Coating, preparation method thereof and application of coating on surface of TZM alloy

Abstract

The invention provides a coating, a preparation method thereof and application of the coating on the surface of a TZM alloy. The coating comprises the following raw materials in percentage by weight: 2-12 parts of glass powder A, 15-20 parts of glass powder B, 3-15 parts of glass powder C, 5-13 parts of Cr2O3, 8-12 parts of an organic binder and 25-42 parts of a solvent. Preparing glass powder A, glass powder B and glass powder C by adopting a melting quenching method; the preparation method comprises the following steps: preparing glass powder A, glass powder B, glass powder C, Cr2O3, an organic binder and a solvent into slurry according to the proportion in claim 1, performing ball milling for 2-12 hours by a ball mill, and aging for 12-60 hours to obtain the coating. The coating disclosed by the invention has better oxidation resistance; compared with dry friction, a coating coated by the prepared paint has better lubricating property; the coating can adopt a spraying method, the operation is simple and convenient, the cost is low, and the original production process is not changed.

Description

Technical Field

[0001] The present invention relates to the field of high-temperature coating manufacturing, and particularly to a coating, a preparation method thereof, and an application thereof on the surface of TZM alloy. Background Art

[0002] The unique high-temperature strength, dimensional stability, and thermal conductivity of TZM alloy make it a highly potential die material for metal forming processes above 1000 °C. However, TZM alloy begins to oxidize above 400 °C and rapidly oxidizes to volatile MoO3 above 780 °C, resulting in serious material loss. TZM alloy usually uses silicide coatings (MoSi2), aluminide coatings (NiAl, TiAl, Al-Cr), heat-resistant alloy coatings (Ni-Cr, Hf-Ta, W-Cr-Pb), etc. to improve its oxidation resistance, which relies on the passivation layer formed by high-temperature oxidation of the coating. However, these coatings often require thermal spraying, ion plating, or pack cementation methods, which lead to complex production processes, increased costs, and reduced production efficiency. Therefore, there is an urgent need to develop a new type of coating that can provide oxidation resistance for TZM alloy without changing the original production process.

[0003] Glass, as a commonly used hot-forming processing lubricant, is formed by eutectic melting of various oxides and is mainly divided into silicate glass, phosphate glass, and borate glass. The glass melt after high-temperature heat treatment has high density, low shear, and chemical inertness, and has been widely used as a lubricant for hot-forming processing of metals such as titanium alloy, aluminum alloy, and steel, and also has multiple functions such as oxidation resistance, lubrication, and reduction of forming force. However, in the current related research with molybdenum alloy as the application material, there is little development of lubricating and oxidation-resistant integrated coatings. This is mainly because MoO3 generated by molybdenum oxidation will react with the glass melt to form molybdate, and the solubility of molybdate in glass is extremely small (≤3%). The dissolution of excessive MoO3 will cause the glass to crystallize or even completely crystallize, thereby losing the lubricating and oxidation-resistant functions.

[0004] Therefore, there is an urgent need to develop a coating with oxidation resistance, lubrication performance, and the ability to resist continuous erosion of MoO3. Summary of the Invention

[0005] Aiming at the deficiencies in the background art, the present invention uses three composite glasses as the main raw materials and adds a certain content of Cr2O3 with antioxidant and wear-resistant properties. The prepared coating can have oxidation resistance and lubrication performance at 1100 °C on the surface of TZM alloy and is used in the forging process of alloys such as FGH4096 alloy turbine disks.

[0006] On the one hand, the present invention provides a coating, comprising the following raw materials in parts by weight: 2-12 parts of glass powder A, 15-20 parts of glass powder B, 3-15 parts of glass powder C, 5-13 parts of Cr2O3, 8-12 parts of an organic binder, and 25-42 parts of a solvent; The glass powder A, calculated by mass percentage, comprises the following components: 35-50 wt% of SiO2, 10-25 wt% of B2O3, 2-8 wt% of Al2O3, 15-30 wt% of Na2O, 0.1-2 wt% of K2O, 5-11 wt% of CaO, 2-5 wt% of MgO, 0.1-0.8 wt% of TiO2, 0.1-0.8 wt% of Fe2O3; The glass powder B, calculated by mass percentage, comprises the following components: 45-60 wt% of SiO2, 5-10 wt% of B2O3, 10-20 wt% of Al2O3, 0.1-3.5 wt% of Na2O, 0.1-2 wt% of K2O, 2-6 wt% of CaO, 0.1-2.3 wt% of MgO, 0.5-0.3 wt% of TiO2, 0.1-0.8 wt% of Fe2O3, 0.1-0.8 wt% of ZnO2, 0.1-1 wt% of ZrO2, 2-10 wt% of BaO; The glass powder C, calculated by mass percentage, comprises the following components: 45-55 wt% of SiO2, 10-15 wt% of B2O3, 8-15 wt% of Al2O3, 12-18 wt% of Na2O, 1-6 wt% of K2O, 1-5 wt% of CaO, 1-5 wt% of MgO, 0.8-2 wt% of ZnO2.

