Brazed diamond hole drill and method of making

Abstract

The present application relates to the field of diamond hole drill, in particular to a brazed diamond hole drill and a preparation method thereof. The brazed diamond hole drill comprises a hole drill base, the hole drill base comprises an end face and a side wall arranged around the end face, the side wall comprises an outer wall and an inner wall arranged oppositely; the outer wall and the end face of the hole drill base are provided with brazed diamond lines; wherein the brazed diamond line comprises a brazing alloy base and diamond particles, the brazing alloy base comprises a contact surface in contact with the hole drill base and an exposed surface arranged around the contact surface, the exposed surface is an outward convex arc surface, and the brazing alloy base is embedded with diamond particles on the side close to the exposed surface. The brazed diamond hole drill, the diamond particles are distributed on the exposed surface, can form a high-low staggered multi-layer cutting structure, and further improve the cutting stability and the service life of the hole drill.

Description

Technical Field

[0001] This invention relates to the field of diamond hole drilling, and more specifically to a brazed diamond hole drill and its preparation method. Background Technology

[0002] Brazed diamond drills are widely used in drilling hard and brittle materials such as ceramics and granite due to their excellent cutting performance. Currently, most brazed diamond drills employ a disordered single-layer arrangement, with diamond particles randomly attached to the drill matrix surface. This disordered distribution leads to uneven cutting force distribution during drilling, easily causing problems such as excessive localized wear, rapid loss of sharpness, and short service life, making it difficult to meet the actual needs of the construction and installation industry for efficient and durable drilling tools.

[0003] To achieve an ordered distribution of diamonds on a brazed diamond drill bit, a template method can be used. However, the template method can only achieve a limited ordered distribution on the sidewall of the drill bit; the drill bit lip (end face) remains mostly a disordered single-layer structure. Due to the disordered single-layer arrangement of diamond particles, the self-sharpening property is poor and the lifespan is short during cutting. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one objective of this invention is to provide a brazed diamond hole drill and its preparation method, thereby solving the problem of disordered diamond arrangement in brazed diamond hole drills.

[0005] In a first aspect of the present invention, a brazing diamond hole drill is provided, the brazing diamond hole drill includes a hole drill body, the hole drill body includes an end face and a side wall disposed around the end face, the side wall includes an outer wall and an inner wall disposed opposite to each other; Brazed diamond lines are provided on the outer wall and end face of the drill bit base; The brazed diamond line includes a brazing alloy matrix and diamond particles. The brazing alloy matrix includes a contact surface that contacts the hole drill matrix and an exposed surface that surrounds the contact surface. The exposed surface is a convex arc-shaped surface. Diamond particles are embedded on the side of the brazing alloy matrix near the exposed surface.

[0006] The brazed diamond drill of this application has diamond particles distributed on the exposed surface, forming a multi-layered cutting structure with varying heights. During cutting, diamond particles at different heights participate in the work sequentially, achieving layered cutting, thereby effectively reducing the cutting load of a single particle, reducing impact and wear, and improving cutting stability and the service life of the drill.

[0007] A second aspect of the present invention provides a method for preparing a brazed diamond hole drill, comprising the following steps: (1) A hole drill base is provided, the hole drill base including an end face and a side wall disposed around the end face, the side wall including an outer wall and an inner wall; A soldering paste is provided, the soldering paste comprising solder powder and a binder; (2) Apply the brazing paste to the hole drill substrate using a dispensing machine in accordance with the pattern of the brazing diamond lines to form three-dimensional brazing paste lines; (3) Sprinkle diamond particles on the three-dimensional solder paste lines so that the diamond particles are at least partially embedded in the three-dimensional solder paste lines; (4) Drying and vacuum brazing are performed to form the brazed diamond lines on the borehole substrate; The brazed diamond wire includes a brazing alloy matrix and diamond particles. The brazing alloy matrix includes a contact surface that contacts the hole drill matrix and an exposed surface that surrounds the contact surface. The exposed surface is a convex arc-shaped surface. The diamond particles are embedded in the brazing alloy matrix on the side near the exposed surface.

[0008] In a second aspect of the present invention, the method for preparing the brazed diamond hole drill utilizes a three-dimensional brazing paste line on the hole drill substrate as a substrate. By sprinkling diamond particles, a densely arranged diamond layer can be formed on its exposed surface. After drying and vacuum brazing, brazed diamond lines can be formed. Vacuum brazing can maintain the basic shape of the three-dimensional brazing paste line formed by dispensing adhesive. At the same time, the diamond particles are embedded in the brazing alloy substrate and are conformally loaded on the convex arc surface, so that the brazed diamond lines and the hole drill substrate form a firm bond.

[0009] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0010] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of a brazed diamond hole drill according to an embodiment of the present invention; Figure 2 This is a front view of a brazing diamond hole drill according to an embodiment of the present invention; Figure 3 This is a top view of a brazing diamond hole drill according to an embodiment of the present invention; Figure 4 This is a schematic cross-sectional view of the first line according to an embodiment of the present invention; Figure 5This is a schematic cross-sectional view of the first line according to another embodiment of the present invention.

