A method for preparing a modified MoSi2 anti-oxidation coating on the surface of molybdenum or molybdenum alloys

Abstract

This invention belongs to the field of metal coating preparation technology, specifically a method for preparing a modified MoSi2 anti-oxidation coating on the surface of molybdenum or molybdenum alloys. MoSi2 powder and TiNbVZrAl high-entropy alloy powder are selected, and a MoSi2-TiNbVZrAl composite coating is prepared on the surface of molybdenum or molybdenum alloys via laser cladding. MoSi2, as the base material of the coating, ensures the anti-oxidation performance of the composite coating. Adding an appropriate amount of TiNbVZrAl multi-element high-entropy alloy powder, where Al, Zr, and Ti further improve the anti-oxidation performance of the coating, and Nb alloy exhibits good plasticity, ultimately achieving good anti-oxidation performance, good density, and good bonding properties in the composite coating. This method can be applied to the surface protection of molybdenum and molybdenum alloys under high-temperature service environments.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of metal coating preparation, and particularly relates to a preparation method of a modified MoSi2 oxidation-resistant coating on the surface of molybdenum or molybdenum alloy. BACKGROUND

[0002] Molybdenum and molybdenum alloy are commonly used refractory metals, and are widely used in aerospace, metallurgy, glass, electronics and other industries for structural parts in high-temperature service environments due to their high strength and hardness at temperatures up to 1500 DEG C, high melting point, low thermal expansion coefficient, good electrical and thermal conductivity and excellent corrosion resistance. However, molybdenum and molybdenum alloy are prone to rapid oxidation in high-temperature service environments, which leads to the loss of their excellent high-temperature performance and causes structural parts to fail, thereby limiting the more extensive application of molybdenum and molybdenum alloy. Therefore, improving the oxidation resistance of molybdenum and molybdenum alloy is the key to ensuring their long-term safe service. The existing technology often uses surface coating to improve the oxidation resistance of molybdenum and molybdenum alloy and ensure their safe service. The coating formed by MoSi2 powder is widely used in the oxidation-resistant design of the surface of molybdenum and molybdenum alloy because it can react with O2 at high temperatures to form a stable SiO2 glass phase, and its low oxygen diffusion rate can block the diffusion of O2 into the coating to reduce the erosion rate of oxygen elements on the coating. However, due to the large difference in the thermal expansion coefficient between the MoSi2 coating and the molybdenum and molybdenum alloy substrate, cracking easily occurs in the coating, the density is relatively low, and the interface bonding between the coating and the substrate is poor, so it is necessary to modify and optimize the MoSi2 powder and its coating. SUMMARY

[0003] To solve the problems in the prior art, the main purpose of the present application is to provide a preparation method of a modified MoSi2 oxidation-resistant coating on the surface of molybdenum or molybdenum alloy.

[0004] To solve the above technical problems, according to one aspect of the present application, the present application provides the following technical scheme:

[0005] A preparation method of a modified MoSi2 oxidation-resistant coating on the surface of molybdenum or molybdenum alloy, comprising the following steps:

[0006] B1, the modified MoSi2 oxidation-resistant powder is laid on the surface of molybdenum or molybdenum alloy; in the modified MoSi2 oxidation-resistant powder, the mass percentage of high-entropy alloy powder is 10-20wt%;

[0007] B2, the modified MoSi2 oxidation-resistant powder is laser cladded on the surface of molybdenum or molybdenum alloy under a protective atmosphere with laser as a heat source to obtain the modified MoSi2 oxidation-resistant coating.

[0008] As a preferred scheme of the preparation method of the modified MoSi2 oxidation-resistant coating of the molybdenum or molybdenum alloy surface, wherein: before the step B1, further comprising,

[0009] B0, sandpaper is used to polish the molybdenum or molybdenum alloy substrate, and then anhydrous ethanol is used for cleaning, and then drying is performed for standby use.

[0010] As a preferred scheme of the preparation method of the modified MoSi2 oxidation-resistant coating of the molybdenum or molybdenum alloy surface, wherein: in the step B1, the thickness of the modified MoSi2 oxidation-resistant powder laid on the molybdenum or molybdenum alloy surface is 250-320 μm.

[0011] As a preferred scheme of the preparation method of the modified MoSi2 oxidation-resistant coating of the molybdenum or molybdenum alloy surface, wherein: in the step B2, the protective atmosphere is argon, and the argon flow rate is 10-12 L / min.

