A gh4169 powder for eliminating original particle boundaries, a preparation method and applications thereof

Abstract

The application belongs to the technical field of powder metallurgy, and particularly discloses a GH4169 powder for eliminating original particle boundaries, a preparation method and application thereof, the GH4169 powder adopts a core-shell structure, a standard GH4169 powder is used as a core, a transition layer alloy powder is used as a shell, the shell reduces interface brittle phases by reducing C and Si contents, B elements are added to promote diffusion and strengthen the interface, and the core and the shell match in particle size to form a continuous transition layer; the preparation method adopts an argon gas atomization method to prepare two kinds of powders respectively, and then realizes uniform coating through a fluidized bed coating process; the powder is loaded into a package, vacuum sealing and hot isostatic pressing treatment are performed to obtain a GH4169 product. The GH4169 product prepared by the application has no original particle boundaries (PPB) and excellent comprehensive mechanical properties, effectively solves the performance decline problem of traditional powder metallurgy products caused by PPB, and is suitable for high-end equipment fields such as aerospace.

Description

Technical Field

[0001] This invention belongs to the field of powder metallurgy technology, specifically relating to a GH4169 powder for eliminating original particle boundaries, its preparation method, and its application. Background Technology

[0002] GH4169 alloy is a typical precipitation-strengthened nickel-based superalloy. With its excellent tensile strength, fatigue performance, oxidation resistance and machinability, it has become a key structural material in high-end equipment fields such as aerospace, nuclear energy, and petrochemicals. It is widely used in core components such as turbine disks, blades, combustion chambers of aero engines and pressure vessels of nuclear reactors.

[0003] In recent years, with the increasing demands on component performance from high-end equipment, powder metallurgy technology has become the mainstream manufacturing process for GH4169 alloy parts due to its ability to form complex structural parts near-net-shapes and reduce component segregation. Among these processes, hot isostatic pressing (HIP) technology, with its advantages of achieving full densification and uniform mechanical properties, has become the core process for GH4169 powder metallurgy parts. However, GH4169 powder metallurgy parts generally face the problem of original particle boundaries (PPB) during the manufacturing process. Due to compositional differences (such as elemental segregation and impurity enrichment), the powder particle interface is prone to forming brittle phases dominated by carbides (such as NbC) and silicides (such as SiO2). These brittle phases are continuously distributed along the particle boundaries, which significantly reduces the mechanical properties of the parts (such as strength, plasticity, and toughness). In severe cases, this can lead to sudden failures of the components during service, thus limiting the reliability of GH4169 powder metallurgy alloys.

[0004] To address the PPB (Potentially Brittle Phase) problem, existing technologies have explored various approaches, but all have significant limitations, specifically: 1) Powder pretreatment technologies, such as vacuum degassing and plasma surface cleaning, can reduce adsorbed gaseous impurities (O, N, etc.) on the powder surface, but cannot alter the compositional gradient of the powder particles themselves, making it difficult to fundamentally suppress the nucleation and growth of brittle phases at the interface; 2) Hot isostatic pressing (HIP) process optimization: Increasing the temperature or extending the holding time can promote element diffusion, but it easily leads to excessive grain coarsening, which in turn reduces the strength and toughness of the parts, creating a performance contradiction; 3) Subsequent heat treatment control: High-temperature solution treatment (temperatures typically exceeding 1100℃) can partially dissolve the brittle phase, but it consumes extremely high energy and easily causes part deformation, requiring stringent equipment precision and making it difficult to adapt to industrial production. Therefore, there is an urgent need to develop a technical solution that can eliminate the brittle phase at the interface of GH4169 powder particles and suppress PPB through precise composition design and process control, which is of great significance for improving the mechanical properties and service reliability of GH4169 powder metallurgy parts.

[0005] In view of this, this invention is hereby proposed. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a GH4169 powder for eliminating original particle boundaries, a preparation method, and its application. It is mainly used to solve the problem of decreased mechanical properties caused by the presence of original particle boundaries (PPB) in the preparation of existing powder metallurgy GH4169 parts. By using a gradient core-shell structure design and supporting preparation process, the brittle phase at the particle interface is eliminated from the root, and the formation of PPB is inhibited, thereby improving the mechanical properties and service reliability of GH4169 parts.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] In a first aspect, the present invention provides a GH4169 powder for eliminating original particle boundaries, the GH4169 powder having a core-shell structure, including a core and a shell covering the surface of the core, the core being standard GH4169 powder and the shell being a transition layer alloy powder;

[0009] The standard GH4169 powder contains the following components by mass percentage: Cr: 17.0%–21.0%, Ni: 50.0%–55.0%, Nb: 4.75%–5.50%, Mo: 2.8%–3.3%, Ti: 0.65%–1.15%, Al: 0.2%–0.8%, C: 0.02%–0.08%, Si: 0.3%–0.7%, with the balance being Fe and unavoidable impurities.

