A gene design and preparation method of high-temperature wear-resistant corrosion-resistant and self-lubricating NiCrCoAlTiWCS alloy

Abstract

This invention discloses a genetic design and preparation method for a high-temperature wear-resistant, corrosion-resistant, and self-lubricating NiCrCoAlTiWCS alloy. Using a combination of simulation calculations and experiments, a NiCrCoAlTiWCS alloy powder capable of in-situ generation of high-temperature wear-resistant, corrosion-resistant, and self-lubricating genetic phases through laser cladding was designed. This alloy powder exhibits good laser formability. The microstructure of the clad alloy sample mainly consists of in-situ generated M7C3 and TiC wear-resistant phases, γ / γ′ corrosion-resistant phases, and TiS and Ti2SC self-lubricating phases, among which the needle-like Ti2SC phase exhibits excellent high-temperature self-lubricating properties. The friction coefficient of the clad alloy sample at 800℃ is 0.18–0.22, and the wear rate is 2.20–2.45 × 10⁻⁶. ‑5 mm 3 / (N·m), corrosion potential -0.16~-0.14V, corrosion current density 1.0~1.4×10 ‑7 A / cm 2 .

Description

Technical Field

[0001] This invention belongs to the field of laser additive manufacturing and remanufacturing technology, specifically relating to a gene design and preparation method for a high-temperature wear-resistant, corrosion-resistant, and self-lubricating NiCrCoAlTiWCS alloy. Background Technology

[0002] Key components of metallurgical equipment, such as rolls, mandrels, and furnace rolls, are critical friction parts operating under complex "thermal-mechanical-fluid" conditions. Their operating temperatures typically reach 800–1200℃, and they are subject to damage mechanisms from multiple factors, including friction and lubricant corrosion. This often leads to severe wear, corrosion, oxidation, fatigue, and nodulation failures, resulting in significant economic losses. There is an urgent need to research new alloy materials and advanced remanufacturing technologies for repair and manufacturing to meet the industry's critical needs. Laser cladding, due to its advantages of short process, wide alloy selection, and unique microstructure and properties, is one of the mainstream repair and remanufacturing technologies for key metallurgical components and has been widely applied. However, because the damage mechanisms under complex operating conditions are interconnected, it is difficult to prepare alloys with high wear resistance, corrosion resistance, and self-lubrication properties simultaneously when studying laser-clad high-temperature alloy reinforcement layers. Furthermore, the quantity, size, and distribution of the corresponding phases for wear resistance, corrosion resistance, and self-lubrication in the alloy determine the overall performance of the prepared alloy. Achieving a scientific match between these phases presents numerous challenges, such as innovative alloy composition design and the mechanisms of laser cladding microstructure evolution and performance enhancement, requiring further in-depth and systematic research to resolve. Therefore, researching novel alloys possessing high performance characteristics such as wear resistance, corrosion resistance, and self-lubrication, as well as advanced theories and technologies for laser cladding, holds significant scientific research and practical application value.

[0003] Currently, researchers both domestically and internationally often improve the wear resistance of alloys by adding alloying elements (Cr, Ni, W, Ta, Mo), external reinforcing phases (WC, TaC, NbC, M7C3, TiC), and lubricants (CrS, WS2, MoS2, TiS, Cu, Ag). However, achieving a balance and simultaneous improvement of wear resistance, corrosion resistance, and self-lubrication remains a critical challenge. For example, solid lubricants improve wear resistance by significantly reducing the coefficient of friction; however, high contents of soft metals, such as CrS, WS2, and MoS2, can significantly weaken the material's hardness, reducing its wear resistance and making it difficult to achieve both self-lubrication and wear resistance simultaneously. Secondly, in recent years, significant progress has been made in the composition design and cladding microstructure control of laser-clad wear-resistant, corrosion-resistant, and self-lubricating high-temperature nickel-based alloys. However, research on the composition design and microstructure of nickel-based alloys that are based on laser cladding to prepare key high-temperature service parts in metallurgy and simultaneously possess high-temperature wear resistance, corrosion resistance, and self-lubrication is still insufficient. In particular, there are few reports on the design of new alloys that meet the requirements of service under complex "thermal-mechanical-fluid" conditions and the research and invention of new nickel-based high-temperature alloys that simultaneously possess wear resistance, corrosion resistance, and self-lubrication properties through laser cladding.

[0004] Wear resistance of nickel-based superalloys and M 23 The addition of C6, M7C3, TiC, TaC, and WC contributes to the particle-enhanced hardness and wear resistance. Research on self-lubrication primarily focuses on the external addition or in-situ generation of self-lubricating phases such as graphite, MoS2, CaF2, and M... n+1 AX n These are used to improve the self-lubricating properties of high-temperature nickel-based alloys. Among them, Ti2SC is M... n+1 AX n Ti2SC is a special type of material with low density and high Vickers hardness (8±2 GPa), exhibiting unique ceramic and metallic properties. Furthermore, Ti2SC also possesses excellent self-lubricating and corrosion-resistant properties. Therefore, the key to preparing alloys with good high-temperature wear resistance, corrosion resistance, and self-lubricating properties lies in how to generate the Ti2SC phase in situ within wear-resistant and corrosion-resistant nickel-based superalloys.

