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

Abstract

The invention discloses titanium-containing iron-based alloy repairing powder with a self-healing function and application of the titanium-containing iron-based alloy repairing powder, and belongs to the technical field of metal material repairing. The repairing powder comprises, by mass, 3%-5% of Ti and the balance iron-based alloy. The titanium-containing iron-based alloy powder is used as a repairing material to be added to the iron-based alloy part repairing area, a transition phase structure can be formed at the interface of the repairing area by means of the diffusion characteristic of the titanium element, a dislocation source is provided for plastic deformation of the alloy part repairing area, meanwhile, bridging of a matrix and a repairing fusion area can be promoted, and the repairing effect is improved. By optimizing the propagation path of the dislocation region, the generation and propagation of cracks generated at the grain boundary of the fusion region due to dislocation accumulation are effectively inhibited, the structure uniformity can be improved, the formation of brittle phases is reduced, and the mechanical property anisotropy of the repair region is reduced, so that the morphology repair of the alloy part is realized, and the mechanical property anisotropy of the repair region is improved. And the repaired alloy can keep good mechanical properties and long service life.

Description

Technical Field

[0001] The invention belongs to the technical field of metal material repair, and relates to titanium-containing iron-based alloy repair powder with self-healing function and application thereof. Background Art

[0002] In the industrial field, the repair of alloy parts is of great significance for extending the life of equipment and reducing costs. Especially in high-end precision parts, scratches, pits and other damages often appear on the surface of the parts due to long-term use or harsh working conditions. For high-precision parts, even a small dimensional deviation of tens of microns may greatly affect the stability and other performance of the parts. It is costly to directly replace these parts, so repairing damaged parts becomes a more economical option.

[0003] At present, the repair technologies for alloy parts include laser cladding, supersonic flame spraying, plasma spraying, arc spraying, etc. Among them, laser cladding technology has become the preferred technology for repairing alloy parts because it can form a metallurgical bond between the repair material and the matrix of the repaired alloy part, and the repaired repair area has a high bonding strength between the repair material and the matrix. However, there are still some problems in the laser cladding repair process:

[0004] 1. Performance degradation of the repair area: When the depth of the repair area reaches 1 mm or more, the mechanical properties (especially toughness) of the repair area will decrease significantly.

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

[0006] 3. Anisotropy of mechanical properties: The dendritic structure at the interface of the repair area causes the toughness of the material to vary greatly in different directions, making it prone to brittle fracture.

[0007] 4. Stress concentration: The unique "scar structure" of the repair area makes it impossible for the dislocation caused by stress during the stretching process to expand, causing the crack to expand along the repair interface and eventually leading to the failure of the repaired component.

[0008] Therefore, in the prior art, although the laser cladding remanufacturing technology can be used to repair the alloy parts in terms of morphology and restore the morphological integrity of the alloy parts, 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, which can easily lead to cracks or failure in the repaired alloy parts again under actual working conditions. Therefore, the aforementioned problems in the repair area need to be solved urgently.

[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, etc., and at the same time restore the mechanical properties of the repaired area to a better level, effectively extending the service life of the alloy parts. Summary of the invention

[0010] In order to overcome the problems in the background technology, the present invention improves the mechanical properties of the repair area, especially the fracture toughness and self-healing ability, by adding titanium-containing iron-based alloy powder as a repair material to the repair area of ​​the iron-based alloy component. By introducing the titanium element and utilizing its diffusion characteristics to form a transition phase at the interface of the repair area, it can not only effectively improve the fracture toughness of the repair area, but also achieve self-healing of the microstructure under stress, thereby significantly extending the service life of the component. In addition, the alloy components repaired by the repair material of the present invention do not require additional heat treatment steps, which simplifies the repair process and reduces the repair cost. It is particularly suitable for the repair needs of high-precision components and more complex working conditions.

[0011] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0012] The present invention provides a titanium-modified iron-based alloy repair powder with self-healing function, wherein the repair powder includes 3% to 5% Ti by mass and the remainder is 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 to 150 μm, so as to ensure that the repair powder has good fluidity and cladding effect during the laser cladding process.

[0014] Preferably, the repair powder has a sphericity of ≥90%, thereby reducing pores and inclusion defects during the cladding process.

[0015] The repair powder of the present invention can be prepared by smelting process and mechanical alloying process:

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

[0017] The titanium-containing iron-based alloy ingot is then crushed into 5-10mm particles and placed in a high-energy ball mill for mechanical alloying. The ball mill is made of stainless steel, and the ball milling balls are made of zirconium oxide. The mass ratio of the ball to the powder is 5:1-10:1. The ball milling speed is set to 300-500r / min and lasts for 10-20 hours. During the ball milling process, the ball mill is periodically turned over to ensure the uniformity of the powder. After the ball milling is completed, the repair powder with consistent particle size and sphericity ≥90% is obtained by screening.