[0012] As a preferred scheme of the preparation method of the modified MoSi2 oxidation-resistant coating of the molybdenum or molybdenum alloy surface, wherein: in the step B2, the laser power of the laser cladding is 3000-5000 W, the laser scanning speed is 300-500 mm / min, and the spot diameter is 3-5 mm.

[0013] As a preferred scheme of the preparation method of the modified MoSi2 oxidation-resistant coating of the molybdenum or molybdenum alloy surface, wherein: the preparation method of the modified MoSi2 oxidation-resistant powder comprises the following steps:

[0014] S1. MoSi2 powder and high-entropy alloy powder are prepared, and the particle size of the MoSi2 powder and the high-entropy alloy powder is 5-50 μm;

[0015] S2. The MoSi2 powder and the high-entropy alloy powder are placed in a ball mill for mixing to obtain a mixed powder;

[0016] S3. The mixed powder is placed in a drying machine for drying for 9-12 h to obtain the modified MoSi2 oxidation-resistant powder.

[0017] As a preferred scheme of the preparation method of the modified MoSi2 oxidation-resistant coating of the molybdenum or molybdenum alloy surface, wherein: the high-entropy alloy powder is a TiNbVZrAl multi-element high-entropy alloy powder.

[0018] As a preferred scheme of the preparation method of the modified MoSi2 oxidation-resistant coating of the molybdenum or molybdenum alloy surface, wherein: in the step S1, the MoSi2 powder is prepared by a mechanical alloying method, and the high-entropy alloy powder is prepared by a gas atomization method.

[0019] As a preferred scheme of the preparation method of the modified MoSi2 oxidation-resistant coating of the molybdenum or molybdenum alloy surface, in the step S2, the ball milling speed is 100-200 rpm, and the ball milling time is 2-3 h; the forward and reverse rotation is carried out during the ball milling, and the forward and reverse rotation time is the same.

[0020] The beneficial effects of the present application are as follows:

[0021] The present application provides a preparation method of a modified MoSi2 oxidation-resistant coating of a molybdenum or molybdenum alloy surface, MoSi2 powder and TiNbVZrAl high-entropy alloy powder are selected, and a MoSi2-TiNbVZrAl composite coating is prepared on the surface of the molybdenum or molybdenum alloy by a laser cladding process, MoSi2 is used as the base material of the coating, which can ensure the oxidation resistance of the composite coating, and an appropriate amount of TiNbVZrAl multi-element high-entropy alloy powder is added, wherein Al, Zr and Ti can further improve the oxidation resistance of the coating, and Nb alloy has good plasticity, so that the composite coating has good oxidation resistance, good density and good bonding performance, and can be applied to the surface protection of molybdenum and molybdenum alloys in high-temperature service environment. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained according to the structures shown in the drawings without creative labor for those skilled in the art.

[0023] Figure 1 A schematic diagram of the modified MoSi2 oxidation-resistant coating of the molybdenum or molybdenum alloy surface of the present application;

[0024] Figure 2 The surface macroscopic morphology of the coating of Example 1 of the present application;

[0025] Figure 3 The SEM diagram of the coating surface of Example 1 of the present application;

[0026] Figure 4 The surface macroscopic morphology of the coating of Comparative Example 1 of the present application;

[0027] Figure 5 The SEM diagram of the coating surface of Comparative Example 1 of the present application;

[0028] Figure 6 The SEM diagram of the coating cross section of Example 4 of the present application;

[0029] Figure 7 The SEM diagram of the coating cross section of Example 10 of the present application;

[0030] The objectives, functional characteristics and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0032] The present application provides a preparation method of a modified MoSi2 oxidation-resistant coating on a molybdenum or molybdenum alloy surface, which optimizes the density and microstructure of the existing MoSi2 coating and realizes better oxidation resistance and durability.

[0033] According to one aspect of the present application, the present application provides the following technical solutions:

[0034] A preparation method of a modified MoSi2 oxidation-resistant coating on a molybdenum or molybdenum alloy surface, comprising the following steps:

[0035] B1, the modified MoSi2 oxidation-resistant powder is laid on the molybdenum or molybdenum alloy surface; the preparation method of the modified MoSi2 oxidation-resistant powder comprises the following steps:

[0036] S1. MoSi2 powder and high-entropy alloy powder are taken for standby, and the particle size of the MoSi2 powder and the high-entropy alloy powder is 5-50 μm;

[0037] S2. The MoSi2 powder and the high-entropy alloy powder are placed in a ball mill for mixing to obtain a mixed powder;

[0038] S3. The mixed powder is placed in a drying machine for drying for 9-12 h to obtain the modified MoSi2 oxidation-resistant powder;

[0039] B2, under a protective atmosphere, the modified MoSi2 oxidation-resistant powder is laser cladded on the molybdenum or molybdenum alloy surface by using laser as a heat source to obtain a modified MoSi2 oxidation-resistant coating, as shown in Figure 1 The surface of the laser cladded TiNbVZrAl modified MoSi2 coating is flat and has no obvious macroscopic defects.