[0005] In summary, although significant progress has been made in the composition design and microstructure control of laser cladding for wear-resistant, corrosion-resistant, and self-lubricating high-temperature nickel-based alloys, the various failure modes of key metallurgical components under complex service conditions (800–1200°C) still require innovative research and design methods and laser cladding preparation technologies to address. In recent years, materials genome design has become one of the fastest, most scientific, and effective methods for designing high-performance alloy compositions in the composition design of alloy powders for high-performance parts manufactured by laser additive manufacturing. Progress has been made in the design of wear-resistant and corrosion-resistant iron-based alloy powders and the laser cladding preparation of high-performance alloy powders. However, research on materials genome design and preparation methods for laser cladding alloy powders for friction parts under complex "thermal-mechanical-fluid" conditions in the metallurgical industry remains a novel topic. Therefore, a novel NiCrCoAlTiWCS alloy gene design and preparation method based on laser cladding with high-temperature wear resistance, corrosion resistance and self-lubricating properties was developed using the materials gene design method. This method can provide important theoretical and technical support for laser additive manufacturing and remanufacturing of key parts that meet the complex working conditions of "thermal-mechanical-fluid" and multiple damage failures. Summary of the Invention

[0006] To overcome the bottlenecks of existing technologies, this invention addresses the challenge of low service life caused by various failures in friction parts under complex "thermal-mechanical-fluid" conditions in the metallurgical industry. It innovatively researches and designs a novel NiCrCoAlTiWCS alloy gene design and preparation method for laser cladding, achieving high-temperature wear resistance, corrosion resistance, and self-lubrication. Based on the concept of a three-phase microstructure design (wear resistance, corrosion resistance, and self-lubrication), it studies and constructs a novel high-temperature nickel-based alloy powder composition design system with high wear resistance, corrosion resistance, and self-lubrication properties under service conditions of 800–1200℃. The invention elucidates the influence of the formability and microstructure of the laser cladding alloy on its performance. Laser cladding is then performed on the surface of metallurgical parts to obtain alloys with not only good laser formability but also excellent high-temperature wear resistance, corrosion resistance, and self-lubrication properties. This advanced method lays an important foundation for the repair and remanufacturing of key components in metallurgical equipment.

[0007] To achieve the above-mentioned objectives, this invention provides a genetic design for a high-temperature wear-resistant, corrosion-resistant, and self-lubricating NiCrCoAlTiWCS alloy. The genetic design includes: defining key gene phases, establishing a database system for alloy powder composition, establishing a theoretical prediction model, and designing target alloy powder composition that matches the key gene phases according to screening criteria. The key gene phases include wear-resistant key gene phases, corrosion-resistant key gene phases, and self-lubricating key gene phases.

[0008] Based on the wear resistance, corrosion resistance, and self-lubricating properties required for high-temperature friction parts in the metallurgical industry, key gene phases for wear resistance, corrosion resistance, and self-lubrication were constructed. A database system of 4,191,264 designed alloy powder compositions was established, which has the function of designing target alloy powder compositions with three key gene structures for high-temperature wear resistance, corrosion resistance, and self-lubrication in laser cladding according to screening criteria. Alloys prepared under optimized laser cladding parameters exhibit excellent high-temperature wear resistance, corrosion resistance, and self-lubricating properties.

[0009] Furthermore, the key phases for wear resistance are M7C3 and TiC; the key phases for corrosion resistance are γ / γ′; and the key phases for self-lubrication are Ti2SC and TiS.

[0010] Furthermore, based on the aforementioned key gene phase, the first candidate metallic element composition (mass percentage) of the NiCrCoAlTiWCS alloy powder was determined; the mass percentage content range of the main elements in the alloy powder composition is Cr: 7-17%, Co: 10-23%, Al: 7-12%, Ti: 0-10%, W: 0-6%, C: 0-2%, S: 0-2%; the step size for C is set to 0.1, the step size for S is set to 0.5, and the step size for other elements is set to 1.

[0011] Furthermore, a basic database of NiCrCoAlTiWCS alloy powder compositions with different contents of various metal elements is established; the solid solution strengthening factor, precipitation strengthening factor, and hardness factor of different NiCrCoAlTiWCS alloy powder compositions in the database are calculated, and a three-dimensional model with the solid solution strengthening factor, precipitation strengthening factor, and hardness factor as coordinate axes is established to determine the NiCrCoAlTiWCS alloy powder composition.

[0012] Furthermore, the solid solution strengthening factor is the sum of the solid solution strengthening effects of Co, Cr, Al, Ti, W and C, with a value range of 200 to 400; the precipitation strengthening factor is the sum of the precipitation strengthening effects of M7C3, TiC and Ti2SC, with a value range of 200 to 700; the total strengthening factor is the sum of the solid solution strengthening factor and the precipitation strengthening factor.

[0013] Furthermore, the optimized NiCrCoAlTiWCS alloy powder for laser cladding with high-temperature wear-resistant, corrosion-resistant, and self-lubricating properties is mainly composed of the following metal elements by mass percentage: Cr: 15-17%, Co: 10-12%, Al: 7-9%, Ti: 4-6%, W: 2-4%, C: 1.8-2%, and S: 0.5-1.5%.

[0014] A method for preparing the above-mentioned high-temperature wear-resistant, corrosion-resistant, and self-lubricating NiCrCoAlTiWCS alloy involves taking pure elemental powders of each metal element according to the optimized alloy powder composition and mass content, and preparing the alloy using an elemental powder mixing method. The parameters for the mixing method are: ball-to-powder ratio of 3:5, rotation speed of 400 r / min, and mechanical mixing for 7–9 h to obtain nickel-based alloy powder with an average particle size of 45–105 μm. The powder is then placed in a drying oven and kept at 100 °C for 4 h.

