PDC (Polycrystalline Diamond Compact) bit matrix as well as preparation method and application thereof

Abstract

The invention relates to a PDC drill bit matrix and a preparation method and application thereof. The PDC drill bit matrix comprises cast tungsten carbide powder, sintered tungsten carbide powder, tungsten fibers, copper alloy, nickel powder, tin, boron, lead, titanium, cobalt powder and agarose sol. According to the PDC drill bit blank body provided by the invention, the tungsten fibers, the nickel powder, the copper alloy, the tin, the boron, the lead, the cobalt, the titanium and other powder are added into the PDC drill bit blank body material, so that the erosion resistance, the impact resistance, the hardness and the wear resistance of the PDC drill bit blank body material are improved, and the overall strength of the PDC drill bit blank body material is improved; furthermore, three types of cast tungsten carbide particles with different diameters are adopted, so that the PDC drill bit blank material has high hardness and excellent wear resistance.

Description

Technical Field

[0001] The invention relates to the technical field of powder metallurgy, and in particular to a PDC drill bit matrix and a preparation method and application thereof. Background Art

[0002] At present, PDC drill bits generally refer to polycrystalline diamond composite drill bits. Polycrystalline diamond composite drill bits are circular composite pieces that are welded on cylindrical cutting tools. The cutting tools are mounted on the drill bit body, which is called a PDC drill bit. The PDC drill bit includes PDC cutting teeth and a matrix. The PDC cutting teeth are brazed on the matrix. The function of the matrix is ​​to fix the PDC cutting teeth and connect them to the drill bit steel body. It is the key to ensuring the quality of the drill bit and is crucial to the overall drilling efficiency, service life, drilling cycle and cost of the drill bit.

[0003] For example, CN101886524A discloses an impregnated PDC drill bit consisting of a PDC composite sheet, an impregnated diamond layer, a matrix, a steel core and a joint. The impregnated diamond layer, the matrix and the steel core are sintered into a drill bit body. Flow channels are arranged on the impregnated diamond layer and the matrix of the drill bit body. The PDC composite sheet is brazed in the impregnated diamond layer or in the impregnated diamond layer and the matrix, exposing 0 to PDC composite sheet diameter / 3, in an impregnated surface state, and covering the crown contour line of the drill bit. The joint is connected to the drill bit body.

[0004] Furthermore, the quality of the matrix directly determines the performance of the entire PDC drill bit. For example, CN110983143A discloses a PDC matrix drill bit powder formula, which is composed of the following components in weight ratio: 32%-40% of crystalline dock powder, 45%-55% of iron-nickel powder, and the remaining 13%-15% of nickel powder.

[0005] However, the existing PDC drill bit blank materials have certain defects in practical applications. For example, the wear resistance, impact resistance, hardness, erosion resistance and overall strength of the matrix are all weak, which has a serious impact on the performance of the PDC drill bit. At the same time, when the matrix falls off, the blade breaks, the core is worn, and cracks occur due to poor performance, the drilling speed will be seriously affected and the drilling cost will be increased. Summary of the invention

[0006] In view of the problems existing in the prior art, the purpose of the present invention is to provide a PDC drill bit matrix and a preparation method and use thereof, so as to solve the problems of poor wear resistance, impact resistance, hardness and erosion resistance as well as overall strength of the current PDC drill bit matrix.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a PDC drill bit matrix, the PDC drill bit matrix comprising: cast tungsten carbide powder, sintered tungsten carbide powder, tungsten fiber, copper alloy, nickel powder, tin, boron, lead, titanium, cobalt powder and agarose sol;

[0009] The cast tungsten carbide powder comprises at least three cast tungsten carbide powders with gradient particle size distribution.

[0010] The PDC drill bit matrix provided by the present invention is beneficial to improving the erosion resistance, impact resistance, hardness and wear resistance of the PDC drill bit body material by adding tungsten fiber, nickel powder, copper alloy, tin, boron, lead, cobalt and titanium powders into the PDC drill bit body material, thereby improving the overall strength of the PDC drill bit body material, and further adopting three kinds of cast tungsten carbide particles with different diameters, so that the PDC drill bit body material has high hardness and excellent wear resistance.

