CN103981496B - A device and method for preparing TiAlCrN multi-layer coating - Google Patents

Abstract

The patent of the present invention relates to TiAlCrN multi-component coatings, in particular to a device for preparing TiAlCrN multi-component coatings by closed-field unbalanced magnetic sputtering and a method for preparing coatings using the device. The device is unique in that it contains four magnetrons , so that the magnetic force lines can extend directly from one magnetron to another magnetron, forming a closed magnetic trap, which can effectively prevent electrons from escaping, thereby improving sputtering efficiency and ionization rate.

Description

A device and method for preparing TiAlCrN multi-layer coating

technical field

The patent of the invention relates to TiAlCrN multi-component coatings, in particular to a device and method for preparing TiAlCrN multi-component coatings by closed-field unbalanced magnetic sputtering method, and designed an advanced closed-field non-balanced magnetic sputtering method to prepare TiAlCrN multi-component coatings The device has good bonding strength between the coating and the substrate. When it is used in strong cutting, the coating on the tool and high extrusion force die is not easy to peel off, and it can also be used for composite and multi-layer coatings.

Background technique

With the progress of modern industry and the development of metal cutting technology, especially the emergence of high-speed cutting, hard cutting and dry cutting technology, higher and higher requirements are put forward for metal cutting tools; The material surface modification technology developed in response to market demand; superhard nitride coating can not only effectively prolong the service life of cutting tools, but also give full play to its advantages of superhardness, toughness, wear resistance and self-lubrication, thereby improving the quality of metal Cutting tool durability and adaptability in modern machining processes.

Adding Al element to the TiN coating, the deposited TiAlN coating can significantly improve its corrosion resistance and working temperature range, while the TiAlN coating exhibits better high temperature oxidation resistance and corrosion resistance after adding Cr element to the TiAlN coating. Therefore, compared with traditional TiN and TiAlN coatings deposited on cemented carbide tools, the new TiAlCrN coating has higher wear resistance, hardness, high temperature oxidation resistance and high thermal stability, especially It is suitable for high-speed dry cutting. The invention designs a device for preparing TiAlCrN multi-layer coating by closed-field unbalanced magnetic sputtering method, which can effectively improve the bonding strength of TiAlCrN multi-layer coating film and substrate.

Contents of the invention

The patent of the present invention is to prepare TiAlCrN multi-layer coating on the surface of the tool base material by adopting closed-field unbalanced magnetron sputtering ion plating technology. Extend directly to another magnetron to form a closed magnetic trap, which can effectively prevent electrons from escaping, thereby improving sputtering efficiency and ionization rate. The device of the present invention is shown in Figure 1, mainly composed of a vacuum system, a power supply system, and a control system , Cooling system consists of four parts.

The vacuum system includes: vacuum chamber, target material, sample holder, unbalanced magnetron, iodine-tungsten lamp heating device, mechanical pump and diffusion pump, which are respectively connected to the vacuum chamber; sample holder for installing samples Located in the center of the vacuum chamber; during the coating deposition process, the sample rotates with the workpiece frame to make the coating evenly distributed; 4 targets are installed on the furnace wall of the vacuum chamber: Ti target, Cr target, Al target, Cr target; 4 targets The material is symmetrically distributed; each target is equipped with an unbalanced magnetron so that the unbalanced magnetron is also symmetrically distributed; the iodine-tungsten lamp heating device is built in the bottom of the vacuum chamber.

The first level of vacuum is rough pumped by a mechanical pump, and the second level of vacuum is finely pumped by a diffusion pump. The vacuum chamber has a built-in iodine tungsten lamp heating device. The sample is installed on the sample holder in the center of the vacuum chamber and rotates with the sample holder during the coating deposition process. , so that the coating is evenly distributed. Four targets are installed on the furnace wall of the vacuum chamber: Ti target, Cr target, Al target, and Cr target. Unbalanced magnetrons are installed on the targets, and the magnetrons are symmetrically distributed, which makes the magnetic field lines It can be directly extended from one magnetron to another to generate a closed magnetic field, effectively prevent electrons from escaping, and improve sputtering efficiency and ionization rate.

The power supply system is divided into two parts: one part provides 4 sputtering power supplies with DC voltage for 4 unbalanced magnetrons respectively, and the sputtering power supply is connected to the target; the other part provides pulse bias voltage for the sample and is connected to the sample.

The control system includes: the reaction gas _N2 and the protective gas Ar are introduced into the vacuum chamber through the flow control meter, and the flow is adjusted to control the sputtering pressure. The operation of the whole system is controlled by computer software;

Cooling system: In order to prevent the target temperature from being too high due to sputtering, the target is a hollow through hole, which is similar to a water pipe structure, as shown in Figure 5. The hollow through hole is used as a cooling water tank, so it can be directly cooled by water.

