Welding tooling, assembly and method for an integral welded cutting tool

Abstract

The present invention discloses a welding tooling for integral welded cutting tools, which relates to the technical field of superhard composite tool welding. It includes a bottom plate and several fasteners. The fasteners slide in the grooves on the bottom plate. The bottom plate and the fasteners are made of macor ceramics. There are several tool positioning blind holes and positioning posts in the grooves. The fasteners include a first slider and a second slider. There are bottom plate positioning blind holes at the four corners of the bottom plate. The present invention also provides a welding assembly including the above welding tooling and a method for welding tools using the welding assembly. By adopting ultrasonic cleaning and vacuum hydrogen purification, the impurities on the welding surface are effectively reduced. The welding tooling made of macor ceramic material can tightly fasten the welded body in a high-temperature environment to ensure the welding quality. Aluminum foil is also used to adsorb the harmful impurities generated during the melting of the solder, avoiding the generation of pores on the welding surface and affecting the welding strength. The welding yield can reach over 98%.

Description

Technical Field

[0001] The present invention relates to the technical field of superhard composite tool welding, and specifically to a welding tooling, a combination body and a method for an integral welding tool. Background Art

[0002] Superhard tools are divided into two types: diamond-based and CBN-based, and their processing objects are different. CBN tools are widely used due to their excellent thermal stability and chemical inertness to iron-based elements. CBN tools are further divided into integral tools, composite welding tools, and integral welding tools. The development of integral welding tools is relatively late, but they have certain advantages. They are formed by dividing an integral tool into several small cutting inserts and welding these small cutting inserts to a cemented carbide body through various processing means. They are cheaper than integral tools and have more cutting edges than composite welding tools, with the highest comprehensive cost performance.

[0003] The main problem in producing integral welding tools is that it is difficult to control the welding quality, and problems such as de-welding, opening, insecure welding, and turning around often occur, thus affecting the use of integral welding tools. Currently, the qualified rate of welding in most factories is only 70%-80%, and the phenomenon of turning around during use often occurs even with good appearance. Summary of the Invention

[0004] The purpose of the present invention is to provide a welding tooling, a combination body and a method for an integral welding tool, which can reduce the situations of de-welding, opening, insecure welding, and turning around during the welding process, so as to improve the overall qualified rate of integral welding tools.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A welding tooling for an integral welding tool, including a bottom plate and several fasteners. A groove is provided on the upper surface of the bottom plate, and the fasteners slide in the groove. The bottom plate and the fasteners are made of macor ceramics. Several tool positioning blind holes and tool positioning posts are provided in the groove. The lower end of the tool positioning post is inserted into the tool positioning blind hole. The fasteners include a first slider and a second slider. A notch is provided on the adjacent side of the first slider and the second slider along the vertical direction. Bottom plate positioning blind holes are provided at the four corners of the bottom plate.

[0007] Preferably, the fasteners are in close contact with the groove, and the included angle between the side surface and the bottom surface of the groove is an obtuse angle.

[0008] The present invention also provides a welding assembly, which includes any one of the above welding jigs, and further includes a first metal foil, a welding body, and a second metal foil. The first metal foil is at least laid on the bottom of the groove. The welding body includes a welding base body and a cutting insert. An inner hole is provided in the middle of the welding base body, and the diameter of the inner hole is equal to the diameter of the upper end of the tool positioning post. The cutting insert is embedded in the welding base body. The welding base body is made of cemented carbide, and the cutting insert is a CBN cutting insert. The welding body is fixed by the tool positioning post and fasteners. The second metal foil covers the welding body.

[0009] The present invention also provides a welding method, which uses the above welding assembly and includes the following steps:

[0010] S1: Cut the CBN monocrystalline polycrystalline blank into a cutting insert blank, and prepare a welding base body using cemented carbide;

[0011] S2: Trim the cutting insert blank using an angle jig to obtain a cutting insert, and clean the surface of the welding base body using a sandblaster;

[0012] S3: Put the welding base body and the cutting insert into an ultrasonic cleaning machine and clean them using a cleaning agent;

[0013] S4: Put the cleaned welding base body and cutting insert into a vacuum furnace, heat them to not less than 900 °C under 5×10 -3 Pa and below, pass hydrogen to reduce for 1 hour, cool down, take out the welding base body and the cutting insert, and vacuum seal them for standby;

