High-temperature oxidation-resistant and wear-resistant composite coating on surface of cast high-temperature alloy and preparation method thereof

Abstract

This invention discloses a high-temperature oxidation-resistant and wear-resistant composite coating for the surface of cast superalloys, comprising an Al metal transition layer, an AlSi high-temperature oxidation-resistant layer, and a TiCN wear-resistant layer deposited sequentially from the inside out on the surface of a nickel-based cast superalloy. The invention also discloses a method for preparing the composite coating, which involves first ion bombarding the substrate for cleaning, and then sequentially depositing Al, AlSi, and TiCN coatings on the substrate surface. Each deposition process includes two stages: low-power weak ionization and high-power strong ionization. The substrate is subjected to high-temperature heating treatment before the TiCN coating deposition. The composite coating of this invention exhibits excellent high-temperature oxidation resistance and wear resistance. The preparation method of this invention features high deposition efficiency, low internal stress and high adhesion between the heterogeneous coatings, and high surface quality.

Description

Technical Field

[0001] This invention belongs to the field of surface coating and protection technology for cast metal parts, and relates to a high-temperature oxidation-resistant and wear-resistant composite coating for the surface of cast high-temperature alloys. This invention also relates to a method for preparing the above-mentioned high-temperature oxidation-resistant and wear-resistant composite coating. Background Technology

[0002] Nickel-based cast superalloys refer to high-temperature alloy materials with nickel as the main component, which are directly used to manufacture parts by casting. They possess excellent comprehensive mechanical properties such as high-temperature strength, fatigue stability, and fracture toughness, and are widely used in key fields such as aerospace, automotive, and gas turbines. However, while nickel-based cast superalloys have good high-temperature mechanical properties, it is difficult to simultaneously achieve high-temperature oxidation resistance and wear resistance. Therefore, coating the surface of the base material with excellent high-temperature mechanical properties with a high-temperature oxidation-resistant and wear-resistant composite coating is an effective way to solve this contradiction.

[0003] AlSi coatings are excellent high-temperature oxidation resistant coatings with good wear resistance. TiCN coatings, possessing both amorphous carbon and nanocrystalline structures, exhibit higher hardness, better toughness, and a lower coefficient of friction compared to traditional TiC and TiN coatings, making them a widely used wear-resistant protective coating for metal surfaces. AlSi-TiCN composite coatings can be prepared using physical vapor deposition (PVD), but related patents and literature indicate few successful cases, primarily due to limitations in various PVD coating preparation methods. Current PVD methods mainly include magnetron sputtering, multi-arc ion plating, and high-power pulsed magnetron sputtering. Magnetron sputtering utilizes the principle of gas glow discharge to achieve low-temperature deposition of high-surface-quality coatings, but its deposition efficiency is low and the coating uniformity is poor for complex parts. Multi-arc ion plating utilizes the principle of gas arc discharge to achieve efficient coating deposition, but the coating contains many large molten particles with a diameter of about 2~20μm, which seriously reduces the mechanical properties of the coating. High-power pulsed magnetron sputtering is a magnetron sputtering technology with a high metal ionization rate. Its working principle is to use a high-power pulsed power supply control mode and obtain a high instantaneous metal ionization rate by reasonably adjusting electric field parameters such as frequency and duty cycle, thereby achieving high ionization. It has significant advantages in improving the density and uniformity of coatings and improving the overall performance of coatings, but its average deposition rate is low, only 15%~50% of that of ordinary magnetron sputtering, and the residual stress of the prepared coating is relatively large.

[0004] Therefore, designing and preparing a high-temperature oxidation-resistant and wear-resistant composite coating with a dense structure and good bonding between heterogeneous coatings has become the key to solving the surface protection of nickel-based cast high-temperature alloy parts. Summary of the Invention

[0005] The purpose of this invention is to provide a high-temperature oxidation-resistant and wear-resistant composite coating for the surface of cast high-temperature alloys, which is an Al-AlSi-TiCN composite coating with excellent high-temperature oxidation resistance and wear resistance.

[0006] Another objective of this invention is to provide a method for preparing the above-mentioned composite coating, which features high deposition efficiency, low internal stress and high bonding strength between the prepared heterogeneous coatings, and high surface quality.

[0007] The technical solution adopted in this invention is a high-temperature oxidation-resistant and wear-resistant composite coating on the surface of a cast high-temperature alloy, comprising an Al metal transition layer, an AlSi high-temperature oxidation-resistant layer, and a TiCN wear-resistant layer deposited sequentially from the inside to the outside on the surface of a nickel-based cast high-temperature alloy.

