Inconel 617 nickel-based alloy suitable for additive manufacturing and having good mechanical properties and a preparation method thereof

Abstract

The application provides an Inconel 617 nickel-based alloy suitable for additive manufacturing and having good mechanical properties and a preparation method thereof. The Inconel 617 nickel-based alloy suitable for additive manufacturing and having good mechanical properties has a component range expressed in atomic percentage, and the component range includes: Ni 50.0-60.0%, Cr 20.0-24.0%, Co 10.0-14.0%, Mo 8.0-10.0%, Al 0.6-1.5%, X 0.01-10%, wherein X is one or more of Ti, Fe, Cu, Mn, C and Si. The application controls the content and proportion of key elements of the Inconel 617 alloy, optimizes the solidification characteristics, phase transformation behavior and thermal physical properties of the alloy, significantly improves the additive manufacturing process window of the alloy and inhibits crack generation. The solid solution elements such as Cr, Co and Mo can effectively distort the crystal lattice, hinder the dislocation movement, enhance the deformation resistance, improve the yield strength and tensile strength of the matrix and thus improve the density and mechanical properties of the alloy.

Description

Technical Field

[0001] This invention relates to the field of nickel-based superalloy materials technology, specifically to an Inconel 617 nickel-based alloy suitable for additive manufacturing and possessing good mechanical properties, and its preparation method. Background Technology

[0002] Inconel 617 is a solid solution-strengthened nickel-based superalloy with added chromium, cobalt, molybdenum, and other elements. Due to its excellent oxidation resistance, carburization resistance, and good microstructural stability at high temperatures, this alloy is widely used in critical high-temperature load-bearing fields such as supercritical power plants, hot-end components of gas turbines, nuclear energy systems, and aerospace. As energy and power equipment develop towards higher efficiency and higher parameters, increasingly stringent requirements are being placed on the mechanical properties and service reliability of key high-temperature structural materials under extreme environments.

[0003] However, manufacturing Inconel 617 alloy parts using traditional casting and forging processes presents a series of challenges. First, the alloy has a narrow hot working window, making it prone to cracking and uneven microstructure during traditional hot deformation, resulting in low yield and significant performance fluctuations. Second, for components with complex internal cavities, fine flow channels, or customized geometries, traditional subtractive or equal-material manufacturing methods are often difficult to process, time-consuming, have low material utilization, and may even be impossible to form. In recent years, metal additive manufacturing (i.e., rapid prototyping) technologies, such as selective laser melting and laser-directed energy deposition, have provided revolutionary solutions for short-cycle, high-performance complex metal parts. This technology can directly manufacture solid parts with extremely high geometric freedom by melting metal powder layer by layer.

[0004] However, directly applying Inconel 617 alloy with existing standard composition to rapid prototyping processes faces significant technical bottlenecks. The inherent chemical composition of this alloy makes it extremely susceptible to cracking under rapid melting, solidification, and cyclic thermal effects. During additive manufacturing, the rapid cooling of the molten pool leads to stress concentration, elemental segregation, and the formation of low-melting-point eutectic phases at grain boundaries, easily inducing macroscopic and microcracks. This results in forming failures or numerous defects within the part, drastically deteriorating density and mechanical properties (especially ductility and fatigue performance), failing to meet application requirements. Therefore, to date, a significant technological breakthrough has not been achieved in successfully achieving defect-free, high-performance additive manufacturing using Inconel 617 alloy with existing standard composition.

[0005] To address this challenge, an innovative redesign was undertaken from the source of the alloy composition. By adjusting the content and proportion of key elements, the solidification characteristics, phase transformation behavior, and thermophysical properties of the alloy were optimized. The goal was to develop a novel Inconel 617 derivative alloy composition adapted to rapid prototyping processes. This new composition needs to significantly improve its additive manufacturing process window and suppress crack initiation while retaining its core high-temperature performance advantages (such as oxidation resistance and creep resistance). This will enable, for the first time, high-quality, defect-free rapid prototyping manufacturing of this alloy system, resulting in molded parts with excellent combined mechanical properties at both room temperature and high temperature.

[0006] Therefore, developing a novel Inconel 617 nickel-based alloy composition with good mechanical properties, specifically optimized for rapid prototyping processes, and its supporting preparation method, is key to breaking through the barriers to the application of this high-end material in advanced manufacturing. It has significant technical value and engineering significance for realizing the rapid, high-performance, and integrated manufacturing of complex high-temperature components. Summary of the Invention

[0007] This invention aims to solve the technical problem that existing standard Inconel 617 nickel-based alloys cannot be directly applied to rapid prototyping processes and are difficult to obtain high-density and high-mechanical-performance molded parts due to their strong sensitivity to solidification cracking. It provides an Inconel 617 nickel-based alloy suitable for additive manufacturing and with good mechanical properties, as well as its preparation method.