Description of drawings

Fig. 1 Schematic diagram of the device for preparing TiAlCrN multi-layer coatings by the closed-field unbalanced magnetic sputtering method.

1-iodine tungsten lamp heating device; 2-magnetron; 3-Ti target; 4-sputtering power supply; 5-sample holder; 6-Cr target; 7-vacuum chamber; 8-Al target; 9-bias power supply 10-Cr target; 11-mechanical pump; 12-diffusion pump; 13-flow control meter; 14-N ₂ ; 15-Ar; 16-cooling water pipe.

Fig. 2 Surface morphology of TiAlCrN multi-layer coating; (a) low-magnification morphology; (b) high-magnification morphology.

Fig. 3 EDS analysis of TiAlCrN multi-component coating.

Fig. 4 Bonding strength of TiAlCrN multi-layer coating.

Figure 5 Schematic diagram of target structure.

detailed description

(1) Using a strong magnet and soft iron to form an unbalanced magnetic field, select Ti target, Al target and Cr target with a purity of 99.99% as the sputtering target, the specification is 100×100mm, and the sample is passed through No. 80 to No. 1200 sandpaper and Grinding with metallographic sandpaper, polishing to the mirror surface with diamond polishing agent with a particle size of 2.5, and then putting in acetone and alcohol solution for ultrasonic cleaning for 10 minutes to remove impurities and grease on the surface of the substrate; Cr target and Cr target, Ti target and Al are respectively installed in a vacuum On the furnace wall of the chamber, the sample is placed on the sample holder. During the coating deposition process, the sample rotates with the workpiece holder. The rotation speed of the workpiece holder is set at 20 r/min to make the coating uniform.

(2) Two-stage vacuum system is used: the front stage uses a mechanical pump for rough pumping, and the latter stage uses a diffusion pump for fine pumping to pump the ultimate vacuum of the system to 5×10 ^-3 Pa; use a built-in iodine-tungsten lamp device in the vacuum chamber for heating , the substrate temperature was controlled at 200°C, and Ar gas with a purity of 99.99% was introduced into the sputtering chamber through a flowmeter. The pulse power supply of the sputtering target is 25kHz, 0~3A adjustable power supply, the voltage of 50-500V is applied to the sputtering target (provided by the sputtering power supply), the rated voltage of the sputtering furnace is 100V~600V, and the rated power is 50kW ( pulsed bias supplied).

(3) The magnetrons are distributed symmetrically, which enables the magnetic lines of force to extend directly from one magnetron to another, so as to generate a closed magnetic field, effectively prevent electrons from escaping, and improve sputtering efficiency and ionization rate.

(4) Atoms on the surface of the target are bombarded by Ar ions (that is, sputtering). Atoms are electrically neutral and can directly rush out of the magnetic potential well without being constrained by a magnetic field. These atoms bombard and deposit on the surface of the workpiece to form a dense coating.

(5) Electrons are sputtered from the surface of the target. The electrons are electronegative subatomic particles, which will be captured by the magnetic potential well, and will be cyclotron accelerated in the magnetic potential well, and then bombard the Ar atoms in this area, causing the ionization to go out. When more and more Ar ions are added, when the sputtering process begins, more and more Ar ions will be generated, so that the glow discharge can be self-sustained, and the sputtering process continues.

(6) The bombardment of a large number of high-energy particles will cause the temperature of the target and the magnetron to rise. A cooling water tank is added to the target, so that the target can be cooled by circulation.

(7) The surface morphology of TiAlCrN coating prepared by closed-field non-equilibrium magnetic sputtering device is shown in Figure 2. The mass fraction of surface chemical elements (mass, %): Ti 7.41, Al 18.57, Cr 20.54, N 34.32, C 9.74, O 7.09, Fe 0.15, Co 0.37, W 1.81, atomic fraction (at, %): Ti 3.12, Al 13.87, Cr 7.96, N 49.39, C 16.35, O 8.94, Fe 0.05, Co 0.13, W 0.20, such as As shown in Figure 3, elements such as Ca, K, and Cl are impurities, and their contents are not shown. Elements such as C, O, Fe, Co, and W are diffraction peaks of the tool matrix.

(8) The TiAlCrN coating has a high interface bonding strength, which is 87.6N measured by the scratch method, as shown in Figure 4.

