Titanium-containing iron-based alloy repair powder with self-healing function and application thereof

Abstract

The application discloses a titanium-containing iron-based alloy repairing powder with a self-healing function and application thereof, and belongs to the technical field of metal material repairing. The repairing powder comprises, in mass fraction, Ti: 3-5%, and the balance is an iron-based alloy. The titanium-containing iron-based alloy powder is used as a repairing material and is added to an iron-based alloy part repairing area. By using the diffusion characteristics of titanium, a transition phase structure is formed at the interface of the repairing area, dislocation sources are provided for the plastic deformation of the alloy part repairing area, the base body and the repairing fusion area are promoted to be filled, the crack initiation and expansion at the grain boundary of the fusion area due to the dislocation accumulation are effectively inhibited through the extension path optimization of the dislocation area, the uniformity of the structure is improved, the formation of brittle phases is reduced, the mechanical property anisotropy of the repairing area is reduced, and thus the appearance of the alloy part is repaired, and the repaired alloy can have good mechanical properties and a long service life.

Description

Technical Field

[0001] This invention belongs to the field of metal material repair technology, and relates to a titanium-iron-based alloy repair powder with self-healing function and its application. Background Technology

[0002] In the industrial sector, the repair of alloy components is crucial for extending equipment lifespan and reducing costs. This is especially true for high-precision components, where scratches, pits, and other damage often appear on their surfaces due to prolonged use or harsh operating conditions. For high-precision components, even minute dimensional deviations of tens of micrometers can significantly impact stability and other performance characteristics. Directly replacing these components is costly; therefore, repairing damaged parts is a more economical option.

[0003] Currently, repair technologies for alloy components include laser cladding, supersonic flame spraying, plasma spraying, and arc spraying. Among these, laser cladding is the preferred technology for alloy component repair because it enables the repair material to form a metallurgical bond with the substrate of the alloy component being repaired, resulting in high bond strength between the repaired area and the substrate. However, some problems still exist in the laser cladding repair process:

[0004] 1. Decreased performance of the repaired area: When the depth of the repaired area reaches 1 mm or more, the mechanical properties (especially toughness) of the repaired area decrease significantly.

[0005] 2. Formation of brittle structures: During laser cladding, rapid cooling leads to the formation of brittle structures (such as martensite or coarse grains) in the weld zone and heat-affected zone.

[0006] 3. Anisotropic mechanical properties: The dendritic structure at the interface of the repair area leads to significant differences in the toughness of the material in different directions, making it prone to brittle fracture.

[0007] 4. Stress concentration: The unique "scar structure" of the repair area prevents dislocations caused by stress during the tensile process from propagating, causing cracks to spread along the repair interface and ultimately leading to the failure of the repaired component.

[0008] Therefore, although existing technologies can repair alloy parts in terms of morphology and restore their morphological integrity through laser cladding remanufacturing, there are still obvious defects in the performance of the repaired area, especially the problems of insufficient toughness and brittle structure formation in the repaired area. In actual working conditions, these problems can easily lead to the repaired alloy parts cracking or failing again. Therefore, the aforementioned problems in the repaired area urgently need to be solved.

[0009] Therefore, it is necessary to provide a titanium-modified iron-based alloy repair powder with self-healing function and its application, which can effectively repair the damage of iron-based alloy parts caused by wear, corrosion and other factors, while restoring the mechanical properties of the repaired area to a better level and effectively extending the service life of the alloy parts. Summary of the Invention

[0010] To overcome the problems in the prior art, this invention improves the mechanical properties of the repaired area of ​​iron-based alloy components by adding titanium-containing iron-based alloy powder as a repair material, particularly enhancing fracture toughness and self-healing ability. By introducing titanium and utilizing its diffusion properties, a transition phase is formed at the interface of the repair area. This not only effectively improves the fracture toughness of the repair area but also enables self-healing of the microstructure under stress, thereby significantly extending the service life of the component. Furthermore, alloy components repaired using the material of this invention do not require additional heat treatment, simplifying the repair process and reducing repair costs. This invention is particularly suitable for repairing high-precision components and components under complex operating conditions.

[0011] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0012] This invention proposes a titanium-modified iron-based alloy repair powder with self-healing function. The repair powder comprises, by mass fraction, 3%–5% Ti, with the balance being an iron-based alloy. The main components of the iron-based alloy include Fe, Cr, Ni, Mo, and V.

[0013] Preferably, the repair powder has a particle size of 50–150 μm. This ensures that the repair powder has good flowability and cladding effect during the laser cladding process.

[0014] Preferably, the sphericity of the repair powder is ≥90%, which reduces porosity and inclusion defects during the cladding process.

[0015] The repair powder described in this invention can be prepared through a smelting process and a mechanical alloying process.