[0007] Preferably, the organic binder is one or more of polyurethane, sodium carboxymethyl cellulose, acrylic emulsion, and polyurethane solution.

[0008] Preferably, the solvent is one of water and alcohol.

[0009] The present invention also provides a method for preparing the coating, which comprises Preparing glass powder A, glass powder B, and glass powder C by the melt quenching method; Mixing glass powder A, glass powder B, glass powder C, Cr2O3, the organic binder, and the solvent according to the above ratios to form a slurry, and ball milling with a ball mill for 2-12 h and aging for 12-60 h to obtain the coating.

[0010] Preferably, the process of preparing glass powder A, glass powder B, and glass powder C is as follows: The components of glass powder A, glass powder B, and glass powder C described in Claim 1 are respectively mixed evenly, then melted for 2 - 4 h respectively, ball-milled and refined, and passed through a sieve to obtain glass powder A, glass powder B, and glass powder C.

[0011] Preferably, the melting temperature of glass powder A is 1200 °C, the melting temperature of glass powder B is 1400 °C, and the melting temperature of glass powder C is 1650 °C.

[0012] Preferably, the sieving is carried out using a 400-mesh dividing sieve.

[0013] The present invention also provides an application of a coating on the surface of a TZM alloy.

[0014] Preferably, the coating is applied to the surface of the TZM alloy, and the thickness of the coating is 0.1 - 2 mm.

[0015] Preferably, the coating method is one of spraying, brushing, or dipping.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The coating provided by the present invention has better oxidation resistance (mass loss rate is only 1.7% / h) compared with a commercial glass lubricant (mass loss rate is 7.51 - 7.83% / h); The coating prepared by the present invention has better lubrication performance compared with dry friction; the coating can be applied by spraying, which is simple in operation, low in cost, and does not change the original production process; The coating in the present invention forms an adaptive multi-level structure during use, which can avoid continuous erosion of the coating by the substrate oxide, maintain good bonding between the interface layers, and resist the erosion of external oxygen. Description of the Drawings

[0017] Figure 1 It is a graph of the oxidation resistance test results provided in Example 1 of the present invention. Among them, (a) is the oxidation resistance test without a coating, and (b) is the oxidation resistance test with a coating.

[0018] Figure 2 It is a micrograph of the oxidation-resistant coating on the surface of the TZM alloy provided in Example 1 of the present invention. Among them, (a) is the SEM-EDS of the surface of the TZM alloy with a coating, and (b) is the HAADF and EDS images at the FIB1 position in Figure (a).

[0019] Figure 3 It is a graph of the friction coefficients of the coated and uncoated samples provided in Example 2 of the present invention.

[0020] Figure 4 It is the friction coefficient diagram with a coating provided by Embodiment 3 of the present invention. Specific implementation method

[0021] In order to make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of the present disclosure without creative efforts also fall within the scope of protection of the present disclosure.

[0022] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which the subject matter of the present disclosure belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the specification and the relevant art, and will not be interpreted in an idealized or overly formal form unless otherwise clearly defined herein.

[0023] Reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0024] The present invention provides a coating used as a lubricating and antioxidant coating for TZM alloy under high-temperature conditions. The preparation method of the coating includes: Step 1: Prepare glass powder A, glass powder B, and glass powder C by the melt quenching method; Step 2: Configure glass powder A, glass powder B, glass powder C, Cr2O3, an organic binder, and a solvent into a slurry in proportion, ball mill it for 2 - 12 h, and age it in air for 12 - 60 h, for example, it can be 12 h, 24 h, 48 h, 52 h, 60 h, to obtain the coating.