[0010] The transition layer alloy powder has the following composition by mass percentage: Cr: 17.0%–21.0%, Ni: 50.0%–55.0%, Nb: 4.75%–5.50%, Mo: 2.8%–3.3%, Ti: 0.65%–1.15%, Al: 0.2%–0.8%, B: 0.005%–0.02%, C≤0.02%, Si≤0.05%, with the balance being Fe and unavoidable impurities.

[0011] Furthermore, the particle size of the standard GH4169 powder is 50μm to 150μm, and the particle size of the transition layer alloy powder is 5μm to 20μm.

[0012] Preferably, the thickness of the outer shell is generally 5μm to 30μm.

[0013] Furthermore, the unavoidable impurities in the transition layer alloy powder include O≤0.015%, N≤0.01%, P≤0.01%, S≤0.005%, other single impurities≤0.005%, and total impurities≤0.03%.

[0014] It should be noted that the design of the GH4169 powder in this invention is based on the principle of interfacial composition regulation, as detailed below:

[0015] 1) Mechanism of C and Si content reduction in transition layer alloy powder: The C (0.02%–0.08%) and Si (0.3%–0.7%) content in standard GH4169 powder are the main causes of the formation of primary particle boundaries (PPBs), as they readily form brittle phases such as carbides (e.g., NbC) and silicides (e.g., SiO2) at the particle interface. Experimental verification shows that by controlling the C content to ≤0.02% and the Si content to ≤0.05%, the nucleation driving force of brittle phases at the interface can be significantly reduced in the transition layer; however, when C > 0.02% and Si > 0.05%, the precipitation of brittle phases increases sharply.

[0016] 2) The role mechanism of boron (0.005%–0.02%) in transition layer alloy powder: As a grain boundary strengthening element, boron preferentially accumulates at the particle interface, promoting element diffusion between the core and shell by reducing interfacial energy, thereby enhancing interfacial bonding. Experiments show that controlling the boron content within the range of 0.005%–0.02% can simultaneously achieve a balance between "promoting diffusion" and "not forming low-melting-point borides"; when the boron content > 0.02%, a brittle Ni3B phase will appear.

[0017] 3) Core-shell particle size matching mechanism: A core with a particle size of 50μm to 150μm is matched with a shell with a particle size of 5μm to 20μm. The fine-particle shell can completely cover the coarse-particle core through physical coating, forming a continuous transition layer, thereby avoiding the compositional abrupt change caused by direct contact between the cores.

[0018] Secondly, the present invention also provides a method for preparing the above-mentioned GH4169 powder, comprising the following steps:

[0019] Step 1: Prepare standard GH4169 powder and transition layer alloy powder respectively;

[0020] Step 2: Place the standard GH4169 powder in a fluidized bed coating device, and introduce an inert gas as a carrier gas to fluidize the standard GH4169 powder; then feed the transition layer alloy powder into the fluidized bed coating device at a preset rate so that the transition layer alloy powder is uniformly coated on the surface of the standard GH4169 powder, thereby obtaining the GH4169 powder.

[0021] Furthermore, in step 1, both the standard GH4169 powder and the transition layer alloy powder are prepared by argon atomization.

[0022] When preparing the standard GH4169 powder, the atomization pressure is 6MPa~8MPa and the atomization temperature is 1500℃~1600℃.

[0023] When preparing the transition layer alloy powder, the atomization pressure is 7MPa~9MPa and the atomization temperature is 1550℃~1650℃.

[0024] Further, in step 2, the ratio of the flow rate of the inert gas to the feed rate of the transition layer alloy powder is (10-40):1, the operating temperature of the fluidized bed coating equipment is 80℃-120℃, and the coating time is 2h-4h.

[0025] Further, in step 2, the flow rate of the inert gas is 10 L / min to 20 L / min, and the feed rate of the transition layer alloy powder is 0.5 g / min to 1.0 g / min.