[0015] Furthermore, the nickel-based alloy powder, after being dried under heat preservation, is used to prepare a high-temperature wear-resistant, corrosion-resistant, and self-lubricating NiCrCoAlTiWCS alloy under high-purity Ar gas protection via laser cladding. The optimized parameters of the laser cladding process are: a pre-coated powder layer thickness (t) of 0.5 mm, a scanning interval (d) of 2 mm, an overlap rate of 50%, and a laser energy density of 50–200 J / cm². 3 .

[0016] A high-temperature wear-resistant, corrosion-resistant, and self-lubricating NiCrCoAlTiWCS alloy prepared by the above method, wherein the microstructure of the NiCrCoAlTiWCS alloy mainly consists of 19.5–23 vol.% of M7C3 and TiC wear-resistant phases (19–21% M7C3 and 0.5–2% TiC hard phase), 60–70 vol.% of γ / γ′ corrosion-resistant phase (high-temperature resistant phase), 7–14 vol.% of TiS, and Ti2SC self-lubricating phase (5–10% TiS and 2–4% Ti2SC); in the laser cladding alloy, needle-like Ti2SC phase with high-temperature solid lubrication is generated in situ, wherein the Ti2C layer has strong covalent Ti-C bonds and is interwoven with weaker Ti-S, and the Ti-S layer is its easy-slip surface, playing a lubricating role.

[0017] Furthermore, the NiCrCoAlTiWCS alloy prepared above has a density of 98.5%–99.8% and a hardness of 410–460 HV. 0.2 The coefficient of friction at room temperature is 0.40–0.45, and the wear rate is 1.50–1.65 × 10⁻⁶. -5 mm 3 / (N·m); The coefficient of friction at 800℃ is 0.18~0.22, and the wear rate is 2.20~2.45×10. -5 mm 3 / (N·m), corrosion potential is -0.16 to -0.14V, corrosion current density is 1.0 to 1.4×10 -7 A / cm 2 .

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] ① This invention successfully establishes a material gene design method for novel NiCrCoAlTiWCS alloy powder suitable for laser cladding, exhibiting high-temperature wear resistance, corrosion resistance, and self-lubrication. By defining genes and searching databases, it can rapidly optimize target compositions that meet the non-equilibrium metallurgical characteristics of laser cladding while also possessing high-temperature wear resistance, corrosion resistance, and self-lubrication. It can quickly complete the design of target nickel-based alloy compositions from 4,191,264 possible alloy composition formulations.

[0020] ② The novel NiCrCoAlTiWCS nickel-based alloy sample prepared under optimized laser cladding parameters not only has good laser formability, but also excellent high-temperature wear resistance, corrosion resistance and self-lubricating properties. Compared with Cr28Ni48W5, a high-temperature alloy material for metallurgical parts, its friction coefficient is reduced by 51% and its wear rate is reduced by 97%.

[0021] ③ During the laser cladding process, a needle-like Ti2SC phase with high-temperature solid lubrication is generated in situ in the NiCrCoAlTiWCS nickel-based alloy, resulting in a friction coefficient of 0.18–0.22 at 800℃. This exhibits excellent high-temperature self-lubricating properties, providing an original technology for the laser repair and remanufacturing of high-temperature service friction parts in the metallurgical industry. The NiCrCoAlTiWCS alloy prepared by this method possesses excellent high-temperature wear resistance, corrosion resistance, and self-lubricating properties, showing significant application prospects in the laser repair and remanufacturing of key high-temperature service friction parts in the metallurgical industry. Attached Figure Description

[0022] Figure 1 Screenshots showing the element range, database composition screening, and simulation process of the novel nickel-based alloys used in Examples 1-3;

[0023] Figure 2 The screenshots show partial results of the calculation of solid solution strengthening factor, precipitation strengthening factor and total strengthening factor by Jmatpro software in Examples 1-3.

[0024] Figure 3 Metallographic images of laser cladding samples prepared under different laser energy densities in Examples 1-3;

[0025] Figure 4 Scanning image of the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 1 in backscatter mode;

[0026] Figure 5 EPMA image of the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 1;

[0027] Figure 6XRD patterns of laser-clad NiCrCoAlTiWCS nickel-based alloys prepared in Examples 1-3 (1%, 0.5%, and 1.5% in the figures represent the mass percentage of sulfur in the nickel-based alloy powders of Examples 1-3, respectively).

[0028] Figure 7 Transmission image of the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 1;

[0029] Figure 8 The average hardness of the laser-clad NiCrCoAlTiWCS nickel-based alloys prepared in Examples 1-3;

[0030] Figure 9 The room temperature friction coefficient curve of the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 1;

[0031] Figure 10 The room temperature tribological morphology of the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 1;

[0032] Figure 11 The friction coefficient curve at 800℃ for the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 1;

[0033] Figure 12 The tribological morphology of the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 1 at 800℃;

[0034] Figure 13 Electrochemical test results (polarization curves) of the laser-clad NiCrCoAlTiWCS nickel-based alloys prepared in Examples 1, 2, and 3;

[0035] Figure 14 Scanning image of the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 2 in backscatter mode;

[0036] Figure 15 The room temperature friction coefficient curve of the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 2;

[0037] Figure 16 The room temperature tribological morphology of the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 2;

[0038] Figure 17 The friction coefficient curve at 800℃ for the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 2;

[0039] Figure 18The friction and wear morphology of the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 2 at 800℃;

[0040] Figure 19 Scanning image of the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 3 in backscatter mode;

[0041] Figure 20 The room temperature friction coefficient curve of the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 3;

[0042] Figure 21 The room temperature tribological morphology of the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 3;

[0043] Figure 22 The friction coefficient curve at 800℃ for the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 3;

[0044] Figure 23 The friction and wear morphology of the laser-clad NiCrCoAlTiWCS nickel-based alloy prepared in Example 3 at 800℃. Detailed Implementation

[0045] The following non-limiting embodiments are intended to enable those skilled in the art to more fully understand the present invention, but do not limit the invention in any way. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the reagents and materials mentioned are commercially available.