[0011] As a preferred technical solution of the present invention, the PDC drill bit matrix includes, by weight: 60-100 parts of cast tungsten carbide powder, 40-60 parts of sintered tungsten carbide powder, 10-20 parts of tungsten fiber, 5-15 parts of copper alloy, 20-30 parts of nickel powder, 1-7 parts of tin, 2-6 parts of boron, 3-5 parts of lead, 1-7 parts of titanium, 3-5 parts of cobalt powder and 5-15 parts of agarose sol.

[0012] As a preferred technical solution of the present invention, the cast tungsten carbide powder includes cast tungsten carbide powder with a particle size of 45-65 μm, cast tungsten carbide powder with a particle size of 65-115 μm and cast tungsten carbide powder with a particle size of 115-285 μm.

[0013] Preferably, the particle size of the sintered tungsten carbide is 70-100 μm;

[0014] Preferably, the diameter of the tungsten fiber is 60-90 μm;

[0015] Preferably, the aspect ratio of the tungsten fiber is 30-40.

[0016] As a preferred technical solution of the present invention, the copper alloy includes brass and / or bronze.

[0017] Preferably, the nickel powder has a particle size of 120-130 μm and is spherical particles.

[0018] Preferably, the particle size of the cobalt powder is 50-150 μm.

[0019] In a second aspect, the present invention provides a method for preparing a PDC drill bit matrix as described in the first aspect, the preparation method comprising:

[0020] According to the formula, cast tungsten carbide powder, sintered tungsten carbide powder, tungsten fiber, cobalt powder, nickel powder and agarose sol are mixed to obtain PDC drill bit embryo slurry;

[0021] The obtained PDC drill bit embryo slurry is subjected to heat preservation treatment, and then copper alloy, tin, boron, lead and titanium are added for infiltration to obtain a PDC drill bit matrix.

[0022] As a preferred technical solution of the present invention, the temperature during the mixing is 90-100°C.

[0023] Preferably, the stirring rate during the mixing is 200-350 r / min.

[0024] Preferably, the mixing time is 2-5 hours.

[0025] As a preferred technical solution of the present invention, the temperature of the heat preservation treatment is 450-500°C.

[0026] Preferably, the heat preservation treatment time is 2-4 hours.

[0027] As a preferred technical solution of the present invention, the temperature of the infiltration is 1100-1200°C.

[0028] Preferably, the infiltration time is 1-5h.

[0029] As a preferred technical solution of the present invention, the thermal insulation treatment and melt infiltration are both carried out under vacuum conditions, and the absolute vacuum degree is ≤4Pa.

[0030] In a third aspect, the present invention provides a use of the PDC drill bit matrix as described in the first aspect, wherein the use includes preparing a PDC drill bit using the PDC drill bit matrix.

[0031] Compared with the prior art solutions, the present invention has the following beneficial effects:

[0032] (1) The present invention has good lubrication properties for sintered tungsten carbide particles and cast tungsten carbide particles by using cobalt and tungsten fibers in the PDC drill bit blank material, so that the adhesion and hardness properties between the raw materials have a better combination, which is beneficial to improving the erosion resistance and impact resistance of the PDC drill bit blank material.

[0033] (2) The sintered tungsten carbide particles used not only have high strength, but also help reduce the friction of the contact surface when used in combination with other raw materials, thereby effectively improving the mixing uniformity between the raw materials; the combination of copper alloy, tin, boron, lead and titanium powders can improve the hardness and wear resistance of the PDC drill bit blank material, thereby improving the overall strength of the PDC drill bit blank material.

[0034] (3) The present invention adopts three kinds of cast tungsten carbide particles with different particle sizes. Particles of different diameters are added to the PDC drill bit blank material, which is beneficial to improving the density of the PDC drill bit blank material, thereby increasing the overall strength of the PDC drill bit blank material, so that the PDC drill bit blank material has high hardness and excellent wear resistance. DETAILED DESCRIPTION

[0035] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0036] This embodiment provides a PDC drill bit matrix, the PDC drill bit matrix comprising: cast tungsten carbide powder, sintered tungsten carbide powder, tungsten fiber, copper alloy, nickel powder, tin, boron, lead, titanium, cobalt powder and agarose sol;

[0037] The cast tungsten carbide powder comprises at least three cast tungsten carbide powders with gradient particle size distribution.