[0026] In the preparation method of GH4169 powder of this invention, the core is to achieve uniform adhesion between the outer shell and the inner core through a fluidized state. The specific mechanism is as follows:

[0027] 1) Construction of the fluidized state: An inert gas (such as argon) is introduced into the fluidized bed coating equipment at a flow rate of 10 L / min to 20 L / min, so that the core standard GH4169 powder with a particle size of 50 μm to 150 μm is in a suspended and tumbling "fluidized state". In this state, there is no agglomeration between the core particles, and the force is uniform in all directions, providing a stable physical basis for the uniform coating of the outer shell.

[0028] 2) Adhesion mechanism of the outer shell (transition layer alloy powder): After the fine-particle transition layer alloy powder with a particle size of 5μm to 20μm is carried into the fluidized bed coating equipment by the airflow, it undergoes continuous mechanical collisions with the core powder in a fluidized state. During the collision process, the transition layer alloy powder is uniformly attached to the surface of the core by means of physical actions such as van der Waals forces and electrostatic adsorption, forming a preliminary core-shell structure.

[0029] 3) Coordinated control of process parameters: By controlling the ratio of inert gas flow rate to transition layer alloy powder feed rate (10-40:1), the adhesion efficiency of the outer shell powder can be precisely adjusted, ensuring that the fine-particle outer shell uniformly covers the core surface and effectively avoiding local agglomeration. In addition, controlling the working temperature of the fluidized bed coating equipment to 80℃-120℃ and the coating time to 2h-4h: This temperature environment can prevent the powder from sintering during the coating process, while sufficient coating time can ensure the uniformity of the outer shell thickness. Experiments show that a coating time of 2h-4h can control the outer shell thickness deviation within ±2μm, ultimately forming a stable core-shell structure.

[0030] Thirdly, the present invention provides a method for preparing a GH4169 part, comprising the following steps:

[0031] Step 1: Pack the above GH4169 powder into a pre-made package;

[0032] Step 2: Vacuum the casing until the vacuum level is ≤5×10⁻⁶. -4 The sleeve is sealed at Pa;

[0033] Step 3: Perform hot isostatic pressing on the sealed sleeve, followed by standard solution treatment and aging heat treatment (existing technology, not described in detail) to obtain the GH4169 part.

[0034] Furthermore, in step 1, the material of the sleeve is stainless steel.

[0035] Furthermore, in step 3, the process parameters for the hot isostatic pressing treatment are as follows: temperature is 1100℃~1200℃, pressure is 100MPa~150MPa, holding time is 2h~4h, and cooling rate is 5℃ / min~10℃ / min.

[0036] Fourthly, the present invention also provides a GH4169 part, which is prepared by the above-mentioned preparation method. The GH4169 part has a uniform metallographic structure, no original particle boundaries (PPB), and its mechanical properties meet the following requirements: tensile strength > 1400 MPa, yield strength > 1130 MPa, and elongation ≥ 20%.

[0037] It should be noted that, in the preparation of GH4169 parts, hot isostatic pressing is a key step in achieving interface fusion and eliminating the original particle boundaries in the core-shell structure. Its core mechanism is as follows:

[0038] 1) Preferential softening / melting of the transition layer: The hot isostatic pressing temperature (1100℃~1200℃) is close to the solidus of the transition layer alloy, but lower than the melting point of the core GH4169 (greater than 1260℃), causing the outer shell (transition layer alloy powder) to soften or partially melt before the core. This process can fill the gaps between the core particles, forming a continuous diffusion medium and providing channels for subsequent element migration.

[0039] 2) Element diffusion eliminates gradient: Under pressure of 100MPa to 150MPa, elements diffuse along the concentration gradient between the core and the shell. Specifically, the higher C and Si content in the core diffuses into the transition layer (C≤0.02%, Si≤0.05%), using the concentration difference to drive the homogenization of elements forming the brittle phase; B element in the transition layer diffuses into the core, preferentially enriches at the interface and reduces the interface energy, promoting atomic migration across the interface and eliminating abrupt changes in composition.

