Coating applied to cutter and preparation method of coating

Abstract

The invention relates to the technical field of tool coatings, in particular to a tool coating and a preparation method thereof.The preparation method comprises the steps that a hard alloy milling cutter is selected as a substrate; the matrix is subjected to hydrocarbon cleaning to remove oil stains; the walnut grains are used for polishing the base body, so that the surface roughness is reduced; ultrasonic waves are used for cleaning the base body, and the base body is put into sputter coating equipment; sputtering and depositing an ALTIN + ZrN composite coating on the surface of the cutter; the obtained cutter coating can prolong the service life of a cutter, and has the advantages of high temperature resistance, corrosion resistance and low friction coefficient.

Description

Technical Field

[0001] The invention relates to the technical field of tool coatings, and in particular to a coating applied to a tool and a preparation method thereof. Background Art

[0002] The rapid development of modern manufacturing industry has placed higher and higher requirements on mechanical processing, and high-speed dry cutting technology has become the focus of people's attention. The application of difficult-to-process materials such as titanium alloys, stainless steel and composite materials, as well as the introduction of high-speed dry cutting technology, poses a huge challenge to the performance of machining tools. Problems such as excessive cutting temperature and excessive heating rate have caused the service life of traditional tools to drop sharply. Coating technology can effectively improve the hardness and wear resistance of the tool surface without changing its matrix plasticity and toughness, thereby making the tool have better cutting performance.

[0003] The high-power pulsed magnetron sputtering ZrN+ALTIN ​​mixed coating has the advantages of high density, high ionization rate, low friction coefficient, and no sputtering of large droplets. The ALTIN+ZrN composite coating proposed by this method can significantly increase the wear resistance of the tool, extend the tool life, and improve the processing efficiency. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a coating for cutting tools and a preparation method thereof, so as to solve the problem of a sudden reduction in the service life of existing cutting tools.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A coating for cutting tools and a preparation method thereof, comprising the following steps:

[0007] 1) Surface pretreatment of the substrate: select a carbide milling cutter as the substrate; perform hydrocarbon cleaning on the substrate to remove oil stains; polish the substrate with walnut grains to reduce surface roughness; clean the substrate with ultrasound and place the substrate in a sputtering coating device;

[0008] 2) Evacuate the vacuum chamber to a basic pressure of less than 6.0×10^3Pa and heat it to 400-500°C; then fill the cavity of the vacuum chamber with 99.999% pure Ar to 0.2-0.5Pa; start Ar ion glow discharge and perform plasma etching on the surface of the substrate material for 60-70 minutes;

[0009] 3) Turn on the Cr target, use 99.999% N, and introduce 1pa nitrogen; the deposition temperature is 450°C; the substrate negative bias voltage is 200V-100V, the peak current is 450A, and the film thickness is 200nm-300nm;

[0010] 4) Turn on the Cr target, turn on the ALTI target, introduce 3-3.5pa nitrogen for mixed deposition, and the deposition temperature is 450°C; the substrate negative bias voltage is 60-100V, the peak current is 250A-300A, the duty cycle is 12%-15%, and the film thickness is 700nm-1um;

[0011] 5) The ALTI target is not turned off, and the Zr target is turned on to introduce 3pa nitrogen for mixed deposition; the substrate negative bias voltage is 80-120V for coating, the deposition temperature is 450℃, the duty cycle is 8%-10%, and the peak current is 400-450A;

[0012] 6) Turn off the ALTI target, deposit ZrN alone, and introduce 2 Pa nitrogen for deposition; the substrate negative bias voltage is 80 V, the duty cycle is 18%-20%, and the peak current is 230A-265A for ZrN deposition to obtain an ALTIN+ZrN composite coating.

[0013] Furthermore, the friction coefficient Ra of the ALTIN+ZrN composite coating is 0.1.

[0014] Furthermore, the hardness of the ALTIN+ZrN composite coating is 26.78 GPa.

[0015] Furthermore, the bonding force between the ALTIN+ZrN composite coating and the substrate is 72.23N.

