A method for surface pre-treatment of a round shank carbide tool substrate

Abstract

The application discloses a round-shank hard alloy cutter base surface pretreatment method, which comprises the following steps: S1, spraying soft abrasive to the blade part of the cutter base for micro passivation treatment; S2, inserting the blade part after the micro passivation treatment into hard abrasive, and rotating the blade part to perform friction roughening treatment; and S3, immersing the cutter base after the friction roughening treatment in a mixed acid solution to perform etching treatment. The hard alloy cutter pretreatment method provided by the application is simple in operation and has wide applicability to cutter shapes; the surface state of the cutter after treatment is quantitatively characterized, and the repeatability and stability in industrial production are improved; the soft abrasive is first used to perform micro passivation treatment on the blade part, and then the hard abrasive is used to perform friction roughening treatment on the blade part, so that the cutter surface roughening is more uniform.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material surface pretreatment, and particularly relates to a round-shank hard alloy cutter base surface pretreatment method. BACKGROUND

[0002] The hard alloy cutter with a diamond coating is an ideal cutter for machining ceramic, carbon fiber, glass fiber, graphite, non-ferrous metal and other materials. At present, the mainstream method for depositing a diamond coating on the surface of the hard alloy cutter is the chemical vapor deposition (CVD) method. However, when the diamond coating is deposited, the binder phase Co in the hard alloy base diffuses to the surface at high temperature, catalyzes the C element to transform into graphite phase, and greatly reduces the bonding strength between the coating and the base, which seriously affects the performance of the cutter. Therefore, before the diamond coating is deposited, the surface of the hard alloy cutter base needs to be pretreated to improve the bonding strength between the hard alloy cutter base and the diamond coating. Common methods for pretreating the surface of the hard alloy cutter base include the acid-alkali method, the transition layer method, the sand blasting method and the acid-alkali-free method.

[0003] The acid-alkali method is to first use Marukami alkali solution to corrode the WC on the surface of the hard alloy cutter base to form a loose layer with a certain thickness on the surface of the cutter and expose the Co on the surface layer, and then use a mixed acid solution to remove the exposed Co. The acid-alkali method can not only effectively weaken the adverse effect of Co, but also enhance the roughness of the surface of the base, reduce the surface energy of the surface of the base, thereby improving the nucleation density. However, the alkali treatment in the acid-alkali treatment is prone to form tiny pores in the surface layer of the cutter, and the loose layer obtained after the acid treatment is uneven, which seriously affects the toughness of the surface of the hard alloy cutter base and the adhesion of the diamond coating.

[0004] The transition layer method is to deposit one or more transition layers between the hard alloy cutter base and the diamond coating to isolate the binder phase Co and the diamond coating and improve the adhesion of the diamond coating. However, these transition layers have the problems of complex preparation process and high cost, and are less suitable for the round-shank hard alloy cutter base, which is not conducive to the large-scale production and industrial application of the diamond coating cutter.

[0005] The sand blasting method, as disclosed in the patent with the publication number CN 106544641 A, uses high-pressure quartz sand airflow to perform erosion and roughening treatment on the surface of the hard alloy base, and then uses acid to perform etching treatment. The sand blasting method can reduce the generation of the loose layer and pores on the surface of the hard alloy base and improve the adhesion of the diamond coating. However, the sand blasting method is suitable for flat-piece cutters, and for the round-shank hard alloy cutter, it is easy to cause the cutter edge to break and crack, resulting in the cutter being scrapped. Moreover, the sand blasting treatment cannot make the surface of the cutter roughen uniformly, thereby causing the diamond coating to have adverse properties such as discontinuity, voids or pores, and reducing the performance of the coating.

