Method for magnetron sputtering of high-temperature oxidation resistant Ti-Mo composite coating on stainless steel surface

Abstract

The invention discloses a method for magnetron sputtering of a high-temperature-oxidation-resistant Ti-Mo composite coating on the surface of stainless steel, and relates to a method for surface magnetron sputtering of a coating. The problem that an existing 304 stainless steel coating is poor in high-temperature oxidation resistance is solved. The method comprises the following steps: 1, substrate cleaning and target sputtering pretreatment; and 2, coating deposition. The method is used for magnetron sputtering of the high-temperature-oxidation-resistant Ti-Mo composite coating on the stainless steel surface.

Description

Technical Field

[0001] The invention relates to a method for magnetron sputtering coating on a surface. Background Art

[0002] 304 stainless steel is a common material for steam heat transfer tubes in thermal power generation. In order to improve the conversion efficiency of thermal power and reduce pollution, the steam temperature must be increased, which puts higher requirements on the performance of high-temperature pressure-bearing components of thermal power units. Therefore, it is necessary to improve the oxidation resistance and service life of 304 stainless steel. In order to improve the performance of 304 stainless steel, it is an effective method to modify its surface to prepare a high-temperature oxidation-resistant coating. Magnetron sputtering is one of the most commonly used methods for preparing metal coatings and accurately controlling the composition of the coating. It is an economical and feasible method to improve the high-temperature oxidation resistance of the coating by controlling the process parameters in magnetron sputtering. At present, common high-temperature oxidation-resistant coating materials generally contain Al elements. However, during use, due to the continuous growth and cracking of Al2O3 and the mutual diffusion with the substrate, Al will gradually be exhausted, and the metal coating will gradually lose its protective effect.

[0003] Therefore, developing a new type of 304 stainless steel high temperature resistant layer to improve its high temperature oxidation resistance has become one of the current research focuses. Summary of the invention

[0004] The invention aims to solve the problem that the existing 304 stainless steel coating has poor high temperature oxidation resistance, and further provides a method for magnetron sputtering a high temperature oxidation resistant Ti-Mo composite coating on the stainless steel surface.

[0005] A method for magnetron sputtering a high temperature oxidation resistant Ti-Mo composite coating on a stainless steel surface is carried out in the following steps:

[0006] 1. Substrate cleaning and target sputtering pretreatment:

[0007] The substrate is fixed on the sample stage of the DC magnetron sputtering device, the Ti-Mo composite target is installed on the target position of the DC magnetron sputtering device, the target-substrate distance is adjusted, and then the vacuum is evacuated and the chamber pressure is adjusted, the substrate surface is bias-cleaned, and then the target is ignited for pre-sputtering;

[0008] 2. Coating deposition:

[0009] After pre-sputtering, the rotation speed of the sample stage is adjusted, and magnetron sputtering coating is performed under the conditions of argon atmosphere, temperature of 100°C to 200°C, chamber pressure of 0.4Pa to 0.7Pa, current of 0.2A to 0.4A and negative bias voltage of 0V to 400V. Then the chamber vacuum is maintained and cooled to room temperature. Finally, the sample is taken out, thus completing the method of magnetron sputtering high temperature oxidation resistant Ti-Mo composite coating on the stainless steel surface.

[0010] The beneficial effects of the present invention are:

[0011] The present invention uses magnetron sputtering to prepare a Ti-Mo coating on the surface of 304 stainless steel by adjusting the bias voltage during the sputtering process. The surface uniformity of the Ti-Mo coating is good. Ion bombardment fills the pores on the surface of the coating, thereby deepening the compactness of the coating surface and improving the ion mobility on the coating surface. The high-temperature oxidation behavior test results show that the Ti-Mo coating has significantly reduced oxidation weight gain at high temperatures of 500°C to 700°C, and has excellent high-temperature oxidation resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a GIXRD graph of the high temperature oxidation resistant Ti-Mo composite coating prepared by magnetron sputtering on the stainless steel surface in Example 1 after being placed in air;

[0013] Figure 2 This is a SEM image of the high temperature oxidation resistant Ti-Mo composite coating prepared by magnetron sputtering on the stainless steel surface in Example 1;

[0014] Figure 3 This is an XPS image of the high temperature oxidation resistant Ti-Mo composite coating prepared by magnetron sputtering on the stainless steel surface in Example 1;

[0015] Figure 4 The contact angle diagram of the untreated 304 stainless steel and the high temperature oxidation resistant Ti-Mo composite coating prepared on the stainless steel surface by magnetron sputtering in Example 1;