[0038] In the present invention, the cast tungsten carbide powder includes at least three cast tungsten carbide powders with gradient particle size distributions, which means that the cast tungsten carbide powder is composed of cast tungsten carbide powders distributed in multiple gradient particle size intervals, and there are obvious dividing lines between the multiple gradient particle size intervals, that is, the gradient particle size intervals are discontinuous, such as the particle size intervals of 45-65μm, 50-70μm, 90-100μm, 110-150μm, 180-220μm, 250-285μm and the like.

[0039] In the present invention, the cast tungsten carbide is exemplarily prepared by mixing WC and metal W (tungsten) powder in a graphite tube furnace or a tilting melting furnace, melting the mixture in a furnace chamber with air, cooling the mixture in a graphite casting mold into a thin branch-shaped alloy block, namely, a eutectic of WC·W2C, and then grinding the mixture into powder by a mechanical method such as a ball mill, or preparing the mixture by other preparation methods in the art, or directly using a commercial product of corresponding specifications.

[0040] In the present invention, the sintered tungsten carbide can be exemplarily a commercial product of corresponding specifications, or a sintered tungsten carbide product prepared by a preparation method in the art.

[0041] Specifically, the PDC drill bit matrix includes, by weight: 60-100 parts of cast tungsten carbide powder, 40-60 parts of sintered tungsten carbide powder, 10-20 parts of tungsten fiber, 5-15 parts of copper alloy, 20-30 parts of nickel powder, 1-7 parts of tin, 2-6 parts of boron, 3-5 parts of lead, 1-7 parts of titanium, 3-5 parts of cobalt powder and 5-15 parts of agarose sol.

[0042] In the present invention, other metal elements contained in the copper alloy, such as nickel, tin, boron, lead, titanium, and cobalt, do not interfere with 20-30 parts of nickel powder, 1-7 parts of tin, 2-6 parts of boron, 3-5 parts of lead, 1-7 parts of titanium, and 3-5 parts of cobalt powder, that is, the content of the corresponding metal elements in the copper alloy affects the selection of the proportions of 20-30 parts of nickel powder, 1-7 parts of tin, 2-6 parts of boron, 3-5 parts of lead, 1-7 parts of titanium, and 3-5 parts of cobalt powder.

[0043] In the present invention, the cast tungsten carbide powder in the PDC drill bit matrix is ​​60-100 parts by weight, for example, it can be 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, 90 parts, 95 parts or 100 parts, but is not limited to the listed values, and other unlisted values ​​within this range also meet the requirements.

[0044] In the present invention, the sintered tungsten carbide powder in the PDC drill bit matrix is ​​40-60 parts by weight, for example, it can be 40 parts, 42 parts, 44 parts, 46 parts, 48 ​​parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts or 60 parts, but is not limited to the listed values, and other values ​​not listed within the range also meet the requirements.

[0045] In the present invention, the tungsten fiber in the PDC drill bit matrix is ​​10-20 parts by weight, for example, it can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts or 20 parts, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0046] In the present invention, the copper alloy in the PDC drill bit matrix is ​​5-15 parts by weight, for example, it can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts or 15 parts, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0047] In the present invention, the nickel powder in the PDC drill bit matrix is ​​20-30 parts by weight, for example, it can be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts or 30 parts, but is not limited to the listed values, and other values ​​not listed within the range also meet the requirements.

[0048] In the present invention, the tin content in the PDC drill bit matrix is ​​1-7 parts by weight, for example, it can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts or 7 parts, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0049] In the present invention, the boron content in the PDC drill bit matrix is ​​2-6 parts by weight, for example, it can be 2 parts, 3 parts, 4 parts, 5 parts or 6 parts, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0050] In the present invention, the lead content in the PDC drill bit matrix is ​​3-5 parts by weight, for example, it can be 3 parts, 3.5 parts, 4 parts, 4.5 parts or 5 parts, but is not limited to the listed values, and other unlisted values ​​within this range also meet the requirements.