[0006] Acid-free and alkali-free methods, such as those described in patent publication number CN 113652668 A, use a combination of diamond powder and sandpaper to polish the carbide surface. This wet dispersion of particles is then used to seed the treated substrate. This reduces damage to the carbide and increases the deposition rate, resulting in a coating with high adhesion and crack resistance. However, this method suffers from low efficiency, and the stability and uniformity of the treatment effect cannot be guaranteed. This is particularly true for round-shank tools, where the treatment effect varies across different locations. Grinding with sandpaper can also easily damage the cutting edge, leading to tool failure or scrapping. Summary of the Invention

[0007] In order to solve at least one of the above technical problems, a surface pretreatment method for a cemented carbide substrate of a round shank tool is developed, which can roughen the tool surface more uniformly, effectively remove Co, has a stable process, and is suitable for round shank tools. The present application provides a surface pretreatment method for a cemented carbide tool substrate of a round shank tool.

[0008] The present application provides a method for pretreating the surface of a round-shank carbide tool substrate, comprising the following steps:

[0009] S1, spraying a soft abrasive onto the cutting edge of a round-shank carbide tool substrate to perform a micro-passivation treatment on the cutting edge;

[0010] S2, inserting the slightly passivated blade into a hard abrasive and rotating the blade to perform a friction roughening treatment on the blade;

[0011] S3, soaking the round-shank cemented carbide tool substrate after the friction roughening treatment in a mixed acid solution for etching treatment, and cleaning and drying the round-shank cemented carbide tool substrate after the etching treatment.

[0012] By adopting the above technical solution, soft abrasive is sprayed onto the cutting edge of the round-shank carbide tool base for micro-passivation treatment, which can effectively remove the microscopic serrations on the tool edge and release the surface stress of the cutting edge, thereby improving the performance and service life of the resulting diamond-coated tool; after micro-passivation treatment, the surface roughness Ra of the cutting edge meets the following requirements: 0.1um<Ra<0.3um, and Rz meets the following requirements: 0<Rz<1um.

[0013] The blade part of the tool after the micro passivation treatment is inserted into the hard abrasive to perform the friction roughening treatment, so that the relatively uniform microscale scratch with the depth can be effectively formed on the blade part surface, the surface energy of the blade part is reduced while the nucleation site is increased, and the nucleation density of the blade part is effectively improved; after the friction roughening treatment, the surface roughness Ra of the blade part satisfies 0.3um

[0014] The tool after the friction roughening treatment is soaked in the mixed acid solution to perform the etching treatment, so that the Co on the blade part surface can be effectively removed.

[0015] The hard alloy tool pretreatment method provided by the application is simple in operation, is suitable for not only the flat piece type tool but also the round handle type tool, has wide applicability to the tool shape, quantitatively represents the surface roughness of the tool after the treatment, quantitatively represents the surface state of the tool after the treatment, and improves the repeatability and stability in the industrial production; the micro passivation treatment is first performed on the blade part by using the soft abrasive, and then the friction roughening treatment is performed on the blade part by using the hard abrasive, so that the tool surface roughening is relatively uniform, and the relatively uniform surface is helpful to the uniformity and unity of the initial growth of the diamond particles, and the grown diamond grain boundary stress is smaller.

[0016] Preferably, in the step S1, the total length of the round handle hard alloy tool base is 45-150mm, the blade diameter is 0.5-15mm, and the blade length is 5-90mm.

[0017] Optionally, in the step S1, the soft abrasive includes rubber particles, and the average particle size of the rubber particles is 0.5-1.5um.

[0018] Optionally, the soft abrasive further includes diamond micro powder, and the weight ratio of the rubber particles to the diamond micro powder is (1-2):(0.1-0.3).

[0019] By using the above technical solution, the soft abrasive is the mixture of the rubber particles and the diamond micro powder, and the micro passivation treatment can be sufficiently performed on the blade part.

[0020] Optionally, the particle size of the diamond micro powder is 8000-12000 mesh.