[0016] Figure 5 The graph of weight change and oxidation time during high temperature oxidation of untreated 304 stainless steel and the high temperature oxidation resistant Ti-Mo composite coating prepared on the stainless steel surface by magnetron sputtering in Example 1;

[0017] Figure 6 This is a GIXRD graph of the high temperature oxidation resistant Ti-Mo composite coating prepared by magnetron sputtering on the stainless steel surface after high temperature oxidation in Example 1;

[0018] Figure 7 The SEM and EDS-Mapping images of the high temperature oxidation resistant Ti-Mo composite coating prepared by magnetron sputtering on the stainless steel surface in Example 1 after high temperature oxidation, a is the SEM image, b is the EDS image, and c is the element distribution mapping image;

[0019] Figure 8 This is a comparison chart of the weight changes of the high temperature oxidation resistant Ti-Mo composite coatings prepared by magnetron sputtering on the stainless steel surface in the high temperature oxidation process according to Examples 1 to 4. DETAILED DESCRIPTION

[0020] Specific implementation method 1: This implementation method is a method for preparing a high temperature oxidation resistant Ti-Mo composite coating on a stainless steel surface by magnetron sputtering, which is carried out in the following steps:

[0021] 1. Substrate cleaning and target sputtering pretreatment:

[0022] The substrate is fixed on the sample stage of the DC magnetron sputtering device, the Ti-Mo composite target is installed on the target position of the DC magnetron sputtering device, the target-substrate distance is adjusted, and then the vacuum is evacuated and the chamber pressure is adjusted, the substrate surface is bias-cleaned, and then the target is ignited for pre-sputtering;

[0023] 2. Coating deposition:

[0024] After pre-sputtering, the rotation speed of the sample stage is adjusted, and magnetron sputtering coating is performed under the conditions of argon atmosphere, temperature of 100°C to 200°C, chamber pressure of 0.4Pa to 0.7Pa, current of 0.2A to 0.4A and negative bias voltage of 0V to 400V. Then the chamber vacuum is maintained and cooled to room temperature. Finally, the sample is taken out, thus completing the method of magnetron sputtering high temperature oxidation resistant Ti-Mo composite coating on the stainless steel surface.

[0025] The beneficial effects of this implementation are:

[0026] This embodiment uses magnetron sputtering to prepare a Ti-Mo coating on the surface of 304 stainless steel by adjusting the bias voltage during the sputtering process. The surface uniformity of the Ti-Mo coating is good. Ion bombardment fills the pores on the surface of the coating, thereby deepening the density of the coating surface and improving the ion mobility on the coating surface. The high-temperature oxidation behavior test results show that the oxidation weight gain of the Ti-Mo coating is significantly reduced at a high temperature of 500°C to 700°C, and it has excellent high-temperature oxidation resistance.

[0027] Specific implementation method 2: This implementation method is different from specific implementation method 1 in that the atomic ratio of Ti to Mo in the Ti-Mo composite target material described in step 1 is 1:9; the purity of the Ti-Mo composite target material is 99.99 at.%. The rest is the same as specific implementation method 1.

[0028] Specific implementation method three: This implementation method is different from specific implementation method one or two in that: the substrate described in step one is pretreated 304 stainless steel; the pretreatment is specifically carried out according to the following steps: the 304 stainless steel is ultrasonically cleaned in acetone for 10min to 30min at a power of 50W to 100W, and then ultrasonically cleaned in anhydrous ethanol and deionized water for 10min to 30min respectively at a power of 50W to 100W, and finally vacuum dried for 3h to 6h at a temperature of 40℃ to 70℃. The rest is the same as specific implementation method one or two.

[0029] Specific implementation method 4: This implementation method is different from specific implementation methods 1 to 3 in that the target-substrate distance is adjusted to 4 cm to 8 cm in step 1. The rest is the same as specific implementation methods 1 to 3.

[0030] Specific embodiment 5: This embodiment differs from the specific embodiments 1 to 4 in that the vacuuming and adjusting the chamber pressure in step 1 are specifically performed in the following steps: vacuuming to 1.5×10 -3 Pa~1.5×10 -4 Pa, then Ar gas is introduced and the Ar gas flow rate is adjusted to 90 sccm / min to 120 sccm / min, so that the working pressure in the chamber is 0.4 Pa to 0.7 Pa. The rest is the same as the specific embodiments 1 to 4.

