Nickel-based rare earth composite powder material for high-speed laser cladding and preparation method of nickel-based rare earth composite coating

Abstract

The invention provides a nickel-based rare earth composite powder material for high-speed laser cladding and a preparation method of a nickel-based rare earth composite coating, and relates to the technical field of laser cladding and metal surface modification. The nickel-based rare earth composite coating takes Inconel 625 nickel-based alloy as a matrix phase material; a trace amount of rare earth oxide Y2O3 is introduced into a powder system to serve as a second phase enhancing component, and the material is prepared and formed at a time under the condition of a high-speed laser cladding process; in the high-speed laser cladding process, due to high scanning speed, low heat input per unit length and high cooling rate, metal liquid in a molten pool has the characteristic of rapid solidification; the rare earth oxide Y2O3 can stably exist in a molten pool, the particle surface of the rare earth oxide Y2O3 provides a large number of heterogeneous nucleation cores for the alloy solidification process, meanwhile, grain growth is restrained through the grain boundary pinning effect, and therefore the solidification structure form of the nickel-based cladding coating is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of laser cladding and metal surface modification technology, and in particular to a nickel-based rare earth composite powder material for high-speed laser cladding and a method for preparing a nickel-based rare earth composite coating. Background Technology

[0002] 45 steel is a typical medium-carbon structural steel. Due to its good balance between strength, plasticity, and machinability, coupled with its widely available and relatively inexpensive raw materials, it is widely used in machinery manufacturing, engineering equipment, mold making, and mining equipment. For example, 45 steel is often used to manufacture drive shafts, gears, connecting rods, mold bases, and critical load-bearing components in engineering machinery. However, in actual service, these components are often subjected to complex environments of heavy loads, high friction, and the coupling of corrosive media. Their surfaces are highly susceptible to wear, corrosion, and fatigue failure, leading to decreased precision, performance degradation, and even complete failure.

[0003] To address the aforementioned issues, surface modification techniques, which impart excellent wear and corrosion resistance to the surface of the substrate material while maintaining its overall mechanical properties, are considered an efficient and economical solution. Laser cladding technology, as an advanced surface engineering technique, can prepare high-performance coatings that form a metallurgical bond with the substrate. It offers significant advantages such as a small heat-affected zone, low dilution rate, and high coating density, and has therefore received widespread attention in the field of surface strengthening of engineering steel.

[0004] Among various laser cladding coating systems, nickel-based alloy coatings are considered one of the ideal materials for surface protection of engineering steel due to their excellent corrosion resistance, high high-temperature stability, and good metallurgical compatibility with the steel substrate. Inconel 625 nickel-based alloy, containing alloying elements such as Cr, Mo, and Nb, can form a stable passivation film in corrosive media, thus significantly improving the material's corrosion resistance. However, under high wear or abrasion conditions, the hardness and wear resistance of traditional nickel-based alloy cladding coatings still have certain limitations, and under conventional laser cladding conditions, they tend to form coarse columnar crystal structures, leading to significant anisotropy in the microstructure and consequently affecting the service stability of the coating. Summary of the Invention

[0005] This invention proposes a nickel-based rare earth composite coating for high-speed laser cladding and its preparation method, in order to solve the problems of insufficient hardness and poor wear resistance of nickel-based cladding coatings in the prior art.

[0006] In a first aspect, the present invention provides a nickel-based rare earth composite powder material for high-speed laser cladding, wherein the nickel-based rare earth composite powder comprises Inconel 625 nickel-based alloy powder and rare earth oxide Y2O3 powder; the content of the Y2O3 powder is 0.5 wt% to 2.0 wt% of the Inconel 625 nickel-based alloy powder.

[0007] Furthermore, the Inconel 625 nickel-based alloy powder has a particle size of 15~53μm; the Y2O3 powder has a particle size of 3~10μm.

[0008] Furthermore, the chemical composition of the Inconel 625 nickel-based alloy powder, by mass percentage, includes: Cr 20~23wt%, Nb 3~5wt%, Mo 9~10wt%, Fe 4~5wt%, Mn≤0.01.0wt%, C 0.5~1.0wt%, Cu≤0.1.0wt%, Al≤0.05wt%, with the remainder being Ni.

