-material tools through the accurate control of the powder composition on the plane to be processed, the prepared working layer does not need to be subjected to complicated post-processing, the manufacturing process is shortened, and the product has practical value. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a schematic diagram of the micro-morphology of the nickel-titanium, cobalt-chromium-molybdenum, iron-based Follow100, and copper-tin-titanium alloy powder particles of the embodiment of the present application;

[0032] Figure 2 It is a schematic diagram of the micro-morphology of the diamond powder of different particle sizes and shapes of the embodiment of the present application;

[0033] Figure 3 It is a schematic diagram of the structure of the drill bit matrix prepared in Example 1 combined on the diamond rigid body;

[0034] Figure 4 It is a schematic diagram of the structure of the drill bit matrix prepared in Example 2 combined on the diamond rigid body. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the present application more clear, the following will further describe the embodiments of the present application.

[0036] When the hardness of the stratum rock is general, the integrity is not high, and the grain size of the rock-forming minerals is large, the diamond drill bit needs to use a metal material with moderate hardness and good linear shrinkage performance, such as copper-tin-titanium alloy. At this time, the drill bit working layer should use a low-concentration coarse-grained diamond formula.

[0037] When the hardness of the stratum rock is moderate, the integrity is moderate, and the grain size of the rock-forming minerals is moderate, the diamond drill bit needs to use a metal material with strong brittleness and high hardness, such as an iron-based metal powder with a Follow100 brand. At this time, the drill bit working layer should use a high-concentration low-grained diamond formula.

[0038] When the formation rock has high hardness and completeness and the grain size of the rock-forming mineral is small, the diamond bit needs to use hard and brittle metal materials, such as cobalt-chromium-molybdenum alloy.

[0039] The material for manufacturing the diamond matrix of the present application can be selected according to the formation condition, and the above-mentioned three matrix materials are not considered as the limitation of the material selection of the present application.

[0040] The thickness of each working layer of the matrix of the bit is determined according to the thickness of the formation to be drilled, the rock structure and the degree of fragmentation, and the thickness of each working layer is not necessarily the same.

[0041] The material for manufacturing the diamond matrix of the present application can be selected according to the formation condition, and the above-mentioned three matrix materials are not considered as the limitation of the material selection of the present application.

[0042] The preparation method of the matrix of the bit provided by the present application adopts the 3D printing technology, which is the laser selective melting technology.

[0043] The laser selective melting technology has the forming advantages of fast powder cooling speed, easy to produce strengthening mechanism of metal materials, and processing of complex structure diamond tools.

[0044] The near-equiatomic nickel-titanium alloy has many excellent properties, such as shape memory effect, super-elasticity, good corrosion resistance and biocompatibility.

[0045] The iron-based Follow is a pre-alloy matrix material commonly used for manufacturing diamond by powder metallurgy hot-pressing sintering method, has low use cost, high hardness, and strong holding force for diamond.

[0046] The copper-tin-titanium alloy has the advantages of large adjustable range of processing parameters, low forming energy, strong alloy bonding force and the like.

[0047] The cobalt-chromium-molybdenum alloy has strong hardness and brittleness, is not conductive, has wear resistance and corrosion resistance, and is suitable for deep strong abrasive formation.

[0048] The nickel-titanium alloy particles selected in the embodiment of the present application have a particle size of 15-53 μm, and the micro-morphology thereof is as shown in Figure 1a; cobalt-chromium-molybdenum alloy particles have a particle size of 15 μm to 53 μm, and the microstructure thereof is as shown in Figure 1 b; copper-tin-titanium alloy particles have a particle size of 15 μm to 53 μm, and the microstructure thereof is as shown in Figure 1 c; Follow100 iron-based particles have a particle size of 20 μm to 73 μm, and the microstructure thereof is as shown in Figure 1 d; diamond particles have a particle size of 38 μm to 53 μm, and the specific microstructure thereof is as shown in Figure 2 a and 2b.

