Method for forming a bond layer during machining with an electromagnetic coupling-controlled carbide rotary file

Abstract

The application discloses a method for forming a bonding layer of a cemented carbide rotary file during processing by electromagnetic coupling regulation, and comprises the following steps: designing electromagnetic coupling processing parameters; performing electromagnetic coupling processing on a cemented carbide rotary file to be processed; performing grinding experiments on the cemented carbide rotary file after the electromagnetic coupling processing; observing the morphology of a grinding blade of the cemented carbide rotary file by using a scanning electron microscope to determine the generation state of the bonding layer on the cutting blade of the cemented carbide rotary file under the electromagnetic coupling processing parameters. The application changes the friction characteristics of a grinding interface by using electromagnetic coupling processing, changes the friction coefficient and the cutting force, reduces the wear, changes the formation of the bonding layer, and thus realizes the regulation and control of the service life and the grinding performance of the cemented carbide rotary file.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of machining, and particularly relates to a method for forming a bonding layer of a hard alloy rotary file during machining by electromagnetic coupling regulation. BACKGROUND

[0002] The hard alloy rotary file, also known as a hard alloy high-speed mixed milling cutter or a hard alloy die milling cutter, is used in combination with a high-speed electric grinder or a pneumatic tool, and is widely used in the industries of machinery, automobiles, ships, chemical engineering and process engraving. The hard alloy rotary file can be used to machine cast iron, cast steel, carbon steel, alloy steel, stainless steel, hardened steel, copper and aluminum, etc.; can be used to finish machine various metal die cavities; can be used to clean the flash, burrs and welds of cast, forged and welded parts; can be used to chamfer, round, groove and keyway machine various mechanical parts; can be used to polish the flow channel of an impeller; can be used to clean pipes; can be used to finish machine the inner hole surface of a mechanical part; and can be used to process engrave various metals and non-metals. The hard alloy rotary file has high machining production efficiency, which is nearly ten times higher than that of a hand file or a small grinding wheel with a handle; can machine various metals and non-metals with a hardness of below HRC70; has high smoothness and good machining quality due to its high machining speed; and can be used to finish machine various die cavities. However, the grinding edge of the rotary file is worn out quickly due to its high rotating speed and the fact that it is generally used to machine hard workpieces.

[0003] The bonding layer in the machining process of a tool refers to a layered structure formed by chemical reaction or physical combination between material chips or workpiece material and tool material during the machining process and attached to the surface of the tool. The bonding layer is mainly composed of elements of the workpiece material, cutting lubricant and oxides formed at high temperatures. The formation of the bonding layer has an important influence on the machining process and tool life, and it can affect the cutting force, tool wear, machining temperature and tool oxidation. Therefore, controlling and optimizing the formation of the bonding layer is the key to improving the performance of the tool and prolonging the life of the tool. However, there is no method for regulating the formation of the bonding layer of the hard alloy rotary file during machining of a workpiece on the market, and the hard alloy rotary file cannot be effectively regulated in terms of the formation of the bonding layer to regulate the life and grinding performance of the hard alloy rotary file. SUMMARY

[0004] The present application aims at the above-mentioned deficiencies in the prior art, and provides a method for forming a bonding layer of a hard alloy rotary file during machining by electromagnetic coupling regulation, so as to solve the problem that the prior art cannot effectively regulate the formation of the bonding layer of the hard alloy rotary file during machining of a workpiece to regulate the life and grinding performance of the hard alloy rotary file.

[0005] To achieve the above-mentioned object, the technical scheme adopted by the present application is as follows:

[0006] A method for forming a bonding layer of a hard alloy rotary file during machining by electromagnetic coupling regulation, comprising the following steps:

[0007] S1, design electromagnetic coupling treatment process parameters according to the hard alloy rotary file to be treated;

[0008] S2, based on the designed electromagnetic coupling treatment process parameters, the hard alloy rotary file to be treated is subjected to electromagnetic coupling treatment;

[0009] S3, grinding experiment is conducted on the hard alloy rotary file after electromagnetic coupling treatment;

[0010] S4, scanning electron microscope is used to observe the morphology of the hard alloy rotary file grinding edge, and the generation state of the adhesive layer on the cutting edge of the hard alloy rotary file under the electromagnetic coupling process parameters is determined.

[0011] Further, the electromagnetic coupling treatment process parameters in step S1 include electric field voltage, magnetic field strength, electric field current pulse number, electric pulse string number, electric field pulse frequency, magnetic pulse period and magnetic pulse number.