[0011] Figure label: 1-Drill matrix; 2-Brattered diamond line; 201-First line; 202-Second line; 2011-Diamond particle; 2012-Brattered alloy matrix. Detailed Implementation

[0012] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0013] Currently, there is no technical solution for achieving a three-dimensional orderly distribution of diamond in brazed holes using a dispensing machine. Existing brazing processes generally employ a random application of a single layer of diamond, which cannot achieve either an orderly distribution of diamonds or a multi-layer distribution, thus making it difficult to balance the sharpness and lifespan of the hole drill.

[0014] In a first aspect of the invention, a brazed diamond hole drill is provided, see [link to previous document]. Figures 1-5 The brazed diamond hole drill includes a hole drill base 1, which includes an end face and a side wall surrounding the end face. The side wall includes an outer wall and an inner wall that are disposed opposite to each other. Brazed diamond lines 2 are provided on the outer wall and end face of the drill bit 1; Among them, the brazed diamond line 2 includes a brazed alloy matrix and diamond particles 2011. The brazed alloy matrix 2012 includes a contact surface that contacts the hole drill matrix and an exposed surface arranged around the contact surface. The exposed surface is an outwardly convex arc-shaped surface. Diamond particles 2011 are embedded on the side of the brazed alloy matrix 2012 near the exposed surface.

[0015] The brazed diamond drill of this application has diamond particles 2011 distributed on the exposed surface, forming a multi-layered cutting structure with varying heights. During cutting, diamond particles 2011 at different heights participate in the work sequentially, achieving layered cutting, thereby effectively reducing the cutting load of a single particle, reducing impact and wear, and improving cutting stability and the service life of the drill.

[0016] It should be noted that, in the embodiments of this application, the exposed surface refers to the surface that is not covered and is exposed to the outside.

[0017] In this embodiment, the convex arc-shaped surface can have a circular arc-shaped cross-sectional profile of the exposed surface. The number of diamond particles varies depending on the size of the convex arc-shaped surface; for example, see [link to relevant documentation]. Figure 4 and Figure 5As can be seen, diamond particles 2011 are distributed in a conformal manner on the brazing alloy matrix 2012.

[0018] In the embodiments of this application, the diamond particles are densely arranged in the brazing alloy matrix, and adjacent diamond particles are in contact with each other or the gap between them is smaller than the average particle size of the diamond particles.

[0019] In some embodiments, the brazed diamond lines 2 include first lines 201 located on the outer wall of the drill bit substrate, and the first lines 201 are distributed in an orderly manner on the outer wall. This forms an orderly pattern with equal spacing and unidirectional orientation on the outer wall of the drill bit. This orderly distribution, compared to a disordered random arrangement, ensures consistent diamond density and cutting edge height in each cutting area during drilling, avoiding rapid wear of the substrate caused by areas lacking diamond, and significantly improving the stability and durability of the drill bit.

[0020] In some embodiments, the brazed diamond line 2 includes a second line 202 located on the end face of the hole drill substrate, and the second line 202 is distributed in an orderly manner on the end face.

[0021] In some embodiments, in a brazed diamond drill bit, the angle between the first line 201 and the axis of the drill bit substrate 1 is 0° to 70°. This causes the multilayer diamond particles 2011 attached to the drill bit after brazing to form helical or oblique cutting edges during drilling. Within this angle range, the cutting force is uniformly distributed along the circumferential and axial directions of the drill bit, significantly reducing local overload and minimizing abnormal diamond particle shedding and substrate wear. Simultaneously, by defining a fixed angle between the first line 201 and the axis and distributing it evenly on the outer wall, an ordered pattern with equal spacing and unidirectional orientation is formed on the outer wall of the drill bit. This ordered distribution, compared to a random arrangement, ensures consistent diamond density and cutting edge height in each cutting area during drilling, avoiding rapid substrate wear caused by areas lacking diamond particles, and significantly improving the stability and durability of the drill bit. For example, the angle between the first line 201 and the axis of the drill bit substrate 1 can be 0°, 10°, 20°, 30°, 40°, 50°, 65°, 70°, etc.

[0022] In some embodiments, in brazed diamond drills, the angle between the second line 202 and the radial direction of the drill base 1 is 0° to 45°. This optimizes end-face cutting efficiency: the end face is the primary cutting surface during drilling, and the second line 202 forms a 0° to 45° angle with the radial direction, causing the multilayer diamond particles 2011 attached thereto to form radial or inclined radial cutting edges. When the angle is 0° (i.e., linearly distributed radially), cutting resistance is minimal, suitable for rapid drilling; when the angle increases to 45°, the cutting edges exhibit a helical tendency, increasing the contact length between the cutting edge and the workpiece, improving the cutting amount per rotation, and further enhancing sharpness. Furthermore, the angle between the second line 202 on the end face and the angle (0° to 70°) between the first line 201 on the outer wall together constitute a three-dimensional ordered pattern in the drilling working area, allowing the diamond particles on the end face and outer wall to connect naturally in space, resulting in a smooth cutting transition during drilling, without any abrupt performance changes, and overall improving the sharpness and lifespan of the drill. For example, the included angle between the second line 202 and the radial direction of the hole drill base 1 is 0°, 5°, 15°, 30°, 45°, etc.

[0023] Preferably, the angle between the second line 202 and the radial direction of the drill bit 1 is 15° to 45°. This allows the second line 202 to be more evenly distributed on the end face, avoiding local accumulation or sparse distribution of diamond particles and ensuring consistent cutting capability across the entire annular end face. Simultaneously, an inclination angle within 45° will not cause excessive distortion of the line, facilitating the dispensing process and ensuring a stable line structure.