[0021] Optionally, in the step S1, the soft abrasive is sprayed by using a nozzle, the caliber of the nozzle is 10-30mm, the included angle between the nozzle and the central axis of the round handle hard alloy tool base is 30-45°, the distance between the discharge end of the nozzle and the central axis of the round handle hard alloy tool base is 30-80mm, and the pressure of the soft abrasive flow discharged from the nozzle is 0.1-0.4MPa.

[0022] Optionally, the micro-passivation treatment time is 15-60s, during the micro-passivation treatment, the nozzle moves back and forth along a direction parallel to the central axis of the round shank carbide tool base and in the region corresponding to the blade portion, the moving rate is 0.5-6mm / s, and the blade portion rotates around the central axis of the round shank carbide tool base, the rotating rate is 20-40r / min.

[0023] By adopting the above technical scheme, the nozzle moves back and forth along a direction parallel to the central axis of the round shank carbide tool base and in the region corresponding to the blade portion, and the blade portion rotates around the central axis of the round shank carbide tool base, so that the micro-sawtooth on the tool edge can be effectively removed.

[0024] Optionally, the blade portion rotates forward and reversely around the central axis of the round shank carbide tool base alternately, and the ratio of the time of forward rotation to the time of reverse rotation is (0.5-2):1.

[0025] By adopting the above technical scheme, the micro-sawtooth on the tool edge can be more fully removed.

[0026] Optionally, in the step S2, the friction roughening treatment time is 4-5min, during the friction roughening treatment, the hard abrasive is olive shell particle, the average particle size of the hard abrasive is 0.5-2mm, and the rotating rate of the blade portion is 30-70r / min.

[0027] Optionally, the friction roughening treatment is performed twice, the first friction roughening treatment time is 0.5-1.5min, and the second friction roughening treatment time is 2.5-3.5min,

[0028] During the first friction roughening treatment, the average particle size of the hard abrasive is 1.5-2mm, and the rotating rate of the blade portion is 30-50r / min;

[0029] During the second friction roughening treatment, the average particle size of the hard abrasive is 0.5-1mm, and the rotating rate of the blade portion is 50-70r / min.

[0030] By adopting the above technical scheme, the scratches of micron level depth can be effectively formed on the surface of the blade portion, so that the surface of the blade portion can be effectively roughened and roughened more uniformly.

[0031] Optionally, in the step S3, the etching treatment time is 1-3min, the raw materials of the mixed acid solution include hydrochloric acid and hydrogen peroxide, the mass percentage content of HCl in the hydrochloric acid is 36%, the mass percentage content of H2O2 in the hydrogen peroxide is 30%, and the volume ratio of the hydrochloric acid to the hydrogen peroxide is 3:10.

[0032] By adopting the technical scheme, Co on the blade surface can be effectively removed, and after acid treatment, the mass percentage of Co on the blade surface is less than 0.5%.

[0033] In summary, the present application has at least one of the following beneficial technical effects:

[0034] 1. The present application first adopts soft abrasive to perform micro-passivation treatment on the blade, which can eliminate the original micro-sawtooth of the blade, improve the blade strength, and reduce the thermal stress concentration in the deposition process; and then adopts hard abrasive to perform friction roughening treatment on the blade, which can make the tool surface roughen more uniformly, and the uniformly roughened surface is helpful to the uniformity and unity of the initial growth of diamond particles, and the grown diamond grain boundary stress is smaller.

[0035] 2. The hard alloy tool pretreatment method provided by the present application is simple to operate, and is not only suitable for flat piece type tools, but also suitable for round handle type tools, and has wide applicability to tool shapes.

