A method for brush-composite chemical-assisted rheological polishing of carbide tool tooth surface

Abstract

A brush-composite chemical-assisted rheological polishing method for the tooth surface of a cemented carbide tool comprises the following steps: mounting a workpiece on a clamping device, the clamping device being mounted under an upper polishing turntable, and the upper polishing turntable being mounted under a male turntable; adding a chemical-assisted rheological polishing fluid containing abrasive particles into a lower polishing turntable on which a brush disk is placed; lowering the upper polishing turntable to a suitable height by a lifting system, and making the four chuck mechanisms on the male turntable cooperate with the four slots of a puller; starting the spindle motor, and polishing the workpiece at a high speed under the drive of the puller. The present invention utilizes the shear thickening effect and chemical corrosion of the chemical-assisted rheological polishing fluid and the flow control effect of the brush to provide a method for efficient, high-quality and flexible polishing of the complex edge surface of a cemented carbide blade.

Description

Technical Field

[0001] The invention relates to the field of ultra-precision machining, in particular to a method for composite chemical-assisted rheological polishing of a cemented carbide tool tooth surface with a brush. Background Art

[0002] Cemented carbide has excellent comprehensive mechanical properties and is widely used as a tool material. Coated carbide tools need to be polished before coating to enhance the bonding force between the coating and the substrate. Due to the high hardness and high wear resistance of cemented carbide, polishing is difficult, especially for tools with complex cutting edges such as thread combs. Traditional brush polishing methods are prone to cause problems such as tool chipping and notching. Chemically assisted rheological polishing uses the shear thickening properties of non-Newtonian fluids to form a "flexible fixed abrasive" in the contact area between the polishing liquid and the workpiece, achieving efficient polishing of the workpiece surface. At the same time, the fluidity of the polishing liquid can ensure the polishing requirements for tools with complex shapes.

[0003] In addition, due to the complex tooth shape and small size of the blade, when polishing complex-edge carbide blades using the conventional chemically enhanced rheological polishing method, large clusters will be generated on the front cutting edge at high shear rates, hindering the polishing liquid from flowing through the blade tooth gap. In addition, the tooth roots far from the polishing disk wall are under low flow pressure, resulting in low polishing efficiency. Summary of the invention

[0004] In order to overcome the problems of tool chipping and notching that occur in the existing polishing process of cemented carbide tool tooth surface; the present invention is based on a new polishing method of force rheological polishing, combined with an abrasive brush passivation method, and proposes a composite chemical-assisted force rheological polishing method for the tooth surface of a cemented carbide tool. The shear thickening effect and chemical corrosion of the chemical-assisted force rheological polishing liquid and the flow control effect of the brush are used to achieve efficient, high-quality and flexible polishing of complex edge surfaces, and can achieve efficient and high-quality polishing of difficult-to-polish parts such as tooth roots. The present invention provides a method for efficient, high-quality and flexible polishing of complex edge surfaces of cemented carbide blades.

[0005] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0006] A brush composite chemical-assisted rheological polishing method for the tooth surface of a cemented carbide tool comprises the following steps: mounting a workpiece on a clamping device, the clamping device being mounted under an upper polishing turntable, and the upper polishing turntable being mounted under a male turntable; adding a chemical-assisted rheological polishing fluid containing abrasive particles into a lower polishing turntable on which a brush disk is placed; lowering the upper polishing turntable to a suitable height by a lifting system, and making four chuck mechanisms on the male turntable cooperate with four clamping grooves of a puller; starting a spindle motor, and polishing the workpiece at a high speed under the drive of a puller; during the machining process, the chemical components in the polishing fluid diffuse from the outside to the inside to the surface of the workpiece, and chemical reactions occur on the surface of the workpiece. The raised parts of the workpiece surface are oxidized into an easily removable soft layer, and then a set relative speed is generated between the workpiece and the chemically assisted rheological polishing fluid to produce a shear thickening effect in the contact area. The polyhydroxy polymers evenly dispersed in the polishing fluid gather together with the abrasive particles to form clusters; at high shear speeds, the clusters are too large and the distance between the teeth of the blade is small, which hinders the polishing of the clusters at the root of the tooth. Since the brush has certain flexibility and non-shear thickening characteristics, during the polishing process, the brush drives the polishing fluid to flow in the gap between the tooth roots, so that the clusters are in full contact with the root of the tooth, and the abrasive particles are wrapped to polish the root of the tooth.