[0040] Preferably, before the step B1, there is further

[0041] B0, the molybdenum or molybdenum alloy substrate is polished by using sandpaper, then cleaned by using anhydrous ethanol, and then dried for standby; the sandpaper is sandpaper with a mesh size of 400-2000, and different mesh sizes of sandpaper are selected in sequence according to needs for polishing.

[0042] Preferably, in the step B1, the thickness of the modified MoSi2 oxidation-resistant powder laid on the molybdenum or molybdenum alloy surface is 250-320 μm. Specifically, the thickness of the modified MoSi2 oxidation-resistant powder laid on the molybdenum or molybdenum alloy surface can be, for example but not limited to, any one of 250 μm, 260 μm, 270 μm, 280 μm, 290 μm, 300 μm, 310 μm, 320 μm or a range between any two of them;

[0043] Preferably, in the step B2, the protective atmosphere is argon, the argon flow rate is 10-12 L / min; the laser power for laser cladding is 3000-5000 W, the laser scanning speed is 300-500 mm / min, and the spot diameter is 3-5 mm. Specifically, the argon flow rate can be, for example but not limited to, any one of 10 L / min, 10.5 L / min, 11 L / min, 11.5 L / min, 12 L / min or a range between any two of them; the laser power for laser cladding can be, for example but not limited to, any one of 3000 W, 3500 W, 4000 W, 4500 W, 5000 W or a range between any two of them; the laser scanning speed can be, for example but not limited to, any one of 300 mm / min, 350 mm / min, 400 mm / min, 450 mm / min, 500 mm / min or a range between any two of them; and the spot diameter can be, for example but not limited to, any one of 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm or a range between any two of them.

[0044] Preferably, in the modified MoSi2 oxidation-resistant powder, the mass percentage of the high-entropy alloy powder is 10-20 wt%. The high-entropy alloy powder is a TiNbVZrAl multi-element high-entropy alloy powder. Specifically, in the modified MoSi2 oxidation-resistant powder, the mass percentage of the high-entropy alloy powder can be, for example but not limited to, any one of 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt% or a range between any two of them.

[0045] Preferably, in the step S1, the MoSi2 powder is prepared by a mechanical alloying method, and the high-entropy alloy powder is prepared by a gas atomization method. Specifically, the particle size of the MoSi2 powder and the high-entropy alloy powder can be, for example but not limited to, any one of 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm or a range between any two of them.

[0046] Preferably, in the step S2, the ball milling speed is 100-200 rpm, and the ball milling time is 2-3 h; the ball milling is performed with forward and reverse rotation, and the forward and reverse rotation time is the same. Specifically, the ball milling speed can be, for example but not limited to, any one of 100 rpm, 110 rpm, 120 rpm, 130 rpm, 140 rpm, 150 rpm, 160 rpm, 170 rpm, 180 rpm, 190 rpm, 200 rpm, or a range between any two of them; the ball milling time can be, for example but not limited to, any one of 2 h, 2 h 15 min, 2 h 30 min, 2 h 45 min, 3 h, or a range between any two of them; further preferably, the ball milling with forward and reverse rotation can be performed with forward rotation for half of the ball milling time, and then reverse rotation for the other half of the ball milling time; or it can be performed with forward rotation for a certain time, then reverse rotation for the same time, then forward rotation for a certain time, then reverse rotation for the same time, until the ball milling is completed.

[0047] The technical solutions of the present application are further described below in combination with specific embodiments.