[0051] In the present invention, the titanium content in the PDC drill bit matrix is ​​1-7 parts by weight, for example, it can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts or 7 parts, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0052] In the present invention, the cobalt powder in the PDC drill bit matrix is ​​3-5 parts by weight, for example, it can be 3 parts, 3.5 parts, 4 parts, 4.5 parts or 5 parts, but is not limited to the listed values, and other values ​​not listed within the range also meet the requirements.

[0053] In the present invention, the agarose sol in the PDC drill bit matrix is ​​5-15 parts by weight, for example, it can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts or 15 parts, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0054] Specifically, the cast tungsten carbide powder includes cast tungsten carbide powder with a particle size of 45-65 μm, cast tungsten carbide powder with a particle size of 65-115 μm, and cast tungsten carbide powder with a particle size of 115-285 μm.

[0055] In the present invention, the cast tungsten carbide powder includes 10-20 parts of cast tungsten carbide powder with a particle size of 45-65 μm, 30-50 parts of cast tungsten carbide powder with a particle size of 65-115 μm, and 20-40 parts of cast tungsten carbide powder with a particle size of 115-285 μm.

[0056] In the present invention, the powder particle size is defined as an aggregate of all particles within a limited range that meets the requirements. For example, the aggregate is a uniform particle aggregate or an aggregate of all particles within a certain range. Taking 45-65μm cast tungsten carbide as an example, the uniform particle aggregate may be composed of 45μm particles, or 50μm particles, or 55μm particles, or 60μm particles, or 55μm particles; the aggregate of all particles within a certain range may be composed of all particles within 45-65μm, or all particles within 45-50μm, or all particles within 50-60μm, or all particles within 60-65μm, or all particles within 48-55μm, or all particles within 55-62μm, etc. The particle size selection of other powders can be deduced by analogy.

[0057] Specifically, the particle size of the sintered tungsten carbide is 70-100 μm.

[0058] Specifically, the diameter of the tungsten fiber is 60-90 μm, for example, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm or 90 μm, etc., but is not limited to the listed values, and other values ​​not listed within the range also meet the requirements.

[0059] Specifically, the aspect ratio of the tungsten fiber is 30-40, for example, 30, 32, 34, 36, 38 or 40, but is not limited to the listed values, and other values ​​not listed within the range also meet the requirements.

[0060] Specifically, the copper alloy includes brass and / or bronze.

[0061] Specifically, the nickel powder has a particle size of 120-130 μm and is spherical particles.

[0062] Specifically, the particle size of the cobalt powder is 50-150 μm.

[0063] Furthermore, the present invention provides a method for preparing the aforementioned PDC drill bit matrix, the preparation method comprising:

[0064] According to the formula, cast tungsten carbide powder, sintered tungsten carbide powder, tungsten fiber, cobalt powder, nickel powder and agarose sol are mixed to obtain PDC drill bit embryo slurry;

[0065] The obtained PDC drill bit embryo slurry is subjected to heat preservation treatment, and then copper alloy, tin, boron, lead and titanium are added for infiltration to obtain a PDC drill bit matrix.

[0066] In the present invention, the raw materials of copper alloy, tin, boron, lead and titanium in the infiltration can be alloy products of the corresponding elements, or the corresponding raw materials can be prepared into powders and then mixed and pressed into blocks for use as infiltration materials, or infiltration agent products containing the corresponding elements commonly used in the art, or infiltration agents prepared using the existing technology disclosed in the art, or corresponding metal salts and other commonly used infiltration agents in the art.

[0067] Specifically, the temperature during the mixing is 90-100°C, for example, it can be 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, 96°C, 97°C, 98°C, 99°C or 100°C, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0068] Specifically, the stirring rate in the mixing is 200-350r / min, for example, it can be 200r / min, 210r / min, 220r / min, 230r / min, 240r / min, 250r / min, 260r / min, 270r / min, 280r / min, 290r / min, 300r / min, 310r / min, 320r / min, 330r / min, 340r / min or 350r / min, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0069] Specifically, the mixing time is 2-5 h, for example, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h or 5 h.