[0009] Secondly, the present invention also provides a method for preparing a nickel-based rare-earth composite coating for high-speed laser cladding, comprising the following steps: Step S1: Weigh Inconel 625 nickel-based alloy powder and rare earth oxide Y2O3 powder according to the set ratio, place the two powders in a mixing tank for mechanical mixing, and obtain Y2O3 / Inconel625 composite powder. Step S2: Pre-treat the Y2O3 / Inconel625 composite powder and place the pre-treated powder into a powder container; Step S3: The laser of the high-speed laser cladding equipment is used to perform layer-by-layer cladding of the alloy powder in a ring scanning manner to obtain Y2O3 / Inconel625 composite material specimens; Step S4: Use wire cutting technology to cut the Y2O3 / Inconel625 composite material specimen formed by high-speed laser cladding from the substrate.

[0010] Furthermore, in step S1, the stirring speed in the mixing tank is 100~300 r / min, and the stirring time is 4~6h.

[0011] Furthermore, the pretreatment of Y2O3 / Inconel625 composite powder in step S2 involves placing the Y2O3 / Inconel625 composite powder into an oven for drying. The temperature of the oven is 120~150℃, and the drying time is 4~6h.

[0012] Furthermore, in step S3, the laser power of the high-speed laser cladding equipment is 2800W, the scanning speed is 40m / min, the powder feeding rate is 20g / min, and the overlap rate is 85%; the thickness of each cladding layer is 330μm.

[0013] Furthermore, the layer-by-layer cladding step described in step S3 is as follows: (1) Set the laser spot diameter to 3 mm and use a ring scanning method; (2) The laser beam scans the surface of the substrate, so that the cladding powder is fully melted and clad onto the substrate to form a single cladding layer; (3) Repeat step (2) by layering until Y2O3 / Inconel625 composite material specimens are obtained.

[0014] Furthermore, the substrate is 45 steel.

[0015] Compared with the prior art, the present invention has the following advantages: This invention achieves significant grain refinement in the cladding coating by adding an appropriate amount of rare earth Y2O3 powder to Inconel 625-based powder, thereby improving the uniformity and density of the microstructure. The low heat input and rapid solidification characteristics of the high-speed laser cladding process effectively reduce the tendency of coating defects to form, and reduce the width of the heat-affected zone and the level of residual stress. The prepared nickel-based rare earth composite coating is significantly superior to the nickel-based cladding coating without rare earth in terms of microhardness, wear resistance, and corrosion resistance. The coating can achieve excellent comprehensive performance without subsequent overall heat treatment, simplifying the process and making it suitable for engineering applications. Preferably, the Y2O3 content is 1.0 wt% of the Inconel 625 nickel-based alloy powder. Excessive addition (≥2.0 wt%) will lead to increased porosity and easy crack growth in the coating, which will reduce performance, reflecting the "critical concentration effect" of Y2O3.

[0016] Based on the implementation methods provided in the above aspects, this application can be further combined to provide more implementation methods. Attached Figure Description

