A precise, customized processing technology for reducing the oxygen content of moisture-containing high-temperature alloy powder

Abstract

This invention discloses a precise, customized process for reducing the oxygen content of humid high-temperature alloy powder. By screening high-temperature alloy powders of different particle sizes, powders sensitive to water vapor removal are selected. These powders are then placed in a protective atmosphere programmed temperature desorption device, resulting in a biphasic water vapor removal peak. The measured sensitive temperatures for water vapor removal in the low and medium temperature ranges are used as the water vapor degassing holding temperatures. Combined with the removal temperatures of other oxygen-containing gases tracked during the heating process, a multi-stage degassing process (low, medium, and high temperatures) is derived. This invention uses the biphasic water vapor removal peak to pinpoint the sensitive temperature for actual degassing, thereby achieving a more significant oxygen reduction effect on high-temperature alloy powders. This targeted approach reduces the harmful effects of humid environments on alloys, providing theoretical guidance and technical support for the oxygen reduction treatment of high-quality high-temperature alloy powders used in powder metallurgy and additive manufacturing.

Description

Technical Field

[0001] This invention relates to the field of high-temperature alloy technology, and specifically to a precise customized processing technology for reducing the oxygen content of moisture-containing high-temperature alloy powder. Background Technology

[0002] Currently, advanced aero-engines primarily utilize powder metallurgy for turbine disk fabrication, and the quality of the high-temperature alloy powder is fundamental to ensuring engine service safety. The advantages of powder metallurgy lie in the rapid solidification of micron-diameter alloy droplets into micron-sized powder particles during the atomization process. This results in uniform microstructure, fine grains, and confined compositional segregation to a small dendrite scale, making it advantageous for fabricating thick, large-section turbine disks. In recent years, additive manufacturing technology has demonstrated significant advantages in fabricating complex aero-engine structural components. Since its inception, additive manufacturing technology has been inextricably linked to printing consumables, and the gradual maturation of powder materials technology has made additive manufacturing of complex high-temperature alloy structural components possible.

[0003] High-temperature alloy powders have inherent advantages in the preparation of powder metallurgy turbine disks and additive manufacturing complex components. However, compared to bulk alloys, powders have a larger specific surface area, increasing the tendency for gas adsorption on the powder surface. This leads to an increase in oxygen content, which can affect subsequent forming processes and even adversely affect component performance. Among the adsorbed gases, water vapor is particularly common. Regardless of whether the powder is in a normal air environment, a protective atmosphere, or a humid environment, it will inevitably adsorb water vapor, forming moist high-temperature alloy powder.

[0004] High-temperature alloy powders often require a vacuum degassing process before use to remove adsorbed gases. The selection of degassing parameters is crucial to the effectiveness of the degassing process. Existing technologies often employ an empirical trial-and-error method, using manually set fixed intervals of holding temperature to perform vacuum degassing or stepped heating degassing.

[0005] Its disadvantages are: First, using real vacuum degassing equipment for experimentation is inefficient and costly; second, the number of test temperature points is limited, as the temperature is set intermittently rather than continuously, which may cause the optimal parameter points to be missed. Adding too many test points will further reduce efficiency and increase costs; third, the test temperature range is limited, as most existing vacuum degassing equipment has a low upper temperature limit, which cannot meet the degassing requirements of new powder high-temperature alloys; fourth, the types of gases tested are limited, and the type of gas removed cannot be determined. Usually, the total content of oxygen, nitrogen, and hydrogen in the powder is analyzed after the degassing test, but the type of gas containing these elements cannot be analyzed, such as whether the oxygen element is released in the form of water vapor, oxygen, or carbon dioxide; fifth, the determination of the existing degassing and heat preservation temperature is determined by artificial experimentation and lacks theoretical basis; sixth, recently, a technology has emerged that selects degassing temperature parameters based on the gas desorption curve, but this technology cannot obtain a high-quality water vapor bimodal curve, which has certain limitations in removing water vapor adhering to the surface of moist powder, thus affecting the degassing effect to some extent. Summary of the Invention

[0006] To address the problems existing in the prior art, a precise customized processing technology for reducing the oxygen content of humid high-temperature alloy powder is provided.