[0070] Specifically, the temperature of the insulation treatment is 450-500°C, for example, it can be 450°C, 455°C, 460°C, 465°C, 470°C, 475°C, 480°C, 485°C, 490°C, 495°C or 500°C, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0071] Specifically, the insulation treatment time is 2-4 hours, for example, it can be 2 hours, 2.5 hours, 3 hours, 3.5 hours or 4 hours, but is not limited to the listed values, and other values ​​not listed within the range also meet the requirements.

[0072] In the present invention, the infiltration temperature is reasonably selected according to the infiltration material, but it is necessary to ensure that the performance of the obtained PDC matrix is ​​not affected.

[0073] Specifically, the infiltration temperature is 1100-1200°C, for example, it can be 1100°C, 1110°C, 1120°C, 1130°C, 1140°C, 1150°C, 1160°C, 1170°C, 1180°C, 1190°C or 1200°C, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0074] Specifically, the infiltration time is 1-5h, for example, 1h, 2h, 3h, 4h or 5h, etc., but is not limited to the listed values, and other values ​​not listed within the range also meet the requirements.

[0075] Specifically, the insulation treatment and infiltration are carried out under vacuum conditions, and the absolute vacuum degree is ≤4Pa. For example, it can be 4Pa, 3.8Pa, 3.6Pa, 3.4Pa, 3.2Pa, 3Pa, 2.8Pa, 2.6Pa, 2.4Pa, 2.2Pa, 2Pa, 1.8Pa, 1.6Pa, 1.4Pa, 1.2Pa or 1Pa, but is not limited to the listed values. Other values ​​not listed in this range also meet the requirements.

[0076] Further, in order to illustrate the excellent performance of the PDC drill bit matrix provided by the present invention, the following specific embodiments are specifically provided for illustration, as follows:

[0077] Example 1

[0078] This embodiment provides a PDC drill bit matrix, which includes, by weight: 70 parts of cast tungsten carbide powder, 45 parts of sintered tungsten carbide powder, 15 parts of tungsten fiber, 10 parts of copper alloy, 24 parts of nickel powder, 5 parts of tin, 5 parts of boron, 4 parts of lead, 5 parts of titanium, 4 parts of cobalt powder and 10 parts of agarose sol;

[0079] Among them, the cast tungsten carbide powder is 15 parts of cast tungsten carbide powder with a particle size of 45-55μm, 40 parts of cast tungsten carbide powder with a particle size of 100-115μm and 30 parts of cast tungsten carbide powder with a particle size of 200-285μm; the particle size of the sintered tungsten carbide is 90-100μm; the diameter of the tungsten fiber is 80μm; the aspect ratio of the tungsten fiber is 37; the copper alloy is brass CuZn30; the particle size of the nickel powder is 125-130μm, which is spherical particles; the particle size of the cobalt powder is 100-120μm.

[0080] The preparation process is as follows:

[0081] According to the formula, cast tungsten carbide powder, sintered tungsten carbide powder, tungsten fiber, cobalt powder, nickel powder and agarose sol are mixed to obtain PDC drill bit embryo slurry;

[0082] The obtained PDC drill bit embryo slurry is subjected to heat preservation treatment, and then copper alloy, tin, boron, lead and titanium are added for infiltration to obtain a PDC drill bit matrix;

[0083] The temperature during the mixing is 95°C; the stirring rate during the mixing is 250 r / min; and the mixing time is 4 h.

[0084] The temperature of the heat preservation treatment is 485°C; the time of the heat preservation treatment is 3.5h;

[0085] The infiltration temperature is 1180°C; the infiltration time is 2h;

[0086] The heat preservation treatment and infiltration are both carried out under vacuum conditions, and the absolute vacuum degree is 3Pa.