[0018] Among them, the smelting process can ensure the uniform distribution of various elements 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 more complex compositions.

[0019] Another aspect of the present invention provides the use of the above-mentioned repair powder in the repair of iron-based alloy parts. The iron-based alloy parts can be used as mechanical parts, aerospace parts, automobile parts, energy equipment parts, etc.

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

[0021] Preferably, laser cladding technology is used to repair the damaged area of ​​the iron-based alloy component using titanium-containing iron-based alloy repair powder.

[0022] As a preferred method, during the repair of iron-based alloy parts, the laser power is 1.5-2kW, the scanning speed is 5-8mm / s, and the powder feeding rate is 8-10g / min. After parameter optimization, it is ensured that the repair area of ​​the alloy part forms a good metallurgical bond with the part matrix, while avoiding tissue defects caused by overheating or overcooling.

[0023] Preferably, the repair area of ​​the iron-based alloy component repaired by laser cladding is a double-layer cladding structure, and the thickness of the single-layer cladding layer is 0.6-0.8 mm, ensuring that the uniformity of the structure and mechanical properties of each cladding area have good consistency, while effectively avoiding stress concentration caused by excessive thickness of the single-layer cladding layer.

[0024] Preferably, the laser cladding process for repairing iron-based alloy parts is carried out in an inert gas atmosphere, and the oxygen content in the laser cladding environment does not exceed 100 ppm, thereby ensuring the purity and uniformity of the repaired area of ​​the alloy parts.

[0025] Beneficial effects of the present invention:

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

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

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

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

[0030] 5. The present invention optimizes the amount of titanium added, thereby ensuring that the repaired area of ​​the alloy component has relatively excellent mechanical properties and preventing excessive formation of brittle phases due to excessive addition of titanium.

[0031] 6. The alloy parts can be repaired by the repair powder of the present invention without the need for additional heat treatment and other processes, which is conducive to simplifying the alloy parts repair process, reducing the repair cost, and is suitable for industrial promotion and application.

[0032] 7. The alloy parts repaired by using the repair powder of the present invention have good bending resistance in the repaired area, wherein the bending resistance is improved by more than 100% compared with the traditional filling and repairing materials. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0034] Figure 2 Figures 1 and 2 are actual pictures of the repaired alloy parts of the embodiments and comparative examples of the present invention, wherein Figure (a) is an actual picture of the repaired alloy part of the comparative example, Figure (b) is an actual picture of the repaired alloy part of Example 2, and Figure (c) is an actual picture of the repaired alloy part of Example 1;

[0035] Figure 3 Microstructure diagrams of the repaired area of ​​the alloy components of Example 1 and the comparative example of the present invention, wherein Figure (a) is the microstructure diagram of the repaired area of ​​the alloy component of Example 1, and Figure (b) is the microstructure diagram of the repaired area of ​​the alloy component of the comparative example.

[0036] Figure 4 This is the anti-bending curve diagram of the repaired area of ​​Examples 1 and 2 of the present invention and the comparative example. DETAILED DESCRIPTION

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

[0038] Example 1

[0039] This embodiment repairs the alloy component according to the following method:

[0040] (1) An iron-based alloy repair powder containing 3% titanium is prepared by smelting and ball milling processes. In the repair powder, the mass fraction of titanium is 3%, the mass fraction of the iron-based alloy is 97%, and the iron-based alloy contains elements such as Fe, Cr, Ni, Mo, and V.

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

[0042] After the repair is completed, the temperature is kept at 400-600℃ for 72 hours, and the repaired alloy parts are bent to test the bending resistance of the alloy parts. The test result curve is as follows Figure 4 As shown, the bending strength of the repaired area of ​​the alloy component is 1547Mpa, and there is no deformation.

[0043] The actual picture of the tested alloy parts is as follows Figure 2 As shown in (c), through Figure 2 (c) It can be seen that the repaired area of ​​the alloy component in this embodiment is smooth without 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 repaired area of ​​the present invention and the matrix of the alloy component. The grain size of the repaired area is uniform, and there is no obvious brittle phase. After large-scale deformation, there is no crack in the repaired area, indicating that the diffusion of titanium element improves the toughness of the repaired area of ​​the alloy component, thereby ensuring the safety and long-term effectiveness of the repaired material.

[0045] Example 2

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

[0047] After the repair work is completed, the repaired alloy parts are kept at 400-600℃ for 72 hours, and the bending resistance of the alloy parts is tested. The test result curve is as follows Figure 4 As shown, the repaired area of ​​the alloy component has a higher elastic modulus than that of Example 1, but cracks appear in the repaired area of ​​the alloy component after bending for 2 mm, and the bending strength decreases to 1283 MPa.

[0048] The actual picture of the tested alloy parts is as follows Figure 2 As shown in (b), through Figure 2 (b) It can be seen that cracks appear in the repaired area of ​​the alloy component after repair in this embodiment.