[0007] The technical solution adopted by this invention to solve its technical problem is:

[0008] This invention proposes a precise customized treatment process for reducing the oxygen content of humid high-temperature alloy powder. The method involves screening high-temperature alloy powders of different particle sizes, selecting those sensitive to water vapor removal, and placing the powders in a protective atmosphere programmed temperature rise desorption device to obtain a double peak of water removal. The sensitive temperatures of water vapor removal in the low-temperature and medium-temperature ranges are used as the water vapor degassing and heat preservation temperatures, respectively. Combined with the removal temperatures of other oxygen-containing gases tracked during the heating process, a multi-stage degassing process with low, medium, and high temperatures is obtained.

[0009] Preferably, the method for obtaining the degassing temperature includes the following steps:

[0010] S1: Sieve the high-temperature alloy powder into narrow particle size segments of different particle size grades for later use;

[0011] S2: Using an oxygen and nitrogen gas analyzer, the gas content of the powder in the above particle size range is determined by pulse heating-infrared thermal conductivity method, and high-temperature alloy powder with high oxygen content in a narrow particle size range is selected.

[0012] S3: Place the selected high-temperature alloy powder with a narrow particle size range into a protective atmosphere programmed heating desorption equipment and heat it at a specified heating rate to a temperature below the solidus line of the high-temperature alloy powder.

[0013] S4: Record the gas release curve of high-temperature alloy powder during the heating process using a mass spectrometer;

[0014] S5: Observe the water vapor release peak in the gas release curve, observe whether there is a double peak structure, read the temperature corresponding to the maximum value of the low temperature section peak and the medium temperature section peak, and use the temperature corresponding to the two peaks as the alternative heat preservation temperature for the subsequent full particle size section powder in the actual vacuum degassing medium and low temperature section.

[0015] S6: Observe the extraction peaks of oxygen, carbon dioxide, carbon monoxide and other oxygen-containing gases in the gas extraction curve, read their corresponding peak temperatures, compare them with the double peak temperatures of water vapor to see if there is any overlap, and select the temperature corresponding to the peak as the degassing and heat preservation temperature in the medium and high temperature range under the principle of the simplest number of process parameters.

[0016] S7: The actual degassing heating rate is selected to be the same as the heating rate used when the gas removal curve is obtained by the programmed temperature rise desorption equipment.

[0017] Preferably, in S1, the narrow particle size range includes: ≤15μm, 15~25μm, 25~32μm, 32~45μm, 45~53μm, 53~63μm, 63~75μm, 75~100μm, 100~120μm, and 120~150μm.

[0018] Preferably, in S6, the other oxygen-containing gases include carbon monoxide and carbon dioxide.

[0019] The preferred degassing process includes the following steps:

[0020] S11: Sieve the high-temperature alloy powder into a wide range of actual particle sizes for later use. The particle size range includes: ≤53μm, ≤63μm, 15~53μm, 53~150μm, and 75~150μm.

[0021] S12: High-temperature alloy powder is continuously compacted on a vibrating table and then loaded into a pouch. The pouch filled with powder is connected to the equipment, and a vacuum is drawn at room temperature, with the vacuum level less than 1×10⁻⁶. -3 Pa followed by a time t1;

[0022] S13: Connect the powder-filled package to the equipment and begin evacuation at room temperature, with a vacuum level less than 1 × 10⁻⁶. -3 Pa followed by t4 time;

[0023] S14: Set the heater temperature to 130–150°C, start heating, and heat until the temperature reaches 130–150°C and the vacuum is less than 1×10⁻⁶. -3Pa, automatic heat preservation begins, heat preservation time is t5 time, and heat preservation temperature value is the low temperature peak position of the water vapor double peak in the narrow particle size range fine powder degassing kinetic curve in S6.

[0024] S15: Adjust the heater set temperature to 280–310℃, and heat the jacket along with the furnace until the temperature reaches 280–310℃ and the vacuum is less than 1×10⁻⁶. -3 Pa, automatic heat preservation begins, heat preservation time is t6, and heat preservation temperature value is the mid-temperature peak position of water vapor double peak and carbon dioxide peak position in the narrow particle size range fine powder degassing kinetic curve in S6.