[0012] Further, the electric treatment time and the magnetic treatment time in step S1 are coupled within the same time period, wherein the relationship of the electric field current pulse number, the electric field pulse frequency, the magnetic pulse period and the magnetic pulse number is:

[0013]

[0014] t 磁 =T 磁脉冲 ×n 磁脉冲 ;

[0015] and

[0016] Wherein, f 正 is the positive pulse frequency of the electric field current, f 负 is the negative pulse frequency of the electric field current, t 间 is the time interval between each positive and negative pulse, n 电脉冲 is the number of positive and negative pulses contained in a string of electric pulses, n 电脉冲串 is the number of electric pulse strings, T 磁脉冲 is the magnetic pulse period, n 磁脉冲 is the number of magnetic pulses, t 电 is the electric field treatment time, n 总电脉冲 is the total number of electric pulses, t 磁 is the magnetic field treatment time.

[0017] Further, step S2 specifically includes:

[0018] S2.1, setting the electromagnetic coupling treatment process parameters on the electromagnetic coupling treatment device;

[0019] S2.2, the hard alloy rotary file to be processed is fixed in a processing position, the two ends of the hard alloy rotary file are in contact with the end faces of the electrode clamping head respectively, and the hard alloy rotary file is arranged in the central part of the magnetic field;

[0020] S2.3, the electromagnetic coupling processing device is started to perform electromagnetic coupling processing on the hard alloy rotary file.

[0021] Further, the parameters of the grinding experiment in the step S3 are obtained, including: average grinding edge diameter wear rate, average grinding edge band wear rate, average grinding efficiency and average machining depth.

[0022] Further, the average grinding edge diameter wear rate is calculated as:

[0023]

[0024] Further, the average grinding edge band wear rate is calculated as:

[0025]

[0026] Further, the average grinding efficiency is calculated as:

[0027]

[0028] Further, the average machining depth is calculated as:

[0029]

[0030] The method for regulating the formation of the bonding layer during the machining of the hard alloy rotary file by electromagnetic coupling has the following beneficial effects:

[0031] The present application utilizes electromagnetic coupling processing to change the microstructure of the hard alloy rotary file. Under the action of the electromagnetic field, the grain size, grain boundary distribution and grain boundary structure of the material surface change, which affects the hardness, strength and plasticity of the material, and further affects the friction characteristics of the grinding interface. The electromagnetic coupling processing changes the friction characteristics of the grinding interface, changes the friction coefficient, reduces the cutting force and wear, and thus changes the formation of the bonding layer, and further realizes the regulation of the service life and grinding performance of the hard alloy rotary file. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The flowchart of the method for regulating the formation of the bonding layer during the machining of the hard alloy rotary file by electromagnetic coupling.

[0033] Figure 2 The electron micrograph of the grinding edge of the hard alloy rotary file of the embodiment 2 of the present application; wherein figure (a) is the electron micrograph of the UT; figure (b) is the electron micrograph of the AEMT.

[0034] Figure 3 Electron micrograph of the hard alloy rotary file grinding blade of embodiment 3 of the present application: wherein figure (a) is an electron micrograph of UT; figure (b) is an electron micrograph of BEMT. DETAILED DESCRIPTION

[0035] The specific embodiments of the present application are described below to facilitate the understanding of the present application for those skilled in the art, but it should be clear that the present application is not limited to the scope of the specific embodiments, and for those skilled in the art, it is obvious that various changes are within the spirit and scope of the present application defined and determined by the appended claims, and all the inventions utilizing the concept of the present application are within the scope of protection.

[0036] Embodiment 1

[0037] The method for regulating the formation of the adhesive layer during the processing of the hard alloy rotary file of the present embodiment, the present embodiment regulates the service life and grinding performance of the hard alloy rotary file by regulating the formation of the adhesive layer during the processing of the workpiece by the hard alloy rotary file, with reference to Figure 1 , which specifically includes the following steps:

[0038] Step S1, design the electromagnetic coupling processing parameters according to the hard alloy rotary file to be processed;

[0039] Among them, the main process parameters include electric field voltage, magnetic field strength, secondary parameters include electric field pulse number, electric field pulse frequency, electric pulse string number and magnetic pulse period, magnetic pulse number.

[0040] In the specific electromagnetic coupling processing process, the electric processing time and the magnetic processing time need to be coupled in the same time period, based on this, the relationship between the electric field current pulse number, the electric field pulse frequency and the magnetic pulse period, the magnetic pulse number needs to meet the following:

[0041]

[0042] t 磁 =T 磁脉冲 ×n 磁脉冲 ;

[0043] and

[0044] Among them, f 正 is the positive pulse frequency of the electric field current, f 负 is the negative pulse frequency of the electric field current, t 间 is the time interval between each positive and negative pulse, n 电脉冲 is the number of positive and negative pulses contained in a string of electric pulses, n 电脉冲串 is the number of electric pulse strings, T磁脉冲 is the magnetic pulse cycle, n 磁脉冲 is the number of magnetic pulses, t 电 is the electric field treatment time, n 总电脉冲 is the total number of electric pulses, t 磁 is the magnetic field treatment time.