[0048] Embodiment 1

[0049] A preparation method of a modified MoSi2 oxidation-resistant coating on a molybdenum alloy surface, comprising the following steps:

[0050] B0, sandpaper with a mesh size of 400-2000 is used to polish the molybdenum alloy substrate, then anhydrous ethanol is used for cleaning, and then drying is performed for standby;

[0051] B1, the modified MoSi2 oxidation-resistant powder is laid flat on the molybdenum alloy surface; the thickness of the modified MoSi2 oxidation-resistant powder laid flat on the molybdenum alloy surface is 300 μm, and the modified MoSi2 oxidation-resistant powder is prepared by the following method:

[0052] S1. MoSi2 powder and TiNbVZrAl multi-element high-entropy alloy powder are taken for standby, and the particle size of the MoSi2 powder and the TiNbVZrAl multi-element high-entropy alloy powder is 5-50 μm;

[0053] S2. The MoSi2 powder and the TiNbVZrAl multi-element high-entropy alloy powder are placed in a ball mill for mixing to obtain a mixed powder, the ball milling speed is 200 rpm, the ball milling time is 2 h, and the forward and reverse rotation time is 1 h each;

[0054] S3. The mixed powder is placed in a drying machine for drying for 10 h to obtain the modified MoSi2 oxidation-resistant powder, and in the modified MoSi2 oxidation-resistant powder, the mass percentage of the TiNbVZrAl multi-element high-entropy alloy powder is 10 wt%;

[0055] B2, laser cladding the modified MoSi2 oxidation-resistant powder on the molybdenum alloy surface under a protective atmosphere to obtain a modified MoSi2 oxidation-resistant coating (such as Figures 2-3 As shown in the figure, no obvious cracks are found on the surface of the laser cladding TiNbVZrAl modified MoSi2 coating, and no obvious microcracks are observed on the surface and cross section of the coating, the microstructure is fine, and the interface bonding is good); the protective atmosphere is argon, and the argon flow rate is 10 L / min; the laser power for laser cladding is 5000 W, the laser scanning speed is 300 mm / min, and the spot diameter is 3 mm.

[0056] Example 2

[0057] A method for preparing a modified MoSi2 oxidation-resistant coating on a molybdenum alloy surface, comprising the following steps:

[0058] B0, sandpaper with a mesh size of 400-2000 is used to polish the molybdenum alloy substrate, then anhydrous ethanol is used for cleaning, and then drying is performed for standby;

[0059] B1, the modified MoSi2 oxidation-resistant powder is laid on the molybdenum alloy surface; the thickness of the modified MoSi2 oxidation-resistant powder laid on the molybdenum alloy surface is 250 μm, and the modified MoSi2 oxidation-resistant powder is prepared by the following method:

[0060] S1. MoSi2 powder and TiNbVZrAl multi-element high-entropy alloy powder are taken for standby, and the particle size of the MoSi2 powder and the TiNbVZrAl multi-element high-entropy alloy powder is 5-50 μm;

[0061] S2. The MoSi2 powder and the TiNbVZrAl multi-element high-entropy alloy powder are placed in a ball mill for mixing to obtain a mixed powder, the ball milling speed is 200 rpm, the ball milling time is 2 h, and the forward and reverse rotation time is 1 h each;

[0062] S3. The mixed powder is placed in a drying machine for drying for 12 h to obtain the modified MoSi2 oxidation-resistant powder, and the mass percentage of the TiNbVZrAl multi-element high-entropy alloy powder in the modified MoSi2 oxidation-resistant powder is 10 wt%;

[0063] B2, laser cladding the modified MoSi2 oxidation-resistant powder on the molybdenum alloy surface under a protective atmosphere to obtain a modified MoSi2 oxidation-resistant coating; the protective atmosphere is argon, and the argon flow rate is 12 L / min; the laser power for laser cladding is 3000 W, the laser scanning speed is 500 mm / min, and the spot diameter is 5 mm.

[0064] Example 3

[0065] A preparation method of a modified MoSi2 oxidation-resistant coating on a metal molybdenum surface, comprising the following steps:

[0066] B0, sandpaper with a mesh size of 400-2000 is used to polish the metal molybdenum substrate, then anhydrous ethanol is used for cleaning, and then drying is performed for standby use;

[0067] B1, the modified MoSi2 oxidation-resistant powder is laid on the metal molybdenum surface; the thickness of the modified MoSi2 oxidation-resistant powder laid on the metal molybdenum surface is 320 microns, and the modified MoSi2 oxidation-resistant powder is prepared by the following method:

[0068] S1. MoSi2 powder and TiNbVZrAl multi-element high-entropy alloy powder are taken for standby use, and the particle size of the MoSi2 powder and the TiNbVZrAl multi-element high-entropy alloy powder is 5-50 microns;

