Preparation method of laser welding composite brazing saw blade

Abstract

The present invention relates to a method for preparing a laser-welded composite brazed saw blade, and relates to the technical field of diamond tools. The method for preparing the laser-welded composite brazed saw blade of the present invention comprises the following steps: (1) providing a disc substrate comprising a first main surface, a second main surface and an outer peripheral side wall; (2) forming a diamond coating on the first main surface and the second main surface by brazing; (3) welding a plurality of diamond cutter heads on the outer peripheral side wall by laser. The laser-welded composite brazed saw blade prepared by the preparation method of the present invention can act like a brush to remove more cutting debris and sand during deep cutting; the whirlwind-shaped design can greatly reduce the cutting cooling efficiency, so that the cutter head will not overheat and burn under high-speed cutting conditions, resulting in passivation of the cutting surface, which is conducive to maintaining optimal cutting performance.

Description

Technical Field

[0001] The present invention relates to the technical field of diamond tools, and more particularly to a method for preparing a laser-welded composite brazing saw blade. Background Art

[0002] Against the backdrop of today's rapid economic development, low-carbon and environmentally friendly practices have become a major trend. Diamond saw blades are essential for infrastructure construction. As labor costs rise during concrete pavement construction and engineering construction, energy-efficient tools are increasingly favored by users. However, in the road transportation and construction industries, diamond saw blades, as consumables, remain expensive, and the consumption of diamonds, metal powder, and electricity is substantial. Further reducing production costs and minimizing environmental pollution are key challenges facing the diamond tool industry. Summary of the Invention

[0003] In order to solve the heat dissipation and chip removal problems under high-speed cutting conditions, the present invention aims to provide a method for preparing a laser-welded composite brazing saw blade capable of achieving high-speed cutting performance.

[0004] The method for preparing the laser-welded composite brazing saw blade of the present invention comprises the following steps:

[0005] (1) providing a disc substrate including a first major surface, a second major surface, and a peripheral sidewall;

[0006] (2) forming a diamond coating on the first main surface and the second main surface by brazing;

[0007] (3) A plurality of diamond tips are welded on the outer peripheral side wall by laser.

[0008] Wherein, chip removal grooves are provided between adjacent diamond segments, and the diamond segments have a sawtooth structure.

[0009] Each of the diamond coatings has a whirlwind-shaped horizontal projection shape.

[0010] There are multiple diamond coatings, which are spaced apart in the annular areas of the first main surface and the second main surface adjacent to the outer peripheral side wall.

[0011] The horizontal projection area of ​​the diamond coating accounts for 3-20% of the area of ​​the annular region, preferably 3-15%.

[0012] The diamond segment is made of composite powder composed of copper, iron, tin, nickel, tungsten-cobalt alloy, copper-zinc alloy, liquid paraffin and diamond, which is formed by cold pressing and hot pressing sintering. The hot pressing sintering temperature is 690-750℃ and the pressure is 300-400g / cm 2 .

[0013] The composite powder comprises: 28-39wt% iron, 4-10wt% nickel, 12-23wt% tungsten-cobalt alloy, 5-13wt% tin, 1.5-2.5wt% copper-zinc alloy, 0.8-1.1wt% liquid paraffin, 1.0-2.1wt% diamond, and the balance is copper. Preferably, the composite powder comprises: 30-38wt% iron, 5-9wt% nickel, 13-21wt% tungsten-cobalt alloy, 7-11wt% tin, 1.6-2.3wt% copper-zinc alloy, 1.0-1.2wt% liquid paraffin, 1.2-2.0wt% diamond, and the balance is copper.

[0014] The WC content in the tungsten-cobalt alloy is 80-92 wt%, and the balance is Co.

[0015] Among them, the copper-zinc alloy is preferably aluminum-iron-manganese brass, in which the Cu content is 64-68wt%, the Al content is 6-7wt%, the Fe content is 2-4wt%, the Mn content is 1.5-2.5wt%, and the balance is Zn.

[0016] The diamond coating is formed by brazing a brazing powder layer composed of copper, iron, tin, nickel, tungsten-cobalt alloy, copper-zinc alloy, liquid paraffin and diamond.

[0017] Wherein, the thickness of the diamond coating is 0.10-1.0 mm, preferably 0.10-0.50 mm.