[0024] In some embodiments, in brazed diamond hole drilling, the first line 201 includes straight lines, curves, and / or broken lines. This allows for adaptation to different working conditions: straight lines are the simplest and suitable for standard drilling conditions; curved lines can increase the diamond distribution path on the outer wall, extend the total cutting edge length, and improve wear resistance; broken lines can increase local diamond density without changing the overall direction of the line, making them suitable for efficient drilling of hard and brittle materials. Users can flexibly select or combine these methods according to the specific machining object.

[0025] Furthermore, the curved lines can be sine waves, cosine waves, circular arcs, etc. This allows for adaptation to different working conditions: straight lines are the simplest to produce and suitable for standard drilling conditions; curved lines can increase the distribution path of diamond on the outer wall, extend the total length of the cutting edge, and improve wear resistance; zigzag lines can increase local diamond density without changing the overall direction of the lines, making them suitable for efficient drilling of hard and brittle materials. Users can flexibly select or combine these methods according to the specific machining object.

[0026] In some embodiments, in brazing diamond hole drilling, the second line 202 includes a straight line, a curve, and / or a broken line.

[0027] In some embodiments, in brazed diamond drilling, the spacing between adjacent first lines 201 is 0.1 mm to 2 mm. This balances diamond density and chip removal space: too small a spacing (<0.1 mm) results in overly dense lines, excessive diamond accumulation, narrow chip removal channels, and a tendency to cause chip blockage and overheating; too large a spacing (>2 mm) results in sparse diamond distribution, insufficient local cutting ability, and easy wear of the matrix. This spacing ensures that a sufficient number of diamond particles 2011 participate in cutting per unit area while providing ample chip removal clearance, achieving a balance between efficient drilling and self-cleaning capabilities. For example, the spacing between adjacent first lines 201 can be 0.1 mm, 0.3 mm, 0.5 mm, 1.3 mm, 2.5 mm, 2 mm, etc.

[0028] In some embodiments, in the brazed diamond hole drill, the width of the first line 201 is 0.1 mm to 1.5 mm. For example, the width of the first line 201 can be 0.1 mm, 0.3 mm, 0.5 mm, 0.7 mm, 1.0 mm, 1.2 mm, or 1.5 mm.

[0029] It should be noted that the width of the first line 201 refers to the width of the orthographic projection on the tangent plane of the substrate surface at the attachment position of the first line 201.

[0030] In some embodiments, in brazed diamond hole drilling, the spacing between adjacent second lines 202 is 0.1 mm to 2 mm. This balances diamond density with chip removal space.

[0031] In some embodiments, the width of the second line 202 in the brazed diamond hole drill is 0.1 mm to 1.5 mm. For example, the width of the second line 202 can be 0.1 mm, 0.5 mm, 0.7 mm, 1.0 mm, 1.2 mm, or 1.5 mm.

[0032] In some embodiments, the brazed diamond drill bit 2 may further include a third line located on the inner wall. In this embodiment, the third line is formed by the second line near the inner wall side being suspended and deformed on the inner wall, which can protect the inner wall of the drill bit.

[0033] In some embodiments, in brazed diamond hole drilling, at least one adjacent brazed diamond line 2 forms an outer wall. In this case, a gap is left on the outer wall between adjacent brazed diamond lines 2.

[0034] In some embodiments, a brazed diamond drill bit has a single layer of diamond on the outer wall between at least one adjacent brazed diamond wire 2. This strengthens the brazed diamond wire 2 and improves the drill bit's lifespan.

[0035] Optionally, the single-layer diamond can be bonded to the gaps between adjacent brazed diamond lines 2 using an adhesive.

[0036] In some embodiments, in brazed diamond hole drilling, a gap is left on the end face between at least one adjacent brazed diamond line 2.

[0037] In some embodiments, in a brazed diamond hole drill, a single layer of diamond is provided on the end face between at least one adjacent brazed diamond line. This can strengthen the hole drill.

[0038] In a second aspect of the present invention, a method for preparing a brazed diamond hole drill is provided, comprising the following steps: S1. A hole drill base 1 is provided. The hole drill base 1 includes an end face and a side wall disposed around the end face. The side wall includes an inner wall and an outer wall. Optionally, the drill bit 1 can be cylindrical in shape and can be formed by machining steel (such as 45# steel, 40Cr or spring steel). The drill bit 1 includes an end face (i.e., working face) for cutting and an outer wall (i.e., outer surface of the cylinder wall) surrounding the end face. One end of the drill bit 1 is a connecting shank for connecting to the spindle of a power tool such as an angle grinder or electric drill. The other end of the drill bit 1 is an annular end face, which directly contacts the workpiece during drilling and undertakes the main cutting task. The outer wall is located on the outer periphery of the end face and extends from the end face towards the connecting shank, used for chip removal and assisting cutting during drilling.

[0039] Furthermore, the end face of the drill bit 1 can be an annular plane or slightly tapered (e.g., internal or external tapered), and its width (i.e., wall thickness) can be designed according to the drilling diameter and wall thickness, ranging from 0.8 mm to 3 mm. The end face is the main cutting area during drilling, directly bearing impact and wear, therefore requiring the arrangement of high-density, high-sharpness diamond particles on it; the outer wall is a cylindrical surface, with its outer diameter consistent with the outer diameter of the end face. The outer wall plays a guiding and chip removal role during drilling, while also undertaking some cutting tasks.

