Diamond wire saw

Abstract

The invention relates to the technical field of diamond fretsaws, and discloses a diamond fretsaw, diamond particles are arranged on the surface of the diamond fretsaw, the diamond fretsaw is bonded on a metal wire by brazing metal, the diamond fretsaw is characterized in that the brazing metal contains titanium or chromium as an active element, the main brazing element of the diamond fretsaw is nickel or copper, a main wire of the diamond fretsaw is made of tungsten or molybdenum, the diameter of the main wire is 30-1000 microns, and the diameter of the diamond fretsaw is 10-20 microns. The size of the diamond particles is 2-100 microns, the distance between the diamond particles is 3-10 times of the average size, the fret saw is used for sawing granite or marble, the brazing is carried out in a vacuum or oxygen-free atmosphere, and the fret saw can be a long line or a ring; according to the diamond wire saw, in the preparation process, the slurry containing the acrylic glue and the BNi-2 welding flux is adopted, under the nitrogen protection atmosphere, the temperature is rapidly increased to the welding flux melting point temperature through an induction heating device, the integrated operation of rapid drying of the slurry on the surface of the tungsten filament, welding flux melting and diamond brazing is achieved, and the stable diamond brazing wire saw is continuously formed.

Description

Technical Field

[0001] This invention relates to the field of diamond wire saw technology, specifically a diamond wire saw. Background Technology

[0002] With the widespread application of third-generation semiconductor materials (such as silicon carbide and gallium nitride) and hard natural stone in industry, the durability and cutting performance of traditional steel wire electroplated diamond wire saws are increasingly failing to meet requirements. Especially when sawing silicon carbide wafers, due to the extremely high hardness of the material, the electroplated diamond particles are prone to falling off, resulting in low sawing efficiency, short tool life, and high costs and time wasted due to frequent tool replacements.

[0003] In recent years, brazing technology has gradually emerged. By melting a metal filler metal and fixing diamond onto the surface of a metal wire, the adhesion strength of diamond particles can be significantly improved. However, the brazing process generally suffers from problems such as difficulty in temperature control, poor continuity, and weak adhesion. In particular, the brazing substrate is mostly steel wire, which has limited tensile strength at high temperatures, making wire saws prone to breakage under high loads.

[0004] Therefore, developing a brazed diamond wire saw that uses tungsten wire as a substrate, employs chromium-containing brazing filler metal, and can achieve continuous and efficient production has become an urgent technical challenge to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a diamond wire saw that addresses the aforementioned issue in the background art, which proposes fixing diamond particles to the surface of a metal wire by melting a metal brazing filler metal, thereby significantly improving the adhesion strength of diamond particles. However, the brazing process generally suffers from problems such as difficulty in temperature control, poor continuity, and weak adhesion. In particular, the brazing substrate is often steel wire, which has limited tensile strength at high temperatures, leading to the wire saw being prone to breakage under high loads.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A type of diamond wire saw has diamond microparticles on its surface bonded to metal wires by brazing metal, which contains titanium or chromium as active elements.

[0007] Preferably, the main element for brazing is nickel or copper.

[0008] Preferably, the wire saw has a main wire made of tungsten or molybdenum.

[0009] Preferably, the diameter of the main line is 30 to 1000 micrometers.

[0010] Preferably, the diamond particles in the wire saw are 2-100 micrometers in size.

[0011] Preferably, the spacing between the diamond particles is 3-10 times their average size.

[0012] Preferably, the wire saw is used for sawing granite or marble.

[0013] Preferably, the brazing is performed in a vacuum or oxygen-free atmosphere.

