Hard alloy cutting edge treatment method and tool manufactured through hard alloy cutting edge treatment method

Abstract

The invention relates to the technical field of hard alloy, in particular to a hard alloy cutting edge treatment method and a tool prepared through the method. According to the method, firstly, the cutting edge of the hard alloy cutter is subjected to surface cleaning pretreatment, then the pretreated cutting edge is subjected to ion implantation so as to form a strengthening layer on the surface layer of the cutting edge, and then the cutting edge subjected to ion implantation is subjected to micro-arc oxidation treatment so as to grow a ceramic oxidation film on the surface of the strengthening layer in situ. And then the cutting edge subjected to micro-arc oxidation treatment is subjected to polishing treatment, the surface hardness and toughness of the prepared cutter are improved, a film layer at the cutting edge is uniform, and the service life is longer.

Description

Technical Field

[0001] This invention relates to the field of cemented carbide technology, and in particular to a method for treating the cutting edge of cemented carbide and the cutting tool prepared therefrom. Background Technology

[0002] Current Status and Challenges of Carbide Cutting Tools Carbide cutting tools, due to their excellent hardness (HRA 89-93), wear resistance and thermal stability (red hardness can reach 800-1000℃), occupy a dominant position in modern manufacturing and are widely used in aerospace, automobile manufacturing, mold processing and other fields. As machining technology develops towards high speed, high efficiency and high precision, higher requirements are placed on the performance of cutting tools.

[0003] Currently, during the mechanical grinding and passivation process of cemented carbide cutting edges, residual stress and microcracks are easily introduced, resulting in insufficient durability during subsequent ion implantation. This often leads to a sacrifice in toughness while increasing surface hardness, resulting in increased brittleness of the cutting edge and uneven film layer at the cutting edge. Summary of the Invention Attached Figure Description

[0004] For ease of explanation, the present invention will be described in detail below with reference to the preferred embodiments and accompanying drawings.

[0005] Figure 1 This is a flowchart illustrating the steps of a cemented carbide cutting edge treatment method according to the present invention. Figure 2 This is a test result diagram of Embodiment 1 of the present invention; Figure 3 This is a surface view of the milling cutter prepared according to Embodiment 1 of the present invention. Detailed Implementation

[0007] To make the objectives, technical solutions, and advantages of this invention clearer, the 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 merely illustrative and not intended to limit the invention.

[0008] like Figures 1 to 3 As shown, a method for treating the cutting edge of a cemented carbide cutting tool according to the present invention includes the following steps: S1. Edge pretreatment: Perform surface cleaning pretreatment on the edge of the carbide cutting tool; S2. Ion implantation treatment: Ion implantation is performed on the pretreated cutting edge to form a reinforcement layer on the surface of the cutting edge. S3. Micro-arc oxidation treatment: The cutting edge after ion implantation is subjected to micro-arc oxidation treatment to grow a ceramic oxide film in situ on the surface of the reinforcement layer; S4. Edge polishing treatment: Polish the edge after micro-arc oxidation treatment.

[0009] In this invention, the surface cleaning pretreatment includes mechanical grinding and ultrasonic cleaning. Specifically, constant pressure precision grinding is performed first, using a CNC tool grinder and diamond abrasive with a particle size D50 = 5~20μm. The wheel is ground under a constant pressure P=0.5~2.0MPa, with a linear velocity v=15~30m / s and a coolant flow rate ≥10L / min; then it is ultrasonically cleaned in multiple stages, in an alkaline cleaning agent (pH=9~11), deionized water, and anhydrous ethanol in sequence, with each stage of cleaning time t=3~8min and an ultrasonic frequency f=28~40kHz.

[0010] In this invention, ion implantation is performed using nitrogen ions, and the parameters for nitrogen ion implantation are: ion energy of 30~100 keV and implantation dose of 1×10⁻⁶. 12 ~1×10 17 ions / cm 2 A gradient injection method is used, first injecting high energy (E=80~100keV) with a dose Φ=(2-5)×10⁻⁶. 12 ions / cm 2 Further low-energy injection, E=30~60keV, dose Φ=(3-8)×10 12 ions / cm 2 The injection angle θ can be varied from 0 to 30° to achieve uniform injection on the rake face and flank face of the cutting edge.

[0011] In this invention, the electrolyte used in the micro-arc oxidation treatment comprises sodium hydroxide, sodium silicate, and sodium phosphate in a mass ratio of (5~15):(10~30):(2~10). The parameters for the micro-arc oxidation treatment are: voltage of 300~600V, and current density of 5~20A / dm³. 2 Specifically, the injected cutting tool is used as the anode, and micro-arc oxidation is performed in a specific electrolyte system. A bidirectional pulse power supply and multi-stage voltage control are used. The electrolyte composition is: NaOH 8~12g / L, Na2SiO2 15~25g / L, Na2PO3 5~10 g / L, glycerol 3~8g / L, and rare earth additives 0.1~0.5g / L. The electrical parameters are: positive voltage U=350~500V, negative voltage U=50~150V, frequency f=500~2000Hz, and duty cycle δ=20~40%. A three-stage treatment is adopted: Stage I (0~5min): the voltage is linearly increased to the set value to form a dense bottom layer; Stage II (5~25min): constant voltage treatment is performed to thicken the film layer; Stage III (last 2min): the voltage is reduced to 70% of the original voltage to form a closed surface layer.