[0016] Furthermore, the thickness of the ALTIN+ZrN composite coating is 2.23 μm. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the present invention, the technical solution of the present invention is further described below in conjunction with embodiments.

[0018] Embodiment 1:

[0019] A coating for cutting tools and a preparation method thereof of the present invention comprises the following steps:

[0020] 1) Substrate surface pretreatment:

[0021] Select a carbide milling cutter as the substrate; perform hydrocarbon cleaning on the substrate to remove oil stains; polish the substrate with walnut grains to reduce surface roughness; use ultrasonic waves to clean the substrate and place the substrate in a sputtering coating device;

[0022] 2) Evacuate the vacuum chamber to a basic pressure of less than 6.0×10^3Pa and heat it to 400-500°C; then fill the cavity of the vacuum chamber with 99.999% pure Ar to 0.2-0.5Pa; start Ar ion glow discharge and perform plasma etching on the surface of the substrate material for 60-70 minutes;

[0023] 3) Turn on the Cr target, use 99.999% N, and introduce 1pa nitrogen; the deposition temperature is 450°C; the substrate negative bias voltage is 200V-100V, the peak current is 450A, and the film thickness is 200nm-300nm;

[0024] 4) Turn on the Cr target, turn on the ALTI target, introduce 3-3.5pa nitrogen for mixed deposition, and the deposition temperature is 450°C; the substrate negative bias voltage is 60-100V, the peak current is 250A-300A, the duty cycle is 12%-15%, and the film thickness is 700nm-1um;

[0025] 5) The ALTI target is not turned off, and the Zr target is turned on to introduce 3pa nitrogen for mixed deposition; the substrate negative bias voltage is 80-120V for coating, the deposition temperature is 450℃, the duty cycle is 8%-10%, and the peak current is 400-450A;

[0026] 6) Turn off the ALTI target, deposit ZrN alone, and introduce 2 Pa nitrogen for deposition; the substrate negative bias voltage is 80 V, the duty cycle is 18%-20%, and the peak current is 230A-265A for ZrN deposition to obtain an ALTIN+ZrN composite coating.

[0027] The friction coefficient Ra of the ALTIN+ZrN composite coating is 0.1; the hardness of the ALTIN+ZrN composite coating is 26.78GPa; the bonding force between the ALTIN+ZrN composite coating and the substrate is 72.23N; the thickness of the ALTIN+ZrN composite coating is 2.23μm. Therefore, the ALTIN+ZrN composite coating can extend the service life of the tool and has the advantages of high temperature resistance, corrosion resistance and low friction coefficient.

[0028] Comparative Example 1:

[0029] The production steps of ALTIN+ZrN composite coating are the same as those in Example 1;

[0030] The finite element analysis model of friction and wear between HiPiMS high power pulsed magnetron sputtering ALTiN+ZrN series coated carbide tools and 45# steel high speed ring was established, and the dynamic simulation of the friction process was carried out, and the stress distribution law of the ALTIN+ZrN series coated carbide tools prepared by HIPSMS high power pulsed magnetron sputtering during the friction process was obtained.

[0031] The results show that the maximum equivalent stress and shear stress of cemented carbide tools prepared by traditional arc ion plating are significantly higher than those of HIPIMS high power pulsed magnetron sputtering coating tools, see Table 1 and Table 2:

[0032] Load / sample (N) 10 25 40 55 75 Uncoated 98 147 188 239 302 Arc ALTIN+ZrN 81 139 178 230 287 HiPiMSALTIN+ZrN 69 128 163 198 226

[0033] Table 1: Maximum stress-isolating effect of coatings when different coated tools rub against 45# steel at different loads (rotation speed 100r / min)

[0034]

[0035]

[0036] Table 2: Maximum shear stress of coatings when different coated tools rub against 45# steel at different loads (rotation speed 100r / min)

[0037] Comparative Example 2:

[0038] The production steps of ALTIN+ZrN composite coating are the same as those in Example 1;

[0039] High-speed ring-to-ring friction and wear tests were carried out on two series of coated carbide tools under dry friction conditions at room temperature, and the friction and wear characteristics of the two series of coated carbide tools were obtained.