[0014] S5: Prepare metal powders of copper powder, silver powder, and tin powder, mix them evenly, take out the mixed powder, add a certain proportion of deionized water, and stir evenly to obtain a solder for standby;

[0015] S6: Apply the solder on the welding surface and smear it evenly, and then combine the welding base body and the tool tip into a welding body;

[0016] S7: Place the first metal foil at the bottom of the groove, then fix the welding body through the tool positioning post, align the notches on the first slider and the second slider with the welding body, and then press down the first slider and the second slider to complete the fixation of the welding body;

[0017] S8: After fixing all the welding bodies according to step S7, place the second metal foil above the welding bodies;

[0018] S9: Put the welding assembly into a vacuum welding furnace, heat it to 810 - 860 °C under 5×10 -3 Pa and below, keep it warm for 20 minutes, cool down to below 100 °C and take it out of the furnace to complete the welding.

[0019] Preferably, in step S1, the CBN monocrystalline polycrystalline blank is cut into a tool bit blank by laser cutting. In step S2, an angle tooling is used to trim the tool bit blank, remove the residues on the surface of the tool bit blank, and adjust the size of the tool bit blank.

[0020] Preferably, in step S3, it is cleaned with acetone for more than 25 minutes and then dried in an oven at 80°C.

[0021] Preferably, in step S5, copper powder, silver powder, and tin powder are mixed for 2 hours using a small three-dimensional mixer. After taking it out, deionized water is added and stirred evenly to obtain a solder. Then, a clean syringe is used to take the solder for standby.

[0022] Preferably, in step S5, by weight, the metal powder includes 5-7 parts of copper powder, 2-4 parts of silver powder, 1-3 parts of tin powder, and deionized water accounts for 10%-20% of the weight of the metal powder.

[0023] Preferably, in step S8, the following steps are further included: stacking several welding assemblies and fixing them by passing pins through the positioning blind holes on the bottom plate to obtain the stacked welding assembly.

[0024] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0025] (1) After the substrate and the tool bit are ultrasonically cleaned and then purified by filling hydrogen in a vacuum furnace, the harmful components on the welding contact surface are reduced to the lowest level, ensuring the cleanliness of the welding surface;

[0026] (2) Using macor ceramic material as the fastener. Currently, other manufacturers generally use metal spring clips and buckles to fix the welded body, which lose their fastening function in high-temperature environments. The macor ceramic used in the present invention is a ceramic material in which fine mica crystals are evenly distributed in the glass phase, having good toughness, machinability, heat resistance, and extremely low porosity. Coupled with the fastening method of the fastener, it can ensure good fastening effect even in high-temperature situations;

[0027] (3) Aluminum foil paper is covered on the upper and lower surfaces of the welded body. At high temperatures, aluminum can adsorb harmful impurities such as oxygen and sulfur generated during the melting of the solder. If these impurities cannot be adsorbed in time, pores will be left on the welding surface, thereby reducing the welding strength and affecting the yield. Through the comprehensive application of the above technical means, the welding yield of the present invention is increased by more than 20%, achieving good economic benefits. Description of the Drawings

[0028] Figure 1 It is a perspective view of Example 1.

[0029] Figure 2Isometric view of Example 2.

[0030] Figure 3 Isometric view of the welded body.

[0031] Figure 4 Isometric view of the welding base.

[0032] Figure 5 Schematic diagram of using fasteners to fix the welded body.

[0033] Figure 6 Schematic diagram of combining multiple welded assemblies in Example 4.

[0034] Markings in the figure: 100, bottom plate; 200, fastener; 300, welded body; 101, groove; 102, tool positioning blind hole; 103, positioning post; 104, bottom plate positioning blind hole; 201, first slider; 202, second slider; 301, welding base; 302, insert; 3011, inner hole. Detailed implementation manners

[0035] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] The present invention is used for the processing of a CBN integral welded tool. The integral welded tool generally includes a welding base 301 and several inserts 302. The contact surface between the welding base 301 and the insert 302 is the welding surface. Before the solder is applied to the welding surface until the welding is completed, the combination of the welding base 301 and the insert 302 is called the welded body 300.