[0040] It should be noted that this invention does not specifically limit the dimensions (such as diameter, wall thickness, and length) of the drill bit substrate 1. Those skilled in the art can select conventional dimensions according to actual drilling requirements (such as drilling diameter, drilling depth, and workpiece material). Brazed diamond drills refer to hollow drilling tools used for drilling holes in hard and brittle materials such as ceramics and granite, in which diamond particles are firmly brazed onto a cylindrical metal substrate using a brazing process. They are also known as core drills or thin-walled drills.

[0041] S1 also includes providing solder paste, which comprises filler metal powder and binder. Thus, the solder paste is a paste-like substance composed of filler metal powder, binder, and flux mixed in a specific ratio, exhibiting a certain viscosity and thixotropic properties. During the dispensing and spreading stages, the solder paste acts as an adhesive medium, temporarily fixing the diamond particles to predetermined positions on the substrate surface (i.e., on orderly distributed lines). By controlling the amount and shape of the solder paste, the three-dimensional solder paste lines are made thick enough to provide vertical space for the diamond particles. During vacuum brazing, the filler metal powder in the solder paste melts and, upon cooling, forms a dense alloy layer, firmly brazing the diamond particles to the drill bit substrate 1.

[0042] Optionally, the solder powder can be copper-tin-titanium solder (Cu-Sn-Ti) with a particle size of 10μm-50μm. This allows titanium to chemically react with non-metallic materials (such as diamond) to form interfacial layers such as TiC and TiN, achieving a strong metallurgical bond. It also possesses the excellent electrical and thermal conductivity of copper-based materials, and exhibits good wettability and strong fluidity at the brazing temperature.

[0043] Optionally, the binder can be an organic carrier, such as ethyl cellulose, terpineol, or polyethylene glycol. This allows the brazing filler metal powder to be suspended and formed into a dispensable paste. The binder volatilizes during the drying stage and completely decomposes during the brazing stage.

[0044] Optionally, the brazing process can employ vacuum brazing or inert gas shielded welding. This prevents titanium from oxidizing at high temperatures. In some embodiments, the viscosity of the brazing paste is 100,000 cP to 1,000,000 cP. This viscosity range imparts appropriate thixotropy to the brazing paste; when diamond is sprinkled and an external force is applied, the paste's fluidity increases, making it easier for particles to partially embed; after the external force is removed, the paste returns to a high viscosity, locking the particles in place. This range also prevents particles from settling to the bottom due to excessively low viscosity. For example, the viscosity of the brazing paste can be 100,000 cP, 110,000 cP, 120,000 cP, 130,000 cP, 140,000 cP, 150,000 cP, 160,000 cP, 170,000 cP, 180,000 cP, 190,000 cP, 1,000,000 cP, etc.

[0045] In this application, the viscosity of the solder paste was measured using a Brookfield rotational viscometer at a temperature of 25°C.

[0046] S2. Apply the brazing paste to the drill bit substrate 1 according to the pattern of the brazing diamond line 2 to form a three-dimensional brazing paste line. In this way, the shape of the brazing diamond line 2 can be replicated on the drill bit substrate 1 in the form of a three-dimensional brazing paste line. For the first time, an orderly skeleton structure is established on the outer wall and / or end face of the drill bit, which provides precise spatial guidance for the orderly and compact arrangement of diamond particles in the future. This fundamentally overcomes the problems of uneven force and excessive wear caused by the traditional disordered arrangement.

[0047] In some embodiments, a dispensing machine can be used to apply solder paste to the drill bit substrate 1 according to the pattern of the brazing diamond lines 2, forming an orderly distributed three-dimensional solder paste line. Thus, the dispensing machine possesses multi-axis linkage control capabilities, enabling precise application of continuous three-dimensional solder paste lines on the cylindrical surface (outer wall) and annular surface (end face) of the drill bit according to preset spacing, angles, and shapes (e.g., straight lines, curves, or broken lines), solving the technical problem of difficulty in forming orderly patterns on curved surfaces using manual or stencil methods. Simultaneously, the dispensing nozzle of the dispensing machine has a circular outlet, resulting in cylindrical three-dimensional solder paste lines being extruded. These cylindrical solder paste lines, after brazing, can form a brazing alloy substrate with an arc-shaped exposed surface.

[0048] Furthermore, a dispensing path program can be written based on the pattern of the brazing diamond lines 2, and dispensing can be performed on the outer wall and end face of the drill bit substrate 1 according to the dispensing path program to form an orderly distributed three-dimensional brazing paste lines.

[0049] Optionally, during dispensing, the dispensing pressure is 0.2 MPa to 0.6 MPa, the needle movement speed of the dispensing machine is 1 mm / s to 50 mm / s, and the distance between the needle of the dispensing machine and the surface of the hole drill substrate 1 is 0.1 mm to 0.6 mm. This results in good line dimension consistency and high process stability. For example, the dispensing pressure can be 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, etc.; the needle movement speed of the dispensing machine can be 10 mm / s, 20 mm / s, 30 mm / s, 40 mm / s, 50 mm / s, etc.; and the distance between the needle of the dispensing machine and the surface of the hole drill substrate 1 can be 0.1 mm, 0.2 mm, 0.3 mm, etc.