[0012] In this invention, the polishing process is chemical mechanical polishing (CMP), which uses a polishing slurry containing nano-abrasives. The polishing pressure is 0.01~0.1 MPa, the polishing speed is 50~200 rpm, and the particle size of the nano-abrasives is 20~100 nm. Specifically, the polishing slurry is a nano-diamond or cubic boron nitride suspension with a particle size D50 of 20~80 nm, a concentration of 2~8 wt%, and a pH of 8-10. The polishing pad is a multi-layer composite polyurethane pad with a hardness of Shore A 60~80. The process parameters are: pressure P = 0.02~0.08 MPa, speed n = 80~150 rpm, and amplitude A = 1~3 mm. Online monitoring is performed by monitoring the polishing status through an acoustic emission sensor to achieve endpoint detection.

[0013] The present invention also provides a cemented carbide cutting tool, the cutting edge of which is prepared by the above-described treatment method.

[0014] This invention relates to experiments with milling cutters, and provides the following embodiments and comparative examples, as shown below: Example 1: Edge treatment of carbide end mills (1) Tool specifications Model: Four-flute flat end mill, diameter Φ10 mm; Material: YG8 cemented carbide (WC-8%Co); Initial state: conventional grinding, cutting edge radius R≈15-20μm; (2) Processing parameters and procedures I. Precision cutting edge pretreatment Equipment: Five-axis CNC tool grinder; Grinding wheel: Diamond grinding wheel, grit size 400#; Grinding pressure: 1.2 MPa; Linear velocity: 20 m / s; Coolant: 5% emulsion, flow rate 12L / min; Grinding time: 2 minutes per blade; Ultrasonic cleaning: First tank: Alkaline cleaning agent (50℃), 5 min; Second tank: Deionized water, 5 min; Third tank: Anhydrous ethanol, 5 min; Ultrasonic frequency: 35kHz, power: 300W; II: Selective Ion Implantation Enhancement Equipment: MEVVA source ion implanter; Injection method: Phase 1: E=100 keV, Φ=3×10 12 ions / cm2, θ=0°; Second stage: E=50 keV, Φ=5×10 12 ions / cm2, θ=15°; Sample temperature: 150±10℃; Vacuum degree: ≤5×10 13 Pa; Total injection time: 2.5 h; III. Controlled Micro-arc Oxidation Film Formation Power supply type: bidirectional pulse power supply, positive voltage U: 450V; negative voltage U: 100V, frequency: 1000Hz, duty cycle: 30%, processing time: 25min, temperature control: ≤40℃; IV. Chemical Mechanical Polishing Polishing slurry: nanodiamond suspension (particle size 50 nm, concentration 5%); pressure: 0.05 MPa; rotation speed: 100 rpm; amplitude: 2 mm; polishing time: 12 min; endpoint detection: maintain for 1 min after the acoustic emission signal stabilizes. V. Test results are as follows Figure 2 As shown.

[0015] Comparative Example 1: It adopts a traditional single processing technology, which involves precision grinding followed by coating.

[0016] like Figure 3 As shown, the end mills prepared in Example 1 and Comparative Example 1 are compared. The cutting edge coating of Example 1 is complete and continuous with no obvious defects, while the cutting edge coating of Comparative Example 1 has local peeling, exposing the substrate. The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for treating the cutting edge of a cemented carbide cutting tool, characterized in that, Includes the following steps: S1. Edge pretreatment: Perform surface cleaning pretreatment on the edge of the carbide cutting tool; S2. Ion implantation treatment: Ion implantation is performed on the pretreated cutting edge to form a reinforcement layer on the surface of the cutting edge. S3. Micro-arc oxidation treatment: The cutting edge after ion implantation is subjected to micro-arc oxidation treatment to grow a ceramic oxide film in situ on the surface of the reinforcement layer; S4. Edge polishing treatment: Polish the edge after micro-arc oxidation treatment.

2. The method for treating the cutting edge of cemented carbide cutting tools according to claim 1, characterized in that, Surface cleaning pretreatment includes mechanical grinding and ultrasonic cleaning.

3. The method for treating the cutting edge of cemented carbide cutting tools according to claim 2, characterized in that, Ion implantation was performed using nitrogen ions.

4. The method for treating the cutting edge of cemented carbide cutting tools according to claim 3, characterized in that, The parameters for nitrogen ion implantation are: ion energy of 30~100 keV and implantation dose of 1×10⁻⁶. 12 ~ 1×10 17 ions / cm 2 .

5. The method for treating the cutting edge of cemented carbide cutting tools according to claim 1, characterized in that, The electrolyte used in the micro-arc oxidation process includes sodium hydroxide, sodium silicate, and sodium phosphate in a mass ratio of (5~15):(10~30):(2~10).

6. The method for treating the cutting edge of cemented carbide cutting tools according to claim 1 or 5, characterized in that, The parameters for micro-arc oxidation treatment are: voltage 300~600V, current density 5~20A / dm³. 2 .

7. The method for treating the cutting edge of cemented carbide cutting tools according to claim 1, characterized in that, The polishing process is chemical mechanical polishing, which uses a polishing slurry containing nano-abrasives, with a polishing pressure of 0.01~0.1MPa and a polishing speed of 50~200rpm.

8. The method for treating the cutting edge of cemented carbide cutting tools according to claim 7, characterized in that, The particle size of the nano-abrasive is 20~100nm.

9. A cemented carbide cutting tool, characterized in that, Its cutting edge is obtained by the processing method according to any one of claims 1 to 8.

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