[0049] Example 1

[0050] The stratum to be drilled is A-B-C type stratum, that is, as the depth of the stratum increases, the hardness, drillability grade and abrasiveness of the rock of the stratum gradually increase, and the stratum to be drilled can be divided into three parts of A, B and C.

[0051] According to the thicknesses of the A, B and C strata, the working layer thicknesses of the drill bit are preset, such as 5 mm of the copper-tin-titanium matrix diamond working layer, 5 mm of the iron-based matrix working layer and 10 mm of the cobalt-chromium-molybdenum matrix diamond working layer.

[0052] According to the lithology and structure surface development of the stratum rock, the diamond parameters are set, such as 20% of the diamond volume concentration, 270 / 325 mesh (45-53 μm) of the particle size and dodecahedron of the crystal form of the copper-tin-titanium matrix diamond working layer; 20% of the diamond volume concentration, 270 / 325 mesh (45-53 μm) of the particle size and dodecahedron of the crystal form of the iron-based matrix working layer; and 10% of the diamond volume concentration, 325 / 400 mesh (38-45 μm) of the particle size, irregular shape, and broken dissociation surface and growth steps existing in part of the particles of the cobalt-chromium-molybdenum matrix diamond working layer.

[0053] Preparation of the drill bit matrix:

[0054] Step S1, batching: preparing the powder of the nickel-titanium transition layer, the cobalt-chromium-molybdenum matrix diamond working layer, the Follow100 iron-based matrix diamond working layer and the copper-tin-titanium matrix diamond working layer;

[0055] The powder of the cobalt-chromium-molybdenum matrix diamond working layer: the diamond and the cobalt-chromium-molybdenum alloy material are put into a mixer, wherein the particle size of the diamond particles is 38-45 μm, the shape is irregular, broken dissociation surface and growth steps exist in part of the particles, the diamond volume concentration is 10%, and the cobalt-chromium-molybdenum alloy volume concentration is 90%, and they are uniformly mixed for 20 hours, and the powder is obtained.

[0056] Follow100 iron-based matrix diamond working layer powder: the diamond and iron-based alloy material are put into a mixer, wherein the particle size of the diamond particles is 45-53 mu m, the crystal form is dodecahedron, the volume concentration of the diamond is 20%, and the volume concentration of the iron-based alloy is 80%, and they are uniformly mixed for 20 hours.

[0057] Copper-tin-titanium matrix diamond working layer powder: the diamond and copper-tin-titanium alloy material are put into a mixer, wherein the particle size of the diamond particles is 45-53 mu m, the crystal form is dodecahedron, the volume concentration of the diamond is 20%, and the volume concentration of the copper-tin-titanium alloy is 80%, and they are uniformly mixed for 20 hours.

[0058] Step S2, modeling: the forming material model of the drill bit matrix is modeled by using three-dimensional modeling software, and saved as STL format input into the laser selective melting forming equipment:

[0059] The forming material model of the drill bit matrix is modeled by using three-dimensional modeling software such as Magics, UG, and solid works, and saved as STL format input into the selective laser melting forming equipment.

[0060] Step S3, printing the drill bit matrix:

[0061] Step S31, using a nickel-titanium alloy material substrate, after grinding the substrate, sandblasting treatment is performed, so that the alloy powder can be uniformly laid on it, a layer of nickel-titanium alloy powder with a thickness of about 50 mu m is uniformly laid on the substrate, the forming cabin door is closed, the gas circulation system is started, argon protective gas is injected, so that the oxygen content in the forming cavity is less than 100 ppm, at the same time, the substrate is preheated to 200 DEG C, the nickel-titanium alloy particles on the printing platform are scanned by using high-energy laser, the laser power is 200 W, the scanning speed is 1000 mm / s, the powder layer thickness is 50 mu m, the scanning interval is 120 mu m, and the forming thickness is 5 mm, so that it is melted and solidified on the surface of the printing platform, and a nickel-titanium transition layer is obtained;

[0062] Step S32, the powder particles of the first layer working layer, i.e. the powder of the cobalt-chromium-molybdenum matrix diamond working layer, are laid on the surface of the nickel-titanium transition layer, the laser selective melting process parameters are set, and the powder particles on the printing platform are scanned by using high-energy laser or electron beam to complete the solidification of the first layer of powder particles, and the first working layer, i.e. the cobalt-chromium-molybdenum matrix diamond working layer, is obtained.