[0069] S2. The MoSi2 powder and the TiNbVZrAl multi-element high-entropy alloy powder are placed in a ball mill for mixing to obtain a mixed powder, the ball milling speed is 100 rpm, the ball milling time is 3 hours, and the forward and reverse rotation time is 1.5 hours each;

[0070] S3. The mixed powder is placed in a drying machine for drying for 9 hours to obtain the modified MoSi2 oxidation-resistant powder, and in the modified MoSi2 oxidation-resistant powder, the mass percentage of the TiNbVZrAl multi-element high-entropy alloy powder is 10wt%;

[0071] B2, under a protective atmosphere, the modified MoSi2 oxidation-resistant powder is laser cladded on the metal molybdenum surface by using a laser as a heat source to obtain a modified MoSi2 oxidation-resistant coating; the protective atmosphere is argon, the argon flow rate is 10 L / min; the laser power of the laser cladding is 3000 W, the laser scanning speed is 500 mm / min, and the spot diameter is 3 mm.

[0072] Example 4

[0073] A preparation method of a modified MoSi2 oxidation-resistant coating on a molybdenum alloy surface, comprising the following steps:

[0074] B0, sandpaper with a mesh size of 400-2000 is used to polish the metal molybdenum substrate, then anhydrous ethanol is used for cleaning, and then drying is performed for standby use;

[0075] B1, the modified MoSi2 oxidation-resistant powder is laid on the metal molybdenum surface; the thickness of the modified MoSi2 oxidation-resistant powder laid on the metal molybdenum surface is 320 microns, and the modified MoSi2 oxidation-resistant powder is prepared by the following method:

[0076] S1. Take MoSi2 powder, TiNbVZrAl multi-element high-entropy alloy powder for standby, the particle size of MoSi2 powder, TiNbVZrAl multi-element high-entropy alloy powder is 5-50μm;

[0077] S2. Put MoSi2 powder, TiNbVZrAl multi-element high-entropy alloy powder into a ball mill for mixing, the ball milling speed is 200rpm, the ball milling time is 2h, and each positive and negative rotation is 1h;

[0078] S3. Put the mixed powder into a drying machine for drying for 10h to obtain modified MoSi2 antioxidant powder, in the modified MoSi2 antioxidant powder, the mass percentage of TiNbVZrAl multi-element high-entropy alloy powder is 10wt%;

[0079] B2, under a protective atmosphere, laser is used as a heat source to laser cladding the modified MoSi2 antioxidant powder on the molybdenum alloy surface to obtain a modified MoSi2 antioxidant coating (as shown in Figure 6 The coating is well combined with the substrate, no obvious cracking is observed, and only a small amount of small-sized pores can be seen); the protective atmosphere is argon, the argon flow rate is 10L / min; the laser power of laser cladding is 3000W, the laser scanning speed is 300mm / min, and the spot diameter is 3mm.

[0080] Example 5

[0081] A method for preparing a modified MoSi2 antioxidant coating on a molybdenum alloy surface, comprising the following steps:

[0082] B0, sandpaper with 400-2000 mesh is used to polish the molybdenum alloy substrate, then anhydrous ethanol is used for cleaning, and then drying is carried out for standby;

[0083] B1, the modified MoSi2 antioxidant powder is laid flat on the molybdenum alloy surface; the thickness of the modified MoSi2 antioxidant powder laid flat on the molybdenum alloy surface is 300μm, and the modified MoSi2 antioxidant powder is prepared by the following method:

[0084] S1. Take MoSi2 powder, TiNbVZrAl multi-element high-entropy alloy powder for standby, the particle size of MoSi2 powder, TiNbVZrAl multi-element high-entropy alloy powder is 5-50μm;

[0085] S2. Put MoSi2 powder, TiNbVZrAl multi-element high-entropy alloy powder into a ball mill for mixing, the ball milling speed is 200rpm, the ball milling time is 2h, and each positive and negative rotation is 1h;

[0086] S3. The mixed powder is placed in a drying machine for drying for 10h to obtain the modified MoSi2 antioxidant powder, and the mass percentage of the TiNbVZrAl multi-element high-entropy alloy powder in the modified MoSi2 antioxidant powder is 10wt%;

[0087] B2, laser cladding the modified MoSi2 antioxidant powder on the molybdenum alloy surface under a protective atmosphere to obtain a modified MoSi2 antioxidant coating; the protective atmosphere is argon, and the argon flow rate is 10L / min; the laser power of the laser cladding is 5000W, the laser scanning speed is 500mm / min, and the spot diameter is 3mm.