[0049] Example 3

[0050] This embodiment repairs the alloy component according to the following method:

[0051] (1) An iron-based alloy repair powder containing 3% titanium is prepared by smelting and ball milling processes. In the repair powder, the mass fraction of titanium is 3%, the mass fraction of the iron-based alloy is 97%, and the iron-based alloy contains elements such as Fe, Cr, Ni, Mo, and V.

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

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

[0054] Example 4

[0055] This embodiment repairs the alloy component according to the following method:

[0056] (1) An iron-based alloy repair powder containing 4% titanium is prepared by smelting and ball milling process. In the repair powder, the mass fraction of titanium is 4% and the mass fraction of the iron alloy is 96%.

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

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

[0059] Comparative Example

[0060] This comparative example adopts the same method as Example 1 to repair the alloy parts, except that: the repair powder of this comparative example does not contain titanium element, and the iron-based alloy content is 100%.

[0061] After the repair is completed, the temperature is kept at 400-600℃ for 72 hours, and the repaired alloy parts are bent to test the bending resistance of the alloy parts. The test result curve is as follows Figure 4 As shown, the bending strength of the repaired area of ​​the alloy component is 730Mpa.

[0062] The actual picture of the tested alloy parts is as follows Figure 2 As shown in (a), through Figure 2 (a) It can be seen that serious cracks appear in the repaired area of ​​the alloy component after repair in this comparative example.

[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 repaired area of ​​the comparative alloy component is completely fractured, and obvious dislocation accumulation can be observed at the fracture surface.

[0064] By comparing Example 1 with Example 2, it can be seen that as the titanium content in the repair powder increases, the bending resistance of the repair area decreases. The possible reason is that excessive titanium diffuses and forms a brittle phase. Therefore, the present invention controls the titanium content in the repair powder to 3%-5%.

[0065] By comparing Examples 1-2 with the comparative example, it can be seen that the bending strength of the repaired area of ​​the alloy component in Example 1 is increased by about 111.9% relative to the comparative example, and the bending strength of the repaired area of ​​the alloy component in Example 2 is increased by about 75.8% relative to the comparative example, which fully demonstrates that the repair powder of the present invention can effectively improve the performance of the repaired area of ​​the alloy component.

[0066] When the repaired alloy components were used under actual working conditions, the alloy components showed excellent stability and durability, proving that the repaired area of ​​the alloy components had self-healing capabilities, which effectively extended the service life of the repaired alloy components and reduced equipment maintenance costs.

[0067] In summary, the present invention uses titanium-containing ferroalloy powder as a repair material and adds it to the damaged area of ​​the iron-based alloy component. By utilizing the diffusion characteristics of the titanium element, it can not only form a transition phase structure at the interface of the repair area, providing a dislocation source for the plastic deformation of the repair area of ​​the alloy component, but also promote the bridging of the matrix of the repair area and the fusion area, provide a dislocation source for the expansion of the dislocation zone, and effectively hinder the initiation and expansion of cracks caused by dislocation accumulation at the grain boundary of the fusion zone, so that the repair area has a self-healing effect, and can also improve the uniformity of the organization, reduce the formation of brittle phases, reduce the anisotropy of the mechanical properties of the repair area, and improve the mechanical properties of the alloy component in different directions. Maintain good consistency, thereby not only achieving morphological repair of the alloy component, but also enabling the repaired alloy to maintain good mechanical properties and a longer 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 rather than 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 in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A titanium-containing iron-based alloy repair powder with self-healing function, characterized in that: The repair powder comprises Ti: 3% to 5% by mass, and the remainder is iron-based alloy.

2. The repair powder according to claim 1, characterized in that: The repair powder has a particle size of 50 to 150 μm.

3. The repair powder according to claim 1, characterized in that: The sphericity of the repairing powder is ≥90%.

4. Use of the repair powder according to any one of claims 1 to 3 in repairing iron-based alloy parts.

5. The use according to claim 4, characterized in that: The working environment temperature of the iron-based alloy component is 400-600°C.

6. The use according to claim 4, characterized in that: Laser cladding technology is used to repair the damaged areas of iron-based alloy components using titanium-containing iron-based alloy repair powder.

7. The use according to claim 6, characterized in that: During the repair process of iron-based alloy parts, the laser power is 1.5-2kW, the scanning speed is 5-8mm / s, and the powder feeding rate is 8-10g / min.

8. The use according to claim 6, characterized in that: The repair area of ​​the iron-based alloy parts repaired by laser cladding is a double-layer cladding structure, and the thickness of the single-layer cladding layer is 0.6 to 0.8 mm.

9. The use according to claim 6, characterized in that: The laser cladding process for repairing iron-based alloy parts is carried out in an inert gas atmosphere. The oxygen content in the laser cladding environment does not exceed 100ppm.

Images