Method for modifying aluminide coating based on laser cladding

Abstract

The invention provides a method for modifying an aluminide coating based on laser cladding, and belongs to the technical field of material surface alloying and coating preparation. The method comprises the following steps: weighing solid-phase cladding powder and a liquid-phase binder in proportion, and stirring and ball-milling to obtain cladding slurry; surface cleaning and preheating treatment are conducted on a workpiece to be plated, then the cladding slurry is evenly sprayed to the surface of the workpiece, and drying and curing are conducted after spraying is completed; and the workpiece with the cured spraying layer is placed in an inert atmosphere for laser cladding, and the aluminide cladding coating is obtained after cooling. The infiltrated layer prepared through the method is uniform in organization structure, moderate in thickness, sufficient in Al atom diffusion, good in metallurgical bonding with a base body, not prone to falling off, suitable for austenitic steel and high-temperature alloy parts used for workpieces with the large length-diameter ratio and various complex shapes such as large boilers and oil and gas field conveying pipelines, and extremely good industrial batch production benefits are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of material surface alloying and coating preparation, and specifically relates to a method for modifying an aluminide coating based on laser cladding. Background Art

[0002] In the electric power industry, pipe blockage and burst accidents caused by scale problems on the inner wall of flow-through components account for more than 50% of boiler non-shutdown accidents, resulting in an increase of more than 20% in the operating and material costs of the unit; therefore, it is of great practical significance to research and develop anti-oxidation and corrosion-resistant technologies suitable for the inner and outer wall surfaces of pipes used in boiler units.

[0003] The high-temperature anti-oxidation coating preparation technology currently developed is suitable for the large aspect ratio structural characteristics of energy equipment flow parts, high temperature, long time, and low stress service environment characteristics, mainly based on aluminide coatings; in actual unit operation tests, aluminide coatings also show excellent anti-oxidation service performance. However, with the extension of service time, the increase of unit power, and the complexity of the service environment, a single aluminide coating will inevitably face the phenomenon of decreased oxidation resistance and film peeling. In addition, after long-term service, the Al content of the film decreases, and the density and uniformity of the oxide film will also be lost, reducing the anti-oxidation performance of the coating. Therefore, it is necessary to develop a new type of anti-oxidation coating with excellent oxidation resistance and anti-stripping ability, suitable for the preparation of various complex-shaped workpieces with large aspect ratios. Summary of the invention

[0004] The present invention aims to solve at least one of the problems in the prior art and provides a method for modifying an aluminide coating based on laser cladding.

[0005] The present invention proposes a method for modifying an aluminide coating based on laser cladding, wherein

[0006] Methods include:

[0007] Weigh the solid phase cladding powder and the liquid phase binder in proportion, and prepare the cladding slurry after stirring and ball milling;

[0008] The workpiece to be plated is cleaned and preheated, and then the cladding slurry is evenly sprayed onto the workpiece surface, and dried and solidified after spraying;

[0009] The workpiece after the spray coating is solidified is placed in an inert atmosphere for laser cladding, and an aluminide cladding coating is obtained after cooling.

[0010] Optionally, the solid phase cladding powder includes an infiltration source, a modifier, and an activator.

[0011] Optionally, the infiltration source is FeAl or Al powder;

[0012] The modifiers are Ti and Co;

[0013] The activating agent is NH 4 Cl.

[0014] Optionally, the solid phase cladding powder comprises:

[0015] 60-80% FeAl;

[0016] 10-30% Al;

[0017] 0-5% Ti;

[0018] 0-5% C;

[0019] 2-7% NH 4 Cl.

[0020] Optionally, the liquid binder is ethyl acetate.

[0021] Optionally, the content of the liquid phase binder is 10-30% of the solid phase cladding powder.

[0022] Optionally, in step 2, the thickness of the spray coating is preset to be 1-5 mm;

[0023] The preheating treatment is medium frequency preheating at 200-250° C. for 30-60 minutes.

[0024] Optionally, the coating is dried by natural air drying for 24-48 hours, and the curing treatment is cured at 300-450° C. for 24-48 hours.

[0025] Optionally, the thickness of the aluminide cladding coating is 0.29-1.25 mm.

[0026] Optionally, the laser power of the laser cladding process is 2-2.8KW, the scanning rate is 20-40mm / s, the spot diameter is 3-5mm, the workpiece rotation speed is 0-5r / min, and the Ar gas flow rate is 15-20L / min.