[0016] First, iron (Fe), chromium (Cr), nickel (Ni), molybdenum (Mo), and vanadium (V) with a purity ≥99.5% are weighed with titanium (Ti) with a purity ≥99.0% according to a predetermined mass ratio to ensure that the mass fraction of titanium is 3%-5%. The proportioned raw materials are placed in a vacuum induction melting furnace, and the temperature is set to 1500℃-1600℃. Under argon protection, the mixture is melted for 30-60 minutes to form a homogeneous iron-titanium alloy melt. Then, the melt is poured into a copper mold preheated to 1000℃-1200℃, and the cooling rate is controlled at 100℃ / s-500℃ / s to obtain a titanium-containing iron-based alloy ingot with a good microstructure.

[0017] The titanium-iron-based alloy ingots were then crushed to 5-10mm particles and placed in a high-energy ball mill for mechanical alloying. The grinding jar was made of stainless steel, and the grinding balls were zirconium oxide, with a ball-to-powder mass ratio of 5:1-10:1. The grinding speed was set to 300-500 r / min for 10-20 hours. During the grinding process, the grinding jar was periodically rotated to ensure powder uniformity. After grinding, the powder was sieved to obtain repair powder with uniform particle size and a sphericity ≥90%.

[0018] Among them, the smelting process can ensure the uniform distribution of each element in the alloy; the mechanical alloying process can achieve uniform mixing of elements through high-energy ball milling, which is suitable for the preparation of alloy powders with relatively complex compositions.

[0019] In another aspect, this invention proposes the application of the aforementioned repair powder in the repair of iron-based alloy components. Iron-based alloy components can be used as mechanical parts, aerospace components, automotive parts, energy equipment components, etc.

[0020] Preferably, the working environment temperature of the iron-based alloy component is 400–600°C.

[0021] As a preferred method, laser cladding technology is used to repair the damaged areas of iron-based alloy components using titanium-containing iron-based alloy repair powder.

[0022] As a preferred method, during the repair of iron-based alloy components, the laser power is 1.5–2 kW, the scanning speed is 5–8 mm / s, and the powder feeding rate is 8–10 g / min. Parameter optimization ensures a good metallurgical bond between the repaired area and the component substrate, while avoiding microstructural defects caused by overheating or undercooling.

[0023] Preferably, the repair area of ​​the iron-based alloy component repaired by laser cladding has a double-layer cladding structure, with each cladding layer having a thickness of 0.6–0.8 mm. This ensures good uniformity of microstructure and mechanical properties in each cladding layer, while effectively avoiding stress concentration caused by an excessively thick single cladding layer.

[0024] Preferably, the laser cladding repair process for iron-based alloy components is carried out in an inert gas atmosphere, where the oxygen content does not exceed 100 ppm. This ensures the purity and microstructure uniformity of the repaired area of ​​the alloy component.

[0025] The beneficial effects of this invention are:

[0026] 1. This invention uses titanium-containing iron alloy powder as a repair material. After the iron-based alloy component is repaired, titanium diffuses from the repair powder to the interface of the repair area at its own operating temperature to form a transition phase, which provides a dislocation source for the alloy during plastic deformation, thereby improving the fracture toughness of the repair area of ​​the alloy component.

[0027] 2. Under stress, the microstructure of the repair zone of the alloy component can achieve self-healing: the diffusion of titanium promotes the healing of the matrix and the repair fusion zone of the alloy component, provides a dislocation source for the expansion of the dislocation zone, and effectively hinders the initiation and propagation of cracks caused by dislocation accumulation at the grain boundary of the fusion zone. The self-healing ability of the repair zone of the alloy component significantly improves the fatigue life and crack propagation resistance of the component.

[0028] 3. Through the diffusion of titanium, the uniformity of the microstructure in the repair area is significantly improved, reducing the formation of brittle microstructures (such as martensite or coarse grains). The transition phase structure at the interface of the repair area reduces the formation of dendrites, and the anisotropy of the mechanical properties of the repaired component is effectively reduced, ensuring the performance consistency of the repaired component in different directions.

[0029] 4. After repairing alloy parts with the repair powder of this invention, not only can the morphological integrity of the alloy parts be restored, but the repaired alloy parts also exhibit excellent stability and durability under the original working conditions, effectively extending the service life of the alloy parts, thereby effectively extending the service life of the corresponding equipment.

[0030] 5. By optimizing the amount of titanium added, this invention ensures that the repaired area of ​​the alloy component has excellent mechanical properties, while preventing excessive formation of brittle phases due to excessive addition of titanium.

[0031] 6. The repair powder of this invention can be used to repair alloy parts without additional heat treatment or other processes, which simplifies the repair process, reduces repair costs, and is suitable for industrial application.