[0040] The results show that: (1) The friction coefficient and wear rate of arc ion plating coated tools are significantly higher than those of HIPIMS high power pulse magnetron sputtering coated tools. Under the conditions of load 40N and rotation speed 500r / min, the friction coefficient of the coated tool prepared by conventional arc ion plating is 0.3899 and the wear rate is 4.3008 (×10~(-10)cm~3 / Nm), while the friction coefficient of the coated tool prepared by HIPIMS high power pulse magnetron sputtering is 0.121 and the wear rate is 1.0891 (×10~(-10)cm~3 / Nm). Both coated tools have good friction reduction and anti-wear effects, and the latter is better, as shown in Table 3:

[0041] Knives Load (N) / Speed ​​(r / min) Wear Friction coefficient Uncoated 40N / 500r / min 215 0.65 Arc ALTIN+ZrN 40N / 500r / min 0.65 0.389 HiPiMSALTIN+ZrN 40N / 500r / min 0.45 0.121

[0042] Table 3: Comparison of friction coefficient and friction amount of different coatings

[0043] In summary: Compared with the arc ALTIN+ZrN coating, the HiPiMSALTIN+ZrN composite coating obtained by the present invention can effectively reduce the amount of wear and extend the service life of the tool by 20%, and has the characteristics of high temperature resistance, corrosion resistance, and low friction coefficient.

[0044] The above are only embodiments of the present invention. The common knowledge such as the known specific structures and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field are aware of all the common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement the scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for the ordinary technicians in the relevant field to implement this application. It should be pointed out that for the technicians in this field, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A coating for cutting tools and a preparation method thereof, characterized in that: The following steps are involved: 1) Substrate surface pretreatment: Select a carbide milling cutter as the base; Carry out hydrocarbon cleaning on the substrate to remove oil stains; The substrate was polished with walnut grains to reduce the surface roughness; The substrate is cleaned by using ultrasonic waves and placed in a sputtering coating device; 2) Evacuate the vacuum chamber to a basic pressure of less than 6.0×10^3Pa and heat it to 400-500°C; then fill the cavity of the vacuum chamber with 99.999% pure Ar to 0.2-0.5Pa; start Ar ion glow discharge and perform plasma etching on the surface of the substrate material for 60-70 minutes; 3) Turn on the Cr target, use 99.999% N, and introduce 1pa nitrogen; the deposition temperature is 450°C; the substrate negative bias voltage is 200V-100V, the peak current is 450A, and the film thickness is 200nm-300nm; 4) Turn on the Cr target, turn on the ALTI target, introduce 3-3.5pa nitrogen for mixed deposition, and the deposition temperature is 450°C; the substrate negative bias voltage is 60-100V, the peak current is 250A-300A, the duty cycle is 12%-15%, and the film thickness is 700nm-1um; 5) The ALTI target is not turned off, and the Zr target is turned on to introduce 3pa nitrogen for mixed deposition; the substrate negative bias voltage is 80-120V for coating, the deposition temperature is 450℃, the duty cycle is 8%-10%, and the peak current is 400-450A; 6) Turn off the ALTI target, deposit ZrN alone, and introduce 2 Pa nitrogen for deposition; the substrate negative bias voltage is 80 V, the duty cycle is 18%-20%, and the peak current is 230A-265A for ZrN deposition to obtain an ALTIN+ZrN composite coating.

2. A coating for cutting tools and a method for preparing the same as claimed in claim 1, characterized in that: The friction coefficient Ra of the ALTIN+ZrN composite coating is 0.

1.

3. The coating for cutting tools and the preparation method thereof according to claim 1, characterized in that: The hardness of the ALTIN+ZrN composite coating is 26.78 GPa.

4. The coating for cutting tools and the preparation method thereof according to claim 1, characterized in that: The bonding force between the ALTIN+ZrN composite coating and the substrate is 72.23N.

5. The coating for cutting tools and the preparation method thereof according to claim 1, characterized in that: The thickness of the ALTIN+ZrN composite coating is 2.23 μm.

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