[0008] The technical method of the present invention is as follows: An Inconel 617 nickel-based alloy suitable for additive manufacturing and possessing good mechanical properties, characterized in that the composition of the nickel-based alloy, expressed as atomic percentage, includes the following range: Ni 50.0-60.0%, Cr 20.0-24.0%, Co 10.0-14.0%, Mo 8.0-10.0%, Al 0.6-1.5%, X 0.01-10%, wherein X is one or more of Ti, Fe, Cu, Mn, C, and Si.

[0009] Optionally, the content range of X is: Ti 0.01-2.0%, Fe 0.1-2.5%, Cu 0.01-0.05%, Mn 0.01-0.90%, C 0.05-0.14%, Si 0.01-0.8%.

[0010] Optionally, the composition is Cr 20.0-24.0%, Co 10.0-14.0%, Mo 8.0-10.0%, and Al 0.6-1.5%.

[0011] This invention also provides a method for preparing Inconel 617 nickel-based alloy, comprising the following steps: Step 1: Weigh and mix the various metal raw materials according to the specified proportions, and then melt and refine them using vacuum induction melting or electroslag remelting to obtain alloy ingots. Step 2: Prepare Inconel 617 spherical powder using either gas atomization or plasma rotating electrode atomization. When using gas atomization, the master alloy ingot obtained in Step 1 is remelted and atomized. When using plasma rotating electrode atomization, the master alloy ingot obtained in Step 1 is homogenized and annealed, then subjected to multiple forging processes to finally forge into a round bar of specified dimensions. The obtained round bar is then used as an electrode for rotating atomization. Step 3: The obtained powder is sieved, and powders with different particle size ranges are selected as the molding powder raw materials for selective laser melting or laser melting deposition, and then thoroughly dried; Step 4: Select an alloy as the molding substrate, install the cleaned substrate on the worktable inside the molding chamber of the additive manufacturing equipment, and introduce protective gas. Step 5: Import the 3D model of the target part into the equipment control system, slice it into layers along the vertical forming direction, and set the process parameters; Step 6: Select one of the following molding processes to perform: Process A is selective laser melting: The powder scraping device pre-lays a uniform layer of powder on the substrate, and the laser beam melts the powder of the current layer according to the set path and parameters to achieve metallurgical bonding; after the current layer is scanned, the worktable descends by a layer thickness, and the powder laying and melting process is repeated, layer by layer until the part is formed. Process B is laser melting deposition: The equipment is started to perform synchronous powder feeding melting deposition. A high-power laser beam irradiates the substrate or the deposited layer to form a molten pool. At the same time, the carrier gas sends the metal powder into the molten pool to achieve metallurgical bonding. Layer by layer is deposited until the part is formed. Step 7: After the part is formed, it is cooled to room temperature along with the substrate under the protective atmosphere of the molding chamber, and then the part is separated from the substrate.

[0012] Optionally, in step 1, the purity of the metal raw materials is ≥99.5 wt.%, high-purity argon gas is used for protection, and the materials are layered according to the order of melting point and easy oxidation. Preferably, the high melting point components are layered on top and the low melting point components are layered on the bottom. The arc ignition current is set to 40-60 A during melting, and then the melting current is increased to 280-320 A.

[0013] Optionally, in step 2, the initial forging temperature is controlled at 1150-1200℃, and the final forging temperature is not lower than 950℃.

[0014] Optionally, in step 3, powder with a particle size range of 15-53 μm is selected for selective laser melting preparation, and powder with a particle size range of 53-150 μm is selected for laser melting deposition (LMD) preparation; and the sphericity of the powder is greater than 95%, the flowability is less than 30 s / 50g, and the oxygen content is less than 200 ppm.

[0015] Optionally, when using the gas atomization method, the oxygen content in the atomization chamber is controlled to be <50 ppm, the alloy liquid is superheated to 1550-1600℃, and the inert gas pressure is 2.0-6.0 MPa; when using the plasma rotating electrode atomization method, the electrode rod rotation speed is controlled to be 10000-20000 rpm.

[0016] Optionally, in step 4, 316L stainless steel or the same Inconel 617 alloy is selected as the molding substrate.