[0017] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the invention are illustrated by way of example and not limitation, with the same or corresponding reference numerals denoteing the same or corresponding parts, wherein: Figure 1 This is a flowchart illustrating the preparation of nickel-based alloy rare-earth composite coatings using a high-speed laser cladding device in an embodiment of the present invention. Figure 2Figure (a) shows the SEM morphology of Inconel 625 nickel-based alloy powder; Figure (b) shows the SEM morphology of Y2O3 powder. Figure 3 Figure (a) shows the macroscopic morphology of the Inconel 625 alloy composite coating prepared by high-speed laser cladding; Figure (b) shows the macroscopic morphology of the Y2O3 / Inconel 625 composite coating prepared by high-speed laser cladding, wherein the Y2O3 powder content is 0.5 wt%; Figure (c) shows the macroscopic morphology of the Y2O3 / Inconel 625 composite coating prepared by high-speed laser cladding, wherein the Y2O3 powder content is 1.0 wt%; Figure (d) shows the macroscopic morphology of the Y2O3 / Inconel 625 composite coating prepared by high-speed laser cladding, wherein the Y2O3 powder content is 2.0 wt%. Figure 4 Figures (a1-a3) show the microstructure of the Inconel 625 alloy; figures (b1-b3) show the microstructure of the Y2O3 / Inconel 625 composite coating, where the Y2O3 powder content is 0.5 wt%; figures (b1-b3) show the microstructure of the Y2O3 / Inconel 625 composite coating, where the Y2O3 powder content is 0.5 wt%; figures (c1-c3) show the microstructure of the Y2O3 / Inconel 625 composite coating, where the Y2O3 powder content is 1.0 wt%; figures (d1-d3) show the microstructure of the Y2O3 / Inconel 625 composite coating, where the Y2O3 powder content is 2.0 wt%. Figure 5 X-ray diffraction patterns of Inconel 625 alloy and Y2O3 / Inconel 625 composite coating; Figure 6 shows the microhardness test results of the Y2O3 / Inconel 625 composite coating; Figure 7 shows a comparison of the wear morphology of the substrate, Inconel 625, and Y2O3 / Inconel 625 composite coating under the same conditions. Figure (a) is the substrate; Figure (b) is Inconel 625; Figure (c) shows Y2O3 powder with a content of 0.5 wt%; (d) shows Y2O3 powder with a content of 1.0 wt%; and (e) shows Y2O3 powder with a content of 2.0 wt%. Figure 8 Figures showing wear amount and wear rate of the substrate, Inconel 625 alloy, and Y2O3 / Inconel 625 composite coating. Figure 9 Potentiodynamic polarization curves of the substrate, Inconel 625 alloy, and Y2O3 / Inconel 625 composite coating in 3.5% NaCl solution. Detailed Implementation

[0018] The exemplary embodiments disclosed in this application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of this application and to fully convey the scope of this application to those skilled in the art. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0019] High-speed laser cladding is a highly efficient surface modification technology developed from traditional laser cladding. This technology significantly increases laser scanning speed, effectively reducing heat input per unit length while maintaining cladding quality. This results in a smaller molten pool size and a higher cooling rate, which is beneficial for obtaining a fine and uniform solidification structure and reducing the width of the heat-affected zone. However, research shows that simply adjusting the high-speed laser cladding process parameters is insufficient to fundamentally solve the problems of insufficient hardness and wear resistance in nickel-based cladding coatings. It is necessary to introduce new strengthening mechanisms from the perspective of material system design.

[0020] Rare earth oxides (Y₂O₃) possess characteristics such as high melting point, good thermal stability, and stable chemical properties, and have been widely studied in the field of metallic materials as effective additives for microstructure regulation and performance enhancement. Existing research shows that the appropriate introduction of rare earth oxides can provide heterogeneous nucleation sites during alloy solidification and inhibit grain growth through grain boundary pinning, thereby achieving grain refinement and microstructure homogenization. However, a systematic technical solution combining rare earth oxides with Inconel 625 nickel-based alloys is still relatively lacking for the special rapid solidification process conditions of high-speed laser cladding.

[0021] This invention provides a nickel-based rare earth composite powder material for high-speed laser cladding, wherein the nickel-based rare earth composite powder comprises Inconel 625 nickel-based alloy powder and rare earth oxide Y2O3 powder; the content of the Y2O3 powder is 0.5 wt% to 2.0 wt% of the Inconel 625 nickel-based alloy powder.

[0022] Optionally, the Inconel 625 nickel-based alloy powder has a particle size of 15~53μm; the Y2O3 powder has a particle size of 3~10μm.

[0023] Optionally, the chemical composition of the Inconel 625 nickel-based alloy powder, by mass percentage, includes: Cr 20~23wt%, Nb 3~5wt%, Mo 9~10wt%, Fe 4~5wt%, Mn≤0.01.0wt%, C 0.5~1.0wt%, Cu≤0.1.0wt%, Al≤0.05wt%, with the remainder being Ni.

[0024] like Figure 1 As shown, the present invention also provides a method for preparing a nickel-based rare-earth composite coating for high-speed laser cladding, comprising the following steps: Step S1: Weigh Inconel 625 nickel-based alloy powder and rare earth oxide Y2O3 powder according to the set ratio, place the two powders in a mixing tank for mechanical mixing, and obtain Y2O3 / Inconel625 composite powder. Step S2: Pre-treat the Y2O3 / Inconel625 composite powder and place the pre-treated powder into a powder container; Step S3: The laser of the high-speed laser cladding equipment is used to perform layer-by-layer cladding of the alloy powder in a ring scanning manner to obtain Y2O3 / Inconel625 composite material specimens; Step S4: Use wire cutting technology to cut the Y2O3 / Inconel625 composite material specimen formed by high-speed laser cladding from the substrate.