[0087] Example 2

[0088] This embodiment provides a PDC drill bit matrix, which includes, by weight: 80 parts of cast tungsten carbide powder, 52 parts of sintered tungsten carbide powder, 18 parts of tungsten fiber, 8 parts of copper alloy, 27 parts of nickel powder, 3 parts of tin, 3 parts of boron, 3.5 parts of lead, 3 parts of titanium, 4.2 parts of cobalt powder and 8 parts of agarose sol;

[0089] Among them, the cast tungsten carbide powder includes 12 parts of cast tungsten carbide powder with a particle size of 50-65μm, 45 parts of cast tungsten carbide powder with a particle size of 65-80μm and 25 parts of cast tungsten carbide powder with a particle size of 115-180μm; the particle size of the sintered tungsten carbide is 70-80μm; the diameter of the tungsten fiber is 70μm; the aspect ratio of the tungsten fiber is 35; the copper alloy is brass CuZn10; the particle size of the nickel powder is 120-127μm, which is spherical particles; the particle size of the cobalt powder is 50-100μm.

[0090] The preparation process is as follows:

[0091] According to the formula, cast tungsten carbide powder, sintered tungsten carbide powder, tungsten fiber, cobalt powder, nickel powder and agarose sol are mixed to obtain PDC drill bit embryo slurry;

[0092] The obtained PDC drill bit embryo slurry is subjected to heat preservation treatment, and then copper alloy, tin, boron, lead and titanium are added for infiltration to obtain a PDC drill bit matrix;

[0093] The temperature during the mixing is 98°C; the stirring rate during the mixing is 300 r / min; and the mixing time is 3 h.

[0094] The temperature of the heat preservation treatment is 470°C; the time of the heat preservation treatment is 3 hours;

[0095] The infiltration temperature is 1150°C; the infiltration time is 3 hours;

[0096] The heat preservation treatment and infiltration are both carried out under vacuum conditions, and the absolute vacuum degree is 4Pa.

[0097] Example 3

[0098] This embodiment provides a PDC drill bit matrix, which includes, by weight: 60 parts of cast tungsten carbide powder, 40 parts of sintered tungsten carbide powder, 20 parts of tungsten fiber, 5 parts of copper alloy, 20 parts of nickel powder, 7 parts of tin, 2 parts of boron, 5 parts of lead, 7 parts of titanium, 3 parts of cobalt powder and 15 parts of agarose sol;

[0099] Among them, the cast tungsten carbide powder includes 10 parts of cast tungsten carbide powder with a particle size of 45-65μm, 30 parts of cast tungsten carbide powder with a particle size of 65-90μm and 40 parts of cast tungsten carbide powder with a particle size of 200-285μm; the particle size of the sintered tungsten carbide is 80-90μm; the diameter of the tungsten fiber is 90μm; the aspect ratio of the tungsten fiber is 30; the copper alloy is bronze QSn4-3; the particle size of the nickel powder is 128-130μm, which is spherical particles; the particle size of the cobalt powder is 50-100μm.

[0100] The preparation process is as follows:

[0101] According to the formula, cast tungsten carbide powder, sintered tungsten carbide powder, tungsten fiber, cobalt powder, nickel powder and agarose sol are mixed to obtain PDC drill bit embryo slurry;

[0102] The obtained PDC drill bit embryo slurry is subjected to heat preservation treatment, and then copper alloy, tin, boron, lead and titanium are added for infiltration to obtain a PDC drill bit matrix;

[0103] The temperature during the mixing is 100°C; the stirring rate during the mixing is 350r / min; and the mixing time is 2h.

[0104] The temperature of the heat preservation treatment is 500° C.; the time of the heat preservation treatment is 2 hours;

[0105] The infiltration temperature is 1100°C; the infiltration time is 5 hours;

[0106] The heat preservation treatment and infiltration are both carried out under vacuum conditions, and the absolute vacuum degree is 1Pa.

[0107] Example 4

[0108] This embodiment provides a PDC drill bit matrix, which includes, by weight: 100 parts of cast tungsten carbide powder, 60 parts of sintered tungsten carbide powder, 10 parts of tungsten fiber, 10 parts of copper alloy, 30 parts of nickel powder, 1 part of tin, 6 parts of boron, 3 parts of lead, 1 part of titanium, 5 parts of cobalt powder and 5 parts of agarose sol;

[0109] Among them, the cast tungsten carbide powder includes 20 parts of cast tungsten carbide powder with a particle size of 45-60μm, 50 parts of cast tungsten carbide powder with a particle size of 80-115μm and 20 parts of cast tungsten carbide powder with a particle size of 115-250μm; the particle size of the sintered tungsten carbide is 70-90μm; the diameter of the tungsten fiber is 60μm; the aspect ratio of the tungsten fiber is 30; the copper alloy is bronze QBe2; the particle size of the nickel powder is 120-125μm, which is spherical particles; the particle size of the cobalt powder is 80-150μm.