[0031] Specific embodiment 6: This embodiment is different from specific embodiments 1 to 5 in that: in step 1, the substrate is bias cleaned for 400s to 600s under the conditions of argon atmosphere, temperature of 100°C to 200°C, chamber pressure of 0.4Pa to 0.7Pa, DC current of 0.2A to 0.4A and negative bias of 200V to 400V. The rest is the same as specific embodiments 1 to 5.

[0032] Specific embodiment 7: This embodiment differs from Specific embodiments 1 to 6 in that: in step 1, the substrate is pre-sputtered for 200s to 400s under the conditions of argon atmosphere, temperature of 100°C to 200°C, chamber pressure of 0.4Pa to 0.7Pa, DC current of 0.2A to 0.4A and negative bias of 200V to 400V. The rest is the same as Specific embodiments 1 to 6.

[0033] Specific embodiment 8: This embodiment is different from specific embodiments 1 to 7 in that the thickness of the magnetron sputtering coating in step 2 is 3 μm to 5 μm. The rest is the same as specific embodiments 1 to 7.

[0034] Specific embodiment 9: This embodiment is different from specific embodiments 1 to 8 in that the magnetron sputtering coating in step 2 is performed for 2h to 4h. The rest is the same as specific embodiments 1 to 8.

[0035] Specific embodiment 10: This embodiment differs from specific embodiments 1 to 9 in that the rotation speed of the sample stage is adjusted to 10 r / min to 15 r / min in step 2. The rest is the same as specific embodiments 1 to 9.

[0036] The following examples are used to verify the beneficial effects of the present invention:

[0037] Embodiment 1:

[0038] A method for magnetron sputtering a high temperature oxidation resistant Ti-Mo composite coating on a stainless steel surface is carried out in the following steps:

[0039] 1. Substrate cleaning and target sputtering pretreatment:

[0040] The substrate was fixed on the sample stage of the DC magnetron sputtering device, and the Ti-Mo composite target was installed on the target position of the DC magnetron sputtering device. The target-substrate distance was adjusted to 8 cm, and then the vacuum was pumped to 1.5×10 - 4 Pa, then introduce Ar gas and adjust the Ar gas flow rate to 100 sccm / min, so that the working pressure in the chamber is 0.6 Pa, under the conditions of argon atmosphere, temperature of 150°C, chamber pressure of 0.6 Pa, DC current of 0.3A and negative bias voltage of 300V, bias clean the substrate for 500s, then ignite the target, and pre-sputter the substrate for 300s under the conditions of argon atmosphere, temperature of 150°C, chamber pressure of 0.6 Pa, DC current of 0.3A and negative bias voltage of 300V;

[0041] 2. Coating deposition:

[0042] After pre-sputtering, the sample stage speed was adjusted to 15r / min, and magnetron sputtering coating was carried out for 3 hours under the conditions of argon atmosphere, temperature of 150°C, chamber pressure of 0.6Pa, current of 0.3A and negative bias voltage of 0V. Then the chamber vacuum was maintained and cooled to room temperature. Finally, the sample was taken out to obtain a high-temperature oxidation-resistant Ti-Mo composite coating magnetron sputtered on the stainless steel surface.

[0043] The atomic ratio of Ti to Mo in the Ti-Mo composite target material described in step 1 is 1:9; the purity of the Ti-Mo composite target material is 99.99at.%.

[0044] The substrate described in step 1 is pretreated 304 stainless steel; the pretreatment is specifically carried out according to the following steps: ultrasonically clean the 304 stainless steel in acetone at a power of 100 W for 25 minutes, then ultrasonically clean it in anhydrous ethanol and deionized water at a power of 100 W for 25 minutes respectively, and finally vacuum dry it at a temperature of 60°C for 3 hours.

[0045] The thickness of the magnetron sputtering coating in step 2 is 4 μm.

[0046] Embodiment 2: This embodiment is different from Embodiment 1 in that the negative bias voltage in step 2 is 50 V. The rest is the same as Embodiment 1.

[0047] Embodiment 3: This embodiment is different from Embodiment 1 in that the negative bias voltage in step 2 is 100 V. The rest is the same as Embodiment 1.

[0048] Embodiment 4: This embodiment is different from Embodiment 1 in that the negative bias voltage in step 2 is 200 V. The rest is the same as Embodiment 1.