[0046] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0047] Example 1

[0048] A novel NiCrCoAlTiWCS alloy gene design and preparation method with laser cladding high-temperature wear-resistant, corrosion-resistant, and self-lubricating properties is implemented according to the following steps:

[0049] 1. Definition of key gene phases: Based on the demand for new high-temperature wear-resistant, corrosion-resistant, and self-lubricating nickel-based alloy materials for the repair of equipment parts in the metallurgical industry by laser cladding, key gene phases are defined as wear-resistant key gene phase, corrosion-resistant key gene phase, and self-lubricating key gene phase. Among them, the wear-resistant key gene phase is M7C3 and TiC; the corrosion-resistant key gene phase is γ / γ′; and the self-lubricating key gene phase is TiS and Ti2SC.

[0050] 2. Based on the key gene phases defined in step 1, determine the metal elements and their contents in the alloy to obtain the candidate composition of the nickel-based alloy powder. This candidate composition, by mass percentage, consists of the following metal elements: Co: 10–23%, Cr: 7–17%, Al: 7–12%, Ti: 0–10%, W: 0–6%, C: 0–2%, S: 0–2% (e.g., ...). Figure 1 (As shown).

[0051] 3. Based on the content range of each metal element, determine the variation in the composition of each metal element. Set the step size for C to 0.1, the step size for S to 0.5, and the step size for other elements to 1. Establish a database, such as... Figure 1 The screenshot shows a portion of the total score table in the Chinese database.

[0052] 4. Establish a theoretical prediction model. The optimal composition is determined using a three-dimensional model with solid solution strengthening, precipitation strengthening, and overall strengthening as the three factors. The solid solution strengthening factor, precipitation strengthening factor, and overall strengthening factor for different nickel-based alloy compositions in the database are calculated using JMatPro software, and a three-dimensional model with these three factors as coordinate axes is established to obtain the optimal composition. High-throughput calculation results are shown below. Figure 2 As shown in the figure. The solid solution strengthening factor is the sum of the solid solution strengthening effects of Co, Cr, Al, Ti, W, and C; the precipitation strengthening factor is the sum of the precipitation strengthening effects of M7C3, TiC, and Ti2SC; and the total strengthening factor is the sum of the solid solution strengthening factor and the precipitation strengthening factor. The concentrations of Co, Cr, Al, Ti, and W are 10–23 wt.%, 7–17 wt.%, 7–12 wt.%, 0–10 wt.%, and 0–6 wt.%, respectively. The volume fractions of γ / γ′, M7C3, TiC, Ti2SC, and TiS are 50–70%, 0–25%, 0–10%, 0–10%, and 0–10%, respectively. The value range of the solid solution strengthening factor is 200–400, and the value range of the precipitation strengthening factor is 200–700.

[0053] 5. High-throughput calculation of optimal components. Figure 2 The figure shows the simulation results of the solid solution strengthening factor (SSSF) and precipitation strengthening factor (PHF) of the theoretical model, as well as the influence of different element addition amounts on the proportion of each phase. The results of the solid solution strengthening factor, precipitation strengthening factor, and total strengthening factor are plotted as follows. Figure 2 The following is a summary chart of the three-dimensional simulation results. According to the three-dimensional image, the optimal alloy composition by mass percentage is: Cr: 15–17%, Co: 10–12%, Al: 7–9%, Ti: 4–6%, W: 2–4%, C: 1.8–2%, and S: 0.5–1.5%.

[0054] 6. A novel nickel-based alloy sample was prepared using laser cladding technology. The specific steps are as follows:

[0055] (1) Composition of NiCrCoAlTiWCS nickel-based alloy powder: According to the mass percentage, its chemical composition is Cr: 17%, Co: 10%, Al: 7%, Ti: 5%, W: 3%, C: 2%, S: 1%.

[0056] (2) Preparation of NiCrCoAlTiWCS nickel-based alloy powder: According to the composition ratio of nickel-based alloy powder, pure elemental powders of each metal element are taken and mechanically mixed for 7-9 hours under the conditions of ball-to-material ratio of 3:5 and rotation speed of 400r / min to obtain nickel-based alloy powder. The average particle size of the nickel-based alloy powder is 45-105μm.

[0057] (3) Preparation of novel nickel-based alloy samples using laser cladding process: The equipment used was an FL-Dlight02-3000 W semiconductor laser (spot size 4×4mm). 2 The substrate used was Cr28Ni48W5 alloy, which was pre-polished to make its surface smooth. The NiCrCoAlTiWCS nickel-based alloy powder prepared in step (2) was used for powder-lay printing to prepare a laser-clad NiCrCoAlTiWCS nickel-based alloy sample.

[0058] (4) Laser cladding process parameters: laser energy density is 71 J / mm². 3 (2000W, 7mm / s), powder layer thickness (t) is 0.5mm, scanning interval (d) is 2mm, overlap rate is 50%, and laser cladding of nickel-based alloy samples is completed under argon protection.

[0059] 7. Performance testing of laser-clad nickel-based alloy samples:

[0060] (1) Verify the printability of laser-clad nickel-based alloy samples: such as Figure 3 As shown, the laser cladding of nickel-based alloy samples was performed at a laser energy density of 71 J / mm². 3 The metallographic morphology at (2000W, 7mm / s) shows a relatively dense structure with no cracks and only a few pores. The density, calculated using the area method, is approximately 99.8%. Figure 4 As shown.