[0110] The preparation process is as follows:

[0111] According to the formula, cast tungsten carbide powder, sintered tungsten carbide powder, tungsten fiber, cobalt powder, nickel powder and agarose sol are mixed to obtain PDC drill bit embryo slurry;

[0112] The obtained PDC drill bit embryo slurry is subjected to heat preservation treatment, and then copper alloy, tin, boron, lead and titanium are added for infiltration to obtain a PDC drill bit matrix;

[0113] The temperature during the mixing is 90°C; the stirring rate during the mixing is 200r / min; and the mixing time is 5h.

[0114] The temperature of the heat preservation treatment is 450° C.; the time of the heat preservation treatment is 4 hours;

[0115] The infiltration temperature is 1200°C; the infiltration time is 1h;

[0116] The heat preservation treatment and infiltration are both carried out under vacuum conditions, and the absolute vacuum degree is 0.4Pa.

[0117] Comparative Example 1

[0118] The only difference from Example 1 is that the gradient grade cast tungsten carbide powder is replaced by an equal amount of cast tungsten carbide in a single particle size range, specifically 150-180 μm.

[0119] Comparative Example 2

[0120] The only difference from Example 1 is that the cast tungsten carbide powder is replaced by an equal amount of sintered tungsten carbide powder.

[0121] Comparative Example 3

[0122] The only difference from Example 1 is that the sintered tungsten carbide powder is replaced with an equal amount of macrocrystalline tungsten carbide powder.

[0123] Comparative Example 4

[0124] The only difference from Example 1 is that the sintered tungsten carbide powder is replaced by an equal amount of cast tungsten carbide powder with the same particle size distribution.

[0125] Comparative Example 5

[0126] The only difference from Example 1 is that the tungsten fiber is replaced by tungsten powder, and the average particle size of the tungsten powder is the diameter of the tungsten fiber.

[0127] Comparative Example 6

[0128] The only difference from Example 1 is that the copper alloy is replaced by an equal amount of pure copper.

[0129] Comparative Example 7

[0130] The only difference from Example 1 is that no tin is added.

[0131] Comparative Example 8

[0132] The only difference from Example 1 is that no boron is added.

[0133] Comparative Example 9

[0134] The only difference from Example 1 is that no lead is added.

[0135] Comparative Example 10

[0136] The only difference from Example 1 is that titanium is not added.

[0137] Comparative Example 11

[0138] The only difference from Example 1 is that no cobalt powder is added.

[0139] Comparative Example 12

[0140] The only difference from Example 1 is that the diameter of the tungsten fiber is 100 μm.

[0141] The infiltration process of the above-mentioned embodiments and comparative examples is to mix the copper alloy, tin-lead alloy and aluminum-titanium-boron master alloy powders uniformly, cold press them into a blank and then perform infiltration.

[0142] The tire bodies of the above-mentioned Examples 1-4 and Comparative Examples 1-12 were subjected to erosion resistance, impact resistance, hardness, wear resistance, strength test and hardness test. The results are shown in Table 1.

[0143] Specifically, the erosion resistance test is as follows: 5 samples of the tire bodies obtained in the above embodiments are taken and weighed, and the sample size is 50*30*6.3mm. In a sandblasting machine, a nozzle with an inner diameter of 5mm is placed 2cm away from the sample at an angle of 60 degrees for sandblasting for 3 minutes. The sample is taken out and weighed again. The weight difference is the weight eroded, and the weight eroded divided by the initial weight is the blasting ratio. The smaller the blasting ratio, the better the erosion resistance of the sample. The impact resistance test is carried out in accordance with GB / T 229, the wear resistance is tested by using a DHM-2 wear ratio tester to test the wear resistance of the tire body using the wet VTL test method to calculate the volume wear ratio to evaluate the wear resistance, and the bending strength is tested in accordance with GB / T 3851, and the hardness test is carried out in accordance with GB / T 230.1.