[0007] Furthermore, the chemical action of the chemically assisted polishing liquid on the workpiece material is mainly that the Fenton reagent oxidizes the carbides and the binder phase in the cemented carbide into oxides. The chemical reaction formula that occurs during polishing is W 4+ →WO x The hardness of the generated oxide is much lower than that of the carbide, and the oxide is easier to remove by force rheological polishing. Moreover, the concave surface of the cemented carbide does not participate in the reaction, which prevents corrosion of the concave surface, improves the material removal rate of the uneven part of the cemented carbide surface, and obtains a lower surface roughness.

[0008] Furthermore, the workpiece has two types of carbide inserts: B8N2-3 and B5BN2-3, and the shape is approximately an equilateral triangle. The main components of the carbide are carbide and a binder phase, with carbide being the main component.

[0009] Preferably, the brush material of the brush plate is pig bristle, and the length of the brush is 15 to 30 mm.

[0010] Preferably, the chemically assisted rheological polishing fluid is composed of a rheological base fluid, abrasive particles, active additives and chemical corrosive agents, wherein the abrasive particle size is #3000 to #8000; the abrasive particles are diamonds; the chemical corrosive agent is Fenton's reagent; and the Fenton's reagent ratio is a hydrogen peroxide concentration of 0.1 to 0.25 wt.% and a ferrous sulfate concentration of 0.1 to 0.4 wt.%.

[0011] Furthermore, during the processing, the processing temperature is 20-25°C.

[0012] Furthermore, the liquid level of the chemically assisted rheological polishing liquid is 1 to 2 mm higher than the length of the brush of the brush plate, and the workpiece moves in a circular motion driven by the pulley, and the spindle speed is 50 to 90 rpm.

[0013] Further, when polishing the flank of the carbide insert, the workpiece is lowered to a position where the brush is immersed 1 to 2 mm from the root of the tooth of the insert behind the insert;

[0014] When polishing the front cutting edge of the carbide insert, the workpiece is lowered to a position where the brush is immersed in the insert and exceeds the cutting edge by 1 to 2 mm.

[0015] Preferably, when the polishing sequence of the front cutting face and the rear cutting face is switched, it is only necessary to remove the clamping device, rotate the clamping device 90° and install it on the upper polishing turntable again.

[0016] The technical concept of the present invention is as follows: chemically assisted rheological polishing has the advantages of high efficiency, high quality and low cost, and due to the fluidity of the polishing liquid, during the polishing process, the polishing liquid can highly fit the workpiece with complex shape, and a flexible "quasi-fixed abrasive tool" is used to precisely polish the complex surface of the workpiece. Under high-speed conditions, the shear layer formed is difficult to pass through the small tooth gap of the blade. The rheological shear layer is destroyed by a brush, so that the polishing liquid can smoothly pass through the cemented carbide tooth gap, and the polishing liquid that passes through can then perform efficient chemically assisted rheological polishing on the tooth root; adding Fenton's reagent can form a soft layer on the surface of the cemented carbide blade, thereby accelerating the removal efficiency.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects:

[0018] (1) The present invention provides a method for brush-composite chemical-assisted rheological polishing of cemented carbide tool tooth surfaces, which can achieve efficient, high-quality, and low-cost ultra-precision processing of cemented carbide tool tooth surfaces.

[0019] (2) The present invention provides a method for composite chemical-assisted rheological polishing of the tooth surface of a cemented carbide tool by using a brush, which can be used to polish both the front and rear surfaces of the blade.

[0020] (3) The strong oxidizing effect of Fenton's reagent is utilized to form an easily removable oxide layer on the tool surface during the polishing process. Combined with the principle of force rheological polishing, the polishing removal efficiency is improved.

[0021] (4) Based on chemically assisted rheological polishing, the present invention utilizes the flow control effect of the brush to solve the problem of easy clogging of the polishing liquid caused by the complex shape and small size of the cemented carbide blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is an overall axonometric diagram of the polishing of a workpiece by the method of the present invention;

[0023] Figure 2 It is a front view of the polishing of a workpiece by the method of the present invention;

[0024] Figure 3 It is a top view of the polishing of a workpiece by the method of the present invention;

[0025] Figure 4 It is a left view of the polishing of a workpiece by the method of the present invention;

[0026] Figure 5 It is a schematic diagram of the final assembly of the B5BN2-3 blade;

[0027] Figure 6 It is a schematic diagram of the final assembly of the B8N2-3 blade;

[0028] Figure 7 This is the front view of the B5BN2-3 blade clamping device;

[0029] Figure 8 The three views of the B8N2-3 blade clamping device are shown in FIG. (a) is a front view, (b) is a side view, and (c) is a top view;

[0030] Fig. 9 This is the principle diagram of carbide tool polishing.