[0040] 3) Metallurgical bonding at the interface: After 2 to 4 hours of heat preservation and pressure holding, the interface between the core and the shell changes from a physical adhesion state to a metallurgical bonding state. Through the full diffusion of elements, the composition gradient at the interface disappears, and the original particle boundary (PPB) cannot be generated due to the loss of the brittle phase formation conditions, which ultimately significantly improves the mechanical properties of the part.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. The GH4169 powder provided by this invention, through a gradient core-shell structure design, overcomes the technical bottleneck of "compositional abruptness leading to PPB" in traditional powder metallurgy. The core is standard GH4169 powder, and the outer shell is a transition layer alloy powder. The transition layer alloy powder, by reducing the C and Si content (C≤0.02%, Si≤0.05%), blocks the nucleation conditions of brittle phases such as carbides and silicides from the source; simultaneously, a set amount of B element (0.005%~0.02%) is added to promote diffusion bonding between particles and enhance interfacial properties. Compared with existing core-shell structures that easily introduce heterogeneous interfacial defects, this design achieves a more seamless compositional transition. Experimental verification shows that this design can completely eliminate the original particle boundary (PPB), solving the problem that traditional pretreatment techniques cannot eradicate compositional gradients.

[0043] 2. In preparing GH4169 powder, this invention employs argon atomization to prepare core-shell powder in a graded manner. Furthermore, the pressure and temperature during the preparation of the outer shell (transition layer alloy powder) are higher than those for standard GH4169 powder to ensure powder purity and particle size distribution. Simultaneously, a fluidized bed coating process is used to uniformly coat the transition layer alloy powder onto the surface of the standard GH4169 powder (outer shell thickness deviation ±2μm), ensuring the quality stability of the GH4169 powder.

[0044] 3. The GH4169 component provided by this invention employs a core-shell structure of GH4169 powder combined with a hot isostatic pressing diffusion mechanism (preferential softening / melting of the transition layer → element gradient migration, filling particle gaps and acting as a diffusion medium → interfacial metallurgical bonding). The resulting GH4169 component is free of PPB and exhibits superior mechanical properties compared to traditional methods. Actual testing shows tensile strength > 1400 MPa, yield strength > 1130 MPa, and elongation ≥ 20%. This component can be directly applied to critical components such as turbine disks in aero-engines, significantly improving service safety compared to existing products. Furthermore, this invention is not only applicable to GH4169 alloys but can also be extended to other powder metallurgy high-temperature alloy systems that easily form PPB (such as GH3536, GH4738, etc.). Attached Figure Description

[0045] The accompanying drawings are incorporated in and form part of this specification, and together with the description serve to explain the principles of the invention.

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of the GH4169 powder structure used in this invention to eliminate the original particle boundaries;

[0048] Figure 2 This is a metallographic image of a GH4169 part prepared by hot isostatic pressing using GH4169 powder (used to eliminate the original particle boundaries) in Example 1 of the present invention, at a magnification of 100 μm.

[0049] Figure 3 This is a metallographic image of a GH4169 part prepared by hot isostatic pressing using GH4169 powder (used to eliminate the original particle boundaries) in Example 1 of the present invention, at a magnification of 50 μm.

[0050] Figure 4 This is a metallographic image of a GH4169 part prepared by hot isostatic pressing using conventional GH4169 powder (core-shell structure) in Comparative Example 1 of the present invention, at a magnification of 100 μm.

[0051] Figure 5 The metallographic structure of the GH4169 part prepared by hot isostatic pressing using conventional GH4169 powder (core-shell structure) in Comparative Example 1 of this invention is shown at a magnification of 50 μm.

[0052] Wherein: 1 is standard GH4169 powder; 2 is transition layer alloy powder. Detailed Implementation

[0053] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples consistent with some aspects of the invention as detailed in the appended claims.

[0054] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0055] Example 1

[0056] This embodiment provides a GH4169 powder for eliminating original particle boundaries. This GH4169 powder has a core-shell structure, such as... Figure 1 As shown, it includes a core and a shell covering the surface of the core. The core is standard GH4169 powder 1, and the shell is transition layer alloy powder 2.

[0057] Specifically, the composition of the standard GH4169 powder 1 by mass percentage is: Cr: 18.0%, Ni: 52.0%, Nb: 5.0%, Mo: 3.0%, Ti: 0.9%, Al: 0.5%, C: 0.05%, Si: 0.5%, with the balance being Fe and unavoidable impurities; the particle size of the standard GH4169 powder 1 is 80μm to 120μm.