[0050] In some embodiments, see Figure 2 The pattern of the brazed diamond line 2 includes a first line 201 evenly distributed on the outer wall of the drill bit 1, the angle between the first line 201 and the axis of the drill bit 1 being 0° to 70°. Optionally, the first line 201 can be a straight line, a curve, and / or a broken line.

[0051] In some embodiments, see Figure 3The pattern of the brazed diamond line 2 includes a second line 202 evenly distributed on the end face of the drill bit 1, the second line 202 having an angle of 0° to 45° with the radial direction of the drill bit 1. Optionally, the second line 202 may include a straight line, a curve, and / or a broken line.

[0052] Optionally, the spacing between adjacent second lines 202 is 0.1 mm to 2 mm. This balances diamond density with chip removal space.

[0053] Optionally, the width of the second line 202 is 0.1 mm to 1.5 mm. For example, the width of the second line 202 can be 0.1 mm, 0.3 mm, 0.5 mm, 0.7 mm, 1.0 mm, 1.2 mm, or 1.5 mm.

[0054] S3. Sprinkle diamond particles on the three-dimensional solder paste lines so that the diamond particles are at least partially embedded in the three-dimensional solder paste lines; thereby, the diamond particles can be initially fixed.

[0055] Optionally, the spreading operation can be carried out by sieving or spraying. No complicated alignment or positioning devices are required. With slight pressing or vibration, uniform embedding can be achieved, resulting in high production efficiency and suitability for mass production.

[0056] Optionally, the amount of diamond particles applied can be obtained using the following method: application amount M (mg / mm²) 2 Based on the average particle size d (mm) of diamond particles and the density of a single layer of close packing, the empirical formula is approximately M = 2.13 × d.

[0057] As an example, the thickness of the 3D solder paste lines is 0.1 mm to 1.0 mm, and the diamond particle size is 25 mesh to 150 mesh (i.e., 0.1 mm to 0.71 mm). This allows for adaptation to different particle size requirements and flexibly meets the requirements of different drilling conditions.

[0058] It should be noted that the thickness of the 3D solder paste line refers to the maximum radial distance from the contact surface to the exposed surface on a cross-section perpendicular to the length of the 3D solder paste line. Optionally, the application rate can be controlled in conjunction with vibration to ensure that the diamond particles within the 3D solder paste line are in contact with each other or nearly in contact. That is, adjacent diamond particles are in contact with each other or the gap between them is smaller than the average particle size of the diamond particles.

[0059] S4. Drying and vacuum brazing are performed to form brazed diamond lines 2 on the drill bit substrate 1. The brazed diamond lines 2 include a brazing alloy substrate 2012 and diamond particles 2011. The brazing alloy substrate 2012 includes a contact surface that contacts the drill bit substrate 1 and an exposed surface surrounding the contact surface. The exposed surface is a convex arc-shaped surface, and the diamond particles 2011 are embedded in the brazing alloy substrate on the side near the exposed surface. Thus, the drying process allows the solvent and some binder in the brazing paste to slowly evaporate, and the paste solidifies and shrinks, firmly locking the embedded diamond particles 2011 in their predetermined positions. This prevents the particles from shifting or collapsing due to softening of the solder paste during brazing heating, and also ensures that the diamond particles 2011 remain intact before entering the high-temperature brazing stage. In a vacuum environment, the brazing filler metal powder melts and fully wets the diamond particles 2011 and the surface of the drill bit substrate 1, forming a dense brazing alloy upon cooling. This alloy firmly brazes the diamond particles 2011 to the drill matrix 1, achieving a bonding strength far exceeding that of electroplated or sintered tools, significantly reducing the risk of particle shedding during the drilling process. The ordered solder paste lines and scattered diamond particles constructed in steps S2 and S3 are transformed into brazed diamond lines with a strong metallurgical bond.

[0060] Optionally, the hole drill substrate 1, coated with solder paste and diamond, is placed in a vacuum oven, evacuated to -0.08 MPa ~ -0.1 MPa, heated to 80 ℃ ~ 120 ℃, and held at that temperature for 0.5 h ~ 3 h to allow the solvent in the solder paste to fully evaporate and the binder to solidify. After the holding period, the substrate is cooled to room temperature in the oven while maintaining the vacuum condition before being removed.

[0061] Optionally, when performing vacuum brazing, if the brazing paste is copper-tin-titanium brazing filler metal (Cu-Sn-Ti), the brazing temperature can be 800 ℃~900 ℃, and the holding time can be 20 min~40 min.

[0062] Optionally, during vacuum brazing, the vacuum level can be 5×10⁻⁶. -3 Pa ~ 5×10 -2 Pa.

[0063] Optionally, during vacuum brazing, the heating rate can be 5 ℃ / min ~ 20 ℃ / min.

[0064] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0065] Example 1 I. Structure of Brazed Diamond Hole Drill This embodiment provides a brazed diamond hole drill, see [link]. Figures 1-4The system includes a drill bit body 1. The drill bit body 1 is made of 45# steel and is machined into a cylindrical structure, including an annular end face for cutting and a cylindrical outer wall surrounding the end face. One end of the drill bit body 1 is a connecting shank for connecting to the spindle of an angle grinder (12000 rpm); the other end is an annular end face with a width (wall thickness) of 3 mm.