Claims (5)

1. Utilize a kind of method for preparing TiAlCrN multi-component coating by a device for preparing TiAlCrN multi-component coating, it is characterized in that comprising the steps: (1) Use a strong magnet and soft iron to form an unbalanced magnetic field, select Ti target, Al target and Cr target with a purity of 99.99% as the sputtering target, the specification is 100×100mm, and the sample is passed through No. 80 to No. 1200 sandpaper and Grinding with metallographic sandpaper, polishing to the mirror surface with diamond polishing agent with a particle size of 2.5, and then putting in acetone and alcohol solution for ultrasonic cleaning for 10 minutes to remove impurities and grease on the surface of the substrate; Cr target and Cr target, Ti target and Al are respectively installed in a vacuum On the furnace wall of the chamber, the sample is placed on the sample holder, and the sample rotates with the workpiece holder during the coating deposition process, and the rotation speed of the workpiece holder is set at 20r/min to make the coating uniform; (2) Two-stage vacuum system is used: the front stage uses a mechanical pump for rough pumping, and the latter stage uses a diffusion pump for fine pumping to pump the ultimate vacuum of the system to 5×10 ^-3 Pa; use a built-in iodine tungsten lamp device in the vacuum chamber for heating , the substrate temperature was controlled at 200°C, and Ar gas with a purity of 99.99% was introduced into the sputtering chamber through a flowmeter. The pulse power supply of the sputtering target is 25kHz, 0-3A adjustable power supply, the sputtering target is applied with a voltage of 50-500V, and the sputtering power supply is provided; the rated voltage in the sputtering furnace is 100V-600V, and the rated power is 50kW. Bias supply; (3) The magnetrons are symmetrically distributed, which makes the magnetic force lines extend directly from one magnetron to another magnetron, so as to generate a closed magnetic field, effectively prevent electrons from escaping, and improve sputtering efficiency and ionization rate; (4) Atoms on the surface of the target are bombarded by Ar ions to form sputtering. The atoms are electrically neutral and rush out of the magnetic potential well without being constrained by the magnetic field. These atoms bombard and deposit on the surface of the workpiece to form a dense coating; (5) Electrons are sputtered from the surface of the target. Electrons are electronegativity subatomic particles, which will be captured by the magnetic potential well, accelerated by cyclotron in the magnetic potential well, and then bombard the Ar atoms in this area, causing the ionized out When more and more Ar ions are added, when the sputtering process starts, more and more Ar ions will be generated, so that the glow discharge can be self-sustained, and the sputtering process continues; (6) The bombardment of a large number of high-energy particles will cause the temperature of the target and the magnetron to rise. A cooling water tank is added to the target to circulate the cooling when the target is cooled. 2. the method for preparing TiAlCrN multi-component coating as claimed in claim 1 is characterized in that: described a kind of device for preparing TiAlCrN multi-component coating mainly consists of four parts: vacuum system, power supply system, control system and cooling system Composition, the vacuum system includes: vacuum chamber, target material, sample holder, unbalanced magnetron, iodine tungsten lamp heating device, mechanical pump and diffusion pump; the mechanical pump and diffusion pump are respectively connected to the vacuum chamber for the installation of the sample The sample holder is located in the center of the vacuum chamber. During the coating deposition process, the sample rotates with the workpiece holder to make the coating evenly distributed. The iodine-tungsten lamp heating device is built in the bottom of the vacuum chamber; 4 targets are installed on the furnace wall of the vacuum chamber: Ti target , Cr target, Al target, Cr target; 4 targets are symmetrically distributed; each target is equipped with an unbalanced magnetron so that the unbalanced magnetron is also symmetrically distributed; the magnetic force line extends directly from a magnetron to Another magnetron is used to generate a closed magnetic field, effectively prevent electrons from escaping, and improve sputtering efficiency and ionization rate. 3. the method for preparing TiAlCrN multi-component coating as claimed in claim 2 is characterized in that: power supply system is divided into two parts: a part provides 4 sputtering power supplies of DC voltage respectively for 4 unbalanced magnetrons, sputtering The radio source is connected to the target; the other part provides pulse bias voltage for the sample and is connected to the sample. 4. the method for preparing TiAlCrN multi-component coating as claimed in claim 2 is characterized in that: control system comprises reaction gas N ₂ , protection gas Ar and flow control meter, reaction gas N ₂ and protection gas Ar pass through flow control meter To introduce the vacuum chamber, adjust the flow rate to control the sputtering pressure, and the operation of the whole system is controlled by computer software. 5. The method for preparing TiAlCrN multi-layer coating as claimed in claim 2, characterized in that: the cooling system comprises a target material, and for preventing the target material temperature from being too high due to sputtering, the target material is a hollow through hole, and the hollow through hole As a cooling water tank, so direct water cooling.