[0058] The transition layer alloy powder 2 has the following composition by mass percentage: Cr: 18.0%, Ni: 52.0%, Nb: 5.0%, Mo: 3.0%, Ti: 0.9%, Al: 0.5%, B: 0.01%, C: 0.01%, Si: 0.03%, with the balance being Fe and unavoidable impurities (O: 0.01%, N: 0.005%, P: 0.005%, S: 0.003%, other single impurities ≤0.003%, total impurities ≤0.02%); the particle size of the transition layer alloy powder 2 is 10μm to 15μm.

[0059] This embodiment also provides a method for preparing the above-mentioned GH4169 powder, which specifically includes the following steps:

[0060] Step 1: Standard GH4169 powder 1 and transition layer alloy powder 2 are prepared by argon atomization. Specifically, the atomization pressure for preparing standard GH4169 powder 1 is 7 MPa and the atomization temperature is 1550℃; the atomization pressure for preparing transition layer alloy powder 2 is 8 MPa and the atomization temperature is 1600℃.

[0061] Step 2: Place standard GH4169 powder 1 into a fluidized bed coating device, introduce argon gas as the carrier gas at a flow rate of 15 L / min, and feed the transition layer alloy powder 2 at a rate of 0.75 g / min, i.e., the ratio of argon gas flow rate to transition layer alloy powder 2 feed rate is 20:1. The operating temperature of the fluidized bed coating device is 100℃. Feed the transition layer alloy powder 2 into the fluidized bed coating device for a coating time of 3 hours, so that the transition layer alloy powder 2 is uniformly coated on the surface of standard GH4169 powder 1, forming GH4169 powder with a core-shell structure.

[0062] In this embodiment of the invention, using the GH4169 powder with the core-shell structure described above, a certain type of GH4169 component A for aero-engines was prepared. The detailed preparation process is as follows:

[0063] Step 1: The above-mentioned GH4169 powder with a core-shell structure is loaded into a prefabricated stainless steel sleeve;

[0064] Step 2: Evacuate the casing until the vacuum level is ≤4.5×10⁻⁶. -4 The stainless steel sleeve is sealed at Pa.

[0065] Step 3: Perform hot isostatic pressing (HIP) on the sealed stainless steel sheath. The process parameters for HIP are as follows: temperature 1150℃, pressure 120MPa, holding time 3h, cooling rate 8℃ / min. After HIP, the part A of GH4169 is obtained by standard solution treatment and aging heat treatment.

[0066] Example 2

[0067] This embodiment provides a GH4169 powder for eliminating original particle boundaries. This GH4169 powder has a core-shell structure, such as... Figure 1 As shown, it includes a core and a shell covering the surface of the core. The core is standard GH4169 powder 1, and the shell is transition layer alloy powder 2.

[0068] Specifically, the composition of the standard GH4169 powder 1 by mass percentage is: Cr: 17.0%, Ni: 50.0%, Nb: 4.75%, Mo: 2.8%, Ti: 0.65%, Al: 0.2%, C: 0.02%, Si: 0.3%, with the balance being Fe and unavoidable impurities; the particle size of the standard GH4169 powder 1 is 50μm to 100μm.

[0069] The transition layer alloy powder 2 has the following composition by mass percentage: Cr: 17.0%, Ni: 50.0%, Nb: 4.75%, Mo: 2.8%, Ti: 0.65%, Al: 0.2%, B: 0.005%, C: 0.01%, Si: 0.02%, with the balance being Fe and unavoidable impurities (O: 0.012%, N: 0.008%, P: 0.008%, S: 0.004%, other single impurities ≤0.004%, total impurities ≤0.028%); the particle size of the transition layer alloy powder 2 is 5μm to 10μm.

[0070] This embodiment also provides a method for preparing the above-mentioned GH4169 powder, which specifically includes the following steps:

[0071] Step 1: Standard GH4169 powder 1 and transition layer alloy powder 2 are prepared by argon atomization. Specifically, the atomization pressure for preparing standard GH4169 powder 1 is 6 MPa and the atomization temperature is 1500℃; the atomization pressure for preparing transition layer alloy powder 2 is 7 MPa and the atomization temperature is 1550℃.

[0072] Step 2: Place standard GH4169 powder 1 into a fluidized bed coating device, introduce argon gas as the carrier gas with a flow rate of 20 L / min, and feed rate of transition layer alloy powder 2 at 0.5 g / min, i.e., the ratio of argon gas flow rate to transition layer alloy powder 2 feed rate is 40:1. The operating temperature of the fluidized bed coating device is 80℃. Feed the transition layer alloy powder 2 into the fluidized bed coating device for 2 hours to uniformly coat the surface of standard GH4169 powder 1, forming GH4169 powder with a core-shell structure.