[0017] Optionally, in step 6, if process A is used, the single-layer thickness is set to 20-40 μm, the laser power is 160-300W, the scanning speed is 600-1200 mm / s, and the scanning interval is 60-120 μm; a stripe scanning, checkerboard scanning, or island scanning strategy is used for partitioned filling; the scanning path direction between adjacent layers is rotated 60-90° to disperse thermal stress; if process B is used, the laser power is 600-3000 W, the scanning speed is 5-20 mm / s, the powder feeding rate is 10-30 g / min, the spot diameter is 1-3 mm, the Z-axis single-layer lifting amount is 0.1-1.0 mm, and the overlap rate is 30-60%; the scanning path direction between adjacent layers is rotated 60-90° to disperse thermal stress.

[0018] The beneficial effects of this invention are: 1. This invention optimizes the solidification characteristics, phase transformation behavior, and thermophysical properties of Inconel 617 alloy by controlling the content and proportion of key elements, significantly improving its additive manufacturing process window and suppressing crack initiation. Specifically, solid solution elements such as Cr, Co, and Mo effectively distort the crystal lattice, hinder dislocation movement, enhance deformation resistance, and increase the matrix yield strength and tensile strength, thereby improving the alloy's density and mechanical properties.

[0019] 2. The present invention ultimately yields Inconel 617 alloy components with a density higher than 99.0%, no obvious internal metallurgical defects, uniform and fine microstructure, and excellent comprehensive mechanical properties at both room temperature and high temperature.

[0020] 3. The method of this invention has for the first time achieved high-quality laser additive manufacturing of Inconel 617 alloy, providing an effective way to manufacture complex and precision parts of this alloy. Attached Figure Description

[0021] Figure 1 The images show actual molded components from Examples 1, 2, 3, 4, 5, and 6. Figure 2 The room temperature mechanical tensile stress-strain diagrams are for Comparative Example 1, Comparative Example 2, Example 1, Example 2, Example 3, Example 4, Example 5 and Example 6. Figure 3 The mechanical tensile stress-strain diagrams for Comparative Example 1, Comparative Example 2, Example 1, Example 2, Example 3, Example 4, Example 5 and Example 6 at a high temperature of 750°C are shown. Detailed Implementation

[0022] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] This invention provides an Inconel 617 nickel-based alloy suitable for additive manufacturing and possessing good mechanical properties. The composition of the nickel-based alloy, expressed as atomic percentage, ranges as follows: Ni 50.0-60.0%, Cr 20.0-24.0%, Co 10.0-14.0%, Mo 8.0-10.0%, Al 0.6-1.5%, and X 0.01-10%, wherein X is one or more of Ti, Fe, Cu, Mn, C, and Si. Preferably, the content of X ranges as follows: Ti 0.01-2.0%, Fe 0.1-2.5%, Cu 0.01-0.05%, Mn 0.01-0.90%, C 0.05-0.14%, and Si 0.01-0.8%. Preferably, the composition is Cr 20.0-24.0%, Co 10.0-14.0%, Mo 8.0-10.0%, and Al 0.6-1.5%.

[0024] For example, the composition of the alloy, by weight percentage, is: Cr 20.0-24.0%, Co 10.0-14.0%, Mo 8.0-10.0%, Al 0.6-1.4%, Ti 0.01-0.6%, Fe 0.1-2.5%, Cu 0.01-0.05%, Mn 0.01-0.90%, C 0.05-0.14%, Si 0.01-0.8%. The remainder is Ni and unavoidable trace impurities.

[0025] The present invention preferably uses high-purity nickel plates, metallic chromium, metallic cobalt, molybdenum bars, iron blocks, aluminum ingots, titanium ingots, etc. as raw materials to ensure that the content of impurity elements is controlled.

[0026] This invention also provides a method for preparing Inconel 617 nickel-based alloy, comprising the following steps: Step 1: Weigh and mix the various metal raw materials according to the specified proportions, and then melt and refine them using vacuum induction melting or electroslag remelting to obtain alloy ingots.

[0027] In this embodiment, the purity of the metal raw materials is ≥99.5 wt.%, and high-purity argon gas is used for protection. The materials are layered according to their melting point and ease of oxidation. They are placed in a crucible of a vacuum induction melting furnace and melted into alloy ingots under a high-purity argon atmosphere. The high-melting-point components are placed on top, and the low-melting-point components on the bottom to minimize the loss of low-melting-point components. During the melting process, the arc-ignition current is set to 40-60 A for partial melting of the alloy. The melting current is then slowly increased to 280-320 A until the alloy is completely melted into a bright liquid. The mixture is thoroughly stirred to ensure uniform composition and promote degassing and impurity flotation. Rapid composition analysis is then performed, and fine-tuning is done by adding intermediate alloys if necessary. After confirming the composition is acceptable, the alloy liquid is poured into a preheated steel or copper mold to obtain a master alloy ingot with uniform composition and dense structure.