[0025] In Step 1, Glass Powder A comprises the following components: 35 - 50 wt% of SiO2, 10 - 25 wt% of B2O3, 2 - 8 wt% of Al2O3, 15 - 30 wt% of Na2O, 0.1 - 2 wt% of K2O, 5 - 11 wt% of CaO, 2 - 5 wt% of MgO, 0.1 - 0.8 wt% of TiO2, 0.1 - 0.8 wt% of Fe2O3; Glass Powder B comprises the following components: 45 - 60 wt% of SiO2, 5 - 10 wt% of B2O3, 10 - 20 wt% of Al2O3, 0.1 - 3.5 wt% of Na2O, 0.1 - 2 wt% of K2O, 2 - 6 wt% of CaO, 0.1 - 2.3 wt% of MgO, 0.5 - 0.3 wt% of TiO2, 0.1 - 0.8 wt% of Fe2O3, 0.1 - 0.8 wt% of ZnO2, 0.1 - 1 wt% of ZrO2, 2 - 10 wt% of BaO; Glass Powder C comprises the following components: 45 - 55 wt% of SiO2, 10 - 15 wt% of B2O3, 8 - 15 wt% of Al2O3, 12 - 18 wt% of Na2O, 1 - 6 wt% of K2O, 1 - 5 wt% of CaO, 1 - 5 wt% of MgO, 0.8 - 2 wt% of ZnO2; Mix Glass A, B, and C components evenly respectively, then melt them at 1200 °C, 1400 °C, and 1650 °C for 2 - 4 h respectively, refine by ball milling, and screen with a 400 - mesh sample sieve to obtain Glass Powder A, Glass Powder B, and Glass Powder C with smaller average particle sizes.

[0026] In Step 2, the preparation of the slurry comprises the following raw materials by weight: 2 - 12 parts of Glass Powder A, for example, it can be 2 parts, 4 parts, 6 parts, 8 parts, 10 parts, 12 parts; 15 - 20 parts of Glass Powder B, for example, it can be 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts; 3 - 15 parts of Glass Powder C, for example, it can be 3 parts, 5 parts, 7 parts, 9 parts, 11 parts, 13 parts, 15 parts; 5 - 13 parts of Cr2O3, for example, it can be 3 parts, 5 parts, 7 parts, 9 parts, 11 parts, 13 parts; 8 - 12 parts of organic binder, for example, it can be 8 parts, 9 parts, 10 parts, 11 parts, 12 parts; 25 - 42 parts of solvent, for example, it can be 25 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, 42 parts; Among them, the organic binder is one or more of polyurethane, sodium carboxymethyl cellulose, acrylic emulsion, polyurethane liquid; the solvent is one of water and alcohol.

[0027] If the coating prepared in Step 2 needs to be stored, add a small amount of water to the aged coating and store it in a sealed container.

[0028] In some embodiments of the present invention, when applying the coating to the surface of the TZM alloy, first mechanically stir the placed coating evenly, and then spray / brush / dip-coat it on the surface of the TZM alloy. The thickness of the coated layer is 0.1 - 2 mm.

[0029] The present invention will be further described below through specific embodiments.

[0030] Example 1 Step 1: Mix the glass powder A according to the ratio of 45wt% SiO2, 20wt% B2O3, 8wt% Al2O3, 15wt% Na2O, 2wt% K2O, 5wt% CaO, 2wt% MgO, 0.2wt% TiO2, 0.8wt% Fe2O3; mix the glass powder B according to the ratio of 60wt% SiO2, 10wt% B2O3, 10wt% Al2O3, 3wt% Na2O, 2wt% K2O, 6wt% CaO, 2wt% MgO, 0.5wt% TiO2, 0.5wt% Fe2O3, 0.2wt% ZnO2, 0.8wt% ZrO2, 5wt% BaO; mix the glass powder C according to the ratio of 50wt% SiO2, 10wt% B2O3, 10wt% Al2O3, 12wt% Na2O, 7wt% K2O, 5wt% CaO, 5wt% MgO, 1wt% ZnO2. Mechanically mix them respectively with a mixer, place them in a muffle furnace, melt them at 1200 °C, 1400 °C and 1650 °C for 3 h respectively, then ball-mill them with a ball mill. The ball mill tank is an alumina mill tank, and the grinding medium is alumina tank balls. The diameter of the alumina balls used is 5 mm, 10 mm and 15 mm, and the quantity ratio of the alumina balls is configured according to 20:15:10. The ball-milling speed is 400 r / min for 5 h. Finally, sieve them with a 400-mesh sample sieve to obtain glass powder A, glass powder B and glass powder C with relatively small average particle sizes. Step 2: Mix 5 parts of glass powder A, 15 parts of glass powder B, 10 parts of glass powder C, 8 parts of Cr2O3, 10 parts of polyurethane and 42 parts of water to prepare a slurry, ball-mill it in a ball mill for 5 h, and age it in the air for 48 h to obtain the coating.