[0063] The specific process for forming the diamond working layer of the cobalt-chromium-molybdenum matrix is ​​as follows: Maintaining the oxygen content in the forming chamber below 100 ppm and the substrate temperature at approximately 200°C, the laser power is changed to 220W, the scanning speed to 750 mm / s, the powder layer thickness to 50 μm, and the scanning interval to 120 μm. Using these laser selective melting process parameters, a composite material of cobalt-chromium-molybdenum alloy and diamond is formed, enabling a tight metallurgical bond between the nickel-titanium alloy and the cobalt-chromium-molybdenum alloy, while simultaneously reducing thermal damage to the diamond and preventing its graphitization. The cobalt-based matrix working layer has a forming thickness of 10 mm.

[0064] Step S33: A second working layer of powder particles, namely the Follow100 iron-based matrix diamond working layer, is laid on the surface of the cobalt-chromium-molybdenum matrix diamond working layer. The laser selective melting process parameters are set, and the powder particles on the printing platform are scanned using a high-energy laser or electron beam to complete the consolidation of the second layer of powder particles, thus obtaining the second working layer, namely the Follow100 iron-based matrix diamond working layer.

[0065] The specific process for forming the diamond working layer of the Follow100 iron-based matrix is ​​as follows: keep the oxygen content in the forming chamber below 100ppm, the substrate temperature at about 200℃, change the laser power to 320W, the scanning speed to 650mm / s, the powder layer thickness to 70μm, the scanning interval to 120μm, and the forming thickness to 5mm.

[0066] Step S34: The powder particles of the third working layer, namely the powder of the copper-tin-titanium matrix diamond working layer, are laid on the surface of the Follow100 iron-based matrix diamond working layer. The laser selective melting process parameters are set, and the powder particles on the printing platform are scanned by a high-energy laser or electron beam to complete the consolidation of the third layer of powder particles, thus obtaining the third working layer, namely the copper-tin-titanium matrix diamond working layer.

[0067] The specific process for forming the diamond working layer of the copper-tin-titanium matrix is ​​as follows: keep the oxygen content in the forming chamber below 100ppm, the substrate temperature at about 200℃, change the laser power to 200W, the scanning speed to 300mm / s, the powder layer thickness to 50μm, the scanning interval to 120μm, and the forming thickness to 5mm.

[0068] Step S35: After all working layers have been formed, cool to 40°C, remove the formed material, cut it to obtain the drill bit matrix, and combine the formed drill bit matrix with the drill bit rigid body by hot pressing sintering.

[0069] like Figure 3 The diagram shown is a schematic of the structure of the drill bit matrix prepared in Example 1 after being bonded to the diamond rigid body. The bending strength of the drill bit matrix is ​​over 500 MPa.

[0070] The wear rate of the copper-tin-titanium matrix diamond working layer with a standard size of 15mmx8.5mmx8.5mm in the friction and wear test is not more than 2g / min;

[0071] The wear rate of the Follow100 iron-based matrix diamond working layer with a standard size of 15mmx8.5mmx8.5mm in the friction and wear test is not more than 1g / min;

[0072] The wear rate of the cobalt-chromium-molybdenum matrix diamond working layer with a standard size of 15mmx8.5mmx8.5mm in the friction and wear test is not more than 0.3g / min.

[0073] The performance indicators of the drill bit matrix of the present embodiment in the drilling working condition meet: the drilling pressure is 0-500kN, the rotating speed is 10-50rpm, and the drilling speed is 50-200mm / s.