[0028] Step 2: Prepare Inconel 617 spherical powder using gas atomization or plasma rotating electrode atomization. When using gas atomization, the master alloy ingot obtained in Step 1 is remelted and atomized. When using plasma rotating electrode atomization, the master alloy ingot obtained in Step 1 is homogenized and annealed, then forged multiple times to form a round bar of specified size, which is then used as an electrode for rotating atomization.

[0029] The specific steps of the plasma rotating electrode atomization method include: homogenizing the ingot described in step 1 with annealing to eliminate dendrite segregation, followed by multiple forging processes. The initial forging temperature is controlled at 1150-1200℃, and the final forging temperature is not lower than 950℃, ultimately forging it into a round bar of specified dimensions (e.g., 70-80 mm in diameter) as the consumable electrode blank for subsequent powder preparation. This process aims to obtain a dense, uniformly composed bar, laying a metallurgical foundation for the preparation of high-performance powders. The obtained forged bar is machined to achieve a smooth surface and meet the standard electrode bar dimensions required by the plasma rotating electrode atomization equipment (e.g., 60-70 mm in diameter and 500-1000 mm in length). The electrode bar is mounted on the spindle of the PREP equipment. After the equipment chamber is evacuated, it is filled with high-purity argon or helium as the atomization medium and protective atmosphere. The equipment is started, causing the electrode rod to rotate at high speed (e.g., 10,000-20,000 rpm), while its tip is heated by a plasma arc to melt it into a liquid film. Under the centrifugal force generated by the high-speed rotation, the molten metal is thrown out and atomized into fine droplets, which are then rapidly cooled and solidified in an inert atmosphere to form spherical powder particles. The particle size distribution of the powder is controlled by adjusting parameters such as the electrode rod rotation speed and the plasma arc power, and the resulting powder is collected.

[0030] The specific steps of the gas atomization method include: placing the crucible of the master alloy ingot obtained in step 1 in the melting chamber, sealing it, and evacuating the system to ≤1.0 Pa. Then, high-purity argon (purity ≥99.999%) is introduced to atmospheric pressure, and this process is repeated 2-3 times to fully replace the air in the system, ultimately controlling the oxygen content in the atomization chamber to <50 ppm. Under a protective atmosphere, the master alloy ingot in the crucible is remelted by induction heating. The alloy liquid is superheated to 1550-1600℃ (usually 150-200℃ above the liquidus temperature) and held for 5-10 minutes to obtain a clean, highly fluid molten metal. The stopper at the bottom of the holding tundish is opened, and the superheated molten metal is guided through a ceramic guide tube (usually with an inner diameter of 2-6 mm) to the tightly coupled atomizing nozzle. At the instant the molten metal flows through the nozzle, a high-speed, high-pressure inert gas stream (usually argon or nitrogen, pressure 2.0-6.0 MPa) is ejected through an array of annular nozzles. High-speed airflow exerts intense shearing and abrasive forces on the continuous molten metal stream, pulverizing it into countless tiny droplets. These fragmented droplets then fall within the atomization tower. During this process, due to surface tension, the droplets spontaneously contract into a spherical shape. Simultaneously, under the protection of a high-purity inert gas (usually homogeneous with the atomizing gas), the droplets are rapidly cooled (cooling rates can reach 10³-10⁻¹⁰). 6 K / s), solidifying into solid spherical or near-spherical powder particles. The height of the atomizing tower (usually 5-10 meters) must ensure that the powder has sufficient flight time to complete solidification and collect the resulting powder.

[0031] Step 3: The obtained powder is sieved, and powders with different particle size ranges are selected as the molding powder raw materials for selective laser melting (SLM) or laser melting deposition (LMD), and then thoroughly dried.

[0032] This invention selects powder with a particle size range of 15-53 μm for selective laser melting preparation, and the powder has a sphericity greater than 95%, a flowability of less than 30 s / 50g, and an oxygen content of less than 200 ppm.

[0033] This invention selects powder with a particle size range of 53-150 μm for laser melting deposition (LMD) preparation; and the sphericity of the powder is greater than 95%, the flowability is less than 30 s / 50g, and the oxygen content is less than 200 ppm.

[0034] Step 4: Select an alloy as the molding substrate, install the cleaned substrate on the worktable inside the molding chamber of the additive manufacturing equipment, and introduce protective gas.

[0035] The present invention uses 316 L stainless steel or the same Inconel 617 alloy as the molding substrate.

[0036] In step 4, the cleaning process includes: grinding and polishing the upper surface of the molded substrate, and ultrasonically cleaning it with alcohol or acetone to remove oil stains.