[0027] The present invention proposes a method for modifying an aluminide coating based on laser cladding, the method comprising: weighing a solid-phase cladding powder and a liquid-phase binder in proportion, stirring and ball milling to obtain a cladding slurry; cleaning and preheating the surface of the workpiece to be plated, then spraying the cladding slurry evenly onto the workpiece surface, drying and curing after spraying; placing the workpiece after the spray coating is cured under an inert atmosphere for laser cladding, and obtaining an aluminide cladding coating after cooling. The infiltration layer prepared by the present invention has a uniform structure, moderate thickness, and sufficient Al atom diffusion. The infiltration layer is well metallurgically bonded to the substrate and is not easy to fall off. It is suitable for austenitic steel and high-temperature alloy parts used in large boilers, oil and gas field transportation pipelines and other large aspect ratios and various complex-shaped workpieces, and has excellent industrial mass production benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a flowchart of a method for modifying an aluminide coating based on laser cladding according to an embodiment of the present invention;

[0029] Figure 2 This is the cross-sectional morphology of the aluminide cladding coating in Example 1 of the present invention. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the disclosure. The described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without the need for creative work belong to the scope of protection of the present invention.

[0031] like Figure 1 As shown, the present invention proposes a method S100 for modifying an aluminide coating based on laser cladding, comprising the following specific steps S110 to S130:

[0032] S110, weighing the solid phase cladding powder and the liquid phase binder in proportion, and preparing the cladding slurry after stirring and ball milling.

[0033] In step S110, the solid phase cladding powder includes an infiltration source, a modifier, and an activator, wherein the infiltration source is FeAl, Al powder, the modifier is Ti and Co, and the activator is NH 4 Cl.

[0034] The liquid binder is ethyl acetate.

[0035] In this embodiment, FeAl alloy powder is used as the aluminizing source. In addition to providing the active aluminum atoms necessary for preparing the aluminide coating, it can also be directly clad into the aluminized layer to regulate the aluminized layer structure and inhibit Fe 2 Al 5 Secondly, by introducing Ti element modification, a continuous and dense oxide film can be formed, corrosion products with fine grains can be produced, the "stickiness" of the oxide film can be enhanced, and the anti-stripping performance of the film can be improved. Introducing Co element modification can form stable sulfides and eutectic structures in a sulfur-containing environment, hindering the internal oxidation and internal sulfidation of the parent material, and delaying the occurrence of oxidation behavior. Adding halide NH 4 Cl plays a role in promoting penetration and activation, improving the penetration rate and coating quality.

[0036] In some preferred embodiments, the solid phase cladding powder is weighed by mass percentage and includes 60-80% FeAl, 10-30% Al, 0-5% Ti, 0-5% Co and 2-7% NH 4 Cl, wherein FeAl, Al, Ti, and Co powders are all sieved through a 1000-mesh sieve, and the solid components are mixed by ball milling in a planetary ball mill at a ball milling speed of 350-400 rpm for 12-24 h.

[0037] In other preferred embodiments, the binder ethyl acetate is added to the uniformly mixed solid phase powder at a mass ratio of 10-30% of the solid phase component, and after being fully stirred for 2-4 hours, it is placed in a planetary ball mill for ball milling mixing, and the ball milling speed is 350-400rpm and the time is 8-12 hours.

[0038] S120, cleaning and preheating the surface of the workpiece to be plated, then spraying the cladding slurry evenly onto the surface of the workpiece, and drying and curing after spraying.

[0039] In step S120, the workpiece surface is pretreated by high-pressure water gun cleaning and rinsing with alcohol or acetone; the preheating treatment is medium frequency preheating at 200-250°C for 30-60 minutes. The preset spray layer thickness is 1-5mm and the coating coverage is not less than 98%. In other words, the slurry is sprayed to a suitable thickness at one time, and it cannot be sprayed in layers multiple times. The thickness of the spray layer is kept at 1-5mm. If the slurry layer is too thin, it is not enough to provide sufficient penetration source, and if it is too thick, it is easy to crack and peel off, affecting the uniformity of the penetration layer thickness.

[0040] Furthermore, in step S120, the coating is dried by natural air drying for 24-48 hours and cured at 300-450°C for 24-48 hours. The segmented slurry curing process of natural air drying combined with medium and low temperature curing effectively avoids the problem of micro cracks and tiny holes in the spray coating layer caused by thermal stress during direct drying, and enhances the bonding strength between the slurry layer and the workpiece surface.