[0073] In this embodiment of the invention, using the GH4169 powder with the core-shell structure described above, a certain type of GH4169 component B for aero-engines was prepared. The detailed preparation process is as follows:

[0074] Step 1: The above-mentioned GH4169 powder with a core-shell structure is loaded into a prefabricated stainless steel sleeve;

[0075] Step 2: Evacuate the casing until the vacuum level is ≤4×10⁻⁶. -4 The stainless steel sleeve is sealed at Pa.

[0076] Step 3: Perform hot isostatic pressing (HIP) on the sealed stainless steel sheath. The process parameters for HIP are as follows: temperature 1100℃, pressure 100MPa, holding time 2h, cooling rate 5℃ / min. After HIP, the part B of GH4169 is obtained by standard solution treatment and aging heat treatment.

[0077] Example 3

[0078] This embodiment provides a GH4169 powder for eliminating original particle boundaries. This GH4169 powder has a core-shell structure, such as... Figure 1 As shown, it includes a core and a shell covering the surface of the core. The core is standard GH4169 powder 1, and the shell is transition layer alloy powder 2.

[0079] Specifically, the composition of the standard GH4169 powder 1 by mass percentage is: Cr: 21.0%, Ni: 55.0%, Nb: 5.50%, Mo: 3.3%, Ti: 1.15%, Al: 0.8%, C: 0.08%, Si: 0.7%, with the balance being Fe and unavoidable impurities; the particle size of the standard GH4169 powder 1 is 100μm to 150μm.

[0080] The transition layer alloy powder 2 has the following composition by mass percentage: Cr: 21.0%, Ni: 55.0%, Nb: 5.50%, Mo: 3.3%, Ti: 1.15%, Al: 0.8%, B: 0.02%, C: 0.02%, Si: 0.05%, with the balance being Fe and unavoidable impurities (O: 0.015%, N: 0.01%, P: 0.01%, S: 0.005%, other single impurities ≤0.005%, total impurities ≤0.03%); the particle size of the transition layer alloy powder 2 is 10μm to 20μm.

[0081] This embodiment also provides a method for preparing the above-mentioned GH4169 powder, which specifically includes the following steps:

[0082] Step 1: Standard GH4169 powder 1 and transition layer alloy powder 2 are prepared by argon atomization. Specifically, the atomization pressure for preparing standard GH4169 powder 1 is 8 MPa and the atomization temperature is 1600℃; the atomization pressure for preparing transition layer alloy powder 2 is 9 MPa and the atomization temperature is 1650℃.

[0083] Step 2: Place standard GH4169 powder 1 into a fluidized bed coating device, introduce argon gas as the carrier gas at a flow rate of 10 L / min, and feed the transition layer alloy powder 2 at a feed rate of 1.0 g / min, i.e., the ratio of argon gas flow rate to transition layer alloy powder 2 feed rate is 10:1. The operating temperature of the fluidized bed coating device is 120℃. Feed the transition layer alloy powder 2 into the fluidized bed coating device for a coating time of 4 hours, so that the transition layer alloy powder 2 is uniformly coated on the surface of standard GH4169 powder 1, forming GH4169 powder with a core-shell structure.

[0084] In this embodiment of the invention, using the GH4169 powder with the core-shell structure described above, a certain type of GH4169 component C for aero-engines was prepared. The detailed preparation process is as follows:

[0085] Step 1: The above-mentioned GH4169 powder with a core-shell structure is loaded into a prefabricated stainless steel sleeve;

[0086] Step 2: Evacuate the casing until the vacuum level is ≤1×10⁻⁶. -4 The stainless steel sleeve is sealed at Pa.

[0087] Step 3: Perform hot isostatic pressing (HIP) on the sealed stainless steel sheath. The process parameters for HIP are as follows: temperature 1200℃, pressure 150MPa, holding time 4h, cooling rate 10℃ / min. After HIP, the part C of GH4169 is obtained by standard solution treatment and aging heat treatment.

[0088] Example 4

[0089] This embodiment provides a GH4169 powder for eliminating original particle boundaries. This GH4169 powder has a core-shell structure, such as... Figure 1 As shown, it includes a core and a shell covering the surface of the core. The core is standard GH4169 powder 1, and the shell is transition layer alloy powder 2.