[0037] In step 4, the installation steps include: mounting the cleaned substrate onto the worktable inside the molding chamber of the additive manufacturing equipment and performing leveling. The molding chamber is then sealed, and high-purity argon (Ar) gas is introduced as a protective gas to reduce the oxygen content inside the chamber to below 100 ppm. Optionally, the substrate is preheated to 80-200°C to reduce thermal stress during the molding process.

[0038] Step 5: Import the 3D model of the target part into the equipment control system (SLM equipment control system), perform layer slicing along the vertical forming direction (Z-axis), and set the process parameters.

[0039] When using selective laser melting, the core process parameters are set as follows: single-layer thickness is set to 20-40 μm, laser power is 160-300 W, scanning speed is 600-1200 mm / s, scanning spacing is 60-120 μm, and stripe scanning, checkerboard scanning or island scanning strategies are used for partition filling. The scanning path direction between adjacent layers is rotated by 60-90° to disperse thermal stress.

[0040] Laser melting deposition (LMD) is employed. The 3D model of the target part is imported into the LMD equipment control system. Layers are sliced ​​according to the set layer thickness, and a laser scanning path is generated for each layer. For complex curved surfaces or solid infilling, multiple overlapping scanning paths need to be planned. The core process parameter combinations are set as follows: laser power 600-3000 W, scanning speed 5-20 mm / s, powder feed rate 10-30 g / min, spot diameter 1-3 mm, Z-axis single-layer lift 0.1-1.0 mm, and overlap rate 30-60%. Optionally, the scanning path direction between adjacent layers can be rotated 60-90° to disperse thermal stress.

[0041] Step 6: Select one of the following molding processes to perform: Process A is selective laser melting: The powder scraper pre-lays a uniform layer of powder on the substrate, and the laser beam melts the powder of the current layer according to the set path and parameters to achieve metallurgical bonding; after the current layer is scanned, the worktable descends by a layer thickness, and the powder laying and melting process is repeated, layer by layer until the part is formed.

[0042] The specific steps of selective laser melting include: starting the equipment, and the powder scraper pre-laying a uniform layer of powder on the calibrated substrate. The laser beam melts the powder in the current layer according to the set path and parameters, enabling metallurgical bonding between the powder and the substrate or the already formed lower metal layer. After the current layer is scanned, the stage descends by one layer thickness, and the powder laying and melting process is repeated, layer by layer, until the entire part is formed. Throughout the forming process, the state of the molten pool can be monitored in real time through infrared thermal imaging or a molten pool photoelectric monitoring system, allowing for closed-loop fine-tuning of process parameters to ensure molten pool stability.

[0043] Process B is laser melting deposition: The equipment is started to perform synchronous powder feeding melting deposition. A high-power laser beam irradiates the substrate or the deposited layer to form a molten pool. At the same time, the carrier gas sends the metal powder into the molten pool to achieve metallurgical bonding. Layer by layer is deposited until the part is formed.

[0044] The specific steps of laser melting deposition include: starting the equipment, scanning the laser beam along the first layer path, and simultaneously, a powder feeder precisely delivering powder into the molten pool formed by the laser spot. The powder melts instantly and metallurgically bonds with the substrate surface, forming the first cladding layer. Through multiple overlaps, the deposition of the first planar layer is completed. After one layer is completed, the nozzle or stage is raised along the Z-axis by a set layer height distance (0.1-1.0 mm). The laser beam and powder feeder continue working along the path of the next layer, and the new cladding layer metallurgically bonds with the next layer that has already been deposited. This cycle is repeated, layer by layer, until the part is completely formed. Throughout the forming process, the state of the molten pool can be monitored in real time through infrared thermal imaging or a molten pool photoelectric monitoring system, and the process parameters can be finely adjusted in a closed loop to ensure the stability of the molten pool.

[0045] Step 7: After the part is formed, it is cooled to room temperature along with the substrate under the protective atmosphere of the molding chamber, and then the part is separated from the substrate.

[0046] In this invention, unless otherwise specified, all raw materials used in the preparation are commercially available products well known to those skilled in the art.

[0047] The present invention will be described in detail below through embodiments and experimental examples. However, these are merely examples and do not limit the present invention in any way.

[0048] Example 1 The composition of Inconel 617 alloy (at.%) is: Ni 55.2 Cr 22.2 Co 10.2 Mo 8.4 Al 1.3 Fe 1.8 Ti 0.6 Mn 0.3 The preparation method of the Inconel 617 alloy in Example 1 is as follows: Step 1: Weigh and mix high-purity (≥99.5 wt.%) Ni, Cr, Co, Mo, Al, Ti, Fe, and Mn raw materials according to the specified proportions. Layer the materials according to their melting points and ease of oxidation, and place them in a crucible of a vacuum induction melting furnace. Melt the alloy into an ingot under a high-purity argon (Ar) atmosphere. During the melting process, set the arc current to 50 A for partial melting of the alloy. Then, slowly increase the melting current to 280-320 A until the alloy is completely melted into a bright liquid. Stir thoroughly to ensure uniform composition and promote degassing and impurity flotation. Perform rapid composition analysis, and fine-tune by adding intermediate alloys if necessary. After confirming the composition is acceptable, pour the alloy liquid into a preheated steel or copper mold to obtain a master alloy ingot with uniform composition and dense structure.