[0025] S16: Adjust the heater set temperature to 410–480℃, and heat the jacket along with the furnace until the temperature reaches 410–480℃ and the vacuum is less than 1×10⁻⁶. -3 Pa, start heat preservation, heat preservation time is t7 time, heat preservation temperature value is the high temperature peak position of carbon monoxide in the narrow particle size range fine powder degassing kinetic curve in S6.

[0026] S17: Adjust the heater set temperature to the upper limit temperature of the degassing furnace, and maintain the furnace temperature as it heats up, with a vacuum of less than 1×10⁻⁶. -3 Pa;

[0027] S18: Turn off the heating, maintain the vacuum state and cool for more than t8 hours, then remove the sleeve and perform sleeve sealing welding.

[0028] Preferably, in step S18, the high-temperature alloy powder in the package is used to prepare a high-temperature alloy ingot by hot isostatic pressing, or the high-temperature alloy powder is removed from the package and stored in a vacuum.

[0029] Preferably, the method for testing the gas content in the ingot or powder includes: using an oxygen and nitrogen gas analyzer and measuring it according to the pulse heating-infrared thermal conductivity method.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] 1. This invention addresses the characteristic of high-temperature alloy powders easily adsorbing water in humid air environments. Through targeted process optimization design, water is removed from the powder surface, thereby reducing the oxygen content of the powder and improving its performance. By comparing coarse and fine powders with different narrow particle size ranges, the particle size range corresponding to the high-quality gas extraction curve is selected as the detection target, which facilitates the selection of subsequent processes and improves the overall degassing efficiency and quality.

[0032] 2. The present invention uses fine powder with a narrow particle size range as the detection marker after experimental optimization. This makes it easier to obtain the water vapor removal curve of high-temperature alloy powder with low and medium temperature bimodal distribution. As an optimization of the actual degassing process, it solves the problem that conventionally applied particle size ranges cannot obtain bimodal peaks corresponding to the water vapor removal sensitive temperature, and can only obtain single peaks. The selected low temperature and medium temperature bimodal temperature peaks corresponding to water vapor removal are used as the degassing and heat preservation temperature, which is more efficient for water vapor removal than degassing designed for single peaks, thus making the oxygen reduction effect of high-temperature alloy powder more significant.

[0033] 3. This invention also proposes a degassing process with dual temperature peaks at medium and low temperatures. This process can not only reduce the oxygen content of bulk material ingots in hot isostatic pressing, but also serve as a method for deoxygenating loose powders. It has a wider range of applications. The dual temperature peaks at medium and low temperatures are used as a vacuum degassing and heat preservation treatment aimed at removing water vapor, which provides a more theoretical basis for the treatment method and process parameters.

[0034] 4. This invention uses ultra-narrow particle size range powder with obvious bimodal precipitation characteristics after optimization as the target material to obtain the corresponding temperature of the bimodal precipitation of high temperature alloy powder of the corresponding composition. It is applied to the actual degassing treatment of powders with a wide range or full particle size range. After treatment, it can form ingots formed by hot isostatic pressing or original loose powders in multiple states of deoxygenation treatment.

[0035] 5. This invention reduces powder agglomeration by using water vapor bimodal positioning to remove sensitive temperatures from damp high-temperature alloy powder, and baking the original loose powder under a protective atmosphere or vacuum. This also further reduces the oxygen content, meeting the requirements of additive manufacturing processes for high-temperature alloy powder.