[0014] Preferably, the wire saw can be a long wire or a ring.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a diamond wire saw suitable for efficient sawing of high-hardness workpieces (such as silicon carbide wafers, granite, etc.). The wire saw uses high-strength tungsten wire as the substrate, with diamond microparticles brazed onto the surface using a chromium-containing solder (BNi-2) to achieve a strong bond, avoiding the problem of diamond detachment during sawing of hard materials in traditional electroplated diamond wire saws. In the preparation process, a slurry containing acrylic adhesive and BNi-2 solder is rapidly heated to the solder melting point under a nitrogen protective atmosphere using an induction heating device. This achieves rapid drying of the slurry on the tungsten wire surface, solder melting, and diamond brazing in an integrated process, continuously forming a stable diamond brazed wire saw. This wire saw has advantages such as high adhesion strength, high wear resistance, low wire breakage rate, and continuous production capability, making it particularly suitable for the semiconductor and stone industries. Detailed Implementation

[0016] The present application will be further described in detail below with reference to embodiments. It is to be understood that the specific embodiments described herein are only for explaining the relevant invention and are not intended to limit the invention.

[0017] Please refer to a diamond wire saw, wherein diamond microparticles on the surface are bonded to metal wires by brazing metal, characterized in that the brazing metal contains titanium or chromium as active elements.

[0018] The main elements used in brazing are nickel or copper.

[0019] Among them, the wire saw's main wire is made of tungsten or molybdenum.

[0020] The main line has a diameter of 30 to 1000 micrometers.

[0021] Among them, the diamond particles in the wire saw are 2-100 micrometers in size.

[0022] The spacing between diamond particles is 3-10 times their average size.

[0023] Wire saws are used for sawing granite or marble.

[0024] Brazing is performed in a vacuum or oxygen-free atmosphere.

[0025] The wire saw can be a long line or a ring.

[0026] The specific processing steps for this diamond wire saw are as follows: Step 1: Take 5 kg of Nichrobraz LM solder with a particle size of -325 mesh, and dissolve 3 M acrylic adhesive in a solvent to dilute it. Mix the acrylic adhesive with the above-mentioned metal solder to form a slurry and pour it into a graphite crucible. Step 2: A small hole is made at the bottom of the crucible, through which a tungsten wire about 100 micrometers in diameter is introduced; Step 3: Pull the tungsten wire upwards and extend it into a nitrogen-filled quartz chamber. The oxygen-free chamber contains a copper-tube induction current heating coil, which rapidly heats the slurry coating the tungsten wire to about 1000°C. Step 4: The acrylic adhesive and solvent will evaporate quickly, and the metal solder will melt instantly and braze the diamond onto the tungsten wire, eventually forming a continuous tungsten wire diamond wire saw, which is then wound onto the spool above.

[0027] Among them, brazed diamond tungsten wire saws can be used to saw silicon carbide or granite.

[0028] Among them, brazed diamond tungsten wire saws can be used to saw silicon carbide or granite.

[0029] The substrate is a tungsten wire with a diameter of about 100 μm, and diamond particles are attached to the surface by brazing with chromium-containing BNi-2 solder.

[0030] The diamond particles have a particle size of 10~30μm, preferably 20μm.

[0031] The BNi-2 solder has a particle size of 325 mesh and a melting point temperature between 960 and 1050°C.

[0032] It should be noted that the key to this invention lies in enhancing the bonding strength between diamond and tungsten wire through chemical bonding. The BNi-2 solder contains Cr, which, upon melting, rapidly combines with carbon atoms on the diamond surface to form Cr3C2-type carbides, creating a stable metal-ceramic transition layer and significantly improving adhesion.

[0033] Tungsten wire has a high melting point of 3422℃, far exceeding that of solder, allowing brazing to be performed without affecting the wire's structure. Tungsten wire also boasts high tensile strength, high-temperature resistance, and resistance to oxidation, making it particularly suitable for continuous traction systems. Induction heating is employed, using a high-frequency current to create eddy currents within a copper tube, rapidly heating the conductive material and ensuring a stable temperature control within the range of 900~1100℃. This allows the solder to melt quickly, enabling the diamond and tungsten wire to bond instantly.