[0008] The invention is further characterized by:

[0009] The Al metal transition layer has a thickness of 200nm~300nm, the AlSi high-temperature oxidation resistant layer has a thickness of 800nm~1500nm, and the TiCN wear-resistant layer has a thickness of 1500nm~2000nm; the composite coating is composed of uniform and dense nanocrystals with a grain size of less than 20nm.

[0010] Another technical solution adopted in this invention is a method for preparing a high-temperature oxidation-resistant and wear-resistant composite coating on the surface of a cast high-temperature alloy, which is specifically implemented according to the following steps:

[0011] Step 1: Under vacuum conditions, argon gas is introduced, the Al target is started and a DC current is applied to perform ion bombardment cleaning on the nickel-based cast high-temperature alloy matrix.

[0012] Step 2: Turn on the Al target sputtering mode and deposit an Al metal transition layer on the substrate surface through two stages: weak ionization and strong ionization.

[0013] Step 3: Turn off the Al target and turn on the AlSi20at% target. Through two stages of weak ionization and strong ionization, deposit an AlSi high-temperature oxidation resistant coating on the Al metal transition layer.

[0014] Step 4: Turn off the AlSi20at% target and heat-treat the substrate;

[0015] Step 5: Open the TiCN target and deposit the TiCN wear-resistant layer on the AlSi high-temperature oxidation-resistant layer through two stages: weak ionization and strong ionization.

[0016] Another feature of the technical solution of this invention is that:

[0017] In step 1, the vacuum degree is 2.0~3.0×10⁻⁶. -5Torr, argon flow rate 40~60mL / min, Al target current DC 1.0~2.0A, cleaning time 5~10min.

[0018] In step 2, the peak voltages for the weak ionization and strong ionization stages are 200~250V and 600~750V, respectively; the pulse on-time widths for the weak ionization and strong ionization stages are 4~8ms and 6~8ms, respectively; the pulse off-time width is 10~20ms; the negative bias voltage is -60~-40V; the frequency is 40~60Hz; the argon flow rate is 40~60mL / min; and the deposition time is 10~20min.

[0019] In step 3, the peak voltages for the weak ionization and strong ionization stages are 200~250V and 600~750V, respectively; the pulse on-time widths for the weak ionization and strong ionization stages are 4~8ms and 6~8ms, respectively; the pulse off-time width is 10~20ms; the negative bias voltage is -60~-40V; the frequency is 40~60Hz; the argon flow rate is 40~60mL / min; and the deposition time is 20~30min.

[0020] In step 4, the heating temperature is 400~500℃ and the heating time is 10~15min.

[0021] In step 5, the peak voltages for the weak ionization and strong ionization stages are 200~250V and 600~750V, respectively; the pulse on-time widths for the weak ionization and strong ionization stages are 4~8ms and 6~8ms, respectively; the pulse off-time width is 10~20ms; the negative bias voltage is -60~-40V; the frequency is 40~60Hz; the argon flow rate is 40~60mL / min; and the deposition time is 40~60min.

[0022] The beneficial effects of this invention are:

[0023] (1) The structure of the composite coating of the present invention is an Al metal transition layer, an AlSi high temperature oxidation resistant layer, and a TiCN wear resistant layer. This composite coating has the advantages of both AlSi and TiCN coatings and has excellent high temperature oxidation resistance and wear resistance.

[0024] (2) The method of the present invention first deposits an Al metal transition layer on the surface of the cast high-temperature alloy, and then deposits an AlSi anti-high-temperature oxidation layer and a TiCN wear-resistant layer in sequence. The deposition process of the three coatings is divided into a weak ionization stage and a strong ionization stage. The substrate is heated at high temperature before the TiCN coating is deposited, so that the composite coating has a dense coating structure, a smooth and uniform surface quality, and low internal stress and high bonding force between the heterogeneous coatings. This solves the problem that it is currently difficult to obtain a good anti-high-temperature oxidation and wear-resistant composite coating on the surface of nickel-based cast high-temperature alloys by physical vapor deposition. Attached Figure Description

[0025] Figure 1 A schematic diagram of the electric field design for high-power pulsed magnetron sputtering and dual-stage high-power pulsed magnetron sputtering;

[0026] Figure 2 This is a SEM image of the TiCN wear-resistant coating on the surface of the nickel-based cast high-temperature alloy prepared in Example 1 of the present invention;

[0027] Figure 3 This is a cross-sectional SEM image of the Al-AlSi-TiCN composite coating on the surface of the nickel-based cast high-temperature alloy prepared in Example 1 of the present invention. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0029] The present invention relates to a high-temperature oxidation-resistant and wear-resistant composite coating for casting high-temperature alloy surfaces, comprising an Al metal transition layer, an AlSi high-temperature oxidation-resistant layer, and a TiCN wear-resistant layer. The Al metal transition layer has a thickness of 200-300 nm, the AlSi high-temperature oxidation-resistant layer has a thickness of 800-1500 nm, and the TiCN wear-resistant layer has a thickness of 1500 nm-2000 nm. The composite coating is composed of uniform and dense nanocrystals with a grain size of less than 20 nm.