[0025] Optionally, the stirring speed in the mixing tank in step S1 is 100~300 r / min, and the stirring time is 4~6 h.

[0026] Optionally, the pretreatment of Y2O3 / Inconel625 composite powder in step S2 involves loading the Y2O3 / Inconel625 composite powder into an oven for drying. The temperature of the oven is 120~150℃, and the drying time is 4~6h.

[0027] Optionally, the laser power of the high-speed laser cladding equipment in step S3 is 2800W, the scanning speed is 40m / min, the powder feeding rate is 20g / min, and the overlap rate is 85%; the thickness of each cladding layer is 330μm.

[0028] Optionally, the layer-by-layer cladding step in step S3 is as follows: (1) Set the laser spot diameter to 3 mm and use a ring scanning method; (2) The laser beam scans the surface of the substrate, so that the cladding powder is fully melted and clad onto the substrate to form a single cladding layer; (3) Repeat step (2) by layering until Y2O3 / Inconel625 composite material specimens are obtained.

[0029] Optionally, the substrate is 45 steel.

[0030] Example 1 Following the steps outlined above, Inconel 625 nickel-based alloy powder with a particle size of 15-53 μm and composition as shown in Table 1 was selected. A high-speed laser cladding device, such as a 6kW fiber laser and an RC52 dual-channel powder feeding system, was used for cladding on a 45 steel substrate. The optimized cladding parameters were: laser power 2800W, scanning speed 40m / min, powder feeding rate 20g / min, laser spot diameter 3mm, and inert gas flow rate 10 L / min. A multi-layer cladding coating approximately 3mm thick was formed. The specimen was cut from the substrate using wire cutting technology, and then observed using a metallographic microscope and a scanning electron microscope to obtain the microstructure of the Inconel 625 alloy specimen formed by high-speed laser cladding. Figure 4 As shown in the middle figures (a1~a3), the grain structure exhibits a continuous gradient transformation from planar crystals, cellular crystals, columnar crystals to equiaxed crystals.

[0031] Table 1 shows the chemical composition (wt.%) of 45 steel. Example 2 The difference from Example 1 is that in this example, Inconel 625 nickel-based alloy powder and 0.5 wt% Y2O3 powder (particle size 3~5 μm) are mixed at a mass ratio of 99.5:0.5 and homogenized by ball milling to obtain composite powder; the microstructure of the 0.5 wt% Y2O3 / Inconel 625 alloy composite material specimen formed by high-speed laser cladding melting is shown in the figure. Figure 4 As shown in the middle figures (b1-b3), the microstructure is refined compared to the Inconel 625 coating.

[0032] Example 3 The difference from Example 1 is that this example uses Inconel 625 nickel-based alloy powder ( Figure 2 a) and 1.0wt% Y2O3 powder ( Figure 2 b) The mixture was prepared by ball milling and homogenization at a mass ratio of 99:1 to obtain composite powder; macroscopic morphology and microstructure diagrams of 1.0wt% Y2O3 / Inconel 625 alloy composite material specimens based on high-speed laser cladding and melting were obtained, as shown in the figure. Figure 3 As shown in c, the coating thickness is 3.14 mm. Figure 3(ad) It can be seen that as the Y2O3 content increases from 0 wt% to 2.0 wt%, the corresponding sample thicknesses are 2.74, 2.99, 3.14, and 3.22 mm, respectively, and the forming characteristics of the composite material show a regular change; for example... Figure 4 As shown in the middle figures (c1-c3), the coating grains are significantly refined, and the coating structure tends to be uniform and dense, mainly composed of fine columnar crystals and equiaxed crystals; when the Y2O3 content increases to 2.0 wt%, as... Figure 4 As shown in (d1-d2), the proportion of columnar crystals in the middle of the sample, similar to that of the 1.0wt% Y2O3 / Inconel 625 alloy composite specimen, is significantly reduced. X-ray diffraction analysis is as follows... Figure 5 As shown, the coating substrate is a γ-Ni solid solution phase, and Cr is also present. 23 Peaks for C6, Cr7C3 carbides and Ni3Fe intermetallic compounds were detected; no obvious Y2O3 diffraction peaks were detected, indicating that Y may be partially dissolved in the matrix or form a nanoscale precipitate. Energy dispersive spectroscopy analysis revealed that Y element was enriched in the grain boundary region of the coating, which is conducive to the precipitation of carbides at the grain boundaries. The above results indicate that Y2O3 promotes grain refinement through heterogeneous nucleation and induces the formation of hard carbide phases at the grain boundaries, forming a synergistic mechanism of grain refinement strengthening and grain boundary strengthening.