[0036] 6. The actual degassing heating rate should be the same as the heating rate used to obtain the gas removal curve in the programmed temperature rise desorption equipment to reduce the deviation in results caused by the heating rate. By aligning the multi-stage degassing and single-stage degassing holding times, the influence of time can be eliminated, and the influence of temperature alone can be accurately identified. Attached Figure Description

[0037] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0038] Figure 1 It is the gas extraction curve of fine powder with a narrow particle size range of 15-25μm for high-temperature alloy (1#);

[0039] Figure 2 It is the gas extraction curve of coarse powder with a narrow particle size range of 75-100μm for high-temperature alloy (1#);

[0040] Figure 3It is the gas extraction curve of high-temperature alloy (2#) powder with a wide particle size range of 0~53μm;

[0041] Figure 4 The gas extraction curve of fine powder with a narrow particle size range of 15-25μm for high-temperature alloy (3#)

[0042] Figure 5 It is the gas extraction curve of fine powder with a narrow particle size range of 15-25μm for high-temperature alloy (4#).

[0043] Figure 6 This is a flowchart of a precisely customized process for reducing the oxygen content of moisture-containing high-temperature alloy powder. Detailed Implementation

[0044] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0045] Example 1

[0046] Reference Appendix Figure 1-5 This embodiment proposes a precise, customized processing technology to reduce the oxygen content of humid high-temperature alloy powders. By screening high-temperature alloy powders of different particle sizes, the powders most sensitive to water vapor removal are selected. These powders are then placed in a protective atmosphere programmed temperature desorption apparatus to obtain a double peak in water removal. The sensitive temperatures for water vapor removal in the low-temperature and medium-temperature ranges are used as the water vapor degassing holding temperatures, respectively. Combined with the removal temperatures of other oxygen-containing gases tracked during the heating process, a multi-stage degassing process (low, medium, and high temperatures) is derived. This process allows for the preparation and verification of low-oxygen-content powder high-temperature alloys across a wide particle size range, effectively reducing the harmful effects of humid environments on the alloys. This provides theoretical and technical support for high-quality high-temperature alloy powders used in powder metallurgy and additive manufacturing.

[0047] The method for obtaining the degassing temperature includes the following steps:

[0048] S1: Sieve the high-temperature alloy powder into narrow particle size segments of different particle size grades for later use;

[0049] S2: Using an oxygen and nitrogen gas analyzer, the gas content of the powders in the above particle size range was determined according to the pulse heating-infrared thermal conductivity method of HB5220.49-2008, and the high-temperature alloy powders with high oxygen content and narrow particle size range were selected.

[0050] S3: Place the selected high-temperature alloy powder with a narrow particle size range into a protective atmosphere programmed heating desorption equipment and heat it at a specified heating rate to a temperature below the solidus line of the high-temperature alloy powder (1000℃).

[0051] S4: Record the gas release curve of high-temperature alloy powder during the heating process using a mass spectrometer;

[0052] S5: Observe the water vapor release peak in the gas release curve, observe whether there is a double peak structure, read the temperature corresponding to the maximum value of the low temperature section peak and the medium temperature section peak, and use the temperature corresponding to the two peaks as the alternative heat preservation temperature for the subsequent full particle size section powder in the actual vacuum degassing medium and low temperature section.

[0053] S6: Observe the extraction peaks of oxygen, carbon dioxide, carbon monoxide and other oxygen-containing gases in the gas extraction curve, read their corresponding peak temperatures, compare them with the double peak temperatures of water vapor to see if there is any overlap, and select the temperature corresponding to the peak as the degassing and heat preservation temperature in the medium and high temperature range under the principle of the simplest number of process parameters.

[0054] S7: The actual degassing heating rate is selected to be the same as the heating rate used when the gas removal curve is obtained by the programmed temperature rise desorption equipment.

[0055] In S1, the narrow particle size range includes, but is not limited to: ≤15μm, 15~25μm, 25~32μm, 32~45μm, 45~53μm, 53~63μm, 63~75μm, 75~100μm, 100~120μm, and 120~150μm. Preferably, the selected narrow particle size range is within the full particle size range of the actual application.

[0056] In S6, other oxygen-containing gases include carbon monoxide and carbon dioxide.

[0057] The degassing process includes the following steps:

[0058] S11: Sieve the high-temperature alloy powder into a wide range of actual particle sizes for later use. The particle size range includes, but is not limited to: ≤53μm, ≤63μm, 15~53μm, 53~150μm, 75~150μm;

[0059] S12: High-temperature alloy powder is continuously compacted on a vibrating table and then loaