Composite coating material for PCB milling cutter and preparation method thereof

Abstract

The present invention discloses a composite coating material for a PCB milling cutter and a preparation method thereof, belonging to the technical field of novel functional materials. The present invention achieves a strong bonding force between the coating and the substrate through a carefully designed coating structure, including a Cr bonding layer, a TiAlN transition layer and a NbCrAlY alloy layer. At the same time, the coating exhibits excellent mechanical properties and a low friction coefficient. The preparation method of the coating includes precisely controlled cleaning, sputtering deposition and cooling steps to ensure the uniformity and stability of the coating. The coating material of the present invention adopts an optimized element ratio, especially a specific combination of niobium, chromium, aluminum and the rare earth element yttrium, which further improves the high-temperature oxidation resistance and wear resistance of the coating. Compared with the prior art, the surface composite hardness of the coating obtained by the present invention under a load of 10g is as high as 59GPa, and the friction coefficient with GCr15 is as low as 0.21, which is suitable for PCB processing fields requiring high precision and high efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of novel functional materials, and in particular to a composite coating material for a PCB milling cutter and a preparation method thereof. Background Art

[0002] With the rapid development of the electronics industry, the demand for PCB machining precision and efficiency is increasing. Milling cutters are key tools in PCB machining, and their performance directly impacts machining quality. However, traditional milling cutters are prone to wear and damage during high-speed cutting, resulting in reduced machining precision and shortened tool life. To enhance milling cutter performance, the industry generally uses coating technologies to improve their hardness, wear resistance, and chemical stability.

[0003] Existing coating technologies primarily include single-material coatings and simple composite coatings. While these coatings improve milling cutter performance to a certain extent, they still have limitations. For example, single-material coatings often offer excessive hardness but insufficient toughness, while simple composite coatings can have limited performance improvements due to insufficient interlayer bonding or mismatched material properties.

[0004] Prior art Chinese invention patent CN103436841B discloses a yttrium-modified chromium aluminum carbonitride / silicon nitride nanocomposite coating and its deposition method. This coating aims to improve the coating's hardness while also maintaining toughness and bonding strength to the substrate by nanocompositely designing chromium aluminum carbonitride and silicon nitride. The coating also incorporates the rare earth element Y, further enhancing the coating's mechanical properties and high-temperature oxidation resistance. The result is a nanocomposite coating for high-speed steel, carbide cutting tools, and molds that exhibits strong bonding, high hardness, good toughness, low friction coefficient, and outstanding thermal stability. The coating comprises a chromium aluminum yttrium bonding layer, a chromium aluminum yttrium nitride transition layer, and a nanocomposite layer. The resulting coating exhibits a film-to-substrate bonding strength of 40 to 90 N, a surface composite hardness of 40 to 65 GPa under a 10g load, and a friction coefficient of 0.2 to 0.5 against a GCr15 pair. However, the composite coating prepared by this invention has poor bonding strength, hardness and wear resistance. Summary of the Invention

[0005] In view of the shortcomings of existing technologies, this paper aims to provide a new type of composite coating material that can significantly improve the hardness and wear resistance of the milling cutter while maintaining sufficient toughness and thermal stability, thereby adapting to the needs of high-speed and high-precision PCB processing.

[0006] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0007] A method for preparing a composite coating material for a PCB milling cutter is as follows:

[0008] Step 1: Select a PCB milling cutter as the substrate, and perform degreasing, rust removal, organic solution cleaning, water rinsing, and drying on the substrate;

[0009] Step 2: Place the cleaned and dried substrate into a coating furnace; evacuate the furnace and maintain the temperature at 240-280°C; perform gas plasma cleaning by introducing He and H2;

[0010] Step 3: Turn off the gas ion source, adjust the pulse negative bias voltage, and adjust the He and H2 partial pressures to 0.1~0.3Pa and 0.05~0.1Pa; start the arc ion plating of the Cr target with an arc source current of 80~95A, and perform bombardment sputtering cleaning for 5~10 minutes;

[0011] Step 4: Deposit a Cr bonding layer by adjusting the pulsed negative bias frequency to 80-90 kHz, the peak value to 200-240 V, the duty cycle to 80-90%, the He and H2 partial pressures to 0.3-0.4 Pa and 0.1-0.2 Pa, and the Cr target arc source current to 80-95 A; the deposition time to 3-5 minutes, and the thickness to 0.1-0.5 μm;

[0012] Step 5: Deposit a TiAlN transition layer on the bonding layer, keep the pulse negative bias voltage unchanged, turn off He, and introduce N2 with a partial pressure of 0.3-0.4 Pa; use a TiAl alloy target, deposit for 2-4 minutes, and achieve a thickness of 0.1-0.5 μm;

[0013] Step 6: Keep the pulse negative bias voltage and the N2 and H2 partial pressures unchanged, the Cr target current unchanged, turn on the ion plating NbCrAlY alloy target, and increase the current linearly from 40-60A to 80-100A within 8-12 minutes. The deposition time is 5-15 minutes, and the thickness is 1-1.5 microns.

[0014] Step 7: Keep the pulse negative bias voltage constant and the N2 and H2 partial pressures constant, turn off the ion plating Ti target, keep the ion plating NbCrAlY alloy target arc source current at 80-100A, and deposit the nano-duplex composite layer for 70-100 minutes with a thickness of 3-5 microns; after stopping the coating, cool with ice water for 40-60 minutes and remove the workpiece.

[0015] The PCB milling cutter has a blade length of 20-30 mm and a blade diameter of 0.8-3.175 mm.

[0016] In step 2, the vacuum is pumped to 1×10 ⁻3 ~2×10 ⁻3 Pa.

[0017] In step 2, the gas plasma cleaning setting partial pressures are 0.2~0.3Pa and 0.1~0.2Pa respectively, the ion source current is 10~15A, a pulsed negative bias is applied, the frequency is 80~90kHz, the peak value is 300~350V, the duty cycle is 80~90%, and the cleaning time is 20~40 minutes.

[0018] In step 3, the pulse negative bias voltage is adjusted to a frequency of 80-90 kHz, a peak value of 1100-1300 V, and a duty cycle of 30-40%.

[0019] The atomic percentage of Ti in the TiAl alloy target is 50-70%, and the atomic percentage of Cr is 35-55%.

[0020] The atomic percentage of Nb in the NbCrAlY alloy target is 35-45%, the atomic percentage of Cr is 20-30%, the atomic percentage of Al is 25-35%, and the atomic percentage of Y is 1-10%.

[0021] The organic solution is one of acetone and isopropyl alcohol.

[0022] In the present invention, the functions of each substance are as follows:

[0023] As the carrier of the coating, the PCB milling cutter substrate needs to have certain mechanical strength and thermal stability to ensure the adhesion of the coating and the cutting performance of the milling cutter.

[0024] The steps of degreasing, rust removal and acetone cleaning are to remove oil, rust and other pollutants on the surface of the substrate and ensure good bonding between the coating and the substrate.

[0025] Gas plasma cleaning uses a mixture of helium and hydrogen for plasma cleaning to remove oxides and other adsorbents on the substrate surface, providing a clean surface for coating deposition.

[0026] Pulsed Negative Bias Applying a pulsed negative bias during the sputtering process helps control sputtering efficiency and energy and optimize the quality and structure of the coating.

[0027] The Cr target is used to deposit the Cr bonding layer. The chromium layer as a bonding layer can improve the bonding strength between the coating and the substrate and serve as the base layer for subsequent coatings.

[0028] TiAl alloy target is used to deposit TiAlN transition layer. The titanium and aluminum elements in the titanium aluminum target can form a hard TiAlN phase, which improves the hardness and wear resistance of the coating.

[0029] NbCrAlY alloy targets are used to deposit nano-duplex composite layers. This alloy target contains niobium, chromium, aluminum and the rare earth element yttrium. The specific combination of these elements helps to form a composite coating with excellent properties, improving the hardness, wear resistance and chemical stability of the coating.

[0030] After coating is completed, rapid cooling with ice water helps to reduce the thermal stress of the coating and improve the density and stability of the coating.

[0031] The careful selection and control of each substance and step is to ensure the high performance of the final coating, thereby improving the overall performance and service life of the PCB milling cutter.

[0032] Compared with the existing technology, it has the following beneficial effects:

[0033] 1) This invention forms a composite coating structure by sequentially depositing a Cr bonding layer, a TiAlN transition layer, and a NbCrAlY alloy layer on a PCB milling cutter substrate. This structure not only enhances adhesion between the coating and the substrate but also significantly improves the coating's wear resistance and service life through the optimized combination of different material layers.

[0034] 2) The coating materials and process parameters used in this invention are carefully selected and adjusted, resulting in a composite coating with a lower coefficient of friction and higher hardness. These performance improvements help improve the stability and machining accuracy of the milling cutter during high-speed cutting, while also reducing tool wear and extending tool replacement cycles.

[0035] 3) The coating preparation method of this invention utilizes a series of coating steps, including gas plasma cleaning, pulsed negative bias voltage control, and sputtering deposition of different target materials. This combination of steps ensures uniformity and density of the coating. Furthermore, the introduction of an ice-water cooling step improves the thermal stability of the coating. The overall process design improves production efficiency and reduces production costs. DETAILED DESCRIPTION

[0036] The remaining raw materials in the examples and comparative examples of the present invention are all commercially available products.

[0037] The design concept of the present invention is to adopt a multi-step coating deposition process to achieve the preparation of a composite coating material with excellent performance on the PCB milling cutter substrate. First, a strict substrate pretreatment step is performed to ensure good bonding between the coating and the substrate. Then, gas plasma cleaning technology is used to remove impurities on the substrate surface to provide a clean surface for coating deposition. Next, a Cr bonding layer, a TiAlN transition layer, and a nano-duplex composite layer of a NbCrAlY alloy target are deposited in sequence through precisely controlled sputtering parameters. Each layer is optimized for a specific function to enhance the overall performance of the coating. Finally, rapid heat treatment is achieved through ice water cooling to improve the hardness and stability of the coating. The entire preparation process focuses on the integrity of the coating structure and the precise control of the composition, ensuring the high hardness, strong bonding force and low friction coefficient of the coating, thereby significantly improving the service life and processing performance of the PCB milling cutter.

[0038] Example 1

[0039] A method for preparing a composite coating material for a PCB milling cutter is as follows:

[0040] Step 1: Select a PCB milling cutter as the base, with a blade length of 27.500 mm and a blade diameter of 1.815 mm; degrease, remove rust, clean with acetone, rinse with water, and dry the base;

[0041] Step 2: Load the cleaned and dried substrate into the coating furnace; evacuate to 1.8×10⁻³Pa and maintain the temperature at 260°C; perform gas plasma cleaning by introducing He and H2 with set partial pressures of 0.25Pa and 0.15Pa respectively, the ion source current is 12A, a pulsed negative bias is applied, the frequency is 86kHz, the peak value is 320V, the duty cycle is 88%, and the cleaning time is 30 minutes;

[0042] Step 3: Turn off the gas ion source, adjust the pulse negative bias voltage to 86 kHz, 1200 V peak, and 35% duty cycle, and adjust the He and H2 partial pressures to 0.2 Pa and 0.08 Pa respectively; start arc ion plating of the Cr target with an arc source current of 90 A, and perform bombardment sputtering cleaning for 8 minutes;

[0043] Step 4: Deposit a Cr bonding layer by adjusting the pulsed negative bias frequency to 86 kHz, peak value to 220 V, duty cycle to 88%, He and H2 partial pressures to 0.35 Pa and 0.15 Pa, and the Cr target arc source current to 90 A; the deposition time is 4 minutes, and the thickness is 0.3 μm;

[0044] Step 5: Deposit a TiAlN transition layer on the bonding layer, keep the pulsed negative bias voltage unchanged, turn off He, and introduce N2 with a partial pressure of 0.35 Pa; use a TiAl alloy target, deposit for 3 minutes, and have a thickness of 0.3 μm;

[0045] Step 6: Keep the pulse negative bias voltage and the N2 and H2 partial pressures unchanged, the Cr target current unchanged, turn on the ion plating NbCrAlY alloy target, and increase the current linearly from 50A to 90A within 10 minutes. The deposition time is 10 minutes and the thickness is 1.2 microns.

[0046] Step 7: Keep the pulse negative bias voltage constant and the N2 and H2 partial pressures constant, turn off the ion plating Ti target, keep the ion plating NbCrAlY alloy target arc source current at 90A, and deposit the nano-duplex composite layer for 80 minutes with a thickness of 4 microns; after stopping the coating, cool it with ice water for 50 minutes and remove the workpiece.

[0047] The atomic percentage of Ti in the TiAl alloy target is 60%, and the atomic percentage of Cr is 40%;

[0048] The atomic percentage of Nb in the NbCrAlY alloy target is 40%, the atomic percentage of Cr is 25%, the atomic percentage of Al is 30%, and the atomic percentage of Y is 5%.

[0049] Example 2

[0050] A method for preparing a composite coating material for a PCB milling cutter is as follows:

[0051] Step 1: Select a PCB milling cutter as the base, with a blade length of 27.500 mm and a blade diameter of 1.815 mm; degrease, remove rust, clean with acetone, rinse with water, and dry the base;

[0052] Step 2: Load the cleaned and dried substrate into the coating furnace; evacuate to 1.8×10⁻³Pa and maintain the temperature at 260°C; perform gas plasma cleaning by introducing He and H2 with set partial pressures of 0.25Pa and 0.15Pa respectively, the ion source current is 12A, a pulsed negative bias is applied, the frequency is 86kHz, the peak value is 320V, the duty cycle is 88%, and the cleaning time is 30 minutes;

[0053] Step 3: Turn off the gas ion source, adjust the pulse negative bias voltage to 86 kHz, 1200 V peak, and 35% duty cycle, and adjust the He and H2 partial pressures to 0.2 Pa and 0.08 Pa respectively; start arc ion plating of the Cr target with an arc source current of 90 A, and perform bombardment sputtering cleaning for 8 minutes;

[0054] Step 4: Deposit a Cr bonding layer by adjusting the pulsed negative bias frequency to 86 kHz, peak value to 220 V, duty cycle to 88%, He and H2 partial pressures to 0.35 Pa and 0.15 Pa, and the Cr target arc source current to 90 A; the deposition time is 4 minutes, and the thickness is 0.3 μm;

[0055] Step 5: Deposit a TiAlN transition layer on the bonding layer, keep the pulsed negative bias voltage unchanged, turn off He, and introduce N2 with a partial pressure of 0.35 Pa; use a TiAl alloy target, deposit for 3 minutes, and have a thickness of 0.3 μm;

[0056] Step 6: Keep the pulse negative bias voltage and the N2 and H2 partial pressures unchanged, the Cr target current unchanged, turn on the ion plating NbCrAlY alloy target, and increase the current linearly from 50A to 90A within 10 minutes. The deposition time is 10 minutes and the thickness is 1.2 microns.

[0057] Step 7: Keep the pulse negative bias voltage constant and the N2 and H2 partial pressures constant, turn off the ion plating Ti target, keep the ion plating NbCrAlY alloy target arc source current at 90A, and deposit the nano-duplex composite layer for 80 minutes with a thickness of 4 microns; after stopping the coating, cool it with ice water for 50 minutes and remove the workpiece.

[0058] The atomic percentage of Ti in the TiAl alloy target is 60%, and the atomic percentage of Cr is 40%;

[0059] The NbCrAlY alloy target has an atomic percentage of Nb of 30%, an atomic percentage of Cr of 30%, an atomic percentage of Al of 35%, and an atomic percentage of Y of 5%.

[0060] Example 3

[0061] A method for preparing a composite coating material for a PCB milling cutter is as follows:

[0062] Step 1: Select a PCB milling cutter as the base, with a blade length of 27.500 mm and a blade diameter of 1.815 mm; degrease, remove rust, clean with acetone, rinse with water, and dry the base;

[0063] Step 2: Load the cleaned and dried substrate into the coating furnace; evacuate to 1.8×10⁻³Pa and maintain the temperature at 260°C; perform gas plasma cleaning by introducing He and H2 with set partial pressures of 0.25Pa and 0.15Pa respectively, the ion source current is 12A, a pulsed negative bias is applied, the frequency is 86kHz, the peak value is 320V, the duty cycle is 88%, and the cleaning time is 30 minutes;

[0064] Step 3: Turn off the gas ion source, adjust the pulse negative bias voltage to 86 kHz, 1200 V peak, and 35% duty cycle, and adjust the He and H2 partial pressures to 0.2 Pa and 0.08 Pa respectively; start arc ion plating of the Cr target with an arc source current of 90 A, and perform bombardment sputtering cleaning for 8 minutes;

[0065] Step 4: Deposit a Cr bonding layer by adjusting the pulsed negative bias frequency to 86 kHz, peak value to 220 V, duty cycle to 88%, He and H2 partial pressures to 0.35 Pa and 0.15 Pa, and the Cr target arc source current to 90 A; the deposition time is 4 minutes, and the thickness is 0.3 μm;

[0066] Step 5: Deposit a TiAlN transition layer on the bonding layer, keep the pulsed negative bias voltage unchanged, turn off He, and introduce N2 with a partial pressure of 0.35 Pa; use a TiAl alloy target, deposit for 3 minutes, and have a thickness of 0.3 μm;

[0067] Step 6: Keep the pulse negative bias voltage and the N2 and H2 partial pressures unchanged, the Cr target current unchanged, turn on the ion plating NbCrAlY alloy target, and increase the current linearly from 50A to 90A within 10 minutes. The deposition time is 10 minutes and the thickness is 1.2 microns.

[0068] Step 7: Keep the pulse negative bias voltage constant and the N2 and H2 partial pressures constant, turn off the ion plating Ti target, keep the ion plating NbCrAlY alloy target arc source current at 90A, and deposit the nano-duplex composite layer for 80 minutes with a thickness of 4 microns; after stopping the coating, cool it with ice water for 50 minutes and remove the workpiece.

[0069] The atomic percentage of Ti in the TiAl alloy target is 60%, and the atomic percentage of Cr is 40%;

[0070] The NbCrAlY alloy target has an atomic percentage of Nb of 50%, an atomic percentage of Cr of 20%, an atomic percentage of Al of 25%, and an atomic percentage of Y of 5%.

[0071] Example 4

[0072] A method for preparing a composite coating material for a PCB milling cutter is as follows:

[0073] Step 1: Select a PCB milling cutter as the base, with a blade length of 27.500 mm and a blade diameter of 1.815 mm; degrease, remove rust, clean with acetone, rinse with water, and dry the base;

[0074] Step 2: Load the cleaned and dried substrate into the coating furnace; evacuate to 1.8×10⁻³Pa and maintain the temperature at 260°C; perform gas plasma cleaning by introducing He and H2 with set partial pressures of 0.25Pa and 0.15Pa respectively, the ion source current is 12A, a pulsed negative bias is applied, the frequency is 86kHz, the peak value is 320V, the duty cycle is 88%, and the cleaning time is 30 minutes;

[0075] Step 3: Turn off the gas ion source, adjust the pulse negative bias voltage to 86 kHz, 1200 V peak, and 35% duty cycle, and adjust the He and H2 partial pressures to 0.2 Pa and 0.08 Pa respectively; start arc ion plating of the Cr target with an arc source current of 90 A, and perform bombardment sputtering cleaning for 8 minutes;

[0076] Step 4: Deposit a Cr bonding layer by adjusting the pulsed negative bias frequency to 86 kHz, peak value to 220 V, duty cycle to 88%, He and H2 partial pressures to 0.35 Pa and 0.15 Pa, and the Cr target arc source current to 90 A; the deposition time is 4 minutes, and the thickness is 0.3 μm;

[0077] Step 5: Deposit an AlCrN transition layer on the bonding layer, keep the pulsed negative bias voltage unchanged, turn off He, and introduce N2 with a partial pressure of 0.35 Pa; use an AlCr alloy target, deposit for 3 minutes, and achieve a thickness of 0.3 μm;

[0078] Step 6: Keep the pulse negative bias voltage and the N2 and H2 partial pressures unchanged, the Cr target current unchanged, turn on the ion plating NbCrAlY alloy target, and increase the current linearly from 50A to 90A within 10 minutes. The deposition time is 10 minutes and the thickness is 1.2 microns.

[0079] Step 7: Keep the pulse negative bias voltage constant and the N2 and H2 partial pressures constant, turn off the ion plating Ti target, keep the ion plating NbCrAlY alloy target arc source current at 90A, and deposit the nano-duplex composite layer for 80 minutes with a thickness of 4 microns; after stopping the coating, cool it with ice water for 50 minutes and remove the workpiece.

[0080] The AlCr alloy target has an atomic percentage of Al of 60% and an atomic percentage of Cr of 40%;

[0081] The atomic percentages of the NbCrAlY alloy target are the same as those in Example 1.

[0082] Example 5

[0083] A method for preparing a composite coating material for a PCB milling cutter is as follows:

[0084] Step 1: Select a PCB milling cutter as the base, with a blade length of 27.500 mm and a blade diameter of 1.815 mm; degrease, remove rust, clean with acetone, rinse with water, and dry the base;

[0085] Step 2: Load the cleaned and dried substrate into the coating furnace; evacuate to 1.8×10⁻³Pa and maintain the temperature at 260°C; perform gas plasma cleaning by introducing He and H2 with set partial pressures of 0.25Pa and 0.15Pa respectively, the ion source current is 12A, a pulsed negative bias is applied, the frequency is 86kHz, the peak value is 320V, the duty cycle is 88%, and the cleaning time is 30 minutes;

[0086] Step 3: Turn off the gas ion source, adjust the pulse negative bias voltage to 86 kHz, 1200 V peak, and 35% duty cycle, and adjust the He and H2 partial pressures to 0.2 Pa and 0.08 Pa respectively; start arc ion plating of the Cr target with an arc source current of 90 A, and perform bombardment sputtering cleaning for 8 minutes;

[0087] Step 4: Deposit a Cr bonding layer by adjusting the pulsed negative bias frequency to 86 kHz, peak value to 220 V, duty cycle to 88%, He and H2 partial pressures to 0.35 Pa and 0.15 Pa, and the Cr target arc source current to 90 A; the deposition time is 4 minutes, and the thickness is 0.3 μm;

[0088] Step 5: Deposit a CrAlYN transition layer on the bonding layer, keep the pulse negative bias unchanged, turn off He, and introduce N2 with a partial pressure of 0.35 Pa; use a CrAlY alloy target, deposit for 3 minutes, and have a thickness of 0.3 μm;

[0089] Step 6: Keep the pulse negative bias voltage and the N2 and H2 partial pressures unchanged, the Cr target current unchanged, turn on the ion plating NbCrAlY alloy target, and increase the current linearly from 50A to 90A within 10 minutes. The deposition time is 10 minutes and the thickness is 1.2 microns.

[0090] Step 7: Keep the pulse negative bias voltage constant and the N2 and H2 partial pressures constant, turn off the ion plating Ti target, keep the ion plating NbCrAlY alloy target arc source current at 90A, and deposit the nano-duplex composite layer for 80 minutes with a thickness of 4 microns; after stopping the coating, cool it with ice water for 50 minutes and remove the workpiece.

[0091] The atomic percentage of Cr in the CrAlY alloy target is 55%, the atomic percentage of Al is 40%, and the atomic percentage of Y is 5%;

[0092] The atomic percentages of the NbCrAlY alloy target are the same as those in Example 1.

[0093] Example 6

[0094] A method for preparing a composite coating material for a PCB milling cutter is as follows:

[0095] Step 1: Select a PCB milling cutter as the base, with a blade length of 27.500 mm and a blade diameter of 1.815 mm; degrease, remove rust, clean with acetone, rinse with water, and dry the base;

[0096] Step 2: Load the cleaned and dried substrate into the coating furnace; evacuate to 1.8×10⁻³Pa and maintain the temperature at 260°C; perform gas plasma cleaning by introducing He and H2 with set partial pressures of 0.25Pa and 0.15Pa respectively, the ion source current is 12A, a pulsed negative bias is applied, the frequency is 86kHz, the peak value is 320V, the duty cycle is 88%, and the cleaning time is 30 minutes;

[0097] Step 3: Turn off the gas ion source, adjust the pulse negative bias voltage to 86 kHz, 1200 V peak, and 35% duty cycle, and adjust the He and H2 partial pressures to 0.2 Pa and 0.08 Pa respectively; start arc ion plating of the Cr target with an arc source current of 90 A, and perform bombardment sputtering cleaning for 8 minutes;

[0098] Step 4: Deposit a Cr bonding layer by adjusting the pulsed negative bias frequency to 86 kHz, peak value to 220 V, duty cycle to 88%, He and H2 partial pressures to 0.35 Pa and 0.15 Pa, and the Cr target arc source current to 90 A; the deposition time is 4 minutes, and the thickness is 0.3 μm;

[0099] Step 5: Deposit a TiAlN transition layer on the bonding layer, keep the pulsed negative bias voltage unchanged, turn off He, and introduce N2 with a partial pressure of 0.35 Pa; use a TiAl alloy target, deposit for 3 minutes, and have a thickness of 0.3 μm;

[0100] Step 6: Keep the pulse negative bias voltage and the N2 and H2 partial pressures unchanged, the Cr target current unchanged, turn on the ion plating NbCoSiY alloy target, and increase the current linearly from 50A to 90A within 10 minutes. The deposition time is 10 minutes and the thickness is 1.2 microns.

[0101] Step 7: Keep the pulse negative bias voltage constant, the N2 and H2 partial pressures constant, turn off the ion plating Ti target, keep the ion plating NbCoSiY alloy target arc source current at 90A, and deposit the nano-duplex composite layer for 80 minutes with a thickness of 4 microns; after stopping the coating, cool it with ice water for 50 minutes and remove the workpiece.

[0102] The atomic percentages of the TiAl alloy target are the same as those in Example 1.

[0103] The NbCoSiY alloy target has an atomic percentage of Nb of 40%, an atomic percentage of Co of 25%, an atomic percentage of Si of 30%, and an atomic percentage of Y of 5%.

[0104] Example 7

[0105] A method for preparing a composite coating material for a PCB milling cutter is as follows:

[0106] Step 1: Select a PCB milling cutter as the base, with a blade length of 27.500 mm and a blade diameter of 1.815 mm; degrease, remove rust, clean with acetone, rinse with water, and dry the base;

[0107] Step 2: Load the cleaned and dried substrate into the coating furnace; evacuate to 1.8×10⁻³Pa and maintain the temperature at 260°C; perform gas plasma cleaning by introducing He and H2 with set partial pressures of 0.25Pa and 0.15Pa respectively, the ion source current is 12A, a pulsed negative bias is applied, the frequency is 86kHz, the peak value is 320V, the duty cycle is 88%, and the cleaning time is 30 minutes;

[0108] Step 3: Turn off the gas ion source, adjust the pulse negative bias voltage to 86 kHz, 1200 V peak, and 35% duty cycle, and adjust the He and H2 partial pressures to 0.2 Pa and 0.08 Pa respectively; start arc ion plating of the Cr target with an arc source current of 90 A, and perform bombardment sputtering cleaning for 8 minutes;

[0109] Step 4: Deposit a Cr bonding layer by adjusting the pulsed negative bias frequency to 86 kHz, peak value to 220 V, duty cycle to 88%, He and H2 partial pressures to 0.35 Pa and 0.15 Pa, and the Cr target arc source current to 90 A; the deposition time is 4 minutes, and the thickness is 0.3 μm;

[0110] Step 5: Deposit a TiAlN transition layer on the bonding layer, keep the pulsed negative bias voltage unchanged, turn off He, and introduce N2 with a partial pressure of 0.35 Pa; use a TiAl alloy target, deposit for 3 minutes, and have a thickness of 0.3 μm;

[0111] Step 6: Keep the pulse negative bias voltage and the N2 and H2 partial pressures unchanged, the Cr target current unchanged, turn on the ion plating NbAlTiSi alloy target, and increase the current linearly from 50A to 90A within 10 minutes. The deposition time is 10 minutes and the thickness is 1.2 microns.

[0112] Step 7: Keep the pulse negative bias voltage unchanged, the N2 and H2 partial pressures unchanged, turn off the ion plating Ti target, keep the ion plating NbAlTiSi alloy target arc source current at 90A, and deposit the nano-duplex composite layer for 80 minutes with a thickness of 4 microns; after stopping the coating, cool it with ice water for 50 minutes and remove the workpiece.

[0113] The atomic percentages of the TiAl alloy target are the same as those in Example 1.

[0114] The atomic percentage of Nb in the NbAlTiSi alloy target is 40%, the atomic percentage of Al is 25%, the atomic percentage of Ti is 30%, and the atomic percentage of Si is 5%.

[0115] Comparative Example 1

[0116] A method for preparing a composite coating material for a PCB milling cutter is as follows:

[0117] Step 1: Select a PCB milling cutter as the base, with a blade length of 27.500 mm and a blade diameter of 1.815 mm; degrease, remove rust, clean with acetone, rinse with water, and dry the base;

[0118] Step 2: Load the cleaned and dried substrate into the coating furnace; evacuate to 1.8×10⁻³Pa and maintain the temperature at 260°C; perform gas plasma cleaning by introducing He and H2 with set partial pressures of 0.25Pa and 0.15Pa respectively, the ion source current is 12A, a pulsed negative bias is applied, the frequency is 86kHz, the peak value is 320V, the duty cycle is 88%, and the cleaning time is 30 minutes;

[0119] Step 3: Turn off the gas ion source, adjust the pulse negative bias voltage to 86 kHz, 1200 V peak, and 35% duty cycle, and adjust the He and H2 partial pressures to 0.2 Pa and 0.08 Pa respectively; start arc ion plating of the Cr target with an arc source current of 90 A, and perform bombardment sputtering cleaning for 8 minutes;

[0120] Step 4: Deposit a Cr bonding layer by adjusting the pulsed negative bias frequency to 86 kHz, peak value to 220 V, duty cycle to 88%, He and H2 partial pressures to 0.35 Pa and 0.15 Pa, and the Cr target arc source current to 90 A; the deposition time is 4 minutes, and the thickness is 0.3 μm;

[0121] Step 5: Deposit a TiAlN transition layer on the bonding layer, keep the pulsed negative bias voltage unchanged, turn off He, and introduce N2 with a partial pressure of 0.35 Pa; use a TiAl alloy target, deposit for 3 minutes, and have a thickness of 0.3 μm;

[0122] Step 6: Keep the pulse negative bias voltage and the N2 and H2 partial pressures unchanged, the Cr target current unchanged, turn on the ion plating NbCrAlY alloy target, and increase the current linearly from 50A to 90A within 10 minutes. The deposition time is 10 minutes and the thickness is 1.2 microns. After the coating is stopped, cool it with ice water for 50 minutes and remove the workpiece.

[0123] The atomic percentages of the TiAl alloy target are the same as those in Example 1.

[0124] The atomic percentages of the NbCrAlY alloy target are the same as those in Example 1.

[0125] Comparative Example 2

[0126] A method for preparing a composite coating material for a PCB milling cutter is as follows:

[0127] Step 1: Select a PCB milling cutter as the base, with a blade length of 27.500 mm and a blade diameter of 1.815 mm; degrease, remove rust, clean with acetone, rinse with water, and dry the base;

[0128] Step 2: Load the cleaned and dried substrate into the coating furnace; evacuate to 1.8×10⁻³Pa and maintain the temperature at 260°C; perform gas plasma cleaning by introducing He and H2 with set partial pressures of 0.25Pa and 0.15Pa respectively, the ion source current is 12A, a pulsed negative bias is applied, the frequency is 86kHz, the peak value is 320V, the duty cycle is 88%, and the cleaning time is 30 minutes;

[0129] Step 3: Turn off the gas ion source, adjust the pulse negative bias voltage to 86 kHz, 1200 V peak, and 35% duty cycle, and adjust the He and H2 partial pressures to 0.2 Pa and 0.08 Pa respectively; start arc ion plating of the Cr target with an arc source current of 90 A, and perform bombardment sputtering cleaning for 8 minutes;

[0130] Step 4: Deposit a Cr bonding layer by adjusting the pulsed negative bias frequency to 86 kHz, peak value to 220 V, duty cycle to 88%, He and H2 partial pressures to 0.35 Pa and 0.15 Pa, and the Cr target arc source current to 90 A; the deposition time is 4 minutes, and the thickness is 0.3 μm;

[0131] Step 5: deposit a TiAlN transition layer on the bonding layer, keep the pulse negative bias voltage unchanged, turn off He, and introduce N2 with a partial pressure of 0.35 Pa; use a TiAl alloy target, the deposition time is 3 minutes, and the thickness is 0.3 microns; after the coating is stopped, use ice water to cool for 50 minutes and remove the workpiece.

[0132] The atomic percentages of the TiAl alloy target are the same as those in Example 1.

[0133] Comparative Example 3

[0134] A method for preparing a composite coating material for a PCB milling cutter is as follows:

[0135] Step 1: Select a PCB milling cutter as the base, with a blade length of 27.500 mm and a blade diameter of 1.815 mm; degrease, remove rust, clean with acetone, rinse with water, and dry the base;

[0136] Step 2: Load the cleaned and dried substrate into the coating furnace; evacuate to 1.8×10⁻³Pa and maintain the temperature at 260°C; perform gas plasma cleaning by introducing He and H2 with set partial pressures of 0.25Pa and 0.15Pa respectively, the ion source current is 12A, a pulsed negative bias is applied, the frequency is 86kHz, the peak value is 320V, the duty cycle is 88%, and the cleaning time is 30 minutes;

[0137] Step 3: Turn off the gas ion source, adjust the pulse negative bias voltage to 86 kHz, 1200 V peak, and 35% duty cycle, and adjust the He and H2 partial pressures to 0.2 Pa and 0.08 Pa respectively; start arc ion plating of the Cr target with an arc source current of 90 A, and perform bombardment sputtering cleaning for 8 minutes;

[0138] Step 4: Deposit a Cr bonding layer, adjust the pulse negative bias frequency to 86 kHz, peak value to 220 V, duty cycle to 88%, He and H2 partial pressures to 0.35 Pa and 0.15 Pa, and the Cr target arc source current to 90 A; the deposition time is 4 minutes, and the thickness is 0.3 μm; after the coating is stopped, cool with ice water for 50 minutes and remove the workpiece.

[0139] Comparative Example 4

[0140] A method for preparing a composite coating material for a PCB milling cutter is as follows:

[0141] Step 1: Select a PCB milling cutter as the base, with a blade length of 27.500 mm and a blade diameter of 1.815 mm; degrease, remove rust, clean with acetone, rinse with water, and dry the base;

[0142] Step 2: Load the cleaned and dried substrate into the coating furnace; evacuate to 1.8×10⁻³Pa and maintain the temperature at 260°C; perform gas plasma cleaning by introducing He and H2 with set partial pressures of 0.25Pa and 0.15Pa respectively, the ion source current is 12A, a pulsed negative bias is applied, the frequency is 86kHz, the peak value is 320V, the duty cycle is 88%, and the cleaning time is 30 minutes;

[0143] Step 3: Turn off the gas ion source, adjust the pulse negative bias voltage to a frequency of 86 kHz, a peak of 1200 V, and a duty cycle of 35%, and adjust the He and H2 partial pressures to 0.2 Pa and 0.08 Pa; start the arc ion plating of the Cr target, with an arc source current of 90 A, and perform bombardment sputtering cleaning for 8 minutes; remove the workpiece.

[0144] Test Example 1

[0145] Friction coefficient test

[0146] The friction coefficient of the coating and the GCr15 pair was measured using an HT-1000 friction and wear tester. Each group was tested three times and the average value was taken. The test results are shown in Table 1.

[0147] Table 1

[0148] Experimental plan Friction coefficient Example 1 0.21 Example 2 0.23 Example 3 0.24 Example 4 0.26 Example 5 0.27 Example 6 0.25 Example 7 0.27 Comparative Example 1 0.31 Comparative Example 2 0.34 Comparative Example 3 0.37 Comparative Example 4 0.45

[0149] Test Example 2

[0150] Wear resistance test

[0151] The coating hardness was measured with an MH-5 microhardness tester under a load of 10 g. Each group was tested three times and the average value was taken. The test results are shown in Table 2.

[0152] Table 2

[0153] Experimental plan Hardness (GPa) Example 1 59 Example 2 54 Example 3 53 Example 4 51 Example 5 52 Example 6 49 Example 7 47 Comparative Example 1 45 Comparative Example 2 41 Comparative Example 3 39 Comparative Example 4 32

[0154] It can be seen from test examples 1 and 2 that the composite coating material obtained in Example 1 of the present invention has the smallest friction coefficient and the highest hardness.

[0155] The NbCrAlY alloy target in Example 1 exhibits a lower friction coefficient and higher hardness, mainly due to its specific element ratio and coating characteristics. The 40% niobium (Nb) content optimizes the hardness and wear resistance of the coating, while the ratio of chromium (Cr) and aluminum (Al) is adjusted to 25% and 30%, which may help to form a more stable compound and enhance the coating performance. At the same time, the addition of 5% of the rare earth element yttrium (Y) may improve the high temperature performance and wear resistance of the coating. In terms of microstructure, possible fine grains and uniformly distributed second phases further improve the overall performance of the coating. The phase composition of the coating, which may contain more body-centered cubic phases, and optimized preparation processes, such as sputtering conditions and deposition rate, also provide guarantees for obtaining lower friction coefficients and higher hardness. In addition, the coating of Example 1 may form a denser and more stable oxide layer during the friction process, which helps to reduce the friction coefficient and improve wear resistance. The combined effect of these factors makes the coating of Example 1 superior to Examples 2 and 3 in performance.

[0156] The TiAl alloy target (60% Ti, 40% Al) exhibited a lower friction coefficient and higher hardness in Example 1, likely due to the influence of the structural characteristics of the TiAl alloy itself and the preparation process on the coating properties. TiAl alloy has high hardness and good thermal stability, which enables it to provide a low friction coefficient and high wear resistance when formed into a coating. In the TiAl alloy target, the ratio of Ti to Al significantly influences the structure and properties of the coating. The 60% Ti to 40% Al ratio likely creates a more optimal microstructure, thereby improving the coating's hardness and wear resistance. Furthermore, during the sputtering process of the TiAl alloy target, the Ti and Al elements exist as single phases, with Ti atomic particles embedded in the Al matrix. This structure facilitates the generation of more metal ions during sputtering, thereby improving the deposition rate and quality of the coating. The different element ratios in the AlCr and CrAlY alloy targets may result in different microstructures and phase compositions, affecting the coating's hardness and friction coefficient. During the deposition process of the coating, the Ti and Al elements in the TiAl alloy target are transformed from a single phase structure into an ion flow state with a certain energy. With the participation of the reaction gas, they combine with N atoms, thereby improving the hardness and bonding strength of the coating.

[0157] The NbCrAlY alloy target in Example 1 exhibits a lower coefficient of friction and higher hardness than the NbCoSiY alloy target in Example 6 and the NbAlTiSi alloy target in Example 7. In Example 1, the chromium (Cr) content is higher than the cobalt (Co) and titanium (Ti) content in Examples 6 and 7. Chromium, a hard and chemically stable element, contributes to the coating's hardness and wear resistance, thereby reducing the coefficient of friction. The NbCrAlY alloy contains a high content of aluminum (Al), which generally improves the material's hardness and high-temperature resistance. Furthermore, the combination of aluminum with niobium (Nb) and chromium likely forms a compound with excellent overall properties, which helps stabilize the coating during friction and reduces wear. Different alloy target materials may result in differences in the coating's microstructure, such as grain size and phase composition. The coating in Example 1 may have finer, more uniform grains and a more optimal phase distribution, properties that contribute to its improved hardness and wear resistance.

[0158] In Example 1, the coating structure consists of a bonding layer, a transition layer, and a nano-duplex composite layer. This multi-layered design helps improve the overall performance of the coating. The bonding layer provides a strong bond with the substrate, the transition layer helps distribute stress and reduce coating defects, and the composite layer provides excellent wear resistance and hardness.

Claims

1. A method for preparing a composite coating material for a PCB milling cutter, characterized in that: Here’s how: Step 1: Select a PCB milling cutter as the substrate, and perform degreasing, rust removal, organic solution cleaning, water rinsing, and drying on the substrate; Step 2: Place the cleaned and dried substrate into a coating furnace; evacuate the furnace and maintain the temperature at 240-280°C; perform gas plasma cleaning by introducing He and H2; Step 3: Turn off the gas ion source, adjust the pulse negative bias voltage, and adjust the He and H2 partial pressures to 0.1~0.3Pa and 0.05~0.1Pa; start the arc ion plating of the Cr target with an arc source current of 80~95A, and perform bombardment sputtering cleaning for 5~10 minutes; Step 4: Deposit a Cr bonding layer by adjusting the pulsed negative bias frequency to 80-90 kHz, the peak value to 200-240 V, the duty cycle to 80-90%, the He and H2 partial pressures to 0.3-0.4 Pa and 0.1-0.2 Pa, and the Cr target arc source current to 80-95 A; the deposition time to 3-5 minutes, and the thickness to 0.1-0.5 μm; Step 5: Deposit a TiAlN transition layer on the bonding layer, keep the pulse negative bias voltage unchanged, turn off He, and introduce N2 with a partial pressure of 0.3-0.4 Pa; use a TiAl alloy target, deposit for 2-4 minutes, and achieve a thickness of 0.1-0.5 μm; Step 6: Keep the pulse negative bias voltage and the N2 and H2 partial pressures unchanged, the Cr target current unchanged, turn on the ion plating NbCrAlY alloy target, and increase the current linearly from 40-60A to 80-100A within 8-12 minutes. The deposition time is 5-15 minutes, and the thickness is 1-1.5 microns. Step 7: Keep the pulse negative bias voltage constant and the N2 and H2 partial pressures constant, turn off the ion plating Cr target, keep the arc source current of the ion plating NbCrAlY alloy target at 80-100A, and deposit the nano-duplex composite layer for 70-100 minutes with a thickness of 3-5 microns; after stopping the coating, cool it with ice water for 40-60 minutes and remove the workpiece; The atomic percentage of Ti in the TiAl alloy target is 60%, and the atomic percentage of Al is 40%; The atomic percentage of Nb in the NbCrAlY alloy target is 40%, the atomic percentage of Cr is 25%, the atomic percentage of Al is 30%, and the atomic percentage of Y is 5%.

2. The method for preparing the composite coating material for a PCB milling cutter according to claim 1, wherein: The PCB milling cutter has a blade length of 20-30 mm and a blade diameter of 0.8-3.175 mm.

3. The method for preparing the composite coating material for a PCB milling cutter according to claim 1, wherein: In step 2, the vacuum is pumped to 1×10 -3 ~2×10 -3 Pa.

4. The method for preparing the composite coating material for a PCB milling cutter according to claim 1, wherein: In step 2, the gas plasma cleaning setting partial pressures are 0.2~0.3Pa and 0.1~0.2Pa respectively, the ion source current is 10~15A, a pulsed negative bias is applied, the frequency is 80~90kHz, the peak value is 300~350V, the duty cycle is 80~90%, and the cleaning time is 20~40 minutes.

5. The method for preparing the composite coating material for a PCB milling cutter according to claim 1, wherein: In step 3, the pulse negative bias voltage is adjusted to a frequency of 80-90 kHz, a peak value of 1100-1300 V, and a duty cycle of 30-40%.

6. The method for preparing the composite coating material for a PCB milling cutter according to claim 1, wherein: The organic solution is one of acetone and isopropyl alcohol.

7. A composite coating material for a PCB milling cutter, characterized by: Prepared by the preparation method according to any one of claims 1 to 6.