[0088] Example 6

[0089] A method for preparing a modified MoSi2 antioxidant coating on a molybdenum alloy surface, comprising the following steps:

[0090] B0, sandpaper with a mesh size of 400-2000 is used to polish the molybdenum alloy substrate, and then anhydrous ethanol is used for cleaning, and then drying for use;

[0091] B1, the modified MoSi2 antioxidant powder is laid on the molybdenum alloy surface; the thickness of the modified MoSi2 antioxidant powder laid on the molybdenum alloy surface is 300μm, and the modified MoSi2 antioxidant powder is prepared by the following method:

[0092] S1. MoSi2 powder and TiNbVZrAl multi-element high-entropy alloy powder are taken for standby, and the particle size of the MoSi2 powder and the TiNbVZrAl multi-element high-entropy alloy powder is 5-50μm;

[0093] S2. The MoSi2 powder and the TiNbVZrAl multi-element high-entropy alloy powder are placed in a ball mill for mixing to obtain a mixed powder, the ball milling speed is 200rpm, the ball milling time is 2h, and the positive and negative rotation time is 1h each;

[0094] S3. The mixed powder is placed in a drying machine for drying for 10h to obtain the modified MoSi2 antioxidant powder, and the mass percentage of the TiNbVZrAl multi-element high-entropy alloy powder in the modified MoSi2 antioxidant powder is 20wt%;

[0095] B2, laser cladding the modified MoSi2 antioxidant powder on the molybdenum alloy surface under a protective atmosphere to obtain a modified MoSi2 antioxidant coating; the protective atmosphere is argon, and the argon flow rate is 10L / min; the laser power of the laser cladding is 5000W, the laser scanning speed is 300mm / min, and the spot diameter is 3mm.

[0096] Example 7

[0097] A preparation method of a modified MoSi2 oxidation-resistant coating on a molybdenum alloy surface, comprising the following steps:

[0098] B0, sandpaper with a mesh size of 400-2000 is used to polish the molybdenum alloy substrate, then anhydrous ethanol is used for cleaning, and then drying is performed for standby use;

[0099] B1, the modified MoSi2 oxidation-resistant powder is laid on the molybdenum alloy surface; the thickness of the modified MoSi2 oxidation-resistant powder laid on the molybdenum alloy surface is 300 μm, and the modified MoSi2 oxidation-resistant powder is prepared by the following method:

[0100] S1. MoSi2 powder and TiNbVZrAl multi-element high-entropy alloy powder are taken for standby use, and the particle sizes of the MoSi2 powder and the TiNbVZrAl multi-element high-entropy alloy powder are both 5-50 μm;

[0101] S2. The MoSi2 powder and the TiNbVZrAl multi-element high-entropy alloy powder are placed in a ball mill for mixing to obtain a mixed powder, the ball milling speed is 200 rpm, the ball milling time is 2 h, and each of the forward and reverse rotation is 1 h;

[0102] S3. The mixed powder is placed in a drying machine for drying for 10 h to obtain the modified MoSi2 oxidation-resistant powder, and in the modified MoSi2 oxidation-resistant powder, the mass percentage of the TiNbVZrAl multi-element high-entropy alloy powder is 20 wt%;

[0103] B2, under a protective atmosphere, the modified MoSi2 oxidation-resistant powder is laser cladded on the molybdenum alloy surface by using a laser as a heat source to obtain a modified MoSi2 oxidation-resistant coating; the protective atmosphere is argon, the argon flow rate is 10 L / min; the laser power for laser cladding is 3000 W, the laser scanning speed is 500 mm / min, and the spot diameter is 3 mm.

[0104] Example 8

[0105] A preparation method of a modified MoSi2 oxidation-resistant coating on a molybdenum alloy surface, comprising the following steps:

[0106] B0, sandpaper with a mesh size of 400-2000 is used to polish the molybdenum alloy substrate, then anhydrous ethanol is used for cleaning, and then drying is performed for standby use;

[0107] B1, the modified MoSi2 oxidation-resistant powder is laid on the molybdenum alloy surface; the thickness of the modified MoSi2 oxidation-resistant powder laid on the molybdenum alloy surface is 300 μm, and the modified MoSi2 oxidation-resistant powder is prepared by the following method:

[0108] S1. Take MoSi2 powder, TiNbVZrAl multi-element high-entropy alloy powder for standby, the particle size of MoSi2 powder, TiNbVZrAl multi-element high-entropy alloy powder is 5-50μm;