[0030] The present invention discloses a method for preparing a high-temperature oxidation-resistant and wear-resistant composite coating on the surface of a cast high-temperature alloy. Before the AlSi coating is deposited, an Al metal transition layer is designed. Before the TiCN coating is deposited, a substrate heating box device is used to heat the substrate at high temperature to reduce internal stress and activate the surface, thereby improving the bonding force between the AlSi and TiCN heterogeneous coatings.

[0031] This invention employs a self-developed dual-stage high-power pulsed magnetron sputtering device with a substrate heating chamber. Specifically, it modifies the existing high-power pulsed magnetron sputtering device by replacing the high-power pulsed power supply with a dual-stage high-power pulsed power supply incorporating a weak ionization electric field and a strong ionization electric field gradient design, while simultaneously adding a substrate heating chamber to heat the substrate. This dual-stage high-power pulsed magnetron sputtering device can provide both ordinary DC and dual-stage high-power pulsed power supply modes. The maximum power of the pulsed power supply is 12kW, the duty cycle τ is adjustable from 8% to 100%, and the pulse conduction width T... on Pulse turn-off width T off It can be configured as needed.

[0032] like Figure 1The diagram illustrates the electric field design for high-power pulsed magnetron sputtering and dual-stage high-power pulsed magnetron sputtering. This invention proposes a design concept that increases the duty cycle τ and reduces the peak target current to improve deposition efficiency. The electric field mode is designed as segmented or stepped, meaning there are two continuous and independently adjustable pulse stages within one pulse conduction cycle, with the duty cycle τ reaching 10%~100%. In the first pulse stage, lower power is applied to initially ionize Ar gas, forming a low-density plasma, defined as the weak ionization stage. In the second pulse stage, higher power is applied to further ionize atoms, forming a high-density plasma, defined as the strong ionization stage. The pre-ionization process in the weak ionization stage reduces internal stress and improves film-substrate adhesion, while the strong ionization process in the strong ionization stage significantly improves deposition efficiency. A substrate heating chamber is used to improve the adhesion between heterogeneous coatings.

[0033] The method for preparing a high-temperature oxidation-resistant and wear-resistant composite coating on the surface of a cast high-temperature alloy according to the present invention is implemented according to the following steps:

[0034] First, a 99.99% pure Al target, an AlSi20at% target with 20% Si content, and a TiCN target are installed in a two-stage high-power pulsed magnetron sputtering cavity. A nickel-based cast high-temperature alloy substrate is then installed on a substrate rotating frame, with a rotation speed preferably of 3-8 rpm, more preferably 5 rpm.

[0035] Step 1, Ion cleaning:

[0036] The dual-stage high-power pulsed power supply is turned on. After the vacuum level in the vacuum chamber reaches a certain value, high-purity argon gas is introduced, the aluminum target is started, and a DC current is applied. High-energy argon ions are used to bombard the nickel-based cast high-temperature alloy matrix, improving the surface cleanliness and activating the surface. The vacuum level in the vacuum chamber is 2.0~3.0×10⁻⁶. -5 Torr, preferably 2.0×10 -5 Torr; Argon flow rate is 40~60mL / min, preferably 45mL / min; Aluminum target current is DC 1.0~2.0A, preferably 1.5A; Cleaning time is 5~10min.

[0037] Step 2, Al metal transition layer deposition:

[0038] After ion cleaning, the Al target sputtering mode was activated, and relevant parameters such as peak voltage, pulse on-time width, pulse off-time width, negative bias voltage, frequency, and argon flow rate were set to deposit a pure metallic Al transition layer on the substrate. Specifically, the peak voltages for the weak and strong ionization stages were 200–250 V and 600–750 V, respectively; the pulse on-time widths for the weak and strong ionization stages were 4–8 ms and 6–8 ms, respectively; the pulse off-time width was 10–20 ms; the negative bias voltage was -60–-40 V, preferably -60 V; the frequency was 40–60 Hz, preferably 50 Hz; the argon flow rate was 40–60 mL / min, preferably 55 mL / min; and the deposition time was 10–20 min.