[0041] In this embodiment, the natural air drying method combined with the segmented slurry curing process of medium and low temperature curing effectively avoids the problem of micro cracks and tiny holes in the slurry layer caused by thermal stress during direct drying, and enhances the bonding strength between the slurry layer and the workpiece surface.

[0042] S130, placing the workpiece after the spray coating is solidified in an inert atmosphere for laser cladding, and obtaining an aluminide cladding coating after cooling. The residue is treated by flushing with a high-pressure water gun or high-pressure air flow, and naturally air-dried.

[0043] In step S130, the laser power is 2-2.8KW, the scanning rate is 20-40mm / s, the spot diameter is 3-5mm, the workpiece rotation speed is 0-5r / min, and the Ar gas flow rate is 15-20L / min; after completion, cool to room temperature and rinse the residue on the workpiece surface with a high-pressure water gun or high-pressure air flow.

[0044] In this embodiment, the coating is prepared by a laser cladding process, which has concentrated heat, short action time, small thermal impact in the cladding zone, and high bonding strength between the coating and the base material.

[0045] Through the above-mentioned processes and steps, the present invention prepares an aluminide cladding coating with a thickness of 0.29-1.25 mm and good metallurgical bonding under the conditions of adjusting main process parameters such as solid phase component content, modifier addition content, spray layer thickness and laser cladding parameters; the aluminide cladding coating obtained by the present invention has an oxidation resistance that is 19-65 times higher than that of the parent material in a 600°C pure water vapor environment and 20-78 times higher than that of the parent material in a 650°C pure water vapor environment, which can be explained that the aluminide cladding coating prepared by the method of the present invention effectively improves the oxidation resistance of the alloy parent material in a pure water vapor environment.

[0046] The following is a further description of the method for modifying the aluminide coating based on laser cladding in combination with several specific embodiments:

[0047] Example 1

[0048] Step 1: Weigh the solid phase components according to mass ratio, including 60% FeAl, 30% Al, 3% Ti, 5% Co and 2% NH 4 Cl, place it in a planetary ball mill at 400 rpm for 12 hours to obtain solid phase cladding powder; then, add 10% ethyl acetate and stir it for 4 hours, then place it in a planetary ball mill at 400 rpm for 12 hours, and after completion, obtain a uniformly mixed slurry, which is the cladding slurry.

[0049] Step 2: Use a high-pressure water gun to clean the surface of the workpiece for 5 minutes, and rinse it with alcohol or acetone; then, preheat the workpiece at 250°C for 45 minutes, and use spraying to pre-set the slurry layer thickness to 3mm, keeping the coating coverage rate not less than 98%; then, air dry the workpiece naturally for 48 hours, and cure it at 450°C for 48 hours.

[0050] Step 3: Place the workpiece under Ar for laser cladding, with a laser power of 2KW, a scanning rate of 40mm / s, a spot diameter of 5mm, a workpiece rotation speed of 5r / min, and an Ar gas flow rate of 20L / min; after completion, cool to room temperature and flush the residue on the workpiece surface with high-pressure airflow.

[0051] As shown in Table 1, the thickness of the infiltration layer obtained in this example is 0.38 mm, and the cross-sectional morphology of the infiltration layer is as follows: Figure 2 As shown, it is found that the diffusion layer has uniform structure, moderate thickness, sufficient diffusion of Al atoms, good metallurgical bonding between the diffusion layer and the matrix, and is not easy to fall off.

[0052] Example 2

[0053] The preparation process of the method of this example is the same as that of Example 1, as shown in Table 1, with the difference that the laser power in step 3 is 2.8 KW, and the thickness of the diffusion layer obtained thereby is 0.85 mm.

[0054] Example 3

[0055] The preparation process of the method of this example is the same as that of Example 1, as shown in Table 1, with the difference that the laser power in step 3 is 2.8KW, the scanning rate is 20mm / s, the Ar gas flow rate is 15L / min, and the workpiece rotation speed is 4r / min, so the obtained diffusion layer thickness is 1.18mm.

[0056] Example 4

[0057] The preparation process of the method of this example is the same as that of Example 1, as shown in Table 1, with the difference that the laser power in step 3 is 2.8KW, the scanning rate is 20mm / s, the spot diameter is 2mm, and the Ar gas flow rate is 15L / min, so the thickness of the infiltration layer is 0.95mm.

[0058] Example 5

[0059] The preparation process of the method of this example is the same as that of Example 1, as shown in Table 1, with the difference that the laser power is 2.5KW, the scanning rate is 30mm / s, the spot diameter is 2mm, the workpiece rotation speed is 2r / min, and the Ar gas flow rate is 18L / min, and the obtained diffusion layer thickness is 1.14mm.