[0036] 3. The present application quantitatively characterizes the surface state of the tool after treatment, and improves the repeatability and stability in industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 The present application provides a micro-passivation treatment, and the structure diagram of the nozzle and the round handle hard alloy tool base;

[0038] Figure 2 The SEM micro-morphology diagram of the tool base surface after pretreatment of the present application example 21 and comparative example 1;

[0039] Figure 3 The energy spectrum analysis diagram of the tool base surface after pretreatment of the present application example 21 and comparative example 1;

[0040] Figure 4 The surface photo of the blade edge after depositing diamond coating of the present application example 21 and comparative example 1;

[0041] Figure 5 The SEM micro-morphology diagram of the diamond coating surface of the present application example 21 and comparative example 1;

[0042] Figure 6 The Raman spectrum diagram of the diamond coating surface of the present application example 21 and comparative example 1;

[0043] Figure 7 The blade edge micro-picture after cutting the same material 2h of the diamond coating tool of the present application example 21 and comparative example 1;

[0044] Explanation of reference signs: 1, round shank carbide tool base; 11, shank; 12, blade; 13, central axis; 2, nozzle; 21, discharge end. DETAILED DESCRIPTION

[0045] The application will be further described in detail below in combination with the drawings and examples. DETAILED DESCRIPTION

[0047] Example 1

[0048] The round shank carbide tool base is a round shank YG6A carbide milling cutter, the mass percentage of Co is 6%; the size of the round shank carbide tool base is D4x20x60xSD6, i.e. the blade diameter is 4 mm, the blade length is 20 mm, the total length is 60 mm, and the shank diameter is 6 mm.

[0049] The surface pretreatment method of the round shank carbide tool base of the present embodiment comprises the following steps:

[0050] S1, the shank 11 of the round shank carbide tool base 1 is clamped and fixed by using a clamp, the position of the clamp is adjusted so that the round shank carbide tool base 1 is kept in a vertical state, and the blade 12 faces downward, as shown in Figure 1 ;

[0051] S2, the nozzle 2 is clamped and fixed by using a clamp, the caliber of the nozzle 2 is 30 mm, the position of the clamp is adjusted so that the included angle α between the nozzle 2 and the central axis 13 of the round shank carbide tool base 1 is 25°, and the distance D between the discharge end 21 of the nozzle 2 and the central axis 13 is 85 mm, the sandblasting equipment is started, the soft abrasive is sucked into the compressed air pipeline and sprayed from the nozzle 2 to the blade 12 to perform micro passivation treatment on the blade 12, the time of the micro passivation treatment is 25 s, and the air pressure in the compressed air pipeline is 0.1 MPa;

[0052] S3, the round shank carbide tool base after the micro passivation treatment is wiped with anhydrous ethanol to remove the dust on the surface of the round shank carbide tool base;

[0053] S4, the shank of the round shank carbide tool base is clamped and fixed by using a clamp, the position of the clamp is adjusted so that the round shank carbide tool base is kept in a vertical state, and the blade faces downward, and the blade is located above the hard abrasive, then the clamp is controlled to move downward so that the blade moves downward until the blade completely extends into the hard abrasive, the clamp is controlled to rotate clockwise (forward) or counterclockwise (reverse) at a rotation rate of 45 r / min, and the clamp drives the blade to rotate to perform friction roughening treatment on the blade, and the time of the friction roughening treatment is 5 min;

[0054] S5, the round handle cemented carbide tool substrate after the roughening treatment is ultrasonically cleaned in acetone for 1.5 min, then taken out and dried, and then placed in a mixed acid solution for etching treatment to remove Co, and the etching treatment time is 2 min;

[0055] S6, the round handle cemented carbide tool substrate after the etching treatment is ultrasonically cleaned in anhydrous ethanol and acetone in sequence, and the cleaning time is 2 min, then taken out and dried.

[0056] In S2, the sandblasting equipment of the embodiment is the same in structure as the sandblasting equipment used in the existing sandblasting method; the soft abrasive is EPDM rubber particles with an average particle size of 2 um; in the micro passivation treatment, the nozzle moves up and down along a direction parallel to the central axis, the moving range is within the region corresponding to the blade part, the moving rate is 6 mm / s, and the round handle cemented carbide tool substrate rotates clockwise (forward) or counterclockwise (reverse) around the central axis, and the rotating rate is 20 r / min. Through the up-and-down movement of the nozzle and the rotation of the tool, the sprayed soft abrasive can uniformly and fully impact the surface of the entire blade part.