[0061] (2) Verification of the formation of the gene phase: To analyze the microstructure of the alloy, etching was performed using an etchant, followed by morphological observation using a metallographic microscope. The microstructure of the sample was then identified using a scanning electron microscope and a field emission electron probe microanalysis, respectively. Figure 4 and 5As shown, the results indicate that laser-clad nickel-based alloy samples generated in situ a 65% (v / v) high-temperature resistant phase, 20% M7C3 and 2% TiC hard phases, 10% TiS, and 3% Ti2SC self-lubricating phase. X-ray diffraction analysis showed that ( Figure 6 Microstructure types and Figure 5 Consistent. Furthermore, the precipitated phase was further observed using field emission transmission electron microscopy (FET). Figure 7 This study verified the feasibility of in-situ generation of tetragene phases in novel nickel-based alloys by laser cladding.

[0062] (3) Verification of the high-temperature wear resistance of laser-clad nickel-based alloy samples: The microhardness of each coating was measured using a digital Vickers microhardness tester with a load of 200g and a load time of 10s. The average hardness of the laser-clad nickel-based alloy samples was 451HV. 0.2 ( Figure 8 The MMU-1G high-temperature tribology and wear tester was used. A normal load of 10 N was applied to the contact surface, the rotation speed was 20 r / min, and the friction time was 30 min. The wear pair consisted of Al2O3 ceramic. After the wear test, the samples were placed in an ultrasonic cleaning device and cleaned with alcohol for 5 min. The wear resistance of the coating was evaluated by measuring the wear weight loss of the samples using an analytical electronic balance. This process was repeated three times, and the average value was taken. The coefficient of friction at room temperature was 0.42. Figure 9 The wear rate was 1.57 × 10⁻⁶. -5 mm 3 / (N·m), the coefficient of friction at 800℃ is 0.20 ( Figure 11 The wear rate was 2.31 × 10⁻⁶. -5 mm 3 / (N·m), the SEM morphology of the worn surface at room temperature and 800℃ are as follows: Figure 10 and 12 As shown in Table 1, the friction test results show that, compared with Cr28Ni48W5, a high-temperature alloy material used for metallurgical parts, its room temperature friction coefficient decreased by 43% and its high-temperature friction coefficient decreased by 51%.

[0063] (4) Verification of the corrosion resistance of laser-clad nickel-based alloy samples: To test corrosion resistance, the electrochemical polarization curves of the samples were determined using an electrochemical workstation. This workstation consisted of a three-electrode system. The working electrode was the alloy sample, the auxiliary electrode was a platinum electrode, the reference electrode was a saturated calomel electrode, and the test solution was a 3.5 wt.% NaCl solution. The electrochemical test parameters were: initial potential -0.6 V, termination potential 0.6 V, and scan rate 0.5 mV / s. The corrosion resistance of the cladding layer was evaluated by fitting Tafel curves to the corrosion potential and corrosion current density values. The corrosion potential of the sample was -0.16 V, and the corrosion current density was 1.2 × 10⁻⁶.-7 A / cm 2 ( Figure 13 The laser-clad NiCrCoAlTiWCS nickel-based alloy sample exhibits a relatively high corrosion potential and a low corrosion current density, indicating good corrosion resistance.

[0064] Table 1. Tribological properties of laser-clad alloy samples under different friction temperatures.

[0065]

[0066] Example 2

[0067] A novel NiCrCoAlTiWCS alloy gene design and preparation method with laser cladding high-temperature wear-resistant, corrosion-resistant, and self-lubricating properties is implemented according to the following steps:

[0068] 1. Definition of key gene phases: Based on the demand for new high-temperature wear-resistant, corrosion-resistant, and self-lubricating nickel-based alloy materials for the repair of equipment parts in the metallurgical industry by laser cladding, key gene phases are defined as wear-resistant, corrosion-resistant, and self-lubricating phases. Among them, the wear-resistant phases are M7C3 and TiC; the corrosion-resistant phase is γ / γ′; and the self-lubricating phases are TiS and Ti2SC.

[0069] 2. Based on the key gene phases defined in step 1, determine the metal elements and their contents in the alloy to obtain the candidate composition of the nickel-based alloy powder. This candidate composition consists of the following metal elements by mass percentage: Co: 10–23%, Cr: 7–17%, Al: 7–12%, Ti: 0–10%, W: 0–6%, C: 0–2%, S: 0–2%. Figure 1 ).

[0070] 3. Based on the content range of each metal element, determine the variation in the composition of each metal element. Set the step size for C to 0.1, the step size for S to 0.5, and the step size for other elements to 1. Establish a database, such as... Figure 1 The screenshot shows a portion of the total score table in the Chinese database.

[0071] 4. Establish a theoretical prediction model. The optimal composition is determined using a three-dimensional model with solid solution strengthening, precipitation strengthening, and overall strengthening as the three factors. The solid solution strengthening factor, precipitation strengthening factor, and overall strengthening factor for different nickel-based alloy compositions in the database are calculated using JMatPro software, and a three-dimensional model with these three factors as coordinate axes is established to obtain the optimal composition. High-throughput calculation results are shown below. Figure 2As shown in the figure. The solid solution strengthening factor is the sum of the solid solution strengthening effects of Co, Cr, Al, Ti, W, and C; the precipitation strengthening factor is the sum of the precipitation strengthening effects of M7C3, TiC, and Ti2SC; and the total strengthening factor is the sum of the solid solution strengthening factor and the precipitation strengthening factor. The concentrations of Co, Cr, Al, Ti, and W are 10–23 wt.%, 7–17 wt.%, 7–12 wt.%, 0–10 wt.%, and 0–6 wt.%, respectively. The volume fractions of γ / γ′, M7C3, TiC, Ti2SC, and TiS are 50–70%, 0–25%, 0–10%, 0–10%, and 0–10%, respectively. The value range of the solid solution strengthening factor is 200–400, and the value range of the precipitation strengthening factor is 200–700.