[0039] Step 3, Deposition of AlSi high-temperature resistant oxide layer:

[0040] After the Al transition layer deposition is completed, the Al target is turned off, and the AlSi 20at% target is turned on. Parameters such as peak voltage, pulse on-time width, pulse off-time width, negative bias, frequency, and argon flow rate are set for the weak and strong ionization stages. An AlSi high-temperature oxidation resistant coating is deposited on the Al metal transition layer. Specifically, the peak voltages for the weak and strong ionization stages are 200–250 V and 600–750 V, respectively; the pulse on-time widths for the weak and strong ionization stages are 4–8 ms and 6–8 ms, respectively; the pulse off-time width is 10–20 ms; the negative bias is -60–-40 V, preferably -60 V; the frequency is 40–60 Hz, preferably 50 Hz; the argon flow rate is 40–60 mL / min, preferably 55 mL / min; and the deposition time is 20–30 min.

[0041] Step 4, heating the substrate:

[0042] After the AlSi high-temperature oxidation resistant coating is deposited, the AlSi 20at% target is shut off, and the substrate is heated using a substrate heating chamber to reduce residual stress and improve the adhesion between the AlSi and TiCN heterostructure coatings. The heating temperature is 400~500℃, preferably 450℃, and the heating time is 10~15 min, preferably 10 min.

[0043] Step 5, TiCN wear-resistant layer deposition:

[0044] After heating, the substrate heating chamber was turned off, the TiCN target was turned on, and relevant parameters such as peak voltage, pulse on-time width, pulse off-time width, negative bias voltage, frequency, and argon flow rate were set for the weak and strong ionization stages. A TiCN wear-resistant layer was then deposited on the AlSi high-temperature oxide-resistant layer. Specifically, the peak voltages for the weak and strong ionization stages were 200–250 V and 600–750 V, respectively; the pulse on-time widths for the weak and strong ionization stages were 4–8 ms and 6–8 ms, respectively; the pulse off-time width was 10–20 ms; the negative bias voltage was -60–-40 V, preferably -60 V; the frequency was 40–60 Hz, preferably 55 Hz; the argon flow rate was 40–60 mL / min, preferably 55 mL / min; and the deposition time was 40–60 min.

[0045] Finally, a dense, high-performance, high-temperature oxidation-resistant and wear-resistant composite coating was prepared on the surface of a nickel-based cast high-temperature alloy substrate.

[0046] Example 1

[0047] Step 1, Ion cleaning: When the vacuum level in the vacuum chamber reaches 2.0 × 10⁻⁶ -5 After Torr, high-purity argon gas with a flow rate of 45 mL / min was introduced, the aluminum target was started and a DC current of 1.5 A was applied, and the nickel-based cast high-temperature alloy matrix was bombarded with ions for 5 min.

[0048] Step 2, Al metal transition layer deposition: Turn on the Al target sputtering mode, set the peak voltages for the weak ionization stage to 220V and 600V respectively, the pulse on-time widths for the weak ionization stage to 4ms and 6ms respectively, the pulse off-time width to 12ms, the negative bias voltage to -60V, the frequency to 50Hz, the argon flow rate to 45mL / min, and the deposition time to 10min, depositing a pure metallic Al underlayer transition layer on the substrate.

[0049] Step 3, AlSi high-temperature oxide layer deposition: Turn off the Al target, turn on the AlSi 20at% target, set the peak voltages for the weak ionization and strong ionization stages to 220V and 600V respectively, the pulse on-time widths for the weak ionization and strong ionization stages to 4ms and 6ms respectively, the pulse off-time width to 12ms, the negative bias voltage to -60V, the frequency to 50Hz, the argon flow rate to 45mL / min, and the deposition time to 20min, depositing the AlSi high-temperature oxide layer on the Al transition layer.

[0050] Step 4, Substrate heating: Turn off the AlSi20at% target and use a substrate heating box to heat the substrate at a temperature of 450℃ for 10 minutes.

[0051] Step 5, TiCN wear-resistant layer deposition: Turn off the substrate heating box, turn on the TiCN target, set the peak voltages for the weak ionization and strong ionization stages to 220V and 600V, respectively, the pulse on-time widths for the weak ionization and strong ionization stages to 4ms and 6ms, respectively, the pulse off-time width to 12ms, the negative bias voltage to -60V, the frequency to 50Hz, the preferred argon flow rate to be 45mL / min, and the deposition time to 40min, depositing a TiCN coating on the AlSi high-temperature oxide resistant layer.