[0060] Example 6

[0061] The preparation process of the method of this example is the same as that of Example 1, as shown in Table 1, with the difference that the laser power is 2.4KW, the scanning rate is 25mm / s, the spot diameter is 2mm, the workpiece rotation speed is 2r / min, and the Ar gas flow rate is 15L / min, and the obtained diffusion layer thickness is 1.12mm.

[0062] Example 7

[0063] The preparation process of the method of this example is the same as that of Example 1, as shown in Table 1, with the difference that the laser power is 2.8KW, the scanning rate is 35mm / s, the spot diameter is 3mm, and the thickness of the obtained diffusion layer is 1.21mm.

[0064] Example 8

[0065] The preparation process of the method of this example is the same as that of Example 1, as shown in Table 1, with the difference that the laser power is 2.6KW, the scanning rate is 25mm / s, the spot diameter is 3mm, the workpiece rotation speed is 4r / min, and the Ar gas flow rate is 18L / min, and the obtained diffusion layer thickness is 1.07mm.

[0066] Example 9

[0067] The preparation process of the method of this example is the same as that of Example 1, as shown in Table 1, with the difference that the laser power is 2.8KW, the spot diameter is 4mm, the workpiece rotation speed is 4r / min, and the obtained diffusion layer thickness is 0.68mm.

[0068] By analyzing and studying the above embodiments, the thickness of the diffusion layer was measured to be about 0.29-1.25 mm. The specific results are shown in Table 1.

[0069] Table 1 Process parameters and infiltration layer parameters of Examples 1-9

[0070]

[0071]

[0072] Example 10

[0073] Step 1: Weigh the solid phase components according to mass ratio, including 70% FeAl, 15% Al, 5% Ti, 3% Co and 7% NH 4 Cl, place it in a planetary ball mill at 350 rpm for 24 hours to obtain solid phase cladding powder; then, add 30% ethyl acetate and stir it for 2 hours, then place it in a planetary ball mill at 400 rpm for 12 hours, and after completion, a uniformly mixed slurry is obtained, which is the cladding slurry.

[0074] Step 2: Use a high-pressure water gun to clean the surface of the workpiece for 5 minutes, and rinse it with alcohol or acetone; then, preheat the workpiece at 200°C for 60 minutes, and use spraying to pre-set the slurry layer thickness to 5mm, keeping the coating coverage rate not less than 98%; then, air-dry the workpiece for 24 hours and cure it at 300°C for 48 hours.

[0075] Step 3: Place the workpiece under Ar for laser cladding, with a laser power of 2.5KW, a scanning rate of 20mm / s, a spot diameter of 2mm, a workpiece rotation speed of 5r / min, and an Ar gas flow rate of 15L / min; after completion, cool to room temperature and flush the residue on the workpiece surface with high-pressure airflow.

[0076] Embodiment 11

[0077] Step 1: Weigh the solid phase components according to mass ratio, including 80% FeAl, 10% Al, 3% Ti, 5% Co and 2% NH 4 Cl, place it in a planetary ball mill at 400 rpm for 24 hours to obtain solid phase cladding powder; then, add 20% ethyl acetate and stir it for 2 hours, then place it in a planetary ball mill at 350 rpm for 8 hours, and after completion, a uniformly mixed slurry is obtained, which is the cladding slurry.

[0078] Step 2: Use a high-pressure water gun to clean the surface of the workpiece for 5 minutes, and rinse it with alcohol or acetone; then, preheat the workpiece at 250°C for 30 minutes, and use spraying to pre-set the slurry layer thickness to 2mm, keeping the coating coverage rate not less than 98%; then, air-dry the workpiece for 24 hours and cure it at 450°C for 48 hours.

[0079] Step 3: Place the workpiece under Ar for laser cladding, with a laser power of 2.8KW, a scanning rate of 40mm / s, a spot diameter of 3mm, a workpiece rotation speed of 2r / min, and an Ar gas flow rate of 15L / min; after completion, cool to room temperature and flush the residue on the workpiece surface with high-pressure airflow.

[0080] Example 12

[0081] Step 1: Weigh the solid phase components according to the mass ratio, including 70% FeAl, 20% Al, 5% Co and 5% NH 4 Cl, place it in a planetary ball mill at 400 rpm for 12 hours to obtain solid phase cladding powder; then, add 20% ethyl acetate and stir it for 2 hours, then place it in a planetary ball mill at 350 rpm for 12 hours, and after completion, obtain a uniformly mixed slurry, which is the cladding slurry.