[0072] 5. High-throughput calculation of optimal components. Figure 2 The figure shows the simulation results of the solid solution strengthening factor (SSSF) and precipitation strengthening factor (PHF) of the theoretical model, as well as the influence of different element addition amounts on the proportion of each phase. The results of the solid solution strengthening factor, precipitation strengthening factor, and total strengthening factor are plotted as follows. Figure 2 The following is a summary chart of the three-dimensional simulation results. According to the three-dimensional image, the optimal alloy composition by mass percentage is: Cr: 15–17%, Co: 10–12%, Al: 7–9%, Ti: 4–6%, W: 2–4%, C: 1.8–2%, and S: 0.5–1.5%.

[0073] 6. A novel nickel-based alloy sample was prepared using laser cladding technology. The specific steps are as follows:

[0074] (1) Composition of NiCrCoAlTiWCS nickel-based alloy powder: According to the mass percentage, its chemical composition is Cr: 17%, Co: 10%, Al: 7%, Ti: 5%, W: 3%, C: 2%, S: 0.5%.

[0075] (2) Preparation of NiCrCoAlTiWCS nickel-based alloy powder: According to the composition ratio of nickel-based alloy powder, pure elemental powders of each metal element are taken and mechanically mixed for 7-9 hours under the conditions of ball-to-material ratio of 3:5 and rotation speed of 400r / min to obtain nickel-based alloy powder. The average particle size of the nickel-based alloy powder is 45-105μm.

[0076] (3) Preparation of novel nickel-based alloy samples using laser cladding process: The equipment used was an FL-Dlight02-3000 W semiconductor laser (spot size 4×4mm). 2The substrate used was Cr28Ni48W5 alloy, which was pre-polished to make its surface smooth. The NiCrCoAlTiWCS nickel-based alloy powder prepared in step (2) was used for powder-lay printing to prepare a laser-clad NiCrCoAlTiWCS nickel-based alloy sample.

[0077] (4) Laser cladding process parameters: laser energy density is 71 J / mm². 3 (2000W, 7mm / s), powder layer thickness (t) is 0.5mm, scanning interval (d) is 2mm (overlap rate is 50%), and the preparation of nickel-based alloy samples by laser cladding was completed under argon protection.

[0078] 7. Performance tests were performed on the laser-clad nickel-based alloy samples, including verification of microstructure, high-temperature wear resistance, and corrosion resistance. The verification methods were the same as in Example 1, and the verification results are as follows:

[0079] Characterize the tissue gene phase. Figure 14 Scanning electron microscopy (SEM) results showed that the microstructure of the prepared alloy sample consisted of 66% γ / γ′ high-temperature resistant phase, 24% M7C3, 4% TiC hard phase, 5% TiS, and 1% Ti2SC self-lubricating phase. X-ray diffraction (XRD) phase analysis results showed that... Figure 6 Microstructure types and Figure 14 Consistent. Its average hardness is 435 HV. 0.2 ( Figure 8 The coefficient of friction at room temperature is 0.48. Figure 15 The wear rate was 1.81 × 10⁻⁶. -5 mm 3 / (N·m), the coefficient of friction at 800℃ is 0.22 ( Figure 17 The wear rate was 9.16 × 10⁻⁶. -5 mm 3 / (N·m), the SEM morphology of the worn surface at room temperature and 800℃ are as follows: Figure 16 and Figure 18 As shown in Table 2, the friction test results, compared with Cr28Ni48W5, a high-temperature alloy material used for metallurgical parts, showed a 35% reduction in room temperature friction coefficient and a 46% reduction in high-temperature friction coefficient. The corrosion potential of the sample was -0.16V, and the corrosion current density was 1.11×10⁻⁶. -7 A / cm 2 ( Figure 13 The laser-clad NiCrCoAlTiWCS nickel-based alloy sample exhibits a relatively high corrosion potential and a low corrosion current density, indicating good corrosion resistance.

[0080] Table 2. Tribological properties of laser-clad alloy samples under different friction temperatures.

[0081]

[0082] Example 3

[0083] A novel NiCrCoAlTiWCS alloy gene design and preparation method with laser cladding high-temperature wear-resistant, corrosion-resistant, and self-lubricating properties is implemented according to the following steps:

[0084] 1. Definition of key gene phases: Based on the demand for new high-temperature wear-resistant, corrosion-resistant, and self-lubricating nickel-based alloy materials for the repair of equipment parts in the metallurgical industry by laser cladding, key gene phases are defined as wear-resistant gene phase, corrosion-resistant gene phase, and self-lubricating gene phase. Among them, the wear-resistant gene phase is M7C3 and TiC; the corrosion-resistant gene phase is γ / γ′; and the self-lubricating gene phase is TiS and Ti2SC.

[0085] 2. Based on the key gene phases defined in step 1, determine the metal elements and their contents in the alloy to obtain the candidate composition of the nickel-based alloy powder. This candidate composition consists of the following metal elements by mass percentage: Co: 10–23%, Cr: 7–17%, Al: 7–12%, Ti: 0–10%, W: 0–6%, C: 0–2%, S: 0–2%. Figure 1 ).