[0018] Compared with the prior art, the laser welding composite brazing saw blade prepared by the preparation method of the present invention has the following beneficial effects:

[0019] The diamond coating is applied to the side of the substrate through a brazing process. The coating has an uneven structure, which can act like a brush to remove more cutting debris and sand during deep cutting, keeping the cutting groove unobstructed and free of debris accumulation. In addition, its cyclone-like shape design ensures smooth airflow, greatly reducing the cutting cooling efficiency, so that the cutter head will not overheat and burn under high-speed cutting, resulting in blunting of the cutting surface, which is conducive to maintaining optimal cutting performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the planar structure of the laser welded composite brazing saw blade of the present invention.

[0021] Figure 2 Schematic diagram of the annular region where the brazing layer is located in the saw blade of the present invention. DETAILED DESCRIPTION

[0022] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention. The following paragraphs describe the present invention in more detail by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are all in a very simplified form and are not in exact proportions. They are only used to facilitate and clearly illustrate the purpose of the embodiments of the present invention.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] The manufacturing process of the laser welding composite brazing saw blade of the present invention is as follows:

[0025] 1. Matrix processing

[0026] According to the drawing requirements, the steel plate is quenched and heat treated, tempered, laser cut into shape, tempered, flattened, inner hole ground, outer circle ground, and deburred.

[0027] 2. Diamond Segment Production Process

[0028] According to the specific requirements, copper, tungsten-cobalt alloy, nickel, iron, tin, copper-zinc alloy, liquid paraffin and diamond are mixed evenly, and then cold pressed, hot pressed and sintered, and polished with grinding wheels and belts to make diamond segments. The hot pressed and sintered temperature is 690-750℃ and the pressure is 300-400Kg / cm 2 , insulation time is 120 to 250 seconds.

[0029] 3. Coat the steel substrate with a diamond brazing powder layer according to the shape designed in the drawing and send it into a vacuum brazing furnace to prepare a diamond coating. Copper-based solder can be used for vacuum brazing, and the brazing temperature is 920-950°C. After passing the inspection, it will be put into storage.

[0030] 4. Laser welding

[0031] Place the cutter head and the base together on the base position according to the drawing requirements, adjust the light spot of the laser welding machine to the appropriate position of the cutter head and the base, start the laser welding machine to weld the cutter head and the base together at the moment the laser penetrates, and then 2 Strength Standards Each diamond segment is subjected to welding strength testing.

[0032] 5. Polishing, painting and inspection

[0033] After welding, the laser welded composite brazing high performance saw blade is first sandblasted on the inner side of the blade head, and then the working surface of the diamond blade is polished with a special grinding wheel to expose the diamond. After welding, the laser welded composite brazing high performance saw blade is polished with a grinder to make the base surface bright, and then the blade is polished with a grinding machine at 600N / mm 2 Each diamond cutter head is tested for safety welding strength according to strength standards. If it fails, it will be reworked. If it passes, it will be surface-painted and dried to prevent surface rust. Finally, it will be silk-screened, laser-marked, packaged, and put into storage.