[0052] Figure 2 The SEM image of the TiCN wear-resistant coating on the surface of the nickel-based cast high-temperature alloy shows that the surface is composed of fine and uniform particles, without obvious defects and impurities, and the surface quality is good. Figure 3 A cross-sectional SEM image of the Al-AlSi-TiCN composite coating on the surface of a nickel-based cast superalloy shows that the Al transition layer thickness is 210 nm, the AlSi high-temperature oxidation-resistant layer thickness is 825 nm, and the TiCN wear-resistant layer thickness is 1956 nm. Furthermore, the oxidation weight gain per unit area of ​​the composite coating after 500 hours of isothermal oxidation at 1000℃ is 0.765 mg. 2 ·cm -4 The oxidation rate is 2.86 × 10⁻⁶. -4 mg 2 ·cm -4 ·h -1 Compared with existing technologies, the coating exhibits significantly improved resistance to high-temperature oxidation. The average coefficient of friction of the composite coating at room temperature is 0.13, and the mass wear rate is 1.02 × 10⁻⁶. -4 g / s.

[0053] In summary, the composite coating obtained in this embodiment has a dense overall structure and excellent performance.

[0054] Example 2

[0055] Step 1, Ion cleaning: When the vacuum level in the vacuum chamber reaches 2.5 × 10⁻⁶ -5 After Torr, high-purity argon gas with a flow rate of 50 mL / min was introduced, the aluminum target was started and a DC current of 1.5 A was applied, and the nickel-based cast high-temperature alloy matrix was bombarded with ions for 5 min.

[0056] Step 2, Al metal transition layer deposition: Turn on the Al target sputtering mode, set the peak voltages for the weak ionization stage to 200V and 650V respectively, the pulse on-time widths for the weak ionization stage to 6ms and 8ms respectively, the pulse off-time width to 10ms, the negative bias voltage to -60V, the frequency to 50Hz, the argon flow rate to 50mL / min, and the deposition time to 10min, depositing a pure metallic Al underlayer transition layer on the substrate.

[0057] Step 3, AlSi high-temperature oxide-resistant layer deposition: Turn off the Al target, turn on the AlSi 20at% target, set the peak voltages for the weak ionization and strong ionization stages to 200V and 650V respectively, the pulse on-time widths for the weak ionization and strong ionization stages to 6ms and 8ms respectively, the pulse off-time width to 10ms, the negative bias voltage to -60V, the frequency to 50Hz, the argon flow rate to 50mL / min, and the deposition time to 30min, depositing the AlSi high-temperature oxide-resistant layer on the Al transition layer.

[0058] Step 4, Substrate heating: Turn off the AlSi20at% target and use a substrate heating box to heat the substrate at a temperature of 500℃ for 10 minutes.

[0059] Step 5, TiCN wear-resistant layer deposition: Turn off the substrate heating box, turn on the TiCN target, set the peak voltages for the weak ionization and strong ionization stages to 200V and 650V respectively, the pulse on-time widths for the weak ionization and strong ionization stages to 6ms and 8ms respectively, the pulse off-time width to 10ms, the negative bias voltage to -60V, the frequency to 50Hz, the preferred argon flow rate to 50mL / min, and the deposition time to 40min, depositing a TiCN coating on the AlSi high-temperature oxide resistant layer.

[0060] Testing revealed that the TiCN wear-resistant coating in this embodiment consists of fine, uniform particles without obvious defects or impurities, indicating good surface quality. The Al-AlSi-TiCN composite coating thickness on the nickel-based cast superalloy surface is 3450 nm. The weight gain of the composite coating after 500 hours of constant-temperature oxidation at 1000℃ is 0.745 mg. 2 ·cm -4 The oxidation rate is 2.48 × 10⁻⁶. -4 mg 2 ·cm -4 ·h -1 Compared with existing technologies, the coating exhibits significantly improved high-temperature oxidation resistance. The average coefficient of friction of the composite coating at room temperature is 0.125, and the mass wear rate is 0.98 × 10⁻⁶. -4 g / s.

[0061] Example 3

[0062] Step 1, Ion cleaning: When the vacuum level in the vacuum chamber reaches 2.5 × 10⁻⁶ -5 After Torr, high-purity argon gas with a flow rate of 50 mL / min was introduced, the aluminum target was started and a DC current of 1.5 A was applied, and the nickel-based cast high-temperature alloy matrix was bombarded with ions for 5 min.

[0063] Step 2, Al metal transition layer deposition: Turn on the Al target sputtering mode, set the peak voltages for the weak ionization stage to 250V and 680V respectively, the pulse on-time widths for the weak ionization stage to 8ms and 8ms respectively, the pulse off-time width to 12ms, the negative bias voltage to -55V, the frequency to 50Hz, the argon flow rate to 45mL / min, and the deposition time to 15min, depositing a pure metallic Al underlayer transition layer on the substrate.