[0032] 7. When alloy parts repaired by the repair powder of this invention are used, the repaired area exhibits good bending resistance, which is more than 100% higher than that of traditional filling and repair materials. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the repair process of the present invention;

[0034] Figure 2 Figure 1 shows the actual repaired alloy components of the embodiments and comparative examples of the present invention. Figure 2 shows the actual repaired alloy components of the comparative example, Figure 3 shows the actual repaired alloy components of Example 2, and Figure 4 shows the actual repaired alloy components of Example 1.

[0035] Figure 3 The present invention provides microstructure diagrams of the repair area of ​​the alloy component in Example 1 and the comparative alloy component in Example 2. Figure (a) is a microstructure diagram of the repair area of ​​the alloy component in Example 1, and Figure (b) is a microstructure diagram of the repair area of ​​the alloy component in the comparative alloy component.

[0036] Figure 4 These are comparative bending resistance curves of the repaired area in Embodiments 1 and 2 of the present invention. Detailed Implementation

[0037] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0038] Example 1

[0039] This embodiment repairs the alloy components using the following method:

[0040] (1) Iron-based alloy repair powder containing 3% titanium was prepared by smelting and ball milling. The mass fraction of titanium in the repair powder was 3%, and the mass fraction of iron-based alloy was 97%. The iron-based alloy contained elements such as Fe, Cr, Ni, Mo, and V.

[0041] (2) First, milling or turning techniques are used to pre-treat the damaged area to achieve a smooth arc-shaped interface and reduce thermal stress. Then, laser cladding technology is used in an inert gas protective atmosphere to spray the above-mentioned repair powder onto the area of ​​the iron-based alloy component to be repaired. During the repair process, the laser power is 1.8kW, the scanning speed is 5mm / s, the powder feeding rate is 8g / min, the thickness of a single cladding layer is 0.8mm, and there are a total of 2 cladding layers.

[0042] After repair, the alloy component was held at 400-600℃ for 72 hours, then bent to test its bending resistance. The test results are shown in the curve below. Figure 4 As shown, the bending strength of the repaired area of ​​the alloy component is 1547 MPa, and there is no deformation.

[0043] Actual picture of the test alloy component is shown below. Figure 2 As shown in (c), via Figure 2 (c) It can be seen that the repaired area of ​​the alloy component after this embodiment is smooth and free of defects such as cracks.

[0044] The microstructure of the repaired area of ​​the alloy component in this embodiment was observed, and the results are as follows: Figure 3 As shown in (a), through Figure 3 (a) It can be seen that a dense structure is formed between the repair area and the alloy component matrix in this invention. The grain size of the repair area is uniform and there is no obvious brittle phase. After large-scale deformation, there are no cracks in the repair area, indicating that the diffusion of titanium element improves the toughness of the repair area of ​​the alloy component, thereby ensuring the safety and long-term effectiveness of the material after repair.

[0045] Example 2

[0046] This embodiment uses the same method as in Embodiment 1 to repair alloy parts, the difference being that: in this embodiment, the repair powder contains 5% titanium and the mass fraction of iron-based alloy is 95%, the iron-based alloy contains elements such as Fe, Cr, Ni, Mo, and V.

[0047] After the repair work was completed, the alloy component was held at 400-600℃ for 72 hours. The repaired alloy component was then bent to test its bending resistance. The test results are shown in the curve below. Figure 4 As shown, the repaired area of ​​the alloy component has a higher elastic modulus than that of Example 1. However, the repaired area of ​​the alloy component developed cracks after bending for 2 mm, and the bending strength decreased to 1283 MPa.

[0048] Actual picture of the test alloy component is shown below. Figure 2 As shown in (b), through Figure 2 (b) It can be seen that cracks appeared in the repaired area of ​​the alloy component after repair in this embodiment.

[0049] Example 3

[0050] This embodiment repairs the alloy components using the following method:

[0051] (1) Iron-based alloy repair powder containing 3% titanium was prepared by smelting and ball milling. The mass fraction of titanium in the repair powder was 3%, and the mass fraction of iron-based alloy was 97%. The iron-based alloy contained elements such as Fe, Cr, Ni, Mo, and V.

[0052] (2) The above-mentioned repair powder was sprayed onto the iron-based alloy component to be repaired in an inert gas protective atmosphere using laser cladding technology. During the repair process, the laser power was 2kW, the scanning speed was 6mm / s, the powder feeding rate was 10g / min, the thickness of a single cladding layer was 0.6mm, and there were a total of 2 cladding layers.

[0053] The performance of the repaired area of ​​the alloy component in this embodiment is similar to that in Embodiment 1.

[0054] Example 4

[0055] This embodiment repairs the alloy components using the following method:

[0056] (1) Iron-based alloy repair powder containing 4% titanium was prepared by smelting and ball milling. The mass fraction of titanium in the repair powder was 4%, and the mass fraction of iron alloy was 96%.