[0074] The drill bit matrix prepared in Example 1 is applied to a drill bit, the nickel-titanium transition layer of the drill bit matrix is sintered and connected with the drill bit rigid body to form a drill bit, and the drill bit is connected with a drill rod in a drilling engineering site through threads. After the drilling machine is started, the drill rod starts to rotate to drive the drill bit to rotate, and the working layer of the drill bit matrix contacts and crushes the stratum. In actual working conditions, the drill bit matrix will undergo the following changes:

[0075] As the drilling footage increases, the drill bit working layer is continuously worn out. When the copper-tin-titanium matrix diamond working layer is worn out, the Follow100 iron-based matrix diamond working layer is exposed and contacts the stratum matched therewith to crush the stratum;

[0076] As the drilling footage continues to increase, when the Follow100 iron-based matrix diamond working layer is worn out and the stratum matched therewith is crushed, the cobalt-chromium-molybdenum matrix diamond working layer is exposed and contacts the stratum matched therewith to crush the stratum, until the cobalt-chromium-molybdenum matrix diamond working layer is completely worn out and the nickel-titanium alloy transition layer is exposed;

[0077] When the working layer of the drill bit is completely worn out, the drill bit reaches the service life and needs to be replaced.

[0078] Example 2

[0079] When the drilling stratum is A1-B-A2-C type stratum, that is, from the overall trend, as the stratum depth increases, the hardness, drillability grade and abrasiveness of the stratum rock gradually increase, but there is a soft rock layer between two high hardness rock layers. The soft stratum is more likely to be inclined by other strata, and the stratum thickness is relatively thin. The stratum to be drilled can be divided into four parts of A1, B, A2 and C.

[0080] According to the thicknesses of the A1, B, A2 and C strata, preset the working layer thickness of the drill bit, such as the copper-tin-titanium matrix diamond working layer of 3 mm, the iron-based matrix working layer of 5 mm, the A2 copper-tin-titanium matrix diamond working layer of 2 mm, and the cobalt-chromium-molybdenum matrix diamond working layer of 10 mm.

[0081] According to the lithology and structural plane development of the strata, the diamond parameters are set, the copper-tin-titanium matrix diamond working layer has a diamond volume concentration of 20%, a particle size of 270 / 325 mesh (45-53 μm), and a dodecahedron crystal form; the iron-based matrix working layer has a diamond volume concentration of 20%, a particle size of 270 / 325 mesh (45-53 μm), and a dodecahedron crystal form; and the cobalt-chromium-molybdenum matrix diamond working layer has a diamond volume concentration of 10%, a particle size of 325 / 400 mesh (38-45 μm), and an irregular shape, and some particles have broken dissociation surfaces and growth steps.

[0082] Preparation of the drill bit matrix:

[0083] Step S1, batching: prepare the powder of the nickel-titanium transition layer, the cobalt-chromium-molybdenum matrix diamond working layer, the Follow100 iron-based matrix diamond working layer, and the copper-tin-titanium matrix diamond working layer;

[0084] The powder of the cobalt-chromium-molybdenum matrix diamond working layer: put the diamond and cobalt-chromium-molybdenum alloy material into a mixer, wherein the particle size of the diamond particles is 38-45 μm, the shape is irregular, some particles have broken dissociation surfaces and growth steps, the diamond volume concentration is 10%, and the cobalt-chromium-molybdenum alloy volume concentration is 90%, and uniformly mix for 20 hours to obtain the powder;

[0085] The powder of the Follow100 iron-based matrix diamond working layer: put the diamond and iron-based alloy material into a mixer, wherein the particle size of the diamond particles is 45-53 μm, the crystal form is dodecahedron, the diamond volume concentration is 20%, and the iron-based alloy volume concentration is 80%, and uniformly mix for 20 hours to obtain the powder;

[0086] The powder of the copper-tin-titanium matrix diamond working layer: put the diamond and copper-tin-titanium alloy material into a mixer, wherein the particle size of the diamond particles is 45-53 μm, the crystal form is dodecahedron, the diamond volume concentration is 20%, and the copper-tin-titanium alloy volume concentration is 80%, and uniformly mix for 20 hours to obtain the powder.