[0090] Specifically, the composition of the standard GH4169 powder 1 by mass percentage is: Cr: 17.0%, Ni: 55.0%, Nb: 5.50%, Mo: 2.8%, Ti: 1.15%, Al: 0.2%, C: 0.08%, Si: 0.3%, with the balance being Fe and unavoidable impurities; the particle size of the standard GH4169 powder 1 is 60μm to 100μm.

[0091] The transition layer alloy powder 2 has the following composition by mass percentage: Cr: 17.0%, Ni: 55.0%, Nb: 5.50%, Mo: 2.8%, Ti: 1.15%, Al: 0.2%, B: 0.005%, C: 0.02%, Si: 0.05%, with the balance being Fe and unavoidable impurities (O: 0.015%, N: 0.01%, P: 0.01%, S: 0.005%, other single impurities ≤0.005%, total impurities ≤0.03%); the particle size of the transition layer alloy powder 2 is 8μm to 15μm.

[0092] This embodiment also provides a method for preparing the above-mentioned GH4169 powder, and a method for preparing a certain type of GH4169 component D of an aero-engine based on the GH4169 powder. The method for preparing the GH4169 powder and the method for preparing the GH4169 component D are the same as those in Embodiment 1, and will not be described in detail here.

[0093] Comparative Example 1

[0094] This comparative example aims to prepare a GH4169 component E of a certain type for aero-engines. The specifications of GH4169 component E are completely identical to those of GH4169 component A in Example 1. The key difference between the two is that this comparative example uses conventional GH4169 powder (i.e., non-core-shell GH4169 powder). Furthermore, the preparation process of this comparative example is the same as that of Example 1, and the same hot isostatic pressing process, solution treatment, and aging heat treatment are also used.

[0095] Performance testing

[0096] To further verify the technical effects of the present invention, the inventors conducted the following tests and analyses:

[0097] 1. Microstructure observation: Metallographic analysis was performed on the GH4169 parts finally prepared in Example 1 and Comparative Example 1, and metallographic images at two magnifications of 100 μm and 50 μm were obtained (see details). Figures 2-5 );

[0098] 2. Mechanical property testing: The mechanical properties of the GH4169 parts prepared in Examples 1 to 4 and Comparative Example 1 were tested. The test results are shown in Table 1 below.

[0099] Table 1. Test results of mechanical properties of GH4169 parts prepared in Examples 1-4 and Comparative Example 1

[0100]

[0101] Depend on Figure 2 , 3 As can be seen, the GH4169 part prepared by using core-shell structured GH4169 powder in Example 1 of this invention has no obvious original particle boundaries (PPB) in its microstructure, no continuous brittle phase distribution at the particle interface, uniform grain size, and exhibits dense and integrated metallurgical bonding characteristics, indicating that the transition layer of the core-shell structure effectively achieves compositional gradient elimination and interface fusion. In contrast, Comparative Example 1 uses conventional GH4169 powder, and the resulting GH4169 part has a metallographic structure as follows: Figure 4 , 5 As shown, there are clearly visible original particle boundaries (PPBs) at the particle interfaces in this metallographic structure, and continuous brittle phases such as carbides and silicides are distributed along the boundaries. This is consistent with the interface defect characteristics caused by abrupt changes in composition in traditional powders, which corroborates the significant effect of the core-shell structure of the present invention on eliminating PPBs.

[0102] Furthermore, as shown in Table 1, the mechanical property test results indicate that the parts prepared using GH4169 powder with a core-shell structure in Examples 1-4 outperformed the part prepared using Comparative Example 1, which used conventional GH4169 powder, in all mechanical property indicators. Specifically, the tensile strength of Examples 1-4 all exceeded 1400 MPa, with Example 3 reaching 1431 MPa, while the tensile strength of Comparative Example 1 was only 1090 MPa. In terms of yield strength, Examples 1-4 were all above 1138 MPa, while Comparative Example 1 was 980 MPa, showing a significant improvement in yield strength compared to the Comparative Example. Regarding elongation, the values ​​of Examples 1-4 were between 20% and 22%, while Comparative Example 1 was only 15%, demonstrating a significant advantage in elongation for the Examples. This improvement in mechanical properties, echoing the microstructure observations, is precisely because the gradient core-shell structure of this invention effectively eliminates the original particle boundary (PPB) and brittle phases at the interface, achieving a better metallurgical bond. This results in a simultaneous improvement in the strength and plasticity of the part, fully verifying the effectiveness of the technical solution of this invention in improving the performance of GH4169 parts.