[0045] Step S2, based on the designed electromagnetic coupling treatment process parameters, the hard alloy rotary file to be treated is subjected to electromagnetic coupling treatment, which specifically comprises:

[0046] Step S2.1, setting the electromagnetic coupling treatment process parameters on the electromagnetic coupling treatment equipment;

[0047] Step S2.2, fixing the hard alloy rotary file to be treated at the treatment position, the two ends of the hard alloy rotary file respectively contact the end face of the electrode clamp, and the hard alloy rotary file is arranged in the central magnetic field;

[0048] Step S2.3, starting the electromagnetic coupling treatment equipment to perform electromagnetic coupling treatment on the hard alloy rotary file.

[0049] Step S3, grinding experiment is performed on the hard alloy rotary file after electromagnetic coupling treatment, and the grinding material is selected from 45 steel, wherein the grinding experiment parameters are shown in Table 1:

[0050] Table 1 Three elements of cutting amount

[0051] Cutting speed (V C )]]> Feed rate (f) grinding depth (a p )]]> Number of feeds 950 m / min 0.015 mm / r 0.1 mm 90

[0052] After the grinding experiment is completed, the following parameters are obtained, including: average grinding edge diameter wear rate (μm / time), average grinding edge band wear rate (mm / time), average grinding efficiency (g / time) and average machining depth (mm).

[0053] Specifically, the average grinding edge diameter wear rate is calculated as:

[0054]

[0055] The average grinding edge band wear rate is calculated as:

[0056]

[0057] The average grinding efficiency is calculated as:

[0058]

[0059] The average machining depth is calculated as:

[0060]

[0061] Step S4, the morphology of the hard alloy rotary file grinding blade is observed by a scanning electron microscope to determine the generation state of the adhesive layer on the cutting edge of the hard alloy rotary file under the electromagnetic coupling process parameters.

[0062] When the hard alloy rotary file is used to polish a workpiece, severe friction occurs between the grinding blade and the workpiece, and the temperature of the hard alloy rotary file and the machined workpiece surface rapidly rises. During this process, the hard alloy rotary file mainly undergoes oxidation wear. During this process, due to the high processing temperature and large processing pressure between the hard alloy rotary file and the machined workpiece, a small amount of hard alloy rotary file material and machined workpiece material melt and undergo oxidation reaction. The product after the reaction solidifies and adheres to the surface of the hard alloy rotary file grinding blade to form an adhesive layer. The presence of appropriate adhesive layer substances can reduce the wear of the hard alloy rotary file, provide thermal insulation, and reduce oxidation of the hard alloy rotary file.

[0063] Electromagnetic field coupling treatment technology is one of special energy field assisted manufacturing technologies, which has the advantages of cleanliness, high efficiency, energy saving, etc. This technology is to strengthen the treatment of ferromagnetic materials by coupling external pulse electric field and magnetic field, which is a process technology to control the microstructure defects of materials to realize the macro modification of materials.

[0064] Example 2

[0065] In this embodiment 2, the A-type hard alloy rotary file made of WC-10Co is taken as a specific object, and the method steps of example 1 are used for specific implementation:

[0066] Step A1, set the electromagnetic coupling treatment parameters, as shown in Table 2.

[0067] Table 2 Electromagnetic coupling treatment process parameter table

[0068]

[0069]

[0070] Among them, UT sample is not treated by electromagnetic field, which is untreated sample; the main process parameters of AEMT are electric field voltage 0.3V and magnetic field strength 2.0T. In order to meet the coupling of electric treatment time and magnetic treatment time in the same time period, the relationship among electric field current pulse number, electric field pulse frequency, magnetic pulse cycle and magnetic pulse number is as follows:

[0071]

[0072] In this embodiment, the data in Table 2 is substituted into the formula as follows:

[0073]

[0074] Magnetic field treatment time t 磁 = T磁脉冲 x n 磁脉冲 = 300 s,

[0075] Electric field processing time

[0076] The electric processing time is the same as the magnetic processing time, satisfying The electric field and the magnetic field coupling meet the requirements.