[0087] Step S2, modeling: use a three-dimensional modeling software to model the forming material model of the drill bit matrix, save it in the STL format, and input it into a laser selective melting forming device:

[0088] The forming material model of the drill bit matrix is modeled by using three-dimensional modeling software such as Magics, UG, and solid works, and is saved in STL format and input into a selective laser melting forming device.

[0089] Step S3, printing preparation of the drill bit matrix:

[0090] Step S31, a nickel-titanium alloy material substrate is used, after the substrate is ground flat, sand blasting treatment is performed, so that the alloy powder can be uniformly laid on the substrate, a layer of nickel-titanium alloy powder with a thickness of about 50 μm is uniformly laid on the substrate, the forming cabin door is closed, the gas circulation system is opened, argon protective gas is injected, so that the oxygen content in the forming cavity is less than 100 ppm, at the same time, the substrate is preheated to 200°C, the nickel-titanium alloy particles on the printing platform are scanned by using high-energy laser, the laser power is 200 W, the scanning speed is 1000 mm / s, the powder layer thickness is 50 μm, the scanning interval is 120 μm, and the forming thickness is 5 mm, so that it is melted and solidified on the surface of the printing platform, and a nickel-titanium transition layer is obtained;

[0091] Step S32, the powder particles of the first layer of working layer, i.e. the powder of the cobalt-chromium-molybdenum matrix diamond working layer, are laid on the surface of the nickel-titanium transition layer, the laser selective melting process parameters are set, the powder particles on the printing platform are scanned by using high-energy laser or electron beam, the solidification of the first layer of powder particles is completed, and the first working layer, i.e. the cobalt-chromium-molybdenum matrix diamond working layer, is obtained;

[0092] The forming process of the cobalt-chromium-molybdenum matrix diamond working layer is as follows: the oxygen content in the forming cabin is kept below 100 ppm, the substrate temperature is about 200°C, the laser power is changed to 220 W, the scanning speed is 750 mm / s, the powder layer thickness is 50 μm, the scanning interval is 120 μm, and the laser selective melting process parameters are used to form the cobalt-chromium-molybdenum alloy and diamond composite material, so that the nickel-titanium alloy and the cobalt-chromium-molybdenum alloy can be closely metallurgically combined, and the thermal damage of the diamond is reduced, and the graphitization of the diamond is prevented. The forming thickness of the cobalt-based matrix working layer is 10 mm.

[0093] Step S33, the powder particles of the second layer of working layer, i.e. the powder of the copper-tin-titanium matrix diamond working layer, are laid on the surface of the cobalt-chromium-molybdenum matrix diamond working layer, the laser selective melting process parameters are set, the powder particles on the printing platform are scanned by using high-energy laser or electron beam, the solidification of the second layer of powder particles is completed, and the second working layer, i.e. the copper-tin-titanium matrix diamond working layer, is obtained;

[0094] The forming process of the copper-tin-titanium matrix diamond working layer is as follows: the oxygen content in the forming cabin is kept below 100 ppm, the substrate temperature is about 200°C, the laser power is changed to 200 W, the scanning speed is 300 mm / s, the powder layer thickness is 50 μm, the scanning interval is 120 μm, and the forming thickness is 2 mm.

[0095] Step S34: The powder particles of the third working layer, namely the powder of the Follow100 iron-based matrix diamond working layer, are laid on the surface of the copper-tin-titanium matrix diamond working layer. The laser selective melting process parameters are set, and the powder particles on the printing platform are scanned by a high-energy laser or electron beam to complete the consolidation of the third layer of powder particles, thus obtaining the third working layer, namely the Follow100 iron-based matrix diamond working layer.

[0096] The specific process for forming the diamond working layer of the Follow100 iron-based matrix is ​​as follows: keep the oxygen content in the forming chamber below 100ppm, the substrate temperature at about 200℃, change the laser power to 320W, the scanning speed to 650mm / s, the powder layer thickness to 70μm, the scanning interval to 120μm, and the forming thickness to 5mm.