[0066] The outer wall and end face of the drill matrix 1 are provided with orderly distributed brazed diamond lines 2. The brazed diamond lines 2 include diamond particles 2011 and brazed alloy matrix 2012.

[0067] The inner wall of the drill bit 1 is provided with a third line to resist the erosion and wear of the inner wall by the chips.

[0068] II. Preparation method of brazed diamond hole drill (1) Pretreatment Provide hole drill base 1: A hole drill base with the above structure is made of 45 steel.

[0069] Solder paste provided: This embodiment uses copper-tin-titanium solder (Cu-Sn-Ti solder powder particle size of 20 μm~30 μm), and the binder is a mixture of ethyl cellulose and terpineol. The viscosity of this solder paste, measured by a Brookfield rotational viscometer at 25 °C, is 500,000 cPcP.

[0070] Place the drill bit 1 into an ultrasonic cleaning device, add cleaning agent, clean for 15 minutes to remove surface oil and oxide layer, then rinse with distilled water and let it dry for later use.

[0071] (2) Apply three-dimensional solder paste to lines A dispensing machine is used to apply solder paste to the hole drill substrate 1 according to the pattern, forming an orderly distributed three-dimensional solder paste line.

[0072] The dispensing path program is written based on the pattern. The dispensing parameters are: dispensing pressure 0.4 MPa, dispensing needle movement speed 30 mm / s, and distance between the needle and the surface of the hole drill substrate 1 0.2 mm.

[0073] The pattern includes: a first line 201 evenly distributed on the outer wall of the drill bit 1, the first line 201 forming an angle of 30° (clockwise) with the axis of the drill bit 1, the first line 201 being a straight line, and the spacing between adjacent first lines 201 being 1.0 mm. A second line 202 evenly distributed on the end face of the drill bit 1, the second line 202 forming an angle of 30° with the radial direction of the drill bit 1, the second line 202 being parallel lines, and the spacing between adjacent second lines 202 being 1.0 mm.

[0074] Apply a small amount of three-dimensional solder paste to the inner wall of the drilled substrate 1 to ensure adhesion to the inner wall and form a third line.

[0075] After dispensing, an orderly distributed three-dimensional solder paste line is formed. Measurements show that the thickness of the three-dimensional solder paste line is 0.6 mm and the width is 0.5 mm.

[0076] (3) Sprinkle diamond particles In this embodiment, diamond particles with a particle size of 50 mesh (approximately 0.3 mm) were selected. Calculations show that the theoretical amount required to form a single layer of close-packed diamond particles is approximately 0.64 mg / mm². 2 (According to the formula M≈2.13×d, d=0.3 mm).

[0077] By using a sieving and spreading method, the theoretical amount of diamond particles required for a single-layer tight arrangement is evenly spread on the three-dimensional solder paste lines, so that the diamond particles are partially embedded in the three-dimensional solder paste lines.

[0078] (4) Drying and vacuum brazing Drying: Place the hole drill substrate 1, which is coated with solder paste and diamond particles, into a vacuum oven, evacuate to -0.09 MPa, heat to 80 ℃, and hold for 1 h to allow the solvent in the solder paste to fully evaporate and the binder to solidify. After the holding period, keep the vacuum state and cool with the oven to room temperature before removing it.

[0079] Vacuum brazing: Place the dried hole drill substrate 1 into a vacuum brazing furnace and evacuate to a vacuum level of 1×10⁻⁶. -2 Pa. The temperature is increased to 850℃ at a heating rate of 10℃ / min and held for 20 min. After the holding period, the temperature is cooled to below 100℃ with the furnace at a cooling rate of 10℃ / min. The vacuum system is then turned off, nitrogen is introduced to atmospheric pressure, the furnace door is opened, and the product is removed to obtain the brazed diamond hole drill.

[0080] Example 2 The structure of the brazed diamond hole drill in Example 2 is the same as that in Example 1, and will not be described again here.

[0081] The method for preparing brazed diamond hole drills in Example 2 includes: (1) Pretreatment A hole drill substrate (1) and solder paste are provided. In this embodiment, copper-tin-titanium solder (Cu-Sn-Ti solder powder with a particle size of 10 μm to 15 μm) is used, and ethyl cellulose is used as the binder. The viscosity of the solder paste is 100,000 cP as measured by a Brookfield rotational viscometer at 25°C.

[0082] Place the borehole substrate in an ultrasonic cleaning device for 15 minutes, rinse with distilled water, and air dry for later use.

[0083] (2) Applying 3D solder paste lines: The solder paste is applied to the hole drill substrate according to the pattern using a dispensing machine. Dispensing parameters: dispensing pressure 0.2 MPa, needle movement speed 10 mm / s, distance between needle and substrate surface 0.1 mm.

[0084] Pattern: The first line on the outer wall forms a 0° angle with the axis of the drill bit base (parallel to the axis), the first line is a straight line, and the spacing between adjacent lines is 0.3 mm. The second line on the end face forms a 0° angle with the radial direction of the drill bit base (distributed along the radial direction), the second line is a straight line, arranged as several parallel individual lines, and the spacing between adjacent lines is 0.3 mm.

[0085] Apply a small amount of 3D solder paste to the inner wall to create lines.