[0103] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.

[0104] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A GH4169 powder for eliminating original particle boundaries, characterized in that, The GH4169 powder adopts a core-shell structure, including a core and a shell covering the surface of the core. The core is standard GH4169 powder, and the shell is a transition layer alloy powder. The standard GH4169 powder contains the following components by mass percentage: Cr: 17.0%–21.0%, Ni: 50.0%–55.0%, Nb: 4.75%–5.50%, Mo: 2.8%–3.3%, Ti: 0.65%–1.15%, Al: 0.2%–0.8%, C: 0.02%–0.08%, Si: 0.3%–0.7%, with the balance being Fe and unavoidable impurities. The transition layer alloy powder has the following composition by mass percentage: Cr: 17.0%–21.0%, Ni: 50.0%–55.0%, Nb: 4.75%–5.50%, Mo: 2.8%–3.3%, Ti: 0.65%–1.15%, Al: 0.2%–0.8%, B: 0.005%–0.02%, C≤0.02%, Si≤0.05%, with the balance being Fe and unavoidable impurities.

2. The GH4169 powder for eliminating original particle boundaries according to claim 1, characterized in that, The standard GH4169 powder has a particle size of 50μm to 150μm, and the transition layer alloy powder has a particle size of 5μm to 20μm.

3. The GH4169 powder for eliminating original particle boundaries according to claim 1, characterized in that, The unavoidable impurities in the transition layer alloy powder include O≤0.015%, N≤0.01%, P≤0.01%, S≤0.005%, and other single impurities≤0.005%, with total impurities ≤0.03%.

4. A method for preparing the GH4169 powder according to any one of claims 1 to 3, characterized in that, Includes the following steps: Step 1: Prepare standard GH4169 powder and transition layer alloy powder respectively; Step 2: Place the standard GH4169 powder in a fluidized bed coating device, and introduce an inert gas as a carrier gas to fluidize the standard GH4169 powder; then feed the transition layer alloy powder into the fluidized bed coating device at a preset rate so that the transition layer alloy powder is uniformly coated on the surface of the standard GH4169 powder, thereby obtaining the GH4169 powder.

5. The method for preparing GH4169 powder according to claim 4, characterized in that, In step 1, both the standard GH4169 powder and the transition layer alloy powder are prepared by argon atomization. When preparing the standard GH4169 powder, the atomization pressure is 6MPa~8MPa and the atomization temperature is 1500℃~1600℃. When preparing the transition layer alloy powder, the atomization pressure is 7MPa~9MPa and the atomization temperature is 1550℃~1650℃.

6. The method for preparing GH4169 powder according to claim 4, characterized in that, In step 2, the ratio of the inert gas flow rate to the feed rate of the transition layer alloy powder is (10-40):1, the operating temperature of the fluidized bed coating equipment is 80℃-120℃, and the coating time is 2h-4h.

7. The method for preparing GH4169 powder according to claim 4, characterized in that, In step 2, the flow rate of the inert gas is 10 L / min to 20 L / min, and the feed rate of the transition layer alloy powder is 0.5 g / min to 1.0 g / min.

8. A method for preparing a GH4169 part, characterized in that, Includes the following steps: Step 1: Load the GH4169 powder according to any one of claims 1 to 3 into a pre-made package; Step 2: Vacuum the casing until the vacuum level is ≤5×10⁻⁶. -4 The sleeve is sealed at Pa; Step 3: Perform hot isostatic pressing on the sealed casing. After hot isostatic pressing, perform standard solution treatment and aging heat treatment to obtain the GH4169 part.

9. The method for preparing the GH4169 part according to claim 8, characterized in that, In step 3, the process parameters for the hot isostatic pressing treatment are as follows: temperature is 1100℃~1200℃, pressure is 100MPa~150MPa, holding time is 2h~4h, and cooling rate is 5℃ / min~10℃ / min.

10. A GH4169 component, characterized in that, The GH4169 part is prepared by the preparation method described in claim 8 or 9. The metallographic structure of the GH4169 part is uniform, and its mechanical properties meet the following requirements: tensile strength > 1400 MPa, yield strength > 1130 MPa, and elongation ≥ 20%.

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