[0037] Example 1

[0038] This embodiment provides a welding tool for an integral welded tool, which is used in the production process of a CBN integral welded tool. More specifically, it is used to fix the welded body 300 during the welding process, such as Figure 1As shown in the figure, the welding tooling includes a bottom plate 100 and seven fasteners 200. The upper surface of the bottom plate 100 is provided with a groove 101 having a trapezoidal cross-section. Blind holes 104 for positioning the bottom plate are provided at the four corners of the bottom plate 100. The fasteners 200 slide within the groove 101. The bottom plate 100 and the fasteners 200 are made of macor ceramics. Seven tool positioning blind holes 102 are provided within the groove 101, and tool positioning posts 103 are installed within the tool positioning blind holes 102 for fixing the welded body. The fasteners 200 include a first slider 201 and a second slider 202. On the adjacent sides of the first slider 201 and the second slider 202, notches are provided in the vertical direction. The shape of the notches is adapted to the shapes at both ends of the welded body 300 so as to embed the welded body 300 between the first slider 201 and the second slider 202.

[0039] The side surface of the fastener 200 is in close contact with the groove 101. The included angle between the side surface and the bottom surface of the groove 101 is an obtuse angle, and the included angles between the two side surfaces and the bottom surface of the groove 101 are equal, that is, the cross-sectional shape of the groove 101 is an isosceles trapezoid. In other embodiments, it can also be two included angles with different angles.

[0040] Embodiment 2

[0041] This embodiment provides a welding assembly, which includes the welding tooling in Embodiment 1, and further includes a first metal foil, a second metal foil, and seven welded bodies 300. As Figures 2 to 4 shown, the first metal foil is laid at the bottom of the groove 101. The welded body 300 includes a welding matrix 301 and two cutting inserts 302. The welding matrix 301 is made of cemented carbide. An inner hole 3011 is provided in the middle of the welding matrix 301. The diameter of the inner hole 3011 is equal to the diameter of the upper end of the tool positioning post 103. V-shaped notches for installing the cutting inserts 302 are provided at both ends of the welding matrix 301 to enable the cutting inserts 302 to be embedded in the welding matrix 301. The cutting inserts 302 are made of CBN material. The welded body 300 is fixed by the tool positioning post 103 and the fastener 200. After all the welded bodies 300 are fixed, the second metal foil is covered above the welded bodies 300.

[0042] In this embodiment, the cemented carbide used for the welding matrix 301 is YG8.

[0043] The first metal foil and the second metal foil are aluminum foils, which can prevent the welding agent from bonding with the bottom plate at high temperatures. Magnesium foils, copper foils, silver foils, etc. that can withstand high temperatures can also be used. The selection of aluminum foil is mainly considered for its relatively low cost.

[0044] In other embodiments, the first metal foil can also be an aluminum foil with a larger area, which is laid at the bottom and side of the groove 101.

[0045] Embodiment 3

[0046] This embodiment provides a welding method for producing a CBN integral welding tool using the welding assembly in Embodiment 2, including the following steps:

[0047] S1: Take a number of CBN integral polycrystalline blanks (such as C1204 integral CBN blade blanks). The shape of the blank is a rhombus with an inner angle of 80°. Process it on a surface grinder to a thickness of 5.15 + 0.05 mm, then use a lapping machine to double-side lap it to a thickness of 5.1 + 0.05 mm, and then perform grinding on the four sides on the surface grinder until the side dimension is 13.1 + 0.05 mm;

[0048] Use a laser cutting machine to divide each piece of the semi-finished product in the above step into 9 small rhombic cutting grains, which are the cutting grain blanks. The projected shape of the cutting grain blank is a rhombus with an inscribed circle size of 4.3 + 0.05 mm and an inner angle of 80°;

[0049] Prepare a number of welding substrates 301 made of cemented carbide. The welding substrates 301 are purchased externally. There is 1 V-shaped notch at each end. The angle of the notch is 80°, and the inscribed circle size is 4.0 + 0.05 mm.

[0050] S2: Use an angle tooling on a surface grinder to modify the cutting grain blanks into rhombic cutting grains with an inscribed circle size of 4.1 + 0.05 mm and an angle of 80°. At this time, the laser cutting burrs are completely ground flat, and the welding surface is smooth.

[0051] S3: Clean the prepared cutting grains and substrates in an ultrasonic cleaning machine with a cleaning agent for 25 minutes or longer. Take them out and dry them in an oven at 80 °C, and then take them out for standby. The cleaning agent is acetone, and ethanol or common metal cleaning agents on the market can also be used instead.