[0034] Figure 1-2The laser-welded composite brazed saw blade produced by the method of the present invention comprises a disc base 10 having a first major surface, a second major surface, and an outer peripheral sidewall. Multiple diamond segments 20 are laser-welded onto the outer peripheral sidewall, while diamond coatings 3 are brazed onto the first and second major surfaces. The diameter of the disc base 10 can be designed to be between 100 mm and 500 mm, depending on the requirements. The number of diamond segments 20 can range from 12 to 30. For example, the number of diamond segments in the following embodiments and comparative examples is 24. Chip removal grooves are provided on the disc base between adjacent diamond segments 20, adjacent to the gaps between them. A mounting hole is provided in the center of the disc base 10. The working surface of the diamond cutter head 20 is serrated. During the cutting process, the cutter head can form an interval of concave and convex surface, which can reduce the contact area between the cutter head and the cutting material and reduce the cutting impact resistance on the one hand, and increase the chip removal of the cutter head, reduce the ineffective friction of cutting, reduce the cutting resistance, and enable the saw blade to complete the cutting more smoothly. When the cutting machine cuts concrete pavement and other materials at high speed, it meets the construction requirements of high-strength concrete structure pavement and wall application sites. As an innovative design point of the present invention, the diamond coating is a non-continuous and non-integral structural design, and each diamond coating has a whirlwind-shaped horizontal projection shape. Each main surface in the figure is provided with 12 diamond coatings in the annular area adjacent to the outer peripheral side wall, and the sum of the horizontal projection areas of the diamond coatings accounts for 3 to 20% of the area of ​​the annular area. The diamond coating has an uneven structure, which can act like a brush to remove more cutting debris, sand, etc., especially when cutting deeply, so that the cutting groove remains unobstructed and there is no debris accumulation. In addition, the cyclone-shaped structural design makes the air flow smooth and greatly reduces the cutting cooling efficiency, significantly improving the heat dissipation and cutting performance of the cutter head under high-speed cutting conditions. When the diamond coating accounts for more than 20% of the annular area, it not only increases the raw material cost of metal powder and diamond, but also affects the air cooling, so it is not preferred. When the total projected area of ​​the diamond coating accounts for less than 3% of the annular area, its chip removal and cooling effects will be significantly reduced during deep cutting, so it is also not preferred. Preferably, the total projected area of ​​the diamond coating accounts for 3 to 15% of the annular area, more preferably 5 to 15%. In the following embodiments and comparative examples, unless otherwise specified, the total projected area of ​​the diamond coating accounts for about 10% of the annular area. In the present invention, the diamond segment is formed by cold pressing and hot pressing sintering of composite powder consisting of copper, iron, tin, nickel, tungsten-cobalt alloy, copper-zinc alloy, liquid paraffin and diamond. The hot pressing sintering temperature is 690-750°C and the pressure is 300-400g / cm 2. In the composite powder: the iron content is 28-39wt%, the nickel content is 4-10wt%, the tungsten-cobalt alloy is 12-23wt%, the tin is 5-13wt%, the copper-zinc alloy is 1.5-2.5wt%, the liquid paraffin is 0.8-1.1wt%, the diamond is 1.0-2.1wt%, and the balance is copper. Preferably, in the composite powder: the iron content is 30-38wt%, the nickel content is 5-9wt%, the tungsten-cobalt alloy is 13-21wt%, the tin is 7-11wt%, the copper-zinc alloy is 1.6-2.3wt%, the liquid paraffin is 1.0-1.2wt%, the diamond is 1.2-2.0wt%, and the balance is copper. The WC content in the tungsten-cobalt alloy is 80-92wt%, and the balance is Co (in the following embodiments and comparative examples, the WC content is 92wt% and the Co content is 8wt%). The copper-zinc alloy can be made of brass with a zinc content of 10 to 38 wt%, which is not specifically limited in the present invention. The composite powder of the present invention takes into account both cutting performance and heat dissipation performance, wherein the addition of tungsten-cobalt alloy is beneficial for high-speed cutting of high-strength concrete structures. However, tungsten-cobalt alloy has a certain brittleness. When conventional metal powder is compounded, its wear is large, which affects its service life. By adding a small amount of copper-zinc alloy to the composite powder, it is beneficial to improve the hot pressing sintering performance, improve the overall toughness, and help reduce the wear. More preferably, the selection of aluminum-iron-manganese brass is more conducive to reducing wear and tear during cutting. Specifically, in the aluminum-iron-manganese brass, the Cu content is 64 to 68 wt%, the Al content is 6 to 7 wt%, the Fe content is 2 to 4 wt%, the Mn content is 1.5 to 2.5 wt%, and the balance is Zn. In the present invention, the diamond coating is formed by brazing a brazing powder layer composed of copper, iron, tin, nickel, tungsten-cobalt alloy, copper-zinc alloy, liquid paraffin and diamond. The diamond coating has essentially the same composition as the composite powder used in the diamond tool head, except that liquid paraffin as a porogen is not added. Specifically, the brazing powder layer contains 28-39wt% iron, 4-10wt% nickel, 12-23wt% tungsten-cobalt alloy, 5-13wt% tin, 1.5-2.5wt% copper-zinc alloy, 1.0-2.1wt% diamond, and the remainder is copper. Preferably, the composite powder contains 30-38wt% iron, 5-9wt% nickel, 13-21wt% tungsten-cobalt alloy, 7-11wt% tin, 1.6-2.3wt% copper-zinc alloy, 1.2-2.0wt% diamond, and the remainder is copper. The WC content in the tungsten-cobalt alloy is 80-92wt%, and the remainder is Co (in the following examples and comparative examples, the WC content is 92wt% and the Co content is 8wt%). The copper-zinc alloy may be brass with a zinc content of 10 to 38 wt %, which is not particularly limited in the present invention.The diamond coating is formed on the disc substrate by brazing, and has a thickness of 0.10 to 1.0 mm, preferably 0.10 to 0.50 mm. In the embodiments and comparative examples of the present invention, unless otherwise specified, the thickness is 0.50 mm.