[0057] (2) The above-mentioned repair powder was sprayed onto the iron-based alloy component to be repaired in an inert gas protective atmosphere using laser cladding technology. During the repair process, the laser power was 1.5kW, the scanning speed was 8mm / s, the powder feeding rate was 9g / min, the thickness of a single cladding layer was 0.7mm, and there were a total of 2 cladding layers.

[0058] The performance of the repaired area of ​​the alloy component in this embodiment is similar to that in Embodiment 1.

[0059] Comparative Example

[0060] This comparative example uses the same method as Example 1 to repair alloy parts, the difference being that the repair powder in this comparative example does not contain titanium and has an iron-based alloy content of 100%.

[0061] After repair, the alloy component was held at 400-600℃ for 72 hours, then bent to test its bending resistance. The test results are shown in the curve below. Figure 4 As shown, the bending strength of the repaired area of ​​the alloy component is 730 MPa.

[0062] Actual picture of the test alloy component is shown below. Figure 2 As shown in (a), through Figure 2 (a) It can be seen that the repaired area of ​​the alloy component in this comparative example has serious cracks.

[0063] The microstructure of the repaired area of ​​the alloy component in this embodiment was observed, and the results are as follows: Figure 3 As shown in (b), through Figure 3 (b) It can be seen that the repair area of ​​the comparative alloy component is completely fractured, and obvious dislocation accumulation can be observed at the fracture surface.

[0064] A comparison of Example 1 and Example 2 shows that as the titanium content in the repair powder increases, the bending resistance of the repaired area decreases. This may be due to the diffusion of excessive titanium, which forms a brittle phase. Therefore, the present invention controls the titanium content in the repair powder to 3%-5%.

[0065] A comparison of Examples 1-2 with the comparative examples shows that the bending strength of the alloy component repair area in Example 1 is increased by about 111.9% compared to the comparative example, and the bending strength of the alloy component repair area in Example 2 is increased by about 75.8% compared to the comparative example. This fully demonstrates that the repair powder of the present invention can effectively improve the performance of the alloy component repair area.

[0066] When the repaired alloy components were put into operation under actual working conditions, they exhibited excellent stability and durability, proving that the repaired area of ​​the alloy components has self-healing capabilities, effectively extending the service life of the repaired alloy components and reducing equipment maintenance costs.

[0067] In summary, this invention utilizes titanium-containing iron alloy powder as a repair material added to the damaged area of ​​an iron-based alloy component. By leveraging the diffusion characteristics of titanium, it not only forms a transition phase structure at the interface of the repair area, providing dislocation sources for plastic deformation in the repair area, but also promotes the healing of the matrix and fusion zone, providing dislocation sources for the expansion of the dislocation zone. This effectively inhibits the initiation and propagation of cracks caused by dislocation accumulation at the grain boundaries of the fusion zone, giving the repair area a self-healing effect. Furthermore, it improves the uniformity of the microstructure, reduces the formation of brittle phases, reduces the anisotropy of the mechanical properties in the repair area, and improves the consistency of the mechanical properties of the alloy component in different directions. Thus, it not only achieves morphological repair of the alloy component but also ensures that the repaired alloy maintains good mechanical properties and a long service life.

[0068] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A self-healing repair method for iron-based alloy components, characterized in that: Laser cladding technology is used to repair damaged areas of iron-based alloy components using titanium-containing iron-based alloy repair powder; After the iron-based alloy component is repaired, titanium diffuses from the repair powder to the interface of the repair area at its own working temperature, forming a transition phase. The titanium-containing iron-based alloy repair powder contains, by mass fraction, 3% to 5% Ti, with the remainder being an iron-based alloy. The titanium-containing iron-based alloy repair powder is prepared by weighing iron, chromium, nickel, molybdenum, vanadium and titanium raw materials in a predetermined mass ratio, melting, casting, and then mechanically alloying them. The working environment temperature of the iron-based alloy component is 400~600℃.

2. The self-healing repair method for iron-based alloy components according to claim 1, characterized in that: The particle size of the repair powder is 50~150μm.

3. The self-healing repair method for iron-based alloy components according to claim 1, characterized in that: The sphericity of the repair powder is ≥90%.

4. The self-healing repair method for iron-based alloy components according to claim 1, characterized in that: During the repair of iron-based alloy components, the laser power is 1.5~2kW, the scanning speed is 5~8mm / s, and the powder feeding rate is 8-10g / min.

5. The self-healing repair method for iron-based alloy components according to claim 1, characterized in that: The repair area of ​​the iron-based alloy component repaired by laser cladding has a double-layer cladding structure, with a single cladding layer thickness of 0.6~0.8mm.

6. The self-healing repair method for iron-based alloy components according to claim 1, characterized in that: The laser cladding repair process for iron-based alloy components is carried out in an inert gas atmosphere, where the oxygen content does not exceed 100 ppm.

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