[0086] After dispensing, the thickness of the 3D solder paste lines is 0.3 mm and the width is 0.3 mm.

[0087] (3) Sprinkle diamond particles In this embodiment, diamond particles with a particle size of 150 mesh (corresponding to a particle size of approximately 0.10 mm) are selected, and the theoretical amount required to form a single layer of tightly packed diamond particles is approximately 0.213 mg / mm². 2 The amount of material spread is the theoretical amount required to form a single layer of tightly packed material.

[0088] The thickness of the three-dimensional solder paste lines is 0.3 mm, and the diamond particle size is 0.10 mm. The particles are partially embedded by sieving and spreading to form a single-layer stacked diamond layer.

[0089] (4) Drying and vacuum brazing Drying: Place in a vacuum oven, evacuate to -0.08 MPa, heat to 80 ℃, and keep warm for 30 min.

[0090] Vacuum brazing: Place in a vacuum brazing furnace and evacuate to a vacuum level of 5×10. -2 Pa, heat to 800 °C at 5 °C / min, hold for 20 min, then cool to room temperature at 5 °C / min and remove.

[0091] Example 3 The structure of the brazed diamond hole drill in Example 3 is the same as that in Example 1, and will not be described again here.

[0092] The method for preparing brazed diamond hole drills in Example 3 includes: (1) Pretreatment This embodiment uses copper-tin-titanium solder (Cu-Sn-Ti solder powder with a particle size of 40 μm~50 μm) and polyethylene glycol as the binder. The viscosity of this solder paste was measured to be 1,000,000 cP using a Brookfield rotational viscometer at 25°C.

[0093] Place the borehole substrate in an ultrasonic cleaning device for 15 minutes, rinse with distilled water, and air dry for later use.

[0094] (2) Apply three-dimensional solder paste to lines Dispensing parameters: dispensing pressure 0.6 MPa, needle movement speed 50 mm / s, needle distance from substrate surface 0.3 mm.

[0095] Pattern: The first line on the outer wall forms a 70° angle with the axis of the drill bit base. The first line is a broken line (with local bends added to a straight line), and the spacing between adjacent lines is 2.0 mm. The second line on the end face forms a 45° angle with the radial direction of the drill bit base. The second line is a curve (sine wave), arranged in a parallel, reciprocating, continuous line, and the spacing between adjacent lines is 2.0 mm.

[0096] Apply an appropriate amount of 3D solder paste to the inner wall to create lines.

[0097] After dispensing, the thickness of the 3D solder paste lines is 1.0 mm and the width is 1.5 mm.

[0098] (3) Sprinkle diamond particles In this embodiment, 25-mesh diamond particles (approximately 0.71 mm in diameter) were selected. The theoretical amount required to form a single layer of close-packed diamond particles is approximately 1.51 mg / mm². 2 (M≈2.13×0.71). The amount of fabric spread is the theoretical amount required for a single layer of tightly packed fabric.

[0099] The 3D solder paste has a line thickness of 1.0 mm and a diamond particle size of 0.71 mm. It is applied by spreading and vibration to ensure that the particles are fully embedded and form a single layer of dense packing.

[0100] (4) Drying and vacuum brazing Drying: Place in a vacuum oven, evacuate to -0.1 MPa, heat to 120℃, and keep warm for 3 hours.

[0101] Vacuum brazing: Place in a vacuum brazing furnace and evacuate to a vacuum level of 5×10. -3 Pa, heat to 900 ℃ at 20 ℃ / min, hold for 30 min, then cool to room temperature at 20 ℃ / min and remove.

[0102] Example 4 The other steps of Example 4 are the same as those of Example 1, except that in step (1), the viscosity of the selected solder paste is 80000 cP.

[0103] Example 5 The other steps of Example 5 are the same as those of Example 1, except that in step (1), the viscosity of the selected solder paste is 1200000 cP.

[0104] Test case 1. An angle grinder (speed set to 12000 r / min) was used as the driving tool to drill holes vertically downwards into 12 mm thick ceramic tiles. A constant downward pressure of approximately 50 N was applied during the drilling process.

[0105] Sharpness index: For each example or comparative example, take 3 samples of hole drills from the same batch. Drill 5 holes continuously with each hole drill and record the drilling time for each hole (the number of seconds from the start of pressing down to the penetration of the tile). Take the average value as the sharpness index of the hole drill.

[0106] Sharpness improvement rate: calculated based on the drilling time (10 seconds) of a commercially available disordered single-layer brazed diamond hole drill.

[0107] Sharpness retention test: Select the same hole drill and drill 50 holes consecutively. Record the drilling time of the 1st hole and the 50th hole, and calculate the increase in drilling time (%). The smaller the increase, the better the sharpness retention.

[0108] Service life test: Continuous drilling was conducted, with drilling time recorded every 10 holes. When the drilling time exceeded 15 seconds or visual inspection revealed that more than 20% of the diamond had fallen off the drill bit's end face, the drill bit was considered to have failed. The total number of valid holes completed by that drill bit was recorded. The arithmetic mean of the three drill bits in each group was taken as the final service life.

[0109] Sharpness improvement rate: Sharpness improvement rate = (T) 基准 -T 本发明 ) / T 基准 ×100%; T 基准 The drilling time (in seconds) for a single hole of a commercially available disordered single-layer brazed diamond hole drill; T 本发明 The drilling time (in seconds) of a single hole drill for an embodiment or comparative example of the present invention.