[0049] Figure 1 This is the GIXRD diagram of the high temperature oxidation resistant Ti-Mo composite coating prepared by magnetron sputtering on the stainless steel surface in Example 1 after being placed in air; the phase analysis in the figure shows that in addition to the Ti-Mo successfully prepared on the 304 stainless steel surface, there is also TiO. The main reason is that after the coating is prepared, some titanium combines with oxygen to form a dense TiO film in the air. During the preparation process, due to the high substrate temperature, the substrate metal elements diffuse upward and combine with the glow deposited particles at the same time to form a metal compound Fe 6.6 Cr 1.7 Ni 1.2 Si 0.2 Mo 0.1 .

[0050] Figure 2 This is an SEM image of the high-temperature oxidation-resistant Ti-Mo composite coating prepared by magnetron sputtering on the stainless steel surface in Example 1; as can be seen from the figure, the surface of the prepared Ti-Mo coating is flat, uniform and has good density, and the ion bombardment deepens the density of the coating surface, fills the pores on the coating surface, and improves the ion mobility on the coating surface.

[0051] Figure 3 This is the XPS graph of the high temperature oxidation resistant Ti-Mo composite coating prepared by magnetron sputtering on the stainless steel surface in Example 1; 458.8 eV and 228.5 eV correspond to the electron binding energies of Ti and Mo, respectively. The XPS data show that the successful preparation of the Ti-Mo alloy coating plays a vital role in improving the high temperature oxidation resistance of the coating material.

[0052] Figure 4 The contact angle diagram of the high temperature oxidation resistant Ti-Mo composite coating prepared on the surface of untreated 304 stainless steel and the stainless steel surface by magnetron sputtering in Example 1; under the conditions of co-sputtering and high mobility of surface atomic clusters, the hydrophobicity of the coating is significantly improved, and the contact angle is increased to 83.3°. The improvement of the hydrophobicity of the coating surface also helps to improve the corrosion resistance of the coating.

[0053] High temperature oxidation test: During the high temperature air oxidation process, firstly, the samples prepared in Examples 1 to 4 were placed in a muffle furnace, and the program was set to heat up to 500°C at a heating rate of 5°C / min and keep warm for 540 minutes. After the experiment, the samples were naturally cooled to room temperature with the furnace. After the sample was cooled to room temperature as a whole, the sample was taken out, weighed, and its oxidation weight gain was calculated. An electronic balance with an accuracy of 0.01 mg was used to weigh the samples before and after oxidation. To ensure the reliability and authenticity of the data, three samples were selected for each oxidation, and the error before and after each weighing did not exceed 0.05 mg. The mass of each sample was weighed 3 to 5 times and the average value was taken.

[0054] Figure 5 The weight change and oxidation time of the untreated 304 stainless steel and the high temperature oxidation resistant Ti-Mo composite coating prepared by magnetron sputtering on the stainless steel surface in the high temperature oxidation process are shown in the figure. The curve in the figure shows that the oxidation weight gain mode within 10 hours of high temperature oxidation at 500°C is parabolic oxidation. The oxidation of the sample within 10 hours is controlled by the surface oxide layer. The prepared Ti-Mo coating has a certain protective effect compared with the bare 304 stainless steel in the air atmosphere at 500°C, and the oxidation weight gain is significantly reduced from 0.11 mg·cm -2 Reduced to 0.067 mg cm -2 , has excellent high temperature oxidation resistance.

[0055] Figure 6 This is the GIXRD pattern of the high-temperature oxidation-resistant Ti-Mo composite coating prepared by magnetron sputtering on the stainless steel surface in Example 1 after high-temperature oxidation; after high-temperature oxidation of the TiMo coating, the stainless steel substrate is partially exposed after the coating peels off, and the Ti element in the unpeeled coating part is oxidized to form TiO2, and the Mo element combines with Ni to form MoNi4-type compounds.

[0056] Figure 7 The SEM and EDS-Mapping images of the high temperature oxidation resistant Ti-Mo composite coating prepared by magnetron sputtering on the stainless steel surface in Example 1 after high temperature oxidation, a is the SEM image, b is the EDS image, and c is the element distribution mapping image. It can be found that the surface of the coating is relatively flat after oxidation. After 540 minutes of air oxidation at 500°C, the element distribution shows that the main elements are still Ti and Mo, and it has excellent high temperature oxidation resistance.

[0057] Figure 8 The weight change comparison diagram of the high temperature oxidation resistant Ti-Mo composite coating prepared by magnetron sputtering on the stainless steel surface in the high temperature oxidation process in Examples 1 to 4 is shown in the figure. The graphical results show that the oxidation weight gain of the Ti-Mo composite coating prepared under 0V bias is significantly less than that of the other three coatings, and has a more excellent high temperature oxidation resistance.