[0109] S2. Put MoSi2 powder, TiNbVZrAl multi-element high-entropy alloy powder into a ball mill for mixing, the ball milling speed is 100rpm, the ball milling time is 2h, and each positive and negative rotation is 1h;

[0110] S3. Put the mixed powder into a drying machine for drying for 10h to obtain modified MoSi2 antioxidant powder, in the modified MoSi2 antioxidant powder, the mass percentage of TiNbVZrAl multi-element high-entropy alloy powder is 20wt%;

[0111] B2, under the protection of atmosphere, laser is used as heat source to laser cladding the modified MoSi2 antioxidant powder on the molybdenum alloy surface to obtain a modified MoSi2 antioxidant coating; the protection atmosphere is argon, the argon flow is 10L / min; the laser power of laser cladding is 3000W, the laser scanning speed is 500mm / min, and the spot diameter is 3mm.

[0112] Example 9

[0113] A preparation method of a modified MoSi2 antioxidant coating on a molybdenum alloy surface, comprising the following steps:

[0114] B0, sandpaper with 400-2000 mesh is used to polish the molybdenum alloy substrate, then anhydrous ethanol is used for cleaning, and then drying is carried out for standby;

[0115] B1, the modified MoSi2 antioxidant powder is laid on the molybdenum alloy surface; the thickness of the modified MoSi2 antioxidant powder laid on the molybdenum alloy surface is 300μm, and the modified MoSi2 antioxidant powder is prepared by the following method:

[0116] S1. Take MoSi2 powder, TiNbVZrAl multi-element high-entropy alloy powder for standby, the particle size of MoSi2 powder, TiNbVZrAl multi-element high-entropy alloy powder is 5-50μm;

[0117] S2. Put MoSi2 powder, TiNbVZrAl multi-element high-entropy alloy powder into a ball mill for mixing, the ball milling speed is 200rpm, the ball milling time is 2h, and each positive and negative rotation is 1h;

[0118] S3. Put the mixed powder into a drying machine for drying for 10h to obtain modified MoSi2 antioxidant powder, in the modified MoSi2 antioxidant powder, the mass percentage of TiNbVZrAl multi-element high-entropy alloy powder is 20wt%;

[0119] B2, laser cladding the modified MoSi2 oxidation-resistant powder on the molybdenum alloy surface under a protective atmosphere to obtain a modified MoSi2 oxidation-resistant coating; the protective atmosphere is argon, the argon flow rate is 10 L / min; the laser power of the laser cladding is 3000 W, the laser scanning speed is 300 mm / min, and the spot diameter is 3 mm.

[0120] Example 10

[0121] A method for preparing a modified MoSi2 oxidation-resistant coating on a molybdenum alloy surface, comprising the following steps:

[0122] B0, sandpaper with a mesh size of 400-2000 is used to polish the molybdenum alloy substrate, then the molybdenum alloy substrate is cleaned with anhydrous ethanol, and then dried for use;

[0123] B1, the modified MoSi2 oxidation-resistant powder is laid on the molybdenum alloy surface; the thickness of the modified MoSi2 oxidation-resistant powder laid on the molybdenum alloy surface is 300 μm, and the modified MoSi2 oxidation-resistant powder is prepared by the following method:

[0124] S1. MoSi2 powder and TiNbVZrAl multi-element high-entropy alloy powder are taken for standby, and the particle sizes of the MoSi2 powder and the TiNbVZrAl multi-element high-entropy alloy powder are both 5-50 μm;

[0125] S2. The MoSi2 powder and the TiNbVZrAl multi-element high-entropy alloy powder are placed in a ball mill for mixing to obtain a mixed powder, the ball milling speed is 200 rpm, the ball milling time is 2 h, and the forward and reverse rotation times are each 1 h;

[0126] S3. The mixed powder is placed in a drying machine and dried for 10 h to obtain the modified MoSi2 oxidation-resistant powder, and in the modified MoSi2 oxidation-resistant powder, the mass percentage of the TiNbVZrAl multi-element high-entropy alloy powder is 20 wt%;

[0127] B2, laser cladding the modified MoSi2 oxidation-resistant powder on the molybdenum alloy surface under a protective atmosphere to obtain a modified MoSi2 oxidation-resistant coating (as shown in Figure 7 , no obvious defects are observed); the protective atmosphere is argon, the argon flow rate is 10 L / min; the laser power of the laser cladding is 5000 W, the laser scanning speed is 500 mm / min, and the spot diameter is 3 mm.