[0082] Step 2: Clean the surface of the workpiece with a high-pressure water gun for 5 minutes and rinse it with alcohol or acetone; then, preheat the workpiece at 200°C for 60 minutes, and use spraying to pre-set the slurry layer thickness to 5mm, keeping the coating coverage rate not less than 98%; then, air-dry the workpiece for 24 hours and cure it at 400°C for 48 hours.

[0083] Step 3: Place the workpiece under Ar for laser cladding, with a laser power of 2.8KW, a scanning rate of 20mm / s, a spot diameter of 3mm, a workpiece rotation speed of 5r / min, and an Ar gas flow rate of 15L / min; after completion, cool to room temperature and flush the residue on the workpiece surface with high-pressure airflow.

[0084] Embodiment 13

[0085] Step 1: Weigh the solid phase components according to the mass ratio, including 70% FeAl, 18% Al, 5% Ti and 7% NH 4 Cl, place it in a planetary ball mill at 400 rpm for 24 hours to obtain solid phase cladding powder; then, add 30% ethyl acetate and stir it for 2 hours, then place it in a planetary ball mill at 400 rpm for 12 hours, and after completion, a uniformly mixed slurry is obtained, which is the cladding slurry.

[0086] Step 2: Use a high-pressure water gun to clean the surface of the workpiece for 5 minutes, and rinse it with alcohol or acetone; then, preheat the workpiece at 250°C for 45 minutes, and use spraying to pre-set the slurry layer thickness to 5mm, keeping the coating coverage rate not less than 98%; then, air-dry the workpiece for 24 hours and cure it at 450°C for 48 hours.

[0087] Step 3: Place the workpiece under Ar for laser cladding, with a laser power of 2KW, a scanning rate of 30mm / s, a spot diameter of 5mm, a workpiece rotation speed of 5r / min, and an Ar gas flow rate of 18L / min; after completion, cool to room temperature and flush the residue on the workpiece surface with high-pressure airflow.

[0088] Embodiment 14

[0089] Step 1: Weigh the solid phase components according to mass ratio, including 65% FeAl, 25% Al, 4% Ti, 4% Co and 2% NH 4 Cl, place it in a planetary ball mill at 350 rpm for 12 hours to obtain solid phase cladding powder; then, add 30% ethyl acetate and stir it thoroughly for 4 hours, then place it in a planetary ball mill at 400 rpm for 8 hours, and after completion, a uniformly mixed slurry is obtained, which is the cladding slurry.

[0090] Step 2: Use a high-pressure water gun to clean the surface of the workpiece for 5 minutes, and rinse it with alcohol or acetone; then, preheat the workpiece at 250°C for 60 minutes, and use spraying to pre-set the slurry layer thickness to 4mm, keeping the coating coverage rate not less than 98%; then, air-dry the workpiece for 36 hours and cure it at 450°C for 48 hours.

[0091] Step 3: Place the workpiece under Ar for laser cladding, with a laser power of 2.8KW, a scanning rate of 40mm / s, a spot diameter of 5mm, a workpiece rotation speed of 4r / min, and an Ar gas flow rate of 20L / min; after completion, cool to room temperature and flush the residue on the workpiece surface with high-pressure airflow.

[0092] Embodiment 15

[0093] Step 1: Weigh the solid phase components according to mass ratio, including 60% FeAl, 30% Al, 3% Ti, 5% Co and 2% NH 4 Cl, place it in a planetary ball mill at 350 rpm for 24 hours to obtain solid phase cladding powder; then, add 20% ethyl acetate and stir it thoroughly for 4 hours, then place it in a planetary ball mill at 400 rpm for 8 hours, and after completion, a uniformly mixed slurry is obtained, which is the cladding slurry.

[0094] Step 2: Use a high-pressure water gun to clean the surface of the workpiece for 5 minutes, and rinse it with alcohol or acetone; then, preheat the workpiece at 250°C for 60 minutes, and use spraying to pre-set the slurry layer thickness to 5mm, keeping the coating coverage rate not less than 98%; then, air-dry the workpiece naturally for 48 hours, and cure it at 450°C for 48 hours.