[0049] Step 2: The ingot from Step 1 is subjected to homogenization annealing to eliminate dendrite segregation, followed by multiple forging processes. The initial forging temperature is controlled at 1150℃, and the final forging temperature is not lower than 950℃, ultimately forging it into a round bar with a diameter of 80 mm, which will serve as the blank material for consumable electrodes used in subsequent powder production. This process aims to obtain a dense, uniformly composed bar, laying a metallurgical foundation for the preparation of high-performance powders.

[0050] Step 3: Machin the forged bar obtained in Step 2 to achieve a smooth surface. Mount the electrode bar on the spindle of the PREP equipment. After evacuating the equipment chamber, fill it with high-purity argon or helium as the atomizing medium and protective atmosphere. Start the equipment, causing the electrode bar to rotate at a high speed of 15,000 rpm. Simultaneously, heat its end using a plasma arc to melt it into a liquid film. Under the centrifugal force generated by the high-speed rotation, the molten metal is thrown out and atomized into fine droplets, which are then rapidly cooled and solidified in an inert atmosphere to form spherical powder particles. By adjusting parameters such as the electrode bar rotation speed and plasma arc power, the particle size distribution of the powder is controlled, and the resulting powder is collected.

[0051] Step 4: The obtained powder is sieved, and powder with a particle size range of 15-53 μm is selected as the forming raw material for the selective laser melting (SLM) process. The sphericity of the powder is greater than 95%, the flowability is less than 30 s / 50g, and the oxygen content is less than 200 ppm.

[0052] Step 5: Select 316L stainless steel as the molding substrate, grind and polish its upper surface, and ultrasonically clean it with alcohol or acetone to remove oil stains. Install the cleaned substrate on the worktable inside the molding chamber of the molding equipment and perform leveling. Seal the molding chamber and introduce high-purity argon (Ar) as a protective gas to reduce the oxygen content inside the chamber to below 50 ppm.

[0053] Step 6: Import the 3D model of the target part into the SLM equipment control system, and perform layer slicing along the vertical forming direction (Z-axis), with a single layer thickness set to 30 μm. Based on the optimized alloy properties, set the core process parameter combination: laser power of 220 W, scanning speed of 1000 mm / s, and scanning spacing of 60 μm. Use stripe scanning, checkerboard scanning, or island scanning strategies for partitioned filling, and rotate the scanning path direction between adjacent layers by 67° to disperse thermal stress.

[0054] The equipment is started, and the powder scraping device pre-lays a uniform layer of powder on the calibrated substrate. The laser beam melts the powder in the current layer according to the set path and parameters, enabling metallurgical bonding between the powder and the substrate or the already formed lower metal layer. After the current layer is scanned, the worktable descends by one layer thickness, and the powder laying and melting process is repeated, layer by layer, until the entire part is formed. Throughout the forming process, the state of the molten pool can be monitored in real time through infrared thermal imaging or a molten pool photoelectric monitoring system, allowing for closed-loop fine-tuning of process parameters to ensure molten pool stability.

[0055] Step 7: After the part is formed, it is cooled to room temperature along with the substrate under the protective atmosphere of the forming chamber. The part is then separated from the substrate by wire cutting or other methods to obtain Inconel 617 alloy.

[0056] The Inconel 617 alloy has a forming size of 12×40×7 mm.

[0057] Specifically, for subsequent mechanical tensile tests, the Inconel 617 alloy was cut into standard specimens conforming to the tensile testing of metallic materials GB / T 228.1-2021.

[0058] Specifically, the surface roughness of the test samples all met the standard requirements of GB / T 228.1-2021 for tensile testing of metallic materials.

[0059] like Figure 2 As shown in Table 1, the yield strength (σ) of Example 1 s The tensile strength (σ) is 641 MPa. b The strength is 920 MPa and the elongation at break (ε) is 32%.

[0060] Example 2 The preparation method of the Inconel 617 alloy in Example 2 is the same as steps 1-7 in Example 1, except that the composition of the Inconel 617 alloy is (at.%): Ni 51.9 Cr 24.2 Co 11.2 Mo 8.4 Al 1.3 Fe 2.0 Ti 0.8 Mn 0.2 .