[0033] Then, the coating cross-section was subjected to microstructure and performance testing, and observed by metallographic microscope and scanning electron microscope.

[0034] Coating hardness test, such as Figure 6a and Figure 6b The results show that the average microhardness of the composite coating is 371.24 HV1, which is significantly higher than that of the Inconel 625 coating without Y2O3 (approximately 284.12 HV1). This is attributed to the fact that the added Y2O3 in the coating triggered multiple strengthening mechanisms, mainly including grain refinement strengthening, grain boundary strengthening, solid solution strengthening, dispersion strengthening, and precipitation strengthening. Fatigue wear tests are shown in Figure 7. Figure 7 is a comparison of the wear morphology of the substrate, Inconel 625, and the Y2O3 / Inconel 625 composite coating under the same conditions. Figure (a) is the substrate; Figure (b) is Inconel 625; Figure (c) shows Y2O3 powder with a content of 0.5 wt% (Y2O3 / Inconel 625); (d) shows Y2O3 powder with a content of 1.0 wt% (Y2O3 / Inconel 625); (e) shows Y2O3 powder with a content of 2.0 wt% (Y2O3 / Inconel 625). Figure 8 The wear rate shown is only 2.29 × 10⁻⁶ for the coating containing 1.0 wt% Y₂O₃. -4 mm 3 / (N·m), approximately 1 / 3 of the Inconel 625 alloy coating; the wear mechanism is that the originally severe adhesive-abrasive mixed wear gradually transforms into slight cutting wear; this is mainly attributed to the following multi-scale synergistic wear mechanism: the interfacial metallurgical bonding formed between the hard phase and the matrix phase significantly improves the bonding strength, while the uniformly distributed high volume fraction hard phase structure also enhances the overall hardness of the coating; and during the frictional shearing process, micron-sized Y2O3 particles, as hard micro-protrusions, preferentially bear the load, effectively delaying the abrasive plowing process. Electrochemical test results Figure 9 This indicates that the self-corrosion current density of the composite coating is as low as 3.2027 × 10⁻⁶. -6 A / cm 2 The charge transfer resistance is as high as 7.8891 × 10⁻⁶. 4 Ω·cm 2 The coating exhibits significantly better corrosion resistance than pure Inconel 625 coatings. This improvement in electrochemical performance is attributed to the uniform distribution of Y₂O₃ within the coating, resulting in a dispersion strengthening effect. Highly reactive Y can form stable compounds (such as YS) with impurities like S and P, purifying grain boundaries, enhancing grain boundary bonding strength, and promoting the formation of a dense Cr₂O₃ oxide film. Simultaneously, the addition of Y₂O₃ refines the grains, optimizes the microstructure, and reduces surface chemical activity, thereby slowing down the corrosion process. Furthermore, rare earth elements construct a multi-layered protective mechanism by promoting grain densification and optimizing the grain boundary network: on the one hand, they drive structural reorganization to form a diffusion barrier, inhibiting the penetration of corrosive media; on the other hand, they hinder hydrogen diffusion paths through interfacial adsorption, increasing the activation energy of the cathodic reaction and further enhancing overall corrosion resistance.

[0035] Table 2. Polarization parameters of the substrate, Inconel 625 alloy, and Y2O3 / Inconel 625 composite coating. Example 4 The difference from Example 1 is that in this example, Inconel 625 nickel-based alloy powder and 2.0 wt% Y2O3 powder are mixed at a mass ratio of 98:2 and homogenized by ball milling to obtain composite powder. Macroscopic morphology images of the 2.0 wt% Y2O3 / Inconel 625 alloy composite material specimen formed by high-speed laser cladding melting are obtained, as shown in the figure. Figure 3 As shown in d, defects such as cracks and pores appear in the coating.