[0086] 3. Based on the content range of each metal element, determine the variation in the composition of each metal element. Set the step size for C to 0.1, the step size for S to 0.5, and the step size for other elements to 1. Establish a database, such as... Figure 1 The screenshot shows a portion of the total score table in the Chinese database.

[0087] 4. Establish a theoretical prediction model. The optimal composition is determined using a three-dimensional model with solid solution strengthening, precipitation strengthening, and overall strengthening as the three factors. The solid solution strengthening factor, precipitation strengthening factor, and overall strengthening factor for different nickel-based alloy compositions in the database are calculated using JMatPro software, and a three-dimensional model with these three factors as coordinate axes is established to obtain the optimal composition. High-throughput calculation results are shown below. Figure 2As shown in the figure. The solid solution strengthening factor is the sum of the solid solution strengthening effects of Co, Cr, Al, Ti, W, and C; the precipitation strengthening factor is the sum of the precipitation strengthening effects of M7C3, TiC, and Ti2SC; and the total strengthening factor is the sum of the solid solution strengthening factor and the precipitation strengthening factor. The concentrations of Co, Cr, Al, Ti, and W are 10–23 wt.%, 7–17 wt.%, 7–12 wt.%, 0–10 wt.%, and 0–6 wt.%, respectively. The volume fractions of γ / γ′, M7C3, TiC, Ti2SC, and TiS are 50–70%, 0–25%, 0–10%, 0–10%, and 0–10%, respectively. The value range of the solid solution strengthening factor is 200–400, and the value range of the precipitation strengthening factor is 200–700.

[0088] 5. High-throughput calculation of optimal components. Figure 2 The figure shows the simulation results of the solid solution strengthening factor (SSSF) and precipitation strengthening factor (PHF) of the theoretical model, as well as the influence of different element addition amounts on the proportion of each phase. The results of the solid solution strengthening factor, precipitation strengthening factor, and total strengthening factor are plotted as follows. Figure 2 The following is a summary chart of the three-dimensional simulation results. According to the three-dimensional image, the optimal alloy composition by mass percentage is: Cr: 15–17%, Co: 10–12%, Al: 7–9%, Ti: 4–6%, W: 2–4%, C: 1.8–2%, and S: 0.5–1.5%.

[0089] 6. A novel nickel-based alloy sample was prepared using laser cladding technology. The specific steps are as follows:

[0090] (1) Composition of NiCrCoAlTiWCS nickel-based alloy powder: According to the mass percentage, its chemical composition is Cr: 17%, Co: 10%, Al: 7%, Ti: 5%, W: 3%, C: 2%, S: 1.5%.

[0091] (2) Preparation of NiCrCoAlTiWCS nickel-based alloy powder: According to the composition ratio of nickel-based alloy powder, pure elemental powders of each metal element are taken and mechanically mixed for 7-9 hours under the conditions of ball-to-material ratio of 3:5 and rotation speed of 400r / min to obtain nickel-based alloy powder. The average particle size of the nickel-based alloy powder is 45-105μm.

[0092] (3) Preparation of novel nickel-based alloy samples using laser cladding process: The equipment used was an FL-Dlight02-3000 W semiconductor laser (spot size 4×4mm). 2The substrate used was Cr28Ni48W5 alloy, which was pre-polished to make its surface smooth. The NiCrCoAlTiWCS nickel-based alloy powder prepared in step (2) was used for powder-lay printing to prepare a laser-clad NiCrCoAlTiWCS nickel-based alloy sample.

[0093] (4) Laser cladding process parameters: laser energy density is 71 J / mm². 3 (2000W, 7mm / s), powder layer thickness (t) is 0.5mm, scanning interval (d) is 2mm (overlap rate is 50%), and the preparation of nickel-based alloy samples by laser cladding was completed under argon protection.

[0094] 7. Performance tests were performed on the laser-clad nickel-based alloy samples, including verification of microstructure, high-temperature wear resistance, and corrosion resistance. The verification methods were the same as in Example 2, and the verification results are as follows:

[0095] Characterize the tissue gene phase. Figure 19 Scanning electron microscopy (SEM) results showed that the microstructure of the prepared alloy sample consisted of 63% γ / γ′ high-temperature resistant phase, 18% M7C3, 0.5% TiC hard phase, 12.5% ​​TiS, and 6% Ti2SC self-lubricating phase. X-ray diffraction (XRD) phase analysis results showed that... Figure 6 Microstructure types and Figure 19 Consistent. Its average hardness is 416 HV. 0.2 ( Figure 8 The coefficient of friction at room temperature is 0.42. Figure 20 The wear rate was 2.29 × 10⁻⁶. -5 mm 3 / (N·m), the coefficient of friction at 800℃ is 0.19 ( Figure 22 The wear rate was 3.95 × 10⁻⁶. -5 mm 3 / (N·m), the SEM morphology of the worn surface at room temperature and 800℃ are as follows: Figure 21 and Figure 23 As shown in Table 3, the friction test results, compared with Cr28Ni48W5, a high-temperature alloy material used for metallurgical parts, showed a 43% reduction in room temperature friction coefficient and a 54% reduction in high-temperature friction coefficient. The corrosion potential of the sample was -0.14V, and the corrosion current density was 1.23 × 10⁻⁶. -7 A / cm 2 ( Figure 13 The NiCrCoAlTiWCS nickel-based alloy sample obtained by laser melting exhibited a relatively high corrosion potential and a low corrosion current density, indicating that it has good corrosion resistance.

[0096] Table 3. Tribological properties of laser-clad alloy samples under different friction temperatures.