[0077] Step A2, after designing the process parameters, the AEMT is subjected to electromagnetic coupling processing based on the designed parameters. The specific process is as follows: setting the designed electromagnetic coupling processing process parameters on the electromagnetic coupling processing equipment, placing the hard alloy rotary file to be processed in the processing position, making the two ends of the hard alloy rotary file respectively contact with the end face of the electrode clamp, and locating the magnetic field center, and finally starting the electromagnetic coupling processing equipment to process the hard alloy rotary file.

[0078] Step A3, the hard alloy rotary file subjected to electromagnetic coupling processing is subjected to grinding experiment, and the ground material is 45 steel. The grinding experiment parameters are shown in Table 1. After the grinding experiment, the following parameters are obtained: average grinding edge diameter wear rate (mm / time), average grinding edge band wear rate (mm / time), average grinding efficiency (g / time) and machining depth (mm).

[0079] Referring to Table 3, according to the experimental results, the average edge diameter wear rate and the average edge band wear rate of the AEMT after electromagnetic coupling processing are obviously reduced, and compared with the untreated sample UT, the wear rates are reduced by 21.05% and 17.30% respectively; the average grinding efficiency is significantly improved, and compared with the untreated sample, it is improved by 12.25%; the average machining depth is the same as the untreated sample.

[0080] Table 3 Grinding test data

[0081] Specimen UT AEMT Average cutting edge diameter wear rate (μm / feed) 1.33 1.05 Average cutting edge band wear rate (μm / feed) 1.76 1.50 Average machining efficiency (g / feed) 2.04 2.29 Average machining depth (mm) 7.25 7.25

[0082] Step A4, after the grinding experiment, the morphology of the hard alloy rotary file grinding edge is observed by scanning electron microscope, and the generation of the bonding layer is observed.

[0083] Figure 3 (a) is the electron micrograph of UT, the substrate is exposed, and there is no bonding material layer on it;

[0084] Figure 3 (b) is the electron micrograph of AEMT, the substrate is partially exposed, and the rest is covered by the bonding material layer;

[0085] From Figure 2It can be seen that electromagnetic coupling field treatment can regulate the formation of the bonding layer when the carbide rotary file processes the workpiece, and combined with the analysis of the grinding experimental data, it can be found that different formation conditions of the bonding layer will have different effects on the service life and grinding performance of the carbide rotary file.

[0086] Example 3

[0087] This embodiment 3 uses a B-type cemented carbide rotary file made of WC-10Co as a specific object and is specifically implemented using the method and steps of embodiment 1:

[0088] Step B1, setting electromagnetic coupling processing parameters, which are specifically shown in Table 4;

[0089] Table 4 Electromagnetic coupling treatment process parameters

[0090]

[0091] The UT sample was not subjected to electromagnetic treatment and was considered untreated. The main process parameters for BEMT were an electric field voltage of 2.0 V and a magnetic field strength of 1.9 T. To ensure that the electric treatment time and the magnetic treatment time were coupled within the same time period, the relationship between the number of electric field current pulses, the electric field pulse frequency, the magnetic pulse period, and the number of magnetic pulses was as follows:

[0092]

[0093] In this embodiment, the data in Table 3 is substituted into the formula:

[0094]

[0095] Magnetic field treatment time tmagnetic = T 磁脉冲 ×n 磁脉冲 =360s.

[0096] Electric field treatment time

[0097] satisfy Meet the coupling conditions.

[0098] Step B2: After designing the process parameters, electromagnetic coupling treatment is performed on the BEMT based on the designed parameters. The specific process is as follows: The designed electromagnetic coupling treatment process parameters are set on the electromagnetic coupling treatment equipment. The carbide rotary file to be treated is placed and fixed in the treatment position so that both ends of the carbide rotary file contact the end surface of the electrode chuck and are located in the center of the magnetic field. Finally, the electromagnetic coupling treatment equipment is activated to treat the carbide rotary file.

[0099] Step B3, grinding experiment is carried out on the hard alloy rotary bur after electromagnetic treatment, the ground material is 45 steel, and the grinding experiment parameters are shown in Table 1. After the grinding experiment, the following parameters are obtained: average grinding edge diameter wear rate (μm / time), average grinding edge band wear rate (μm / time), average grinding efficiency (g / time) and machining depth (mm), as shown in Table 5. According to the experimental results, the average edge diameter wear rate and the average edge band wear rate of BEMT are significantly reduced, and compared with the untreated sample UT, the wear rate is reduced by 17.95% and 24.86% respectively; the average grinding efficiency is improved, and compared with the untreated sample, it is improved by 12.95%; the average machining depth is improved, and compared with the untreated sample, it is improved by 20.47%.

[0100] Table 5 Cutting detection experiment data

[0101]

[0102]

[0103] Step B5, the grinding edge morphology of the hard alloy rotary bur is observed by a scanning electron microscope after the grinding experiment, and the generation of the bonding layer is observed, as shown in Figure 3 .