[0031] The contents marked in the figure are: 1. workpiece; 2. clamping device; 3. upper polishing turntable; 4. revolving disk; 5. brush disk; 6. lower polishing disk; 7. chemically assisted rheological polishing fluid; 8. lifting system; 9. chuck mechanism; 10. puller; 11. spindle motor; 12. slide; 13. tool pressure block; 14. positioning shaft; 15. spring; 16. stopper; 17. cluster; 18 polyhydroxy polymer; 19. abrasive; 20 shear thickening zone; 21 brush DETAILED DESCRIPTION

[0032] The scheme of the present invention is further described below in conjunction with the accompanying drawings:

[0033] Reference Figures 1 to 9A brush composite chemical-assisted rheological polishing method for the tooth surface of a cemented carbide tool comprises the following steps: mounting a workpiece (1) on a clamping device (2), the clamping device (2) being mounted below an upper polishing turntable (3), and the upper polishing turntable (3) being mounted below a male turntable (4); adding a chemical-assisted rheological polishing liquid (7) containing abrasive particles (19) into a lower polishing turntable (6) on which a brush disk (5) is placed; a lifting system (8) lowers the upper polishing turntable (3) to a suitable height, and enables four chuck mechanisms (9) on the male turntable (4) to cooperate with four chuck grooves of a puller (10); starting a spindle motor (11), and polishing the workpiece at a high speed under the drive of the puller (10); during the machining process, chemical components in the polishing liquid (7) diffuse from the outside to the inside to the surface of the workpiece, chemical reactions occur on the surface of the workpiece, and the raised parts of the surface of the workpiece are oxidized into a soft layer that is easy to remove. Subsequently, a set relative speed is generated between the workpiece (1) and the chemically assisted rheological polishing liquid (7), and a shear thickening effect is generated in the contact area. The polyhydroxy polymer (18) uniformly dispersed in the polishing liquid gathers together with the abrasive particles (19) to form a cluster (17); at a high shear speed, the cluster (17) is too large, and the distance between the teeth of the blade (1) is small, which hinders the polishing of the cluster (17) at the root of the tooth. Since the brush (21) has certain flexibility and non-shear thickening characteristics, during the polishing process, the brush (21) drives the polishing liquid (7) to flow in the gap between the tooth roots, forming a shear thickening area (20), so that the cluster (17) is in full contact with the root of the tooth, wrapping the "abrasive particles" to polish the root of the tooth.

[0034] Furthermore, the chemical action of the chemically assisted polishing liquid (7) on the workpiece material is mainly that the Fenton reagent oxidizes the carbides and the binder phase in the cemented carbide into oxides. The chemical reaction formula that occurs during polishing is W 4+ →WO x The hardness of the generated oxide is much lower than that of the carbide, and the oxide is easier to remove by force rheological polishing. Moreover, the concave surface of the cemented carbide does not participate in the reaction, which prevents corrosion of the concave surface, improves the material removal rate of the uneven part of the cemented carbide surface, and obtains a lower surface roughness.

[0035] Furthermore, the workpiece (1) has two types of carbide blades: B8N2-3 and B5BN2-3, and the shape is approximately an equilateral triangle. The main components of the carbide are carbide and a binder phase, with carbide being the main component.

[0036] Preferably, the brush material of the brush plate (5) is pig bristle, and the length of the brush is 15 to 30 mm.

[0037] Preferably, the chemically assisted rheological polishing liquid (7) is composed of a rheological base liquid, abrasive particles, an active additive and a chemical corrosive agent, wherein the abrasive particle size is #3000 to #8000; the abrasive particles are diamonds; the chemical corrosive agent is Fenton's reagent; and the Fenton's reagent ratio is a hydrogen peroxide concentration of 0.1 to 0.25 wt.% and a ferrous sulfate concentration of 0.1 to 0.4 wt.%.

[0038] Furthermore, the liquid level of the chemically assisted rheological polishing liquid (7) is higher than the brush plate (5), the length of the brush (21) is 1 to 2 mm, the workpiece (1) is driven by the puller (10) to perform circular motion, the spindle speed is 50 to 90 rpm, and the chemically assisted rheological polishing liquid (6) and the brush plate (5) are stationary relative to the workpiece.