[0036] Then, the coating cross-section was subjected to microstructure and performance testing, and observed by metallographic microscope and scanning electron microscope.

[0037] Hardness testing of the coating showed that the average microhardness of the composite coating surface reached 295.71 HV1, which was lower than that of the 1.0 wt% Y2O3 / Inconel 625 alloy composite specimen. This was attributed to the significant increase in undissolved Y2O3 particles during the high-speed laser cladding process. The residual undissolved particles formed stress concentration sources at the grain boundaries, weakening the dispersion strengthening effect, disrupting the coating continuity, and significantly increasing defects such as porosity and cracks. Fatigue wear testing showed that the wear rate of the composite coating was 7.31 × 10⁻⁶. -4 mm 3 The wear rate increased by / N·m compared to the 1.0 wt% Y2O3 coating. This is attributed to interfacial stress concentration caused by hard phase agglomeration and thermophysical property mismatch, which increased the crack initiation rate and consequently reduced wear resistance. Electrochemical test results show that the self-corrosion current density of this composite coating is 4.2806 × 10⁻⁶ N·m. -6 A / cm 2 Compared to the 1.0 wt% Y2O3 coating, the self-corrosion current density increases and the corrosion resistance deteriorates. This is attributed to the fact that excessive Y2O3 (≥2.0 wt%) leads to the aggregation of precipitates, uneven structure, increased number of pores and cracks, and decreased density, providing channels for the penetration of corrosive media and thus accelerating corrosion; grain boundary segregation leads to enhanced local electrochemical activity, inducing selective corrosion.

[0038] In summary, the 1.0 wt% Y2O3 / Inconel 625 composite powder prepared in this embodiment can produce a dense coating with excellent mechanical properties in high-speed laser cladding. Compared with the original Inconel 625 cladding layer, the coating hardness is increased by more than 30%, the wear rate is reduced to 1 / 3 of the original, and the corrosion resistance is improved by about 43%, which fully demonstrates the superiority of the composite powder of the present invention.

[0039] The beneficial technical effects of this invention are as follows: The preferred Y₂O₃ content in this invention is approximately 1.0 wt%. Excessive addition (≥2.0 wt%) leads to increased porosity and crack growth in the coating, thus reducing performance and demonstrating the "critical concentration effect" of Y₂O₃. In summary, by adding an appropriate amount of rare earth Y₂O₃ powder to Inconel 625-based powder, significant grain refinement of the cladding coating is achieved, improving the uniformity and density of the microstructure. The low heat input and rapid solidification characteristics of the high-speed laser cladding process effectively reduce the tendency for coating defects to form, and decrease the width of the heat-affected zone and the level of residual stress.

[0040] Increase the hardness of materials The 1.0 wt% Y2O3 composite coating achieved a peak hardness of 371.24 HV1, an improvement of approximately 30.7% compared to the Inconel 625 alloy coating (284.12 HV1). This is mainly attributed to grain refinement strengthening (Hall-Petch), solid solution strengthening (Y dissolved in γ-Ni), dispersion strengthening (undissolved Y2O3), and precipitation strengthening (Cr7C3, Cr...). 23 Synergistic effect of C6 carbide phase.

[0041] Improve the wear resistance of materials The 1.0 wt% Y2O3 composite coating exhibited optimal wear resistance (wear rate as low as 2.29 × 10⁻⁶). -4 mm 3 The Y₂O₃ content increased by approximately 3 times compared to the Inconel 625 alloy coating. With increasing Y₂O₃ content, the dominant wear mechanism gradually shifted from severe adhesive-abrasive composite wear to slight cutting wear. This was primarily due to the dispersed distribution of hard phases (Y₂O₃, Cr₇C₃, Cr₂O₃). 23 C6) Effectively bears the load and inhibits crack propagation.

[0042] Improve the corrosion resistance of materials The 1.0 wt% Y2O3 composite coating exhibits the best electrochemical corrosion resistance (i corr As low as 3.2027×10 -6 A / cm 2 This composite coating exhibits a 43% improvement over the Inconel 625 alloy coating. It also boasts the highest passivation film stability and lowest charge transfer resistance (R0). t ) reached 7.8891×10 4 Ω·cm 2 It is about 40.7 times better than the Inconel 625 alloy coating; its improved corrosion resistance is due to the synergistic barrier effect of grain refinement and dense passivation film (rich in Cr2O3 and Y2O3).