[0031] Step 3: Coat the coating on the surface of the TZM alloy by dip-coating method and dry it for use as an antioxidant experiment specimen. The size of the TZM alloy used in the antioxidant experiment is Φ30 × 10 mm.

[0032] To avoid the influence of impurities in the muffle furnace, first heat the empty furnace at 1200 °C for 3 h. Subsequently, heat the blank sample and the sample coated with the coating to 1100 °C along with the furnace and hold for 1 h. After the experiment, take out the sample from high temperature and place it in the air for rapid cooling. The heating rate of the muffle furnace used in the oxidation resistance experiment is 10 °C / min, then hold at 1100 °C for 1 h, and finally rapidly cool to room temperature in the air.

[0033] Perform oxidation resistance detection on the surface of the TZM alloy coated with the coating. The oxidation resistance performance is tested in a muffle furnace with a limit temperature of 1700 °C, and the evaluation is carried out by detecting the mass change and cross-sectional layer change before and after oxidation, as Figure 1 shown. The results show that the coating has good oxidation resistance, and the burnout rate is only 1.7%. Compared with other commercial lubricants, the lubricant prepared by the present invention has better oxidation resistance for TZM.

[0034] Example 2 Steps 1 and 2 are the same as those in Example 1; Step 3: Test the lubrication performance of the coating using FGH4096 alloy and TZM alloy. Spray the prepared coating on the surface of the FGH4096 alloy and dry it as a friction experiment specimen for standby. The size of the friction surface of the TZM alloy used in the lubrication experiment is 10 mm, and the size of the FGH4096 alloy is 30 × 3 mm. The heating rate of the friction machine used in the lubrication experiment is 10 °C / min, the load is 10 N, the linear sliding speed is 0.003 m / s, the running time is 2 min, and the test temperature is 1100 °C.

[0035] Evaluate through the pin-on-disk mode of the GF-I-1200 high-temperature friction and wear testing machine under the test conditions of 1000 °C, 1050 °C, and 1100 °C. The coating has good lubrication performance, as Figure 3 shown. The friction coefficient between the FGH4096 alloy with the coating and the TZM alloy is 0.376, and the friction coefficient between the FGH4096 alloy without the coating and the TZM alloy is 0.548. It can be seen that the coating has good performance at 1100 °C.

[0036] Example 3 Steps 1 and 2 are the same as those in Example 1; Step 3: The lubrication performance of the coating was tested using FGH4096 alloy and TZM alloy. The prepared coating was sprayed on the surface of the FGH4096 alloy and dried to be used as a friction test specimen. The friction surface size of the TZM alloy used in the lubrication experiment was 10 ± 0.01 mm, and the size of the FGH4096 alloy was 30 ± 0.05 × 3 ± 0.05 mm. The heating rate of the friction machine used in the lubrication experiment was 10 °C / min, the load was 10 N, the linear sliding speed was 0.003 m / s, the running time was 2 min, and the test temperature was 1050 °C.

[0037] It was evaluated under the test conditions of 1000 °C, 1050 °C and 1100 °C through the pin-on-disk mode of the GF-I-1200 high-temperature friction and wear testing machine, as Figure 4 shown. The coating has good lubrication performance. The friction coefficient between the FGH4096 alloy with the coating and the TZM alloy is about 0.5. It can be seen that the coating has good performance at 1050 °C.