[0061] like Figure 2 As shown in Table 1, the yield strength (σ) of Example 2 s The tensile strength (σ) is 652 MPa. b The strength is 910 MPa and the elongation at break (ε) is 33%.

[0062] Example 3 The preparation method of the Inconel 617 alloy in Example 3 is the same as steps 1-7 in Example 1, except that the composition of the Inconel 617 alloy is (at.%): Ni 57.6 Cr 20.2 Co 10.0 Mo 8.5 Al 1.0 Fe 1.5 Ti 0.9 Mn 0.3 .

[0063] like Figure 2 As shown in Table 1, the yield strength (σ) of Example 3 s The tensile strength (σ) is 651 MPa. bThe strength is 892 MPa and the elongation at break (ε) is 28%.

[0064] Example 4 The preparation method of the Inconel 617 alloy in Example 4 is the same as steps 1-7 in Example 1, except that the composition of the Inconel 617 alloy is (at.%): Ni 54.8 Cr 21.2 Co 10.5 Mo 10.0 Al 1.0 Fe 1.0 Ti 1.0 Mn 0.5 .

[0065] like Figure 2 As shown in Table 1, the yield strength (σ) of Example 4 s The tensile strength (σ) is 648 MPa. b The strength is 899 MPa and the elongation at break (ε) is 29%.

[0066] Example 5 The preparation method of the Inconel 617 alloy in Example 5 is the same as steps 1-7 in Example 1, except that the composition of the Inconel 617 alloy is (at.%): Ni 53.4 Cr 21.8 Co 11.4 Mo 9.6 Al 0.9 Fe 0.9 Ti 1.6 Mn 0.4 .

[0067] like Figure 2 And as shown in Table 1, the yield strength (σ) of Example 5 s The tensile strength (σ) is 663 MPa. b The strength is 911 MPa and the elongation at break (ε) is 28%.

[0068] Example 6 The preparation method of the Inconel 617 alloy in Example 6 is the same as steps 1-7 in Example 1, except that the composition of the Inconel 617 alloy is (at.%): Ni 52.4 Cr 23.2 Co 10.8 Mo 9.5 Al 1.5 Fe 1.2 Ti 1.2 Mn 0.2 .

[0069] like Figure 2 And as shown in Table 1, the yield strength (σ) of Example 6 s The tensile strength (σ) is 657 MPa. b The strength is 902 MPa and the elongation at break (ε) is 32%.

[0070] Figure 1 The images shown are actual pictures of Examples 1, 2, 3, 4, 5 and 6.

[0071] Comparative Example 1 The composition of Inconel 617 alloy (at.%) is: Ni 55.2 Cr 22.2 Co 10.2 Mo 8.4 Al 1.3 Fe 1.8 Ti 0.6 Mn 0.3 The preparation method of the Inconel 617 alloy in Comparative Example 1 is the same as that of the forged bar obtained in steps 1-2 of Example 1.

[0072] like Figure 2 And as shown in Table 1, the yield strength (σ) of Comparative Example 1 s The tensile strength (σ) is 515 MPa. b The strength is 875 MPa and the elongation at break (ε) is 33%.

[0073] Comparative Example 2 The composition of Inconel 617 alloy (at.%) is: Ni 55.2 Cr 22.2 Co 10.2 Mo 8.4 Al 1.3 Fe 1.8 Ti 0.6 Mn 0.3 The preparation method of the Inconel 617 alloy in Comparative Example 2 is the same as that of the alloy master ingot obtained after step 1 in Example 1.

[0074] like Figure 2 And as shown in Table 1, the yield strength (σ) of Comparative Example 2 s The tensile strength (σ) is 340 MPa. b The strength is 496 MPa and the elongation at break (ε) is 27%.

[0075] Table 1 Mechanical property parameters of comparative examples and embodiments under room temperature tensile stress Figure 3Table 2 shows the mechanical tensile stress-strain data of Comparative Example 1, Comparative Example 2, Example 1, Example 2, Example 3, Example 4, Example 5 and Example 6 at a high temperature of 750℃.

[0076] Table 2 Mechanical property parameters of comparative examples and embodiments under tensile stress at 750°C Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible subranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the range referred to.

[0077] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An Inconel 617 nickel-based alloy suitable for additive manufacturing and possessing good mechanical properties, characterized in that, The composition of the nickel-based alloy is expressed as atomic percentage, and the composition range includes: Ni 50.0-60.0%, Cr 20.0-24.0%, Co 10.0-14.0%, Mo 8.0-10.0%, Al 0.6-1.5%, X 0.01-10%, wherein X is one or more of Ti, Fe, Cu, Mn, C and Si.