[0064] Step 3, AlSi high-temperature oxide layer deposition: Turn off the Al target, turn on the AlSi 20at% target, set the peak voltages for the weak ionization and strong ionization stages to 250V and 680V respectively, the pulse on-time widths for the weak ionization and strong ionization stages to 8ms and 8ms respectively, the pulse off-time width to 10ms, the negative bias voltage to -55V, the frequency to 50Hz, the argon flow rate to 45mL / min, and the deposition time to 20min, depositing the AlSi high-temperature oxide layer on the Al transition layer.

[0065] Step 4, Substrate heating: Turn off the AlSi20at% target and use a substrate heating box to heat the substrate at a temperature of 400℃ for 15 minutes.

[0066] Step 5, TiCN wear-resistant layer deposition: Turn off the substrate heating box, turn on the TiCN target, set the peak voltages for the weak ionization and strong ionization stages to 250V and 680V respectively, the pulse on-time widths for the weak ionization and strong ionization stages to 8ms and 8ms respectively, the pulse off-time width to 10ms, the negative bias voltage to -55V, the frequency to 50Hz, the preferred argon flow rate to be 45mL / min, and the deposition time to 50min, depositing a TiCN coating on the AlSi high-temperature oxide resistant layer.

[0067] Testing revealed that the TiCN wear-resistant coating in this embodiment consists of fine, uniform particles without obvious defects or impurities, indicating good surface quality. The Al-AlSi-TiCN composite coating thickness on the nickel-based cast high-temperature alloy surface is 2860 nm. The weight gain of the composite coating after oxidation at 1000℃ for 500 hours is 0.766 mg. 2 ·cm -4 The oxidation rate is 2.93 × 10⁻⁶. -4 mg 2 ·cm -4 ·h -1 Compared with existing technologies, the coating exhibits significantly improved resistance to high-temperature oxidation. The average coefficient of friction of the composite coating at room temperature is 0.131, and the mass wear rate is 1.05 × 10⁻⁶. -4 g / s.

[0068] Example 4

[0069] Step 1, Ion cleaning: When the vacuum level in the vacuum chamber reaches 2.5 × 10⁻⁶ -5 After Torr, high-purity argon gas with a flow rate of 48 mL / min was introduced, the aluminum target was started and a DC current of 1.5 A was applied, and the nickel-based cast high-temperature alloy matrix was bombarded with ions for 5 min.

[0070] Step 2, Al metal transition layer deposition: Turn on the Al target sputtering mode, set the peak voltages for the weak ionization stage to 230V and 700V respectively, the pulse on-time widths for the weak ionization stage to 8ms and 8ms respectively, the pulse off-time width to 12ms, the negative bias voltage to -55V, the frequency to 50Hz, the argon flow rate to 45mL / min, and the deposition time to 15min, depositing a pure metallic Al underlayer transition layer on the substrate.

[0071] Step 3, AlSi high-temperature oxide-resistant layer deposition: Turn off the Al target, turn on the AlSi 20at% target, set the peak voltages for the weak ionization and strong ionization stages to 230V and 700V respectively, the pulse on-time widths for the weak ionization and strong ionization stages to 8ms and 8ms respectively, the pulse off-time width to 10ms, the negative bias voltage to -55V, the frequency to 50Hz, the argon flow rate to 45mL / min, and the deposition time to 20min, depositing the AlSi high-temperature oxide-resistant layer on the Al transition layer.

[0072] Step 4, Substrate heating: Turn off the AlSi20at% target and use a substrate heating box to heat the substrate at a temperature of 450℃ for 10 minutes.

[0073] Step 5, TiCN wear-resistant layer deposition: Turn off the substrate heating box, turn on the TiCN target, set the peak voltages for the weak ionization and strong ionization stages to 230V and 700V respectively, the pulse on-time widths for the weak ionization and strong ionization stages to 8ms and 8ms respectively, the pulse off-time width to 10ms, the negative bias voltage to -55V, the frequency to 50Hz, the preferred argon flow rate to be 45mL / min, and the deposition time to 45min, depositing a TiCN coating on the AlSi high-temperature oxide resistant layer.

[0074] Testing revealed that the TiCN wear-resistant coating in this embodiment consists of fine, uniform particles without obvious defects or impurities, indicating good surface quality. The Al-AlSi-TiCN composite coating thickness on the nickel-based cast superalloy surface is 2914 nm. The weight gain of the composite coating after 500 hours of constant-temperature oxidation at 1000℃ is 0.783 mg. 2 ·cm -4 The oxidation rate is 2.89 × 10⁻⁶. -4 mg 2 ·cm -4 ·h -1Compared with existing technologies, the coating exhibits significantly improved resistance to high-temperature oxidation. The average coefficient of friction of the composite coating at room temperature is 0.128, and the mass wear rate is 1.01 × 10⁻⁶. -4 g / s.