[0095] Step 3: Place the workpiece under Ar for laser cladding, with a laser power of 2.8KW, a scanning rate of 40mm / s, a spot diameter of 4mm, a workpiece rotation speed of 4r / min, and an Ar gas flow rate of 15L / min; after completion, cool to room temperature and flush the residue on the workpiece surface with high-pressure airflow.

[0096] Example 16

[0097] Step 1: Weigh the solid phase components according to mass ratio, including 75% FeAl, 15% Al, 4% Ti, 4% Co and 2% NH 4 Cl, place it in a planetary ball mill at 400 rpm for 24 hours to obtain solid phase cladding powder; then, add 30% ethyl acetate and stir it for 4 hours, then place it in a planetary ball mill at 400 rpm for 8 hours, and after completion, a uniformly mixed slurry is obtained, which is the cladding slurry.

[0098] Step 2: Use a high-pressure water gun to clean the surface of the workpiece for 5 minutes, and rinse it with alcohol or acetone; then, preheat the workpiece at 250°C for 60 minutes, and use spraying to pre-set the slurry layer thickness to 5mm, keeping the coating coverage rate not less than 98%; then, air-dry the workpiece naturally for 24 hours, and cure it at 450°C for 48 hours.

[0099] Step 3: Place the workpiece under Ar for laser cladding, with a laser power of 2.8KW, a scanning rate of 35mm / s, a spot diameter of 4mm, a workpiece rotation speed of 2r / min, and an Ar gas flow rate of 18L / min; after completion, cool to room temperature and flush the residue on the workpiece surface with high-pressure airflow.

[0100] The present invention proposes a method for modifying an aluminide coating based on laser cladding, which has the following beneficial effects compared with the prior art:

[0101] First, the present invention can form a dense and stable oxide film and improve the corrosion resistance of the coating in a sulfur-containing environment by introducing modified elements Ti and Co into the solid phase powder; wherein, the introduction of Ti element modification can form a continuous and dense oxide film, produce corrosion products with fine grains, enhance the "viscosity" of the oxide film, and improve the anti-stripping performance of the film layer; the introduction of Co element modification can form stable sulfides and eutectic structures in a sulfur-containing environment, hinder the internal oxidation and internal sulfidation of the parent material, and delay the occurrence of oxidation behavior;

[0102] Second, the present invention adds halide NH 4 Cl plays a role in promoting penetration and activation, improving the penetration rate and coating quality;

[0103] Third, the present invention prepares the coating by laser cladding process, which has high production efficiency, concentrated heat, short action time, small thermal impact in the cladding area, high bonding strength between the coating and the parent material, and controllable thickness of the coating;

[0104] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for modifying an aluminide coating based on laser cladding, characterized in that: The method comprises: Weigh the solid phase cladding powder and the liquid phase binder in proportion, and prepare the cladding slurry after stirring and ball milling; The workpiece to be plated is cleaned and preheated, and then the cladding slurry is evenly sprayed onto the workpiece surface, and dried and solidified after spraying; The workpiece after the spray coating is solidified is placed in an inert atmosphere for laser cladding, and an aluminide cladding coating is obtained after cooling.

2. The method according to claim 1, characterized in that: The solid phase cladding powder comprises an infiltration source, a modifier and an activator.

3. The method according to claim 2, characterized in that The infiltration source is FeAl or Al powder; The modifiers are Ti and Co; The activating agent is NH4Cl.

4. The method according to claim 3, characterized in that The solid phase cladding powder comprises: 60-80% FeAl; 10-30% Al; 0-5% Ti; 0-5% C; 2-7% NH4Cl.

5. The method according to claim 1, characterized in that The liquid phase binder is ethyl acetate.

6. The method according to claim 5, characterized in that The content of the liquid phase binder is 10-30% of the solid phase cladding powder.

7. The method according to any one of claims 1 to 6, characterized in that: In step 2, the thickness of the spray layer is preset to be 1-5 mm; The preheating treatment is medium frequency preheating at 200-250° C. for 30-60 minutes.

8. The method according to any one of claims 1 to 6, characterized in that: The coating is dried by natural air drying for 24-48 hours, and the curing treatment is cured at 300-450°C for 24-48 hours.

9. The method according to any one of claims 1 to 6, characterized in that: The thickness of the aluminide cladding coating is 0.29-1.25 mm.

10. The method according to any one of claims 1 to 6, characterized in that: The laser power of laser cladding treatment is 2-2.8KW, the scanning rate is 20-40mm / s, the spot diameter is 3-5mm, the workpiece rotation speed is 0-5r / min, and the Ar gas flow rate is 15-20L / min.

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