[0110] Table 1 Example 1 6.0 s 48% +12% 185 Example 2 5.0 s 52% +8% 200 Example 3 4.5 s 53% +6% 250 Example 4 9.0 s 15% +45% 115 Example 5 8.0 s 20% +50% 100 Commercially available 10 s / +60% 50

[0111] As shown in Table 1, Examples 1 through 3 exhibit excellent initial cutting performance and lifespan. This is likely due to the convex arc surface of the exposed surface of the brazed diamond lines, with the diamond particles in contact or near contact with each other. Because of this convex arc surface, diamond particles 2011 at different heights participate in the cutting process sequentially, achieving layered cutting, thereby effectively reducing the cutting load on individual particles, minimizing impact and wear, and improving cutting stability and the lifespan of the drill bit. However, Example 4 shows a significant decrease in cutting ability. This is because the low viscosity prevents the brazing paste from maintaining an orderly pattern and sufficient thickness, causing the particles to become trapped and almost completely losing their cutting ability. While Example 5 shows acceptable initial cutting performance, the weak bonding force of the diamond particles leads to rapid detachment and a shorter lifespan. The high viscosity of the solder paste may have caused issues during dispensing, such as broken lines, blocked needles, and areas without solder paste. Furthermore, excessively viscous solder paste hinders the embedding of diamond particles, resulting in surface adhesion and very shallow embedding (<0.02 mm). This leads to significant detachment after vacuum brazing, leaving isolated diamond particles within the brazed diamond lines. Therefore, the solder paste viscosity must be within the range of 100,000 cP to 1,000,000 cP to simultaneously ensure proper dispensing formability and particle embedding, achieving both tight packing of diamond particles and high bonding strength.

[0112] In the description of this specification, references to the terms "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0113] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A brazing diamond hole drill, characterized in that, The device includes a drill bit base, the drill bit base including an end face and a side wall disposed around the end face, the side wall including an outer wall and an inner wall disposed opposite to each other; Brazed diamond lines are provided on the outer wall and end face of the borehole drill base; The brazed diamond wire includes a brazing alloy matrix and diamond particles. The brazing alloy matrix includes a contact surface that contacts the hole drill matrix and an exposed surface that surrounds the contact surface. The exposed surface is a convex arc-shaped surface. The diamond particles are embedded on the side of the brazing alloy matrix near the exposed surface.

2. The brazing diamond hole drill according to claim 1, characterized in that, The brazed diamond wires include a first wire located on the outer wall of the borehole matrix, the first wires being orderly distributed on the outer wall; and / or The brazed diamond lines include a second line located on the end face of the borehole matrix, and the second line is distributed in an orderly manner on the end face.

3. The brazing diamond hole drill according to claim 2, characterized in that, The angle between the first line and the axis of the hole drill base is 0° to 70°; and / or The angle between the second line and the radial direction of the borehole base is 0° to 45°.

4. The brazing diamond hole drill according to claim 3, characterized in that, The first line includes straight lines, curves, and / or broken lines; and / or The second line includes straight lines, curves, and / or broken lines.

5. The brazing diamond drill bit according to claim 3, characterized in that, The spacing between adjacent first lines is 0.1 mm to 2 mm; and / or The width of the first line is 0.1 mm to 1.5 mm; and / or The spacing between adjacent second lines is 0.1 mm to 2 mm; and / or The width of the second line is 0.1 mm to 1.5 mm.

6. The brazing diamond hole drill according to claim 3, characterized in that, The brazed diamond line includes a third line located on the inner wall.

7. The brazing diamond hole drill according to claim 1 or 2, characterized in that, At least one adjacent brazed diamond line has a single layer of diamond on its outer wall; and / or At least one end face between adjacent brazed diamond lines is provided with a single layer of diamond.

8. A method for preparing a brazed diamond hole drill, characterized in that, Includes the following steps: (1) A hole drill base is provided, the hole drill base including an end face and a side wall disposed around the end face, the side wall including an outer wall and an inner wall; A soldering paste is provided, the soldering paste comprising solder powder and a binder; (2) Apply the brazing paste to the hole drill substrate using a dispensing machine in accordance with the pattern of the brazing diamond lines to form three-dimensional brazing paste lines; (3) Sprinkle diamond particles on the three-dimensional solder paste lines so that the diamond particles are at least partially embedded in the three-dimensional solder paste lines; (4) Drying and vacuum brazing are performed to form the brazed diamond lines on the borehole substrate; The brazed diamond wire includes a brazing alloy matrix and diamond particles. The brazing alloy matrix includes a contact surface that contacts the hole drill matrix and an exposed surface that surrounds the contact surface. The exposed surface is a convex arc-shaped surface. The diamond particles are embedded in the brazing alloy matrix on the side near the exposed surface.

9. The method for preparing the brazed diamond hole drill according to claim 8, characterized in that, In step (2), the viscosity of the solder paste is 100,000 cP to 1,000,000 cP.

10. The method for preparing the brazed diamond hole drill according to claim 9, characterized in that, The thickness of the three-dimensional solder paste lines is 0.1 mm to 1.0 mm, and the particle size of the diamond particles is 25 mesh to 150 mesh.

Images