[0057] In S3, the anhydrous ethanol is of industrial grade, and the purity is ≥95%;

[0058] In S4, the preparation method of the hard abrasive is as follows: olive shell is crushed and sieved to obtain olive shell particles with an average particle size of 1 mm, the hard abrasive is stacked in a container, and the height of the hard abrasive stack is greater than the blade length of the round handle cemented carbide tool substrate.

[0059] In S5, the purity of acetone is 99.7%, the raw materials of the mixed acid solution include hydrochloric acid and hydrogen peroxide, the volume ratio of hydrochloric acid to hydrogen peroxide is 3:10, the mass percentage of HCl in hydrochloric acid is 36%, and the mass percentage of hydrogen peroxide in hydrogen peroxide is 30%.

[0060] In S6, the anhydrous ethanol is of industrial grade, and the purity is ≥95%; the purity of acetone is 99.7%.

[0061] Examples 2-3

[0062] Examples 2-3 are different from Example 1 in that in S2, the average particle size of the soft abrasive is different, and the specific values are shown in Table 1.

[0063] Table 1 Average particle size of soft abrasive

[0064]

[0065] Examples 4-10

[0066] Examples 4-10 differ from Example 3 in that in S2, the soft abrasive is a mixture of EPDM rubber particles and diamond micro-powder, the weight ratio of EPDM rubber particles to diamond micro-powder and the particle size of the diamond micro-powder are shown in Table 2 below, wherein the diamond micro-powder is single crystal diamond micro-powder.

[0067] Table 2 Weight ratio of rubber particles to diamond micro-powder and particle size of diamond micro-powder

[0068]

[0069] Examples 11-15

[0070] Examples 11-15 differ from Example 9 in that in S2, the caliber of the nozzle is different, the angle a and the distance D between the nozzle and the central axis of the round shank carbide tool substrate are different, and the air pressure in the compressed air pipeline is also different, which are shown in Table 3 below.

[0071] Table 3 Caliber of nozzle, angle a and distance D between nozzle and tool substrate

[0072]

[0073] Examples 16-19

[0074] Examples 16-19 differ from Example 14 in that in S2, the moving speed of the nozzle is different, and the direction, speed and time of rotation of the round shank carbide tool substrate around its central axis are different, which are shown in Table 4 below, and the round shank carbide tool substrate rotates forward and backward alternately, as in Example 16, it can rotate forward for 1 s and then rotate backward for 2 s, and so on; in Example 17, it can rotate forward for 1 s and then rotate backward for 1 s, and so on; in Example 18, it can rotate forward for 2 s and then rotate backward for 1 s, and so on.

[0075] Table 4 Moving speed of nozzle, direction and time of rotation of tool substrate

[0076]

[0077] Examples 20-22

[0078] Examples 20-22 differ from Example 17 in that the number of friction roughening treatments is twice, the average particle size of the hard abrasive is different each time, the rotation speed of the blade part is also different, and the treatment time is also different, which are shown in Table 5 below.

[0079] Table 5 Conditions for friction roughening treatment in Examples 20-22

[0080]

[0081] Performance test 1

[0082] Surface roughness performance test

[0083] The surface roughness Ra and Rz of the blade part of the round shank cemented carbide tool substrate after micro passivation treatment in Examples 1-22 were tested; the surface roughness Ra, Rz and Rsm of the blade part of the round shank cemented carbide tool substrate after friction roughening treatment in Examples 1-22 were tested; the testing instrument was JB-4C precision roughness meter of Shanghai Precision Instrument and Meter Co., Ltd., the sampling length was 0.25 mm, the sampling points were 6, the sampling points were randomly sampled, and the test results are shown in Table 6.