[0034] Acrylic adhesive and solvent serve as a temporary carrier, ensuring uniform distribution and adhesion of the slurry on the tungsten wire surface. It rapidly vaporizes at high temperatures without affecting the bonding process between the solder and diamond. The system is filled with nitrogen to prevent adverse reactions such as oxidation and carbonization. Content not described in detail herein is prior art known to those skilled in the art. Example 1

[0035] Diamond micropowder (particle size approximately 30 μm, or micrometer) is mixed with silicon powder (approximately 5 μm) and acrylic binder (5% V). The mixture is then pressed into a cylindrical shape using cold isostatic pressing (CIP), approximately 50 mm in diameter and 40 mm in thickness. This cylinder is placed inside a dolomite sleeve, which is then filled with graphite sheets at the top and bottom to form a cylindrical shape. A graphite sleeve is then added to the outside as a heater. This assembly is placed in the central cavity of a hexagonal dome. The hexagonal dome is then pressurized to approximately 6 GPa, and electricity is applied through the graphite sleeve, heating the diamonds and silicon powder inside to approximately 1400°C. At this point, the acrylic binder has largely evaporated. The silicon powder melts and penetrates into the gaps between the diamond particles, causing the diamonds to connect and sinter together. After approximately half an hour, the power is cut off and the voltage is reduced. The sintered diamond block is then removed, resulting in a polycrystalline diamond sintered body (PCD). This is laser-cut into millimeter-thick slices and then mounted on a rotating iron disc with a slurry containing diamond micropowder applied to the surface. The polished top and bottom surfaces are covered with 10µm thick titanium foil, and then each is pressed with 80µm thick copper foil. The mixture is then heated to 900 degrees Celsius in a vacuum furnace or atmosphere furnace for about half an hour. The diamond sintering process forms strong titanium carbide chemical bonds and an alloy with the copper foil at the interface, thus creating a diamond-clad copper heat sink. Example 2

[0036] Diamond-coated copper is soldered onto a surface-metallized silicon carbide IGBT power chip using silver-tin solder. This creates an effective heat sink, reducing chip temperature and significantly increasing chip power. Example 3

[0037] Take 5 kg of Nichrobraz LM solder manufactured by Walcomonoy Company, USA, with a particle size of -325 mesh. Separately, dissolve 3 M acrylic adhesive in a solvent and dilute it, then mix it with the aforementioned metal solder to form a slurry. Pour this slurry into a graphite crucible. A small hole at the bottom of the crucible allows a tungsten wire approximately 100 micrometers in diameter to be introduced and pulled upwards into a nitrogen-filled quartz chamber. This oxygen-free chamber contains a copper-tube induction heating coil, which rapidly heats the slurry coating the tungsten wire to approximately 1000°C (less than 1 / 3 of the tungsten wire's melting point of 3422°C). At this point, the acrylic adhesive and solvent evaporate rapidly, while the metal solder melts instantly, brazing the diamond onto the tungsten wire. This process continuously produces a tungsten wire diamond wire saw, which is then wound onto an upper spool.

[0038] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A diamond wire saw, characterized in that: The surface has diamond microparticles bonded to the metal wires by brazing metal, characterized in that the brazing metal contains titanium or chromium as active elements.

2. A diamond wire saw according to claim 1, characterized in that: The main elements for brazing are nickel or copper.

3. A diamond wire saw according to claim 1, characterized in that: Wire saws, whose main wire is made of tungsten or molybdenum.

4. A diamond wire saw according to claim 1, characterized in that: The main line has a diameter of 30 to 1000 micrometers.

5. A diamond wire saw according to claim 1, characterized in that: The diamond particles in wire saws range from 2 to 100 micrometers.

6. A diamond wire saw according to claim 1, characterized in that: The spacing between diamond particles is 3 to 10 times their average size.

7. A diamond wire saw according to claim 1, characterized in that: A wire saw is used to cut granite or marble.

8. A diamond wire saw according to claim 1, characterized in that: Brazing is performed in a vacuum or oxygen-free atmosphere.

9. A diamond wire saw according to claim 1, characterized in that: Wire saws can be long lines or circular.