[0039] Furthermore, when polishing the rear face of the cemented carbide blade, the workpiece (1) is lowered to a position where the brush (21) is immersed in the blade and is 1 to 2 mm beyond the blade tooth root; when polishing the front face of the cemented carbide blade, the workpiece (1) is lowered to a position where the brush (21) is immersed in the blade and is 1 to 2 mm beyond the blade edge.

[0040] Reference Figure 5-6 When the polishing sequence of the front cutting edge and the rear cutting edge is switched, it is only necessary to remove the clamping device (2), rotate the clamping device (2) by 90 degrees and install it on the upper polishing turntable (3) again.

[0041] Reference Figure 7-Figure 8 , a processing device (2) for implementing the composite chemical assisted rheological polishing method of the tooth surface of a cemented carbide tool by a brush in this embodiment, comprises a slide groove (12), a tool pressing block (13), a positioning shaft (14), a spring (15) and a baffle (16), wherein the tool pressing block (13) is mounted on the slide groove (12), the positioning shaft (14) is mounted on the slide groove (12), one end of the spring (15) is mounted on a cylinder on the tool slider (13), the other end of the spring (15) is mounted in a countersunk hole of the slide groove (12), and the baffle (16) is mounted on the slide groove (12) by screw connection.

[0042] Furthermore, the upper end face and the back face of the slide groove (12) are respectively provided with two mounting holes for mounting on the upper polishing turntable (3) of the chemically assisted rheological polishing machine, thereby playing a role in fixing the clamping device (2); the groove shape of the slide groove (12) is square; the slide groove (12) is made of POP material with high mechanical strength and good chemical stability, and has a smooth surface.

[0043] Furthermore, the triangular groove of the tool pressing block (13) is at an angle of 60°, and the long side of the 60° angle is in contact with the non-processing surface of the blade. A cylinder is provided above the tool pressing block (13) for positioning the spring (15). Bosses corresponding to the slide groove (12) are provided on both sides of the tool pressing block (13), and the bosses cooperate with the grooves of the slide groove (12). The tool pressing block (13) is made of POP material with a smooth surface. Due to the characteristics of the materials, the friction coefficient between the tool pressing block (13) and the slide groove (12) is very small, and the friction resistance can be ignored during operation.

[0044] Furthermore, the baffle (16) is U-shaped and made of acrylic glass, so as to prevent the mechanorheological fluid (7) from penetrating into the interior of the clamping device during the polishing process.

[0045] Furthermore, the positioning shaft (14) is divided into two sections, wherein the upper section is an optical axis and the lower section is a threaded shaft, the optical axis is used to position the workpiece (1), and the threaded shaft is used to be fixed to the slide groove (12).

[0046] Furthermore, the blade positioning is achieved by circumferential positioning of the positioning shaft (14), surface positioning of the tool pressing block (13) and surface positioning of the slide groove (12), and the clamping force of the workpiece (1) is provided by the elastic force of the spring (15).

[0047] When the workpiece (1) needs to be clamped, the tool pressing block (13) is first pushed up to allow the workpiece (1) to have enough space for installation. After the installation hole of the workpiece (1) is aligned with the positioning shaft (14), the workpiece (1) is installed in the clamping device, the bottom surface of the workpiece (1) contacts the bottom surface of the slide groove (12), and then the position of the workpiece (1) is adjusted to make the non-processing surface of the workpiece (1) parallel to the long side of the tool pressing block (13). Finally, the tool pressing block (13) is released to clamp the workpiece (1) under the pressure of the spring (15). When the back face of the blade needs to be polished, the clamping device (2) is vertically installed on the upper polishing turntable (3) of the chemical-assisted force rheological polishing machine; when the front face of the blade needs to be polished, the clamping device (2) is horizontally installed on the upper polishing turntable (3) of the chemical-assisted force rheological polishing machine.

[0048] The above description is only a preferred embodiment of the present invention, so all equivalent changes or modifications made according to the structure, characteristics and principles described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.