[0052] S4: Put the cleaned welding substrate 301 and cutting grain 302 into a vacuum furnace, heat them to 900 °C under a vacuum degree of 5×10 -3 Pa and below, pass hydrogen to reduce for 1 hour, cool down, take out the welding substrate 301 and cutting grain 302 and vacuum seal them for standby.

[0053] S5: Prepare 60 g of copper powder, 30 g of silver powder, and 10 g of tin powder. Mix them in a small three-dimensional mixer for 2 hours to make them evenly mixed. Take out the mixed powder, add 10 g of deionized water and stir evenly to obtain a solder. Suck it into a clean plastic syringe and prepare for use. Each syringe sucks 20 g of solder.

[0054] In other embodiments, the content of different metals in the metal powder can be 5 - 7 parts of copper powder, 2 - 4 parts of silver powder, 1 - 3 parts of tin powder, and deionized water accounts for 10% - 20% of the weight of the metal powder. The welding effect of the prepared solder is equivalent to that of this embodiment.

[0055] S6: Apply solder onto the welding surface and spread it evenly, then combine the welding substrate 301 and the tool bit to form the welded body 300.

[0056] Squeeze an appropriate amount of solder from the syringe and apply it onto the welding surface of the welding substrate 301. After spreading it evenly with a blade, pick up a tool bit 302 with tweezers, place it onto the welding surface of the welding substrate 301 and align it. Repeat this operation to load another tool bit 302 onto the welding surface at the other end of the welding substrate 301, and then the welded body 300 can be obtained.

[0057] S7: Evenly lay the first metal foil at the bottom of the groove 101, insert the tool positioning post 103 into the tool positioning blind hole 102, then insert the welded body 300 onto the tool positioning post 103. After aligning and placing the notches on the first slider 201 and the second slider 202 with the two ends of the welded body 300, press down the first slider 201 and the second slider 202, so as to generate a lateral extrusion force between the tool bit 302 and the welding substrate 301, as Figure 5 shown, thereby fixing the welded body 300 into the groove 101. Repeat this process until all 7 welded bodies 300 are installed into the groove 101.

[0058] S8: Place the second metal foil above the welded body 300 and keep it flat, then it becomes the welded combination.

[0059] S9: Put the welded combination into a vacuum welding furnace, heat it to 850 °C under 5×10 -3 Pa or below (in other embodiments, it can be selected between 810 - 860 °C), keep it warm for 20 minutes, cool it down to below 100 °C and then take it out of the furnace to complete the welding.

[0060] Example 4

[0061] Based on Example 3, in this example, 5 welded combinations obtained in step S8 of Example 3 are combined vertically, as Figure 6 shown, and are fixed by inserting pins into the bottom plate positioning blind holes 104. Then, 3 such stacked bodies are put into the vacuum welding furnace for welding simultaneously. There are a total of 105 welded bodies 300. After inspection, among the 105 CBN integral welded cutting tools obtained after welding, only 1 has a void formed at the welding surface, and the weld seams of the remaining 104 pieces are not visible to the naked eye. The welding qualification rate reaches 99.05%. Inspection finds that the reason for the defect of the 1 CBN integral welded cutting tool with a void is that the amount of solder at the welding surface is too small, which is caused by human operation errors.

[0062] Those skilled in the art should know that in addition to the above, the solution of the present invention is not only applicable to rhombus-shaped, but also applicable to the welding of superhard material cutting tools of other shapes.