[0097]

[0098] For anyone skilled in the art, many possible variations and modifications can be made to the technical solutions of this invention, or equivalent embodiments can be modified based on the disclosed technical content, without departing from the scope of the technical solutions of this invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this invention without departing from the content of the technical solutions of this invention should still fall within the protection scope of the technical solutions of this invention.

Claims

1. A genetic design method for a high-temperature wear-resistant, corrosion-resistant, and self-lubricating NiCrCoAlTiWCS alloy, characterized in that: Define key gene phases, establish a database system for alloy powder composition, establish a theoretical prediction model, and design target alloy powder composition that matches the key genes based on screening criteria. The key gene phases include wear-resistant key gene phases, corrosion-resistant key gene phases, and self-lubricating key gene phases; The key phases for wear resistance are M7C3 and TiC; the key phases for corrosion resistance are γ / γ′; and the key phases for self-lubrication are Ti2SC and TiS. The mass percentage content range of each element in the candidate composition of the alloy powder is as follows: Cr: 7-17%, Co: 10-23%, Al: 7-12%, Ti: 0-10%, W: 0-6%, C: 0-2%, S: 0-2%; the step size of C is set to 0.1, the step size of S is set to 0.5, and the step size of other elements is set to 1. A basic database of NiCrCoAlTiWCS alloy powder composition with different contents of various metal elements was established; the solid solution strengthening factor, precipitation strengthening factor and hardness factor of different NiCrCoAlTiWCS alloy powder composition in the database were calculated and a three-dimensional model with solid solution strengthening factor, precipitation strengthening factor and hardness factor as coordinate axes was established to determine the NiCrCoAlTiWCS alloy powder composition. The solid solution strengthening factor is the sum of the solid solution strengthening effects of Co, Cr, Al, Ti, W and C, and its value ranges from 200 to 400; the precipitation strengthening factor is the sum of the precipitation strengthening effects of M7C3, TiC and Ti2SC, and its value ranges from 200 to 700; the total strengthening factor is the sum of the solid solution strengthening factor and the precipitation strengthening factor. The optimized NiCrCoAlTiWCS alloy powder for laser cladding with high-temperature wear-resistant, corrosion-resistant, and self-lubricating properties is mainly composed of the following metal elements by mass percentage: Cr: 15-17%, Co: 10-12%, Al: 7-9%, Ti: 4-6%, W: 2-4%, C: 1.8-2%, and S: 0.5-1.5%.

2. A method for preparing a high-temperature wear-resistant, corrosion-resistant, and self-lubricating NiCrCoAlTiWCS alloy, characterized in that, According to claim 1, the alloy powder composition and mass content are optimized and prepared by an elemental powder mixing method. The parameters of the mixing method are a ball-to-powder ratio of 3:5, a rotation speed of 400 r / min, and mechanical mixing for 7-9 h to obtain nickel-based alloy powder. The average particle size of the nickel-based alloy powder is 45-105 μm. The specific steps for preparing nickel-based alloys using laser cladding are as follows: (1) Composition of NiCrCoAlTiWCS nickel-based alloy powder: According to the mass percentage, its chemical composition is Cr: 17%, Co: 10%, Al: 7%, Ti: 5%, W: 3%, C: 2%, S: 1%; (2) Preparation of NiCrCoAlTiWCS nickel-based alloy powder: According to the composition ratio of nickel-based alloy powder, pure elemental powders of each metal element are taken and mechanically mixed for 7-9 hours under the conditions of ball-to-material ratio of 3:5 and rotation speed of 400r / min to obtain nickel-based alloy powder. The average particle size of the nickel-based alloy powder is 45-105μm. (3) A nickel-based alloy is prepared by a laser cladding process: the equipment used is an FL-Dlight02-3000 W semiconductor laser, the spot size of which is 4*4 mm 2 , the substrate used is a Cr28Ni48W5 alloy, which is subjected to grinding and polishing treatment in advance to make its surface flat; the NiCrCoAlTiWCS nickel-based alloy powder prepared in step (2) is used for powder laying printing to prepare a laser cladding NiCrCoAlTiWCS nickel-based alloy; The laser cladding process parameters used are: pre-coated powder layer thickness t = 0.5 mm, scanning interval d = 2 mm, overlap rate = 50%, and laser energy density = 50–200 J / cm². 3 .

3. A high-temperature wear-resistant, corrosion-resistant, and self-lubricating NiCrCoAlTiWCS alloy prepared by the method described in claim 2, characterized in that, The NiCrCoAlTiWCS alloy mainly consists of 19.5–23 vol.% of M7C3 and TiC wear-resistant phases, 60–70 vol.% of γ / γ′ corrosion-resistant phases, 7–14 vol.% of TiS and Ti2SC self-lubricating phases. In the laser cladding alloy, needle-like Ti2SC phases with high-temperature solid lubrication are generated in situ. The Ti2C layer has strong covalent Ti-C bonds and is interwoven with each other through weaker Ti-S bonds. The Ti-S layer is its easy-slip surface.

4. The high-temperature wear-resistant, corrosion-resistant, and self-lubricating NiCrCoAlTiWCS alloy according to claim 3, characterized in that, The NiCrCoAlTiWCS alloy has a density of 98.5–99.8% and a hardness of 410–460 HV. 0.2 The coefficient of friction at 800℃ is 0.18–0.22, and the wear rate is 2.20–2.45 × 10⁻⁶. -5 mm 3 / (N·m), corrosion potential is -0.16 to -0.14V, corrosion current density is 1.0 to 1.4×10 -7 A / cm 2 .

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