[0038] Comparative Example 1 12 parts of glass powder A, 16 parts of glass powder B, 10 parts of glass powder C, 10 parts of polyurethane and 42 parts of water were used to prepare a slurry by mixing. The slurry was ball-milled in a ball mill for 5 h and aged in air for 48 h to obtain the coating. The remaining steps were the same as those in Example 1. The antioxidant performance of the surface of the TZM alloy coated with the coating was detected. The antioxidant performance was tested in a muffle furnace with a limit temperature of 1700 °C, and the evaluation was carried out by detecting the mass change before and after oxidation. The results showed that the antioxidant performance of the coating was significantly reduced compared with that in Example 1. The lubrication performance of the coating was tested using FGH4096 alloy and TZM alloy. The prepared coating was sprayed on the surface of the FGH4096 alloy and evaluated under the test conditions of 1000 °C, 1050 °C and 1100 °C through the pin-on-disk mode of the GF-I-1200 high-temperature friction and wear testing machine. The results showed that the lubrication performance of the coating was significantly reduced compared with that in Example 3.

[0039] The above-given examples are the preferred examples for implementing the present invention. The present invention is not limited to the above examples. Any non-essential addition or replacement made by those skilled in the art according to the technical features of the technical solution of the present invention shall fall within the protection scope of the present invention.

Claims

1. A coating, characterized in that, It includes the following raw materials in parts by weight: 2 - 12 parts of glass powder A, 15 - 20 parts of glass powder B, 3 - 15 parts of glass powder C, 5 - 13 parts of Cr₂O₃, 8 - 12 parts of organic binder, and 25 - 42 parts of solvent; The glass powder A, calculated by mass percentage, includes the following components: 35 - 50wt% of SiO₂, 10 - 25wt% of B₂O₃, 2 - 8wt% of Al₂O₃, 15 - 30wt% of Na₂O, 0.1 - 2wt% of K₂O, 5 - 11wt% of CaO, 2 - 5wt% of MgO, 0.1 - 0.8wt% of TiO₂, 0.1 - 0.8wt% of Fe₂O₃; The glass powder B, calculated by mass percentage, includes the following components: 45 - 60wt% of SiO₂, 5 - 10wt% of B₂O₃, 10 - 20wt% of Al₂O₃, 0.1 - 3.5wt% of Na₂O, 0.1 - 2wt% of K₂O, 2 - 6wt% of CaO, 0.1 - 2.3wt% of MgO, 0.5 - 0.3wt% of TiO₂, 0.1 - 0.8wt% of Fe₂O₃, 0.1 - 0.8wt% of ZnO₂, 0.1 - 1wt% of ZrO₂, 2 - 10wt% of BaO; The glass powder C, calculated by mass percentage, includes the following components: 45 - 55wt% of SiO₂, 10 - 15wt% of B₂O₃, 8 - 15wt% of Al₂O₃, 12 - 18wt% of Na₂O, 1 - 6wt% of K₂O, 1 - 5wt% of CaO, 1 - 5wt% of MgO, 0.8 - 2wt% of ZnO₂.

2. The coating according to claim 1, wherein The organic binder is one or more of polyurethane, sodium carboxymethyl cellulose, acrylic emulsion, and polyurethane liquid.

3. A paint according to claim 1, characterized in that, The solvent is one of water and alcohol.

4. A method for preparing a coating, characterized in that, The preparation method includes Preparing glass powder A, glass powder B, and glass powder C by the melt quenching method; Configuring glass powder A, glass powder B, glass powder C, Cr₂O₃, organic binder, and solvent into a slurry according to the ratio of claim 1, ball milling in a ball mill for 2 - 12 h, and aging for 12 - 60 h to obtain the coating.

5. The preparation method of a coating according to claim 4, characterized in that The process of preparing glass powder A, glass powder B, and glass powder C is to uniformly mix the components of glass powder A, glass powder B, and glass powder C described in claim 1 respectively, then melt them respectively for 2 - 4 h, ball mill and refine them, and obtain glass powder A, glass powder B, and glass powder C after sieving.

6. The preparation method of a coating according to claim 5, wherein, The melting temperature of the glass powder A is 1200 °C, the melting temperature of the glass powder B is 1400 °C, and the melting temperature of the glass powder C is 1650 °C.

7. The preparation method of a coating according to claim 5, characterized in that, The sieving is carried out using a 400 - mesh analytical sieve.

8. Application of the coating according to any one of claims 1 - 7 on the surface of TZM alloy.

9. The application according to claim 8, wherein Coating the coating on the surface of TZM alloy, and the thickness of the coating is 0.1 - 2 mm.

10. The application according to claim 9, wherein The coating method is one of spraying, brushing or dipping.

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