[0063] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A welding assembly, including a welding tooling for an integral welding tool, characterized in that, It includes a bottom plate (100) and several fasteners (200). A groove (101) is provided on the upper surface of the bottom plate (100). The cross-sectional shape of the groove (101) is an isosceles trapezoid. The fasteners (200) slide in the groove (101). It is characterized in that the bottom plate (100) and the fasteners (200) are made of macor ceramics. Several tool positioning blind holes (102) and tool positioning posts (103) are provided in the groove (101). The lower end of the tool positioning post (103) is inserted into the tool positioning blind hole (102). The fastener (200) includes a first slider (201) and a second slider (202). On one side where the first slider (201) and the second slider (202) are adjacent, there is a notch along the vertical direction. The shape of the notch is adapted to the shapes of both ends of the welding body (300) so as to embed the welding body (300) between the first slider (201) and the second slider (202). Bottom plate positioning blind holes (104) are provided at the four corners of the bottom plate (100). The fastener (200) is in close contact with the groove (101). The included angle between the side surface and the bottom surface of the groove (101) is an obtuse angle. It also includes a first metal foil, a welding body (300), and a second metal foil. The first metal foil is at least laid on the bottom of the groove (101). The welding body (300) includes a welding matrix (301) and a cutting insert (302). An inner hole (3011) is provided in the middle of the welding matrix (301). The diameter of the inner hole (3011) is equal to the diameter of the upper end of the tool positioning post (103). V-shaped notches for installing the cutting insert (302) are provided at both ends of the welding matrix (301). The cutting insert (302) is embedded in the welding matrix (301). The welding matrix (301) is made of cemented carbide. The cutting insert (302) is a CBN cutting insert (302). The welding body (300) is fixed by the tool positioning post (103) and the fastener (200). The second metal foil covers the welding body (300) and presses the first slider (201) and the second slider (202) downward, so as to generate a lateral extrusion force between the cutting insert (302) and the welding matrix (301), fix the welding body (300) in the groove (101), and place the welding body (300) in a vacuum welding furnace for welding.

2. A welding method, using the welding assembly according to claim 1, characterized in that It includes the following steps: S1: Cut the CBN monocrystalline polycrystalline blank into a cutting insert blank, and prepare the welding matrix (301) using cemented carbide; S2: Use an angle tooling to trim the cutting insert blank to obtain the cutting insert (302), and use a sandblaster to clean the surface of the welding matrix (301); S3: Put the welding matrix (301) and the cutting insert (302) into an ultrasonic cleaner and clean them using a cleaning agent; S4: Put the cleaned welding substrate (301) and the cutting insert (302) into a vacuum furnace, heat them to no less than 900 °C under 5×10 -3 Pa or less, reduce them with hydrogen for 1 hour, cool down, take out the welding substrate (301) and the cutting insert (302), and vacuum seal them for standby; S5: Prepare metal powders of copper powder, silver powder, and tin powder, mix them evenly, take out the mixed powder, add a certain proportion of deionized water, and stir evenly to obtain a solder for standby; S6: Apply the solder on the welding surface and smear it evenly, and then combine the welding matrix (301) and the cutting insert into the welding body (300); S7: Place the first metal foil at the bottom of the groove (101), then fix the welded body (300) through the tool positioning post (103). Align the notches on the first slider (201) and the second slider (202) with the welded body (300). The shape of the notch is adapted to the shapes at both ends of the welded body (300). Then press down the first slider (201) and the second slider (202) to complete the fixation of the welded body (300). S8: After fixing all the welded bodies (300) according to step S7, place the second metal foil above the welded bodies (300). S9: Place the welded assembly into a vacuum welding furnace, heat it to 810 - 860 °C under 5×10 -3 Pa or below, hold for 20 minutes, cool down to below 100 °C, then take it out of the furnace to complete the welding.

3. A welding method according to claim 2, characterized in that, In step S1, the CBN monocrystalline polycrystalline blank is cut into a cutting insert blank by laser cutting. In step S2, the cutting insert blank is trimmed using an angle tooling to remove the residues on the surface of the cutting insert blank and adjust the size of the cutting insert blank.

4. A welding method according to claim 2, characterized in that, In step S3, the cleaning agents used are acetone and ethanol, and the cleaning time is more than 25 minutes. Then it is placed in an oven and dried at 80 °C.

5. A welding method according to claim 2, characterized in that, In step S5, the copper powder, silver powder, and tin powder are mixed for 2 hours using a small three-dimensional mixer. After taking it out, deionized water is added and stirred evenly to obtain the solder. Then a clean syringe is used to take the solder for standby.

6. A welding method according to claim 2, characterized in that, In step S5, by weight, the metal powder includes 5 - 7 parts of copper powder, 2 - 4 parts of silver powder, 1 - 3 parts of tin powder, and the deionized water accounts for 10% - 20% of the weight of the metal powder.

7. A welding method according to claim 4, characterized in that, In step S8, the following steps are further included: Stack a number of welded combinations and fix them by passing pins through the bottom plate positioning blind holes (104) to obtain the stacked welded combinations.

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