[0035] Example 1

[0036] Take 28.7 parts by weight of copper powder, 28 parts by weight of iron powder, 10 parts by weight of nickel powder, 23 parts by weight of tungsten-cobalt alloy, 5 parts by weight of tin, and 2.5 parts by weight of copper-zinc alloy, put them into a mixing barrel and mix for 1 hour. Then, add 1 part by weight of liquid paraffin and 1.8 parts by weight of diamond, and continue mixing for 3 hours to obtain the composite powder for diamond tool segment molding in this embodiment.

[0037] 29.7 parts by weight of copper powder, 28 parts by weight of iron powder, 10 parts by weight of nickel powder, 23 parts by weight of tungsten-cobalt alloy, 5 parts by weight of tin, and 2.5 parts by weight of copper-zinc alloy were placed in a mixing barrel and mixed for 1 hour. Then, 1.8 parts by weight of diamond was added and mixing was continued for 2 hours to obtain the brazing filler metal powder for diamond coating in this embodiment.

[0038] In this embodiment, the copper-zinc alloy is brass with a zinc content of 22 wt % and a copper content of 78 wt %.

[0039] The obtained composite powder is poured into a mold and cold pressed to form, and then hot pressed and sintered. The hot pressing and sintering temperature is 720℃ and the pressure is 380Kg / cm 2 , keep warm for 200 seconds, then use grinding wheel and sanding belt to grind the cutter head for standby use.

[0040] The prepared brazing powder is coated on the surface of the disc substrate to prepare a cyclone-shaped brazing powder layer as shown in the figure, and then placed in a vacuum brazing furnace, evacuated and kept at 920° C. for 20 minutes to prepare the diamond coating.

[0041] Adjust the laser welding machine's light spot to the appropriate position between the cutter head and the substrate, start the laser welding machine, weld the cutter head and the substrate together at the moment the laser penetrates, and then 2 The strength standard is used to test the welding strength of each diamond cutter head, and then high-frequency welding is used to protect the teeth. After welding, the laser-welded composite brazing high-performance saw blade is polished with a grinder to make the base surface bright, and then the working surface of the diamond cutter head is polished with a special grinding wheel to expose the diamond. The surface is then spray-painted and dried to prevent rust. Finally, the welding strength of each diamond cutter head is tested with a strength standard of 600N / mm2. If it fails, it will be reworked. If it passes, it will be spray-painted and dried to prevent rust. Finally, it is silk-screened, laser marked, packaged, and put into storage.

[0042] Example 2

[0043] Take 27.7 parts by weight of copper powder, 39 parts by weight of iron powder, 4 parts by weight of nickel powder, 12 parts by weight of tungsten-cobalt alloy, 13 parts by weight of tin, and 1.5 parts by weight of copper-zinc alloy, put them into a mixing barrel and mix for 1 hour. Then, add 1 part by weight of liquid paraffin and 1.8 parts by weight of diamond, and continue mixing for 3 hours to obtain the composite powder for diamond tool segment molding in this embodiment.

[0044] 28.7 parts by weight of copper powder, 39 parts by weight of iron powder, 4 parts by weight of nickel powder, 12 parts by weight of tungsten-cobalt alloy, 13 parts by weight of tin, and 1.5 parts by weight of copper-zinc alloy were placed in a mixing barrel and mixed for 1 hour. Then, 1.8 parts by weight of diamond was added and mixing was continued for 2 hours to obtain the brazing filler metal powder for diamond coating in this embodiment.

[0045] In this embodiment, the copper-zinc alloy is brass with a zinc content of 22 wt % and a copper content of 78 wt %.

[0046] The obtained composite powder is poured into a mold for cold pressing and hot pressing sintering. The hot pressing sintering temperature is 720℃ and the pressure is 350Kg / cm 2 , keep warm for 200 seconds, then use grinding wheel and sanding belt to grind the cutter head for standby use.

[0047] The prepared brazing powder is coated on the surface of the disc substrate to prepare a cyclone-shaped brazing powder layer as shown in the figure, and then placed in a vacuum brazing furnace, evacuated and kept at 920° C. for 20 minutes to prepare the diamond coating.

[0048] Adjust the laser welding machine's light spot to the appropriate position between the cutter head and the substrate, start the laser welding machine, weld the cutter head and the substrate together at the moment the laser penetrates, and then 2 The strength standard is used to test the welding strength of each diamond cutter head, and then high-frequency welding is used to protect the teeth. After welding, the laser-welded composite brazing high-performance saw blade is polished with a grinder to make the base surface bright, and then the working surface of the diamond cutter head is polished with a special grinding wheel to expose the diamond. The surface is then spray-painted and dried to prevent rust. Finally, the welding strength of each diamond cutter head is tested with a strength standard of 600N / mm2. If it fails, it will be reworked. If it passes, it will be spray-painted and dried to prevent rust. Finally, it is silk-screened, laser marked, packaged, and put into storage.