Claims

1. A method for brush-composite chemical-assisted rheological polishing of carbide tool tooth surfaces, characterized in that: The workpiece is mounted on the clamping device, which is mounted under the upper polishing turntable, which is mounted under the male turntable; a chemically assisted rheological polishing liquid containing abrasive particles is added to the lower polishing turntable on which the brush disk is placed; the lifting system lowers the upper polishing turntable to a set height, and the four chuck mechanisms on the male turntable cooperate with the four clamping grooves of the puller; The spindle motor is started, and the workpiece is polished at high speed driven by the puller. During the processing, the chemical components in the polishing liquid diffuse from the outside to the inside to the workpiece surface, and a chemical reaction occurs on the workpiece surface, oxidizing the raised parts of the workpiece surface into an easily removable soft layer. Subsequently, a set relative speed is generated between the workpiece and the chemically assisted rheological polishing liquid, and a shear thickening effect is generated in the contact area. The polyhydroxy polymers evenly dispersed in the polishing liquid gather together with the abrasive particles to form clusters; at high shear speeds, the clusters are too large and the distance between the teeth of the blade is small, which hinders the polishing of the clusters at the root of the teeth. Since the brush has certain flexibility and non-shear thickening characteristics, during the polishing process, the brush drives the polishing liquid to flow in the gap between the tooth roots, so that the clusters are in full contact with the root of the teeth, wrapping the "abrasive particles" to polish the root of the teeth.

2. A method for composite chemical-assisted rheological polishing of carbide tool tooth surface using a brush as claimed in claim 1, characterized in that: The chemical action of the chemically assisted polishing liquid on the workpiece material is that the Fenton reagent oxidizes the carbides and the binder phase in the cemented carbide into oxides. The chemical reaction formula occurring during polishing is W 4+ →WO x The hardness of the generated oxide is much lower than that of the carbide, and the oxide is easier to remove by force rheological polishing. Moreover, the concave surface of the cemented carbide does not participate in the reaction, which prevents corrosion of the concave surface, improves the material removal rate of the uneven part of the cemented carbide surface, and obtains a lower surface roughness.

3. A method for composite chemical-assisted rheological polishing of carbide tool tooth surface using a brush as claimed in claim 1 or 2, characterized in that: The workpieces have two types of carbide inserts: B8N2-3 and B5BN2-3. The shape of the workpieces is approximately an equilateral triangle. The components of the carbide inserts are carbides and a binder phase.

4. A method for composite chemical-assisted rheological polishing of carbide tool tooth surface by brush according to claim 1 or 2, characterized in that: The brush material of the brush plate is pig bristle, and the length of the brush is 15 to 30 mm.

5. A method for composite chemical-assisted rheological polishing of carbide tool tooth surface using a brush as claimed in claim 1 or 2, characterized in that: The chemically assisted rheological polishing liquid is composed of a rheological base liquid, abrasive particles, active additives and chemical corrosive agents. The abrasive particle size is #3000-#8000; the abrasive particles are diamonds; the chemical corrosive agent is Fenton's reagent; the Fenton's reagent ratio is that the concentration of hydrogen peroxide is 0.1-0.25wt.%, and the concentration of ferrous sulfate is 0.1-0.4wt.%.

6. A method for composite chemical-assisted rheological polishing of carbide tool tooth surface using a brush as claimed in claim 1 or 2, characterized in that: During the processing, the processing temperature is 20-25°C.

7. A method for composite chemical-assisted rheological polishing of carbide tool tooth surface using a brush as claimed in claim 1 or 2, characterized in that: The liquid level of the chemically assisted rheological polishing liquid is 1 to 2 mm higher than the length of the brush on the brush plate. The workpiece moves in a circular motion driven by the pulley, and the spindle speed is 50 to 90 rpm.

8. A method for composite chemical-assisted rheological polishing of carbide tool tooth surface using a brush as claimed in claim 1 or 2, characterized in that: When polishing the back face of the carbide insert, the workpiece is lowered to a position where the brush is immersed in the insert and exceeds the root of the insert by 1 to 2 mm.

9. A method for composite chemical-assisted rheological polishing of carbide tool tooth surfaces using a brush as claimed in claim 8, characterized in that: When polishing the front cutting edge of the carbide insert, the workpiece is lowered to a position where the brush is immersed in the insert and exceeds the cutting edge by 1 to 2 mm.

10. A method for composite chemical-assisted rheological polishing of carbide tool tooth surfaces using a brush as claimed in claim 9, characterized in that: When the polishing sequence of the front cutting edge and the rear cutting edge is switched, the clamping device only needs to be removed, and the clamping device is rotated 90° and installed on the upper polishing turntable again.

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