[0144] Table 1

[0145]

[0146]

[0147] It can be seen from the results of the above embodiments and comparative examples that the PDC drill bit matrix provided by the present invention, by adding tungsten fiber, nickel powder, copper alloy, tin, boron, lead, cobalt and titanium powders to the PDC drill bit body material, is conducive to improving the erosion resistance, impact resistance, hardness and wear resistance of the PDC drill bit body material, thereby improving the overall strength of the PDC drill bit body material, and further using three different diameters of cast tungsten carbide particles, so that the PDC drill bit body material has high hardness and excellent wear resistance. Among them, the erosion resistance of the PDC drill bit matrix obtained in the present invention has a blasting ratio of ≤1.48%, impact toughness ≥10.8J, hardness ≥42.5, bending strength ≥920.1MPa, volume wear ratio ×10 6 ≥15.3.

[0148] It is stated that the present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0149] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0150] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0151] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A PDC drill bit matrix, characterized in that: The PDC drill bit matrix comprises: cast tungsten carbide powder, sintered tungsten carbide powder, tungsten fiber, copper alloy, nickel powder, tin, boron, lead, titanium, cobalt powder and agarose sol; The cast tungsten carbide powder comprises at least three cast tungsten carbide powders with gradient particle size distribution.

2. The PDC drill bit matrix according to claim 1, characterized in that: The PDC drill bit matrix comprises, by weight: 60-100 parts of cast tungsten carbide powder, 40-60 parts of sintered tungsten carbide powder, 10-20 parts of tungsten fiber, 5-15 parts of copper alloy, 20-30 parts of nickel powder, 1-7 parts of tin, 2-6 parts of boron, 3-5 parts of lead, 1-7 parts of titanium, 3-5 parts of cobalt powder and 5-15 parts of agarose sol.

3. The PDC drill bit matrix according to claim 1 or 2, characterized in that: The cast tungsten carbide powder includes cast tungsten carbide powder with a particle size of 45-65 μm, cast tungsten carbide powder with a particle size of 65-115 μm and cast tungsten carbide powder with a particle size of 115-285 μm; Preferably, the particle size of the sintered tungsten carbide is 70-100 μm; Preferably, the diameter of the tungsten fiber is 60-90 μm; Preferably, the aspect ratio of the tungsten fiber is 30-40.

4. The PDC drill bit matrix according to any one of claims 1 to 3, characterized in that: The copper alloy includes brass and / or bronze; Preferably, the nickel powder has a particle size of 120-130 μm and is spherical particles; Preferably, the particle size of the cobalt powder is 50-150 μm.

5. A method for preparing a PDC drill bit matrix according to any one of claims 1 to 4, characterized in that: The preparation method comprises: According to the formula, cast tungsten carbide powder, sintered tungsten carbide powder, tungsten fiber, cobalt powder, nickel powder and agarose sol are mixed to obtain PDC drill bit embryo slurry; The obtained PDC drill bit embryo slurry is subjected to heat preservation treatment, and then copper alloy, tin, boron, lead and titanium are added for infiltration to obtain a PDC drill bit matrix.

6. The preparation method according to claim 5, characterized in that: The temperature during the mixing is 90-100°C; Preferably, the stirring rate in the mixing is 200-350 r / min; Preferably, the mixing time is 2-5 hours.

7. The preparation method according to claim 5 or 6, characterized in that: The temperature of the heat preservation treatment is 450-500°C; Preferably, the heat preservation treatment time is 2-4 hours.

8. The preparation method according to any one of claims 5 to 7, characterized in that: The infiltration temperature is 1100-1200°C; Preferably, the infiltration time is 1-5h.

9. The preparation method according to any one of claims 5 to 8, characterized in that: The heat preservation treatment and melt infiltration are both carried out under vacuum conditions, with an absolute vacuum degree of ≤4Pa.

10. A use of the PDC drill bit matrix according to any one of claims 1 to 4, characterized in that: The use includes preparing a PDC drill bit by using the PDC drill bit matrix.

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