[0104] Figure 3 (a) is an electron micrograph of UT, and the substrate is completely covered by the bonding material layer;

[0105] Figure 3 (b) is an electron micrograph of BEMT, and the substrate is partially exposed, and the rest is covered by the bonding material layer;

[0106] It can be obtained from Figure 3 that the electromagnetic coupling field treatment can control the formation of the bonding layer when the hard alloy rotary bur processes a workpiece, and it can be found from the analysis of the grinding experiment data that different generation of the bonding layer will have different effects on the service life and grinding performance of the hard alloy rotary bur.

[0107] The experimental results of the A-type rotary bur and the B-type rotary bur in the embodiment 2 and the embodiment 3 of the application are different, which is due to the difference in cutting force caused by the difference in the number of teeth of different types of rotary burs and the difference in electromagnetic treatment process parameters, so that the electromagnetic coupling treatment results are different. That is, for the A-type rotary bur, the electromagnetic coupling treatment can promote the generation of the bonding material layer, and for the B-type rotary bur, the electromagnetic coupling treatment can hinder the generation of the bonding material layer. In short, the electromagnetic coupling treatment can control the formation of the bonding material layer.

[0108] Although the specific embodiments of the application have been described in some detail, by way of example and for clarity of understanding, it should be understood that certain characteristics described herein can be used in various combinations and that other embodiments can be utilized without departing from the spirit of the patent as it is defined by the following claims.

Claims

1. A method for electromagnetic coupling control of bonding layer formation during carbide rotary file processing, characterized in that: The following steps are involved: S1. Design electromagnetic coupling treatment process parameters according to the carbide rotary file to be processed; S2. performing electromagnetic coupling treatment on the cemented carbide rotary file to be treated based on the designed electromagnetic coupling treatment process parameters; S3. Grinding experiment on the carbide rotary file after electromagnetic coupling treatment; S4. Observe the morphology of the grinding edge of the cemented carbide rotary file using a scanning electron microscope to determine the formation state of the bonding layer on the cutting edge of the cemented carbide rotary file under the electromagnetic coupling process parameters; The electromagnetic coupling treatment process parameters in step S1 include electric field voltage, magnetic field strength, number of electric field current pulses, number of electric pulse trains, electric field pulse frequency, magnetic pulse period and number of magnetic pulses; In step S1, the electric treatment time and the magnetic treatment time are coupled within the same time period, wherein the relationship between the number of electric field current pulses, the electric field pulse frequency, the magnetic pulse period, and the number of magnetic pulses is: t 磁 =T 磁脉冲 ×n 磁脉冲 ; and Among them, f 正 is the positive pulse frequency of the electric field current, f 负 is the negative pulse frequency of the electric field current, t 间 is the time interval between each positive and negative pulse, n 电脉冲 is the number of positive and negative pulses contained in a series of electrical pulses, n 电脉冲 String is the number of electrical pulse trains, T 磁脉冲 is the magnetic pulse period, n 磁脉冲 is the number of magnetic pulses, t is the electric field processing time, n 总电脉冲 is the total number of electric pulses, t 磁 is the magnetic field processing time; The step S2 specifically includes: S2.

1. Setting the electromagnetic coupling processing parameters on the electromagnetic coupling processing equipment; S2.

2. Fix the carbide rotary file to be processed at the processing position, with both ends of the carbide rotary file in contact with the end surface of the electrode chuck, and place the carbide rotary file in the center of the magnetic field; S2.

3. Start the electromagnetic coupling processing equipment to perform electromagnetic coupling processing on the carbide rotary file.

2. The method for electromagnetic coupling control of bonding layer formation during machining of a cemented carbide rotary file according to claim 1, characterized in that: The parameters of the grinding experiment in step S3 are obtained, including: average grinding edge wear rate, average grinding edge wear rate, average grinding efficiency and average machining depth.

3. The method for electromagnetic coupling control of bonding layer formation during machining of a cemented carbide rotary file according to claim 2, characterized in that: The average grinding edge wear rate is calculated as:

4. The method for electromagnetic coupling control of bonding layer formation during machining of a cemented carbide rotary file according to claim 2, characterized in that: The average grinding land wear rate is calculated as:

5. The method for electromagnetic coupling control of bonding layer formation during machining of a cemented carbide rotary file according to claim 2, characterized in that: The average grinding efficiency is calculated as:

6. The method for electromagnetic coupling control of bonding layer formation during machining of a cemented carbide rotary file according to claim 2, characterized in that: The average processing depth is calculated as:

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