Claims

1. A method for magnetron sputtering a high temperature oxidation resistant Ti-Mo composite coating on a stainless steel surface, characterized in that It is carried out in the following steps:

1. Substrate cleaning and target sputtering pretreatment: The substrate is fixed on the sample stage of the DC magnetron sputtering device, the Ti-Mo composite target is installed on the target position of the DC magnetron sputtering device, the target-substrate distance is adjusted, and then the vacuum is evacuated and the chamber pressure is adjusted, the substrate surface is bias-cleaned, and then the target is ignited for pre-sputtering; 2. Coating deposition: After pre-sputtering, the rotation speed of the sample stage is adjusted, and magnetron sputtering coating is performed under the conditions of argon atmosphere, temperature of 100°C to 200°C, chamber pressure of 0.4Pa to 0.7Pa, current of 0.2A to 0.4A and negative bias voltage of 0V to 400V. Then the chamber vacuum is maintained and cooled to room temperature. Finally, the sample is taken out, thus completing the method of magnetron sputtering high temperature oxidation resistant Ti-Mo composite coating on the stainless steel surface.

2. The method for preparing a high temperature oxidation resistant Ti-Mo composite coating on a stainless steel surface by magnetron sputtering according to claim 1, characterized in that The atomic ratio of Ti to Mo in the Ti-Mo composite target material described in step 1 is 1:9; the purity of the Ti-Mo composite target material is 99.99at.%.

3. The method for preparing a high temperature oxidation resistant Ti-Mo composite coating on a stainless steel surface by magnetron sputtering according to claim 1, characterized in that The substrate described in step 1 is pretreated 304 stainless steel; the pretreatment is specifically carried out according to the following steps: ultrasonically cleaning the 304 stainless steel in acetone at a power of 50W to 100W for 10min to 30min, then ultrasonically cleaning it in anhydrous ethanol and deionized water at a power of 50W to 100W for 10min to 30min respectively, and finally vacuum drying it at a temperature of 40°C to 70°C for 3h to 6h.

4. The method for preparing a high temperature oxidation resistant Ti-Mo composite coating on a stainless steel surface by magnetron sputtering according to claim 1, characterized in that In step 1, adjust the target-base distance to 4 cm to 8 cm.

5. The method for preparing a high temperature oxidation resistant Ti-Mo composite coating on a stainless steel surface by magnetron sputtering according to claim 1, characterized in that The vacuuming and adjusting of the chamber pressure in step 1 are specifically carried out in the following steps: vacuuming to 1.5×10 -3 Pa~1.5×10 -4 Pa, and then introduce Ar gas and adjust the Ar gas flow rate to 90 sccm / min~120 sccm / min, so that the working gas pressure in the chamber is 0.4Pa~0.7Pa.

6. The method for preparing a high temperature oxidation resistant Ti-Mo composite coating on a stainless steel surface by magnetron sputtering according to claim 1, characterized in that In step 1, the substrate is bias cleaned for 400s to 600s under the conditions of argon atmosphere, temperature of 100°C to 200°C, chamber pressure of 0.4Pa to 0.7Pa, DC current of 0.2A to 0.4A and negative bias of 200V to 400V.

7. The method for preparing a high temperature oxidation resistant Ti-Mo composite coating on a stainless steel surface by magnetron sputtering according to claim 1, characterized in that In step 1, the substrate is pre-sputtered for 200s to 400s under the conditions of an argon atmosphere, a temperature of 100°C to 200°C, a chamber pressure of 0.4Pa to 0.7Pa, a DC current of 0.2A to 0.4A, and a negative bias voltage of 200V to 400V.

8. The method for preparing a high temperature oxidation resistant Ti-Mo composite coating on a stainless steel surface by magnetron sputtering according to claim 1, characterized in that The thickness of the magnetron sputtering coating in step 2 is 3 μm to 5 μm.

9. The method for preparing a high temperature oxidation resistant Ti-Mo composite coating on a stainless steel surface by magnetron sputtering according to claim 1, characterized in that In step 2, the magnetron sputtering coating is performed for 2 h to 4 h.

10. The method for preparing a high temperature oxidation resistant Ti-Mo composite coating on a stainless steel surface by magnetron sputtering according to claim 1, characterized in that In step 2, adjust the sample stage speed to 10 r / min to 15 r / min.

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