[0075] Example 5

[0076] Step 1, Ion cleaning: When the vacuum level in the vacuum chamber reaches 2.5 × 10⁻⁶ -5 After Torr, high-purity argon gas with a flow rate of 50 mL / min was introduced, the aluminum target was started and a DC current of 1.5 A was applied, and the nickel-based cast high-temperature alloy matrix was bombarded with ions for 5 min.

[0077] Step 2, Al metal transition layer deposition: Turn on the Al target sputtering mode, set the peak voltages for the weak ionization stage to 240V and 720V respectively, the pulse on-time widths for the weak ionization stage to 6ms and 8ms respectively, the pulse off-time width to 12ms, the negative bias voltage to -55V, the frequency to 50Hz, the argon flow rate to 45mL / min, and the deposition time to 20min, depositing a pure metallic Al underlayer transition layer on the substrate.

[0078] Step 3, AlSi high-temperature oxide-resistant layer deposition: Turn off the Al target, turn on the AlSi 20at% target, set the peak voltages for the weak ionization and strong ionization stages to 240V and 720V respectively, the pulse on-time widths for the weak ionization and strong ionization stages to 6ms and 8ms respectively, the pulse off-time width to 12ms, the negative bias voltage to -55V, the frequency to 50Hz, the argon flow rate to 45mL / min, and the deposition time to 25min, depositing the AlSi high-temperature oxide-resistant layer on the Al transition layer.

[0079] Step 4, Substrate heating: Turn off the AlSi20at% target and use a substrate heating box to heat the substrate at a temperature of 500℃ for 10 minutes.

[0080] Step 5, TiCN wear-resistant layer deposition: Turn off the substrate heating box, turn on the TiCN target, set the peak voltages for the weak ionization and strong ionization stages to 240V and 720V, respectively, the pulse on-time widths for the weak ionization and strong ionization stages to 6ms and 8ms, respectively, the pulse off-time width to 12ms, the negative bias voltage to -55V, the frequency to 50Hz, the preferred argon flow rate to be 45mL / min, and the deposition time to 55min, depositing a TiCN coating on the AlSi high-temperature oxide resistant layer.

[0081] Testing revealed that the TiCN wear-resistant coating in this embodiment consists of fine, uniform particles without obvious defects or impurities, indicating good surface quality. The Al-AlSi-TiCN composite coating thickness on the nickel-based cast high-temperature alloy surface is 2976 nm. The weight gain of the composite coating after 500 hours of constant-temperature oxidation at 1000℃ is 0.788 mg. 2 ·cm -4 The oxidation rate is 2.87 × 10⁻⁶. -4 mg 2 ·cm -4 ·h -1 Compared with existing technologies, the coating exhibits significantly improved resistance to high-temperature oxidation. The average coefficient of friction of the composite coating at room temperature is 0.126, and the mass wear rate is 1.0 × 10⁻⁶. -4 g / s.

[0082] Example 6

[0083] Step 1, Ion cleaning: When the vacuum level in the vacuum chamber reaches 2.0 × 10⁻⁶ -5 After Torr, high-purity argon gas with a flow rate of 50 mL / min was introduced, the aluminum target was started and a DC current of 1.5 A was applied, and the nickel-based cast high-temperature alloy matrix was bombarded with ions for 5 min.

[0084] Step 2, Al metal transition layer deposition: Turn on the Al target sputtering mode, set the peak voltages for the weak ionization stage to 210V and 750V respectively, the pulse on-time widths for the weak ionization stage to 8ms and 8ms respectively, the pulse off-time width to 12ms, the negative bias voltage to -55V, the frequency to 50Hz, the argon flow rate to 45mL / min, and the deposition time to 20min, depositing a pure metallic Al underlayer transition layer on the substrate.

[0085] Step 3, AlSi high-temperature oxide-resistant layer deposition: Turn off the Al target, turn on the AlSi 20at% target, set the peak voltages for the weak ionization and strong ionization stages to 210V and 750V respectively, the pulse on-time widths for the weak ionization and strong ionization stages to 8ms and 8ms respectively, the pulse off-time width to 10ms, the negative bias voltage to -55V, the frequency to 50Hz, the argon flow rate to 45mL / min, and the deposition time to 20min, depositing the AlSi high-temperature oxide-resistant layer on the Al transition layer.

[0086] Step 4, Substrate heating: Turn off the AlSi20at% target and use a substrate heating box to heat the substrate at a temperature of 450℃ for 15 minutes.