[0084] Table 6 Surface roughness after roughening treatment

[0085]

[0086]

[0087] From the test results in Table 6, after micro passivation treatment of the blade part of the tool substrate, the surface roughness Ra of the blade part satisfies: 0.1 um < Ra < 0.3 um, and Rz satisfies: 0 < Rz < 1 um, the micro passivation treatment method of the present application can effectively remove the micro sawtooth of the tool edge; after friction roughening treatment of the blade part of the tool substrate, the surface roughness Ra of the blade part satisfies: 0.3 um < Ra < 0.6 um, Rz satisfies: 1 um < Rz < 1.5 um, and Rsm satisfies: 0.01 um < Rsm < 0.1 um; the friction roughening treatment method of the present application can effectively form relatively uniform scratches of micron level depth on the surface of the blade part, reduce the surface energy of the blade part, and at the same time increase the nucleation density.

[0088] The difference between Examples 1-3 is that the particle size of the rubber particles is different, thereby resulting in different roughness of the blade surface after micro passivation treatment; the difference between Examples 4-7 and Example 3 is that the soft abrasive also includes diamond powder, and the composition of the soft abrasive is different, which also affects the roughness of the blade surface after micro passivation treatment; the difference between Examples 8-10 and Example 6 is that the particle size of the diamond powder is different, which further affects the roughness of the blade surface after micro passivation treatment; the difference between Examples 11-15 and Example 9 is that the caliber of the nozzle is different, as well as the distance and angle between the nozzle and the tool substrate, which jointly affect the roughness of the blade surface after micro passivation treatment; the difference between Examples 16-19 and Example 14 is that the speed of the nozzle movement is different, as well as the direction and time of the rotation of the blade, which further affect the roughness of the blade surface after micro passivation treatment; the difference between Examples 20-22 and Example 17 is that the number of friction roughening treatment is twice, and the particle size of the hard abrasive in the two times of friction roughening treatment is different, as well as the rotation speed and rotation time of the blade, thereby further affecting the roughness of the blade surface after friction roughening treatment.

[0089] Comparative Example 1

[0090] The composition and structure of the round shank cemented carbide tool substrate are the same as those of Example 1

[0091] The present comparative example adopts the traditional acid-base method to pretreat the surface of the round shank cemented carbide tool substrate, which includes the following steps:

[0092] Step one, place the round shank cemented carbide tool substrate in a Marukami alkali solution composed of K3Fe(CN)6: KOH: H2O in a mass ratio of 1:1:10, and ultrasonic oscillation treatment for 30 min to etch the WC on the substrate surface and expose Co;

[0093] Step two, immerse the tool in a mixed acid solution for 40 s, and the mixed acid solution is the same as that of Example 1 to remove Co on the substrate surface, and then clean and dry.

[0094] The raw material composition involved in Step one is the same as that in the existing acid-base treatment method.

[0095] Performance Test 2

[0096] The SEM test of the tool substrate surface after pretreatment is carried out by using an EM Crafts CUBE-ⅡPlus electron microscope and energy spectrum all-in-one machine.

[0097] The round shank cemented carbide tool substrate after pretreatment in Example 21 is recorded as Group 1, and the round shank cemented carbide tool substrate after pretreatment in Comparative Example 1 is recorded as Group 2, and the surface SEM micro-morphology graphs of Group 1 and Group 2 are as follows:Figure 2 As shown in Figure 2 It can be seen that the tool substrate surface of group 1 after pretreatment is roughened uniformly, has obvious fine scratches, is relatively flat, and has no obvious pits formed by local Co shedding; the tool substrate surface of group 2, i.e., after traditional acid-base treatment, is corroded deeply, the Co removal effect is uneven, resulting in many isolated WC particles exposed, the surface flatness is poor, which easily causes local growth rate unevenness in the subsequent diamond coating deposition process, and further causes large bonding surface stress between the tool substrate surface and the diamond coating.

[0098] Performance test 3

[0099] The energy spectrum detection test was performed by using the same instrument as in example 24.