[0097] Step S35: The powder particles of the fourth working layer, namely the powder of the copper-tin-titanium matrix diamond working layer, are laid on the surface of the Follow100 iron-based matrix diamond working layer. The laser selective melting process parameters are set, and the powder particles on the printing platform are scanned by a high-energy laser or electron beam to complete the consolidation of the fourth layer of powder particles, thus obtaining the fourth working layer, namely the copper-tin-titanium matrix diamond working layer.

[0098] The specific process for forming the diamond working layer of the copper-tin-titanium matrix is ​​as follows: keep the oxygen content in the forming chamber below 100ppm, the substrate temperature at about 200℃, change the laser power to 200W, the scanning speed to 300mm / s, the powder layer thickness to 50μm, the scanning interval to 120μm, and the forming thickness to 3mm.

[0099] Step S36: After all working layers have been formed, cool to 40°C, remove the formed material, cut it to obtain the drill bit matrix, and combine the formed drill bit matrix with the drill bit rigid body by hot pressing sintering.

[0100] like Figure 4 The diagram shown is a schematic of the structure of the drill bit matrix prepared in Example 2 after being bonded to the diamond rigid body. The bending strength of the drill bit matrix is ​​over 500 MPa.

[0101] In the tribological test of the standard-sized copper-tin-titanium matrix diamond working layer, the wear rate did not exceed 2 g / min;

[0102] In the tribological test of the Follow100 iron-based matrix diamond working layer with standard dimensions of 15mm×8.5mm×8.5mm, the wear rate did not exceed 1g / min;

[0103] The wear rate in the friction and wear test of the cobalt-chromium-molybdenum matrix diamond working layer with the standard size of 15mm*8.5mm*8.5mm is not more than 0.3g / min.

[0104] The performance index of the drill bit matrix of the embodiment in the drilling working condition is: the drilling pressure is 0-500kN, the rotating speed is 10-50rpm, and the drilling speed is 50-200mm / s.

[0105] The above-mentioned matters not involved are applicable to the prior art.

[0106] Although some specific embodiments of the present application have been described in detail by way of examples, it should be understood that the above examples are only for illustration and are not intended to limit the scope of the present application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace, but without deviating from the direction of the present application or beyond the scope defined by the appended claims. Those skilled in the art should understand that any modification, equivalent replacement, improvement, etc. made to the above embodiments according to the technical essence of the present application should be included in the protection scope of the present application.

Claims

1. A drill bit carcass, characterized in that, The nickel-titanium transition layer is taken as a substrate, and different working layers are sequentially arranged on the surface of the nickel-titanium transition layer from bottom to top, wherein the working layers include a cobalt-chromium-molybdenum matrix diamond working layer, a Follow100 iron-based matrix diamond working layer and a copper-tin-titanium matrix diamond working layer; the thickness of the nickel-titanium transition layer is 5-20 mm, and the thickness of the cobalt-chromium-molybdenum matrix diamond working layer, the Follow100 iron-based matrix diamond working layer and the copper-tin-titanium matrix diamond working layer is all 2-30 mm; the nickel-titanium transition layer is made of a nickel-titanium alloy, the cobalt-chromium-molybdenum matrix diamond working layer is made of diamond and a cobalt-chromium-molybdenum alloy, the Follow100 iron-based matrix diamond working layer is made of diamond and a Follow100 pre-alloy, and the copper-tin-titanium matrix diamond working layer is made of diamond and a copper-tin-titanium alloy; the volume of diamond in the cobalt-chromium-molybdenum matrix diamond working layer is 5% to 15%, and the volume of the cobalt-chromium-molybdenum alloy is 85% to 95%, the particle size is 15 μm-53 μm, and the oxygen content is less than 1000 ppm; the volume of diamond in the Follow100 iron-based matrix diamond working layer is 10% to 25%, and the particle size is 38 μm-53 μm; the volume of the Follow100 pre-alloy is 75% to 90%, the particle size is 20 μm-73 μm, and the oxygen content is less than 1000 ppm; the volume of diamond in the copper-tin-titanium matrix diamond working layer is 5% to 15%, and the particle size is 38 μm-53 μm; the particle size of the copper-tin-titanium alloy is 15 μm-53 μm, and the oxygen content is less than 1000 ppm.