[0043] This invention demonstrates the preparation and application effects of composite powder materials through examples; the technical solution is not limited to the specific values ​​mentioned above, as long as it meets the scope of the claims, similar beneficial effects can be achieved; it can be seen that the Y2O3 / Inconel625 composite powder material for high-speed laser cladding provided by this invention has the advantages of simple structure, feasible preparation, and moderate cost, and by optimizing the Y2O3 content and particle size, it can significantly improve the microstructure and wear and corrosion resistance of nickel-based coatings, which has important practical value for high-speed laser cladding processing and surface strengthening of high-end equipment parts.

[0044] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A nickel-based rare earth composite powder material for high-speed laser cladding, characterized in that: The nickel-based rare earth composite powder includes Inconel 625 nickel-based alloy powder and rare earth oxide Y2O3 powder; the content of Y2O3 powder is 0.5 wt% to 2.0 wt% of Inconel 625 nickel-based alloy powder.

2. The nickel-based rare earth composite powder material for high-speed laser cladding according to claim 1, characterized in that: The Inconel 625 nickel-based alloy powder has a particle size of 15~53μm; the Y2O3 powder has a particle size of 3~10μm.

3. The nickel-based rare earth composite powder material for high-speed laser cladding according to claim 1, characterized in that: The chemical composition of the Inconel 625 nickel-based alloy powder, by mass percentage, includes: Cr 20~23wt%, Nb 3~5wt%, Mo 9~10wt%, Fe 4~5wt%, Mn≤0.01.0wt%, C 0.5~1.0wt%, Cu≤0.1.0wt%, Al≤0.05wt%, with the remainder being Ni.

4. A method for preparing a nickel-based rare earth composite coating using the material as described in claims 1-3, characterized in that, Includes the following steps: Step S1: Weigh Inconel 625 nickel-based alloy powder and rare earth oxide Y2O3 powder according to the set ratio, place the two powders in a mixing tank for mechanical mixing, and obtain Y2O3 / Inconel625 composite powder. Step S2: Pre-treat the Y2O3 / Inconel625 composite powder and place the pre-treated powder into a powder container; Step S3: The laser of the high-speed laser cladding equipment is used to perform layer-by-layer cladding of the alloy powder in a ring scanning manner to obtain Y2O3 / Inconel625 composite material specimens; Step S4: Use wire cutting technology to cut the Y2O3 / Inconel625 composite material specimen formed by high-speed laser cladding from the substrate.

5. The method for preparing a nickel-based rare earth composite coating for high-speed laser cladding according to claim 4, characterized in that, The stirring speed in the mixing tank in step S1 is 100~300 r / min, and the stirring time is 4~6 h.

6. The method for preparing a nickel-based rare earth composite coating for high-speed laser cladding according to claim 4, characterized in that, The pretreatment of Y2O3 / Inconel625 composite powder in step S2 involves loading the Y2O3 / Inconel625 composite powder into an oven for drying. The oven temperature is 120~150℃ and the drying time is 4~6h.

7. The method for preparing a nickel-based rare-earth composite coating for high-speed laser cladding according to claim 4, characterized in that, The laser power of the high-speed laser cladding equipment described in step S3 is 2800W, the scanning speed is 40m / min, the powder feeding rate is 20g / min, and the overlap rate is 85%; the thickness of each cladding layer is 330μm.

8. The method for preparing a nickel-based rare earth composite coating for high-speed laser cladding according to claim 4, characterized in that, The layer-by-layer cladding step described in step S3 is as follows: (1) Set the laser spot diameter to 3 mm and use a ring scanning method; (2) The laser beam scans the surface of the substrate, so that the cladding powder is fully melted and clad onto the substrate to form a single cladding layer; (3) Repeat step (2) by layering until Y2O3 / Inconel625 composite material specimens are obtained.

9. A method for preparing a nickel-based rare-earth composite coating for high-speed laser cladding according to claim 4, characterized in that, The base material is 45 steel.

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