[0100] The energy spectrum analysis diagrams of group 1 and group 2 are shown in Figure 3 As shown in Figure 3 It can be seen that the mass percentage content of Co on the tool substrate surface of group 1 after pretreatment is 0.5%, the mass percentage content of C is 12.5%, and the mass percentage content of W is 87%; the mass percentage content of Co on the tool substrate surface of group 2, i.e., after traditional acid-base treatment, is 0.38%, the mass percentage content of C is 11%, and the mass percentage content of W is 88%; it can be known that the Co content after pretreatment of group 1 and group 2 meets the requirements, however, after using the pretreatment method of the present application, the tool substrate surface roughening effect is good, the acid treatment time is short, and the Co shedding probability is smaller.

[0101] Performance test 4

[0102] Tool substrate surface diamond coating deposition performance test

[0103] Group 1 and group 2 were placed in a seeding solution for ultrasonic oscillation for 30 min to remove the loose layer on the surface; the seeding solution was a mixed suspension of diamond powder and glycerol solution, and the weight ratio of diamond powder and glycerol solution was 1:100, the average particle size of diamond powder was 2um, the concentration of glycerol solution was 85wt%, the solvent was deionized water, and the purity of deionized water was 99.9%.

[0104] Then, hot wire CVD equipment was used to prepare surface diamond coatings on Group 1 and Group 2 simultaneously. The preparation of diamond coatings includes two stages. The first stage is the nucleation stage. The main reaction process in this stage is: the surface of the tool substrate captures the ionized C-containing groups, and the nucleation sites remaining in the crystal planting process are attached, diffused on the surface, agglomerated, and film-formed. The main process parameters are: nucleation growth time 0.5h, hydrogen flow rate 1200sccm, methane flow rate 40sccm, reaction pressure 2000Pa, and tool substrate temperature 850~950℃; the second stage is the growth stage. The main reaction process is: columnar growth of diamond particles. The main process parameters are: growth time 12h, hydrogen flow rate 1200sccm, methane flow rate 24sccm, reaction pressure 4000Pa, and tool substrate temperature 780~850℃.

[0105] Figure 4 The surface photos of the cutting edges of Group 1 and Group 2 after depositing the diamond coating were taken using a Keyence tool image measuring instrument. Figure 4 It can be seen that after adopting the applied pretreatment process, the microscopic cutting edge serrations caused by grinding of the tool substrate can be effectively eliminated, thereby reducing the thermal stress concentration during the deposition of the diamond coating, and further reducing the stress concentration during the cutting process, delaying the generation of stress cracks, and improving the performance of the tool.

[0106] Figure 5 The SEM micromorphology of the diamond coating surface of Group 1 and Group 2 after the diamond coating was deposited. Figure 5 It can be seen that the surface diamond particles of group 1 are arranged more densely and evenly, and the stress between grain boundaries is smaller. The surface of group 2 is obviously uneven, the size of diamond particles varies greatly, and the grain boundary stress is large.

[0107] Figure 6 The Raman spectra of the diamond coating surface of Group 1 and Group 2 after the diamond coating was deposited were obtained using a Swiss Metrohm laser Raman spectrometer. Figure 6 It can be seen that the diamonds on the surfaces of Group 1 and Group 2 have only one sharp peak in the wavenumber range of 1000 to 1600, and the wavenumber corresponding to the sharp peak is around 1332, indicating that the diamond coating contains diamond components of higher purity. In addition, the peak position of Group 1 has a smaller deviation from the standard peak than that of Group 2, indicating that the coating of Group 1 has lower stress and better impact resistance and toughness.

[0108] Figure 7 The following are microscopic images of the cutting edge of Group 1 and Group 2 after cutting the same material glass fiber for 2 hours after depositing the diamond coating. The instrument used is a Keyence tool image measuring instrument. Figure 7It can be seen that the average wear of the blade edge of group 1 is not more than 0.025 mm; while under the same test conditions, the average wear of the blade edge of group 2 is more than 0.040 mm, and the blade edge has obvious coating peeling, which shows that the pretreatment method of the application can effectively improve the adhesion between the diamond coating and the hard alloy cutter.