2. The Inconel 617 nickel-based alloy according to claim 1, characterized in that, The content range of X is: Ti 0.01-2.0%, Fe 0.1-2.5%, Cu 0.01-0.05%, Mn 0.01-0.90%, C 0.05-0.14%, Si 0.01-0.8%.

3. The Inconel 617 nickel-based alloy according to claim 1, characterized in that, The composition is Cr 20.0-24.0%, Co 10.0-14.0%, Mo 8.0-10.0%, and Al 0.6-1.5%.

4. A method for preparing the Inconel 617 nickel-based alloy as described in any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Weigh and mix the various metal raw materials according to the specified proportions, and then melt and refine them using vacuum induction melting or electroslag remelting to obtain alloy ingots. Step 2: Prepare Inconel 617 spherical powder using either gas atomization or plasma rotating electrode atomization. When using gas atomization, the master alloy ingot obtained in Step 1 is remelted and atomized. When using plasma rotating electrode atomization, the master alloy ingot obtained in Step 1 is homogenized and annealed, then subjected to multiple forging processes to finally forge into a round bar of specified dimensions. The obtained round bar is then used as an electrode for rotating atomization. Step 3: The obtained powder is sieved, and powders with different particle size ranges are selected as the forming powder raw materials for selective laser melting or laser melting deposition, and then thoroughly dried; Step 4: Select an alloy as the molding substrate, install the cleaned substrate on the worktable inside the molding chamber of the additive manufacturing equipment, and introduce protective gas. Step 5: Import the 3D model of the target part into the equipment control system, slice it into layers along the vertical forming direction, and set the process parameters; Step 6: Select one of the following molding processes to perform: Process A is selective laser melting: The powder scraping device pre-lays a uniform layer of powder on the substrate, and the laser beam melts the powder of the current layer according to the set path and parameters to achieve metallurgical bonding; after the current layer is scanned, the worktable descends by a layer thickness, and the powder laying and melting process is repeated, layer by layer until the part is formed. Process B is laser melting deposition: The equipment is started to perform synchronous powder feeding melting deposition. A high-power laser beam irradiates the substrate or the deposited layer to form a molten pool. At the same time, the carrier gas sends the metal powder into the molten pool to achieve metallurgical bonding. Layer by layer is deposited until the part is formed. Step 7: After the part is formed, it is cooled to room temperature along with the substrate under the protective atmosphere of the molding chamber, and then the part is separated from the substrate.

5. The preparation method according to claim 4, characterized in that, In step 1, the purity of the metal raw materials is ≥99.5wt.%, high-purity argon gas is used for protection, and the materials are layered according to the order of melting point and easy oxidation. Preferably, the high melting point components are layered on top and the low melting point components are layered on the bottom. The arc ignition current is set to 40-60 A during melting, and then the melting current is increased to 280-320 A.

6. The preparation method according to claim 4, characterized in that, In step 2, the initial forging temperature is controlled at 1150-1200℃, and the final forging temperature is not lower than 950℃.

7. The preparation method according to claim 4, characterized in that, In step 3, powder with a particle size range of 15-53 μm is selected for selective laser melting preparation, and powder with a particle size range of 53-150 μm is selected for laser melting deposition (LMD) preparation; and the sphericity of the powder is greater than 95%, the flowability is less than 30 s / 50g, and the oxygen content is less than 200 ppm.

8. The preparation method according to claim 4, characterized in that, When using the gas atomization method, the oxygen content in the atomization chamber is controlled to be <50 ppm, the alloy liquid is superheated to 1550-1600℃, and the inert gas pressure is 2.0-6.0 MPa; when using the plasma rotating electrode atomization method, the electrode rod rotation speed is controlled to be 10000-20000 rpm.

9. The preparation method according to claim 4, characterized in that, In step 4, 316L stainless steel or the same Inconel 617 alloy is selected as the molding substrate.

10. The preparation method according to claim 4, characterized in that, In step 6, if process A is used, the single-layer thickness is set to 20-40 μm, the laser power is 160-300 W, the scanning speed is 600-1200 mm / s, and the scanning spacing is 60-120 μm; a stripe scanning, checkerboard scanning, or island scanning strategy is used for partitioned filling; the scanning path direction between adjacent layers is rotated by 60-90° to disperse thermal stress; If process B is used, the laser power is 600-3000 W, the scanning speed is 5-20 mm / s, the powder feeding rate is 10-30 g / min, the spot diameter is 1-3 mm, the Z-axis single-layer lifting amount is 0.1-1.0 mm, and the overlap rate is 30-60%; the scanning path direction between adjacent layers is rotated 60-90° to disperse thermal stress.

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