[0049] Example 3

[0050] The difference from Example 1 is that the copper-zinc alloy used is aluminum-iron-manganese brass, in which the Cu content is 65wt%, the Al content is 6wt%, the Fe content is 4wt%, the Mn content is 2.1wt%, and the balance is Zn.

[0051] Example 4

[0052] The difference from Example 2 is that the copper-zinc alloy used is aluminum-iron-manganese brass, in which the Cu content is 65wt%, the Al content is 6wt%, the Fe content is 4wt%, the Mn content is 2.1wt%, and the balance is Zn.

[0053] Comparative Example 1

[0054] The difference from Example 1 is that the diamond coating is not brazed.

[0055] Comparative Example 2

[0056] The difference from Example 2 is that a continuous diamond coating is applied over the entire annular area.

[0057] Comparative Example 3

[0058] The difference from Example 1 is that copper-zinc alloy is not used. The composition of the composite powder for forming the diamond segment is: 31.2 parts by weight of copper powder, 28 parts by weight of iron powder, 10 parts by weight of nickel powder, 23 parts by weight of tungsten-cobalt alloy, 5 parts by weight of tin, 1 part by weight of liquid paraffin, and 1.8 parts by weight of diamond.

[0059] Comparative Example 4

[0060] The difference from Example 2 is that copper-zinc alloy is not used. The composition of the composite powder for forming the diamond segment is: 29.2 parts by weight of copper powder, 39 parts by weight of iron powder, 4 parts by weight of nickel powder, 12 parts by weight of tungsten-cobalt alloy, 13 parts by weight of tin, 1 part by weight of liquid paraffin, and 1.8 parts by weight of diamond.

[0061] Cutting experiments were carried out using the circular saw blades prepared in Examples 1 to 4 and Comparative Examples 1 to 4. A cutting machine with an output power of 10.0 kW was used to cut concrete (compressive strength of 60 MPa) at a constant pressure (cutting depth of 100 mm). The total cutting length of each diamond saw blade was 100 m. The average cutting speed and the wear performance of the diamond segment were tested. The results are shown in Table 1.

[0062] Table 1

[0063]

[0064] For ordinary technicians in this field, the specific embodiments are only illustrative descriptions of the present invention. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, they are all within the scope of protection of the present invention.

Claims

1. A method for preparing a laser welded composite brazing saw blade, characterized in that The following steps are involved: (1) providing a disc substrate including a first major surface, a second major surface, and a peripheral sidewall; (2) forming a diamond coating on the first main surface and the second main surface by brazing; (3) welding a plurality of diamond cutting tips on the outer peripheral side wall by laser; Each of the diamond coatings has a whirlwind-shaped horizontal projection shape; the diamond coatings are multiple and are spaced apart in an annular area adjacent to the outer peripheral sidewall on the first and second main surfaces; the horizontal projection area of ​​the diamond coating accounts for 3-20% of the area of ​​the annular area; the diamond coating is formed by brazing a brazing powder layer, and the brazing powder layer does not contain a porogen; the diamond segment is formed by cold pressing and hot pressing sintering of a composite powder composed of copper, iron, tin, nickel, tungsten-cobalt alloy, copper-zinc alloy, liquid paraffin and diamond, and the hot pressing sintering temperature is 690-750°C and the pressure is 300-400g / cm 2 The iron content is 28-39wt%, the nickel content is 4-10wt%, the tungsten-cobalt alloy is 12-23wt%, the tin is 5-13wt%, the copper-zinc alloy is 1.5-2.5wt%, the liquid paraffin is 0.8-1.1 wt%, the diamond is 1.0-2.1wt%, and the balance is copper.

2. The preparation method according to claim 1, wherein: Chip removal grooves are provided between adjacent diamond segments, and the diamond segments have a sawtooth structure.

3. The preparation method according to claim 1, wherein: The WC content in the tungsten-cobalt alloy is 80-92 wt %, and the balance is Co.

4. The preparation method according to claim 1, wherein: The copper-zinc alloy is aluminum-iron-manganese brass, in which the content of Cu is 64-68wt%, the content of Al is 6-7wt%, the content of Fe is 2-4wt%, the content of Mn is 1.5-2.5wt%, and the balance is Zn.

5. The preparation method according to claim 1, wherein: The diamond coating is formed by brazing a brazing powder layer consisting of copper, iron, tin, nickel, tungsten-cobalt alloy, copper-zinc alloy, liquid paraffin and diamond.

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