[0109] The above are preferred embodiments of the application, and do not limit the protection scope of the application, so: any equivalent changes made on the basis of the structure, shape, principle of the application should be covered within the protection scope of the application.

Claims

1. A method for pretreating the surface of a round-shank carbide tool substrate, characterized in that: The steps include: S1. Spraying a soft abrasive onto the cutting edge of a round-shank carbide tool base to perform a micro-passivation treatment on the cutting edge. The soft abrasive is sprayed using a nozzle having a diameter of 10 to 30 mm, an angle between the nozzle and the central axis of the round-shank carbide tool base of 30 to 45 degrees, a distance between a discharge end of the nozzle and the central axis of the round-shank carbide tool base of 30 to 80 mm, and a pressure of the soft abrasive flow sprayed through the nozzle of 0.1 to 0.4 MPa. The micro-passivation treatment lasts for 15 to 60 seconds. During the micro-passivation treatment, the nozzle moves back and forth in a direction parallel to the central axis of the round-shank carbide tool base and in an area corresponding to the cutting edge at a movement rate of 0.5 to 6 mm / s, and the cutting edge rotates around the central axis of the round-shank carbide tool base at a rotation rate of 20 to 40 r / min. The cutting edge rotates alternately in a forward and reverse direction around the central axis of the round-shank carbide tool base, and the ratio of the forward rotation time to the reverse rotation time is (0.5-2):1; S2, inserting the slightly passivated blade into a hard abrasive and rotating the blade to perform a friction roughening treatment on the blade; S3, soaking the round-shank cemented carbide tool substrate after the friction roughening treatment in a mixed acid solution for etching treatment, and cleaning and drying the round-shank cemented carbide tool substrate after the etching treatment.

2. The method for pretreating the substrate surface of a round shank carbide tool according to claim 1, characterized in that: In step S1, the soft abrasive includes rubber particles, and the average particle size of the rubber particles is 0.5-1.5 μm.

3. The method for pretreating the surface of a round-shank carbide tool substrate according to claim 2, wherein: The soft abrasive further includes diamond powder, and the weight ratio of the rubber particles to the diamond powder is (1-2):(0.1-0.3).

4. The method for pretreating the surface of a round-shank carbide tool substrate according to claim 3, characterized in that: The particle size of the diamond micropowder is 8000-12000 mesh.

5. The method for pretreating the surface of a round-shank carbide tool substrate according to claim 1, wherein: In step S2, the friction roughening treatment time is 4 to 5 minutes. During the friction roughening treatment, the hard abrasive is olive shell particles, the average particle size of the hard abrasive is 0.5 to 2 mm, and the blade rotation rate is 30 to 70 r / min.

6. The method for pretreating the substrate surface of a round shank cemented carbide tool according to claim 5, characterized in that: The friction roughening treatment is performed twice, the first friction roughening treatment lasts for 0.5 to 1.5 minutes, and the second friction roughening treatment lasts for 2.5 to 3.5 minutes. During the first friction roughening treatment, the average particle size of the hard abrasive is 1.5-2 mm, and the rotation speed of the blade is 30-50 r / min; During the second friction roughening treatment, the average particle size of the hard abrasive is 0.5-1 mm, and the rotation speed of the blade is 50-70 r / min.

7. The method for pretreating the surface of a round-shank carbide tool substrate according to claim 1, characterized in that: In step S3, the etching treatment time is 1 to 3 minutes, and the raw materials of the mixed acid solution include hydrochloric acid and hydrogen peroxide. The mass percentage of HCl in the hydrochloric acid is 36%, the mass percentage of H2O2 in the hydrogen peroxide is 30%, and the volume ratio of the hydrochloric acid to the hydrogen peroxide is 3:10.

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