[0087] Step 5, TiCN wear-resistant layer deposition: Turn off the substrate heating box, turn on the TiCN target, set the peak voltages for the weak ionization and strong ionization stages to 210V and 750V respectively, the pulse on-time widths for the weak ionization and strong ionization stages to 8ms and 8ms respectively, the pulse off-time width to 10ms, the negative bias voltage to -55V, the frequency to 50Hz, the preferred argon flow rate to be 45mL / min, and the deposition time to 60min, depositing a TiCN coating on the AlSi high-temperature oxide resistant layer.

[0088] Testing revealed that the TiCN wear-resistant coating in this embodiment consists of fine, uniform particles without obvious defects or impurities, indicating good surface quality. The Al-AlSi-TiCN composite coating thickness on the nickel-based cast superalloy surface is 3640 nm. The weight gain of the composite coating after 500 hours of isothermal oxidation at 1000℃ is 0.778 mg. 2 ·cm -4 The oxidation rate is 2.90 × 10⁻⁶. -4 mg 2 ·cm -4 ·h -1 Compared with existing technologies, the coating exhibits significantly improved resistance to high-temperature oxidation. The average coefficient of friction of the composite coating at room temperature is 0.128, and the mass wear rate is 1.02 × 10⁻⁶. -4 g / s.

Claims

1. A high-temperature oxidation-resistant and wear-resistant composite coating for cast high-temperature alloy surfaces, characterized in that, This includes an Al metal transition layer, an AlSi high-temperature oxidation resistant layer, and a TiCN wear-resistant layer deposited sequentially from the inside to the outside on the surface of a nickel-based cast high-temperature alloy. The Al metal transition layer has a thickness of 200nm~300nm, the AlSi high-temperature oxidation resistant layer has a thickness of 800nm~1500nm, and the TiCN wear-resistant layer has a thickness of 1500nm~2000nm; the composite coating is composed of uniform and dense nanocrystals with a grain size of less than 20nm; the Al metal transition layer, AlSi high-temperature oxidation resistant layer, and TiCN wear-resistant layer are all deposited using a bipolar high-power pulsed magnetron sputtering device.

2. The method for preparing the high-temperature oxidation-resistant and wear-resistant composite coating on the surface of the cast high-temperature alloy as described in claim 1, characterized in that, The specific steps are as follows: Step 1: Under vacuum conditions, argon gas is introduced, the Al target is started and a DC current is applied to perform ion bombardment cleaning on the nickel-based cast high-temperature alloy matrix. Step 2: Turn on the Al target sputtering mode and deposit an Al metal transition layer on the substrate surface through two stages: weak ionization and strong ionization. Step 3: Turn off the Al target and turn on the AlSi20at% target. Through two stages of weak ionization and strong ionization, deposit an AlSi high-temperature oxidation resistant coating on the Al metal transition layer. Step 4: Turn off the AlSi20at% target and heat-treat the substrate; Step 5: Open the TiCN target and deposit a TiCN wear-resistant layer on the AlSi high-temperature oxidation-resistant layer through two stages: weak ionization and strong ionization. In step 2, the peak voltages for the weak ionization and strong ionization stages are 200~250V and 600~750V, respectively; the pulse on-time widths for the weak ionization and strong ionization stages are 4~8ms and 6~8ms, respectively; the pulse off-time width is 10~20ms; the negative bias voltage is -60~-40V; the frequency is 40~60Hz; the argon flow rate is 40~60mL / min; and the deposition time is 10~20min. In step 3, the peak voltages for the weak ionization and strong ionization stages are 200~250V and 600~750V, respectively; the pulse on-time widths for the weak ionization and strong ionization stages are 4~8ms and 6~8ms, respectively; the pulse off-time width is 10~20ms; the negative bias voltage is -60~-40V; the frequency is 40~60Hz; the argon flow rate is 40~60mL / min; and the deposition time is 20~30min. In step 5, the peak voltages for the weak ionization and strong ionization stages are 200~250V and 600~750V, respectively; the pulse on-time widths for the weak ionization and strong ionization stages are 4~8ms and 6~8ms, respectively; the pulse off-time width is 10~20ms; the negative bias voltage is -60~-40V; the frequency is 40~60Hz; the argon flow rate is 40~60mL / min; and the deposition time is 40~60min.

3. The method for preparing a high-temperature oxidation-resistant and wear-resistant composite coating on the surface of a cast high-temperature alloy according to claim 2, characterized in that, In step 1, the vacuum degree is 2.0 × 10⁻⁶. -5 ~3.0×10 -5 Torr, argon flow rate 40~60mL / min, Al target current DC 1.0~2.0A, cleaning time 5~10min.

4. The method for preparing a high-temperature oxidation-resistant and wear-resistant composite coating on the surface of a cast high-temperature alloy according to claim 2, characterized in that, In step 4, the heating temperature is 400~500℃ and the heating time is 10~15min.

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