2. A method of producing a bit carcass as claimed in claim 1, characterized in that, The laser selective melting technology is adopted to form, and the method specifically comprises the following steps: S1, batching: preparing the powder of the nickel-titanium transition layer, the cobalt-chromium-molybdenum matrix diamond working layer, the Follow100 iron-based matrix diamond working layer and the copper-tin-titanium matrix diamond working layer; S2, modeling: modeling the drill bit matrix by using a three-dimensional modeling software, and saving as an STL format to input into a laser selective melting forming device; S3, printing the drill bit matrix: S31, taking a nickel-titanium alloy material substrate, laying the powder with a thickness of not less than 50 μm, and scanning the nickel-titanium alloy particles on the printing platform by using a high-energy laser to make them melt and then solidify on the surface of the printing platform to obtain the nickel-titanium transition layer; S32, laying the powder particles of the first working layer on the surface of the nickel-titanium transition layer, setting the laser selective melting process parameters, and scanning the powder particles on the printing platform by using a high-energy laser or an electron beam to complete the solidification of the first layer of powder particles to obtain the first working layer; S33, laying the powder particles of the second working layer on the surface of the first working layer, setting the laser selective melting process parameters, and scanning the powder particles on the printing platform by using a high-energy laser or an electron beam to complete the solidification of the second layer of powder particles to obtain the second working layer; S34, sequentially completing the solidification of all working layers layer by layer according to the model of the drill bit matrix; S35, after the formation of all working layers is completed, cooling to 40℃, taking out the formed object, and cutting to obtain the drill bit matrix.

3. The production method according to claim 2, characterized by: The nickel-titanium alloy particle size is 15-53 mu m, and the oxygen content is less than 1000 ppm; the laser selective melting process parameters of the nickel-titanium transition layer are: laser power is 100-200 W, scanning speed is 900-1000 mm / s, laying thickness is 50 mu m, and scanning interval is 120 mu m.

4. The production method according to claim 3, characterized by: The powder particles of the cobalt-chromium-molybdenum matrix diamond working layer include diamond particles and cobalt-chromium-molybdenum alloy particles, the diamond particle size is 38-53 mu m, the cobalt-chromium-molybdenum alloy particle size is 15-53 mu m, and the oxygen content is less than 1000 ppm; the laser selective melting process parameters of the cobalt-chromium-molybdenum matrix diamond working layer are: laser power is 200-300 W, scanning speed is 500-800 mm / s, laying thickness is 50 mu m, and scanning interval is 120 mu m.

5. The production method according to claim 4, characterized by: The powder particles of the Follow100 iron-based matrix diamond working layer include diamond particles and iron-based Follow100 pre-alloy particles, the diamond particle size is 38-53 mu m, the iron-based Follow100 pre-alloy particle size is 20-74 mu m, and the oxygen content is less than 1000 ppm; the laser selective melting process parameters of the Follow100 iron-based matrix diamond working layer are: laser power is 300-400 W, scanning speed is 600-700 mm / s, laying thickness is 70 mu m, and scanning interval is 120 mu m.

6. The production method according to claim 4, characterized by: The powder particles of the copper-tin-titanium matrix diamond working layer include diamond particles and copper-tin-titanium gold alloy particles, the diamond particle size is 38-53 mu m, the copper-tin-titanium particle size is 15-53 mu m, and the oxygen content is less than 1000 ppm; the laser selective melting process parameters of the copper-tin-titanium matrix diamond working layer are: laser power is 300-400 W, scanning speed is 500-600 mm / s, laying thickness is 50 mu m, and scanning interval is 120 mu m.

7. A drill bit, characterized by: The drill bit includes a drill bit rigid body and a drill bit matrix as claimed in claim 1, and the drill bit matrix is fixedly arranged on the drill bit rigid body through the nickel-titanium transition layer.

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