[0128] Comparative Example 1

[0129] The difference from Example 1 is that,

[0130] MoSi2 powder is not modified by TiNbVZrAl high-entropy alloy, and only MoSi2 coating material is prepared by a laser cladding process, as shown in Figures 4-5 The MoSi2 coating prepared by the laser cladding process of the comparative example 1 has obvious cracking phenomenon.

[0131] Comparative example 2

[0132] The difference from the example 1 is that,

[0133] In the modified MoSi2 antioxidant powder, the mass percentage of the high-entropy alloy powder is 30wt%;

[0134] The modified MoSi2 coating prepared by the laser cladding process of the comparative example 1 still has cracking phenomenon.

[0135] The MoSi2-TiNbVZrAl composite coating is prepared on the surface of molybdenum or molybdenum alloy by the laser cladding process by selecting MoSi2 powder and TiNbVZrAl high-entropy alloy powder, MoSi2 as the basic material of the coating can ensure the antioxidant performance of the composite coating, and the addition of appropriate amount of TiNbVZrAl multi-element high-entropy alloy powder can further improve the antioxidant performance of the coating, Al, Zr and Ti can further improve the antioxidant performance of the coating, and Nb alloy has good plasticity, so that the composite coating has good antioxidant performance, good density and good bonding performance, and can be applied to the surface protection of molybdenum and molybdenum alloy in high-temperature service environment.

[0136] The above only describes the preferred embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made by using the content of the present application, or direct / indirect application in other related technical fields within the inventive concept of the present application is included in the patent protection scope of the present application.

Claims

1. A method for producing a modified MoSi2 oxidation resistant coating on a molybdenum or molybdenum alloy surface, characterized by, The method comprises the following steps: B1, spreading modified MoSi2 antioxidant powder on the surface of molybdenum or molybdenum alloy; the mass percentage of high-entropy alloy powder in the modified MoSi2 antioxidant powder is 10-20wt%; the high-entropy alloy powder is TiNbVZrAl multi-element high-entropy alloy powder; B2, laser cladding the modified MoSi2 antioxidant powder on the surface of molybdenum or molybdenum alloy under a protective atmosphere with laser as a heat source to obtain a modified MoSi2 antioxidant coating.

2. The method of claim 1, wherein the modified MoSi2 oxidation-resistant coating is prepared on a molybdenum or molybdenum alloy surface by a process comprising: Before the step B1, the method further comprises the following step: B0, polishing the molybdenum or molybdenum alloy substrate with sandpaper, then cleaning with anhydrous ethanol, and then drying for use.

3. The method of claim 1, wherein the modified MoSi2 oxidation resistant coating is prepared on a molybdenum or molybdenum alloy surface by a process comprising: In the step B1, the thickness of the modified MoSi2 antioxidant powder spread on the surface of molybdenum or molybdenum alloy is 250-320μm.

4. The method of claim 1, wherein the modified MoSi2 oxidation resistant coating is prepared on a molybdenum or molybdenum alloy surface by a process comprising: In the step B2, the protective atmosphere is argon, and the argon flow rate is 10-12L / min.

5. The method of claim 1, wherein the modified MoSi2 oxidation resistant coating is prepared on a molybdenum or molybdenum alloy surface by a process comprising: In the step B2, the laser power of laser cladding is 3000-5000W, the laser scanning speed is 300-500mm / min, and the spot diameter is 3-5mm.

6. The method of claim 1, wherein the modified MoSi2 oxidation resistant coating is prepared on a molybdenum or molybdenum alloy surface by a process comprising: The preparation method of the modified MoSi2 antioxidant powder comprises the following steps: S1. MoSi2 powder and high-entropy alloy powder are prepared for use, and the particle size of the MoSi2 powder and the high-entropy alloy powder is 5-50μm; S2. The MoSi2 powder and the high-entropy alloy powder are mixed in a ball mill to obtain a mixed powder; S3. The mixed powder is dried in a drying machine to obtain the modified MoSi2 antioxidant powder.

7. The method of claim 6, wherein the modified MoSi2 oxidation resistant coating is prepared on a molybdenum or molybdenum alloy surface by a process comprising: In the step S2, the ball milling speed is 100-200rpm, and the ball milling time is 2-3h.

8. The method of claim 6, wherein the modified MoSi2 oxidation resistant coating is prepared on a molybdenum or molybdenum alloy surface by a process comprising: In the step S2, the ball milling is carried out with forward and reverse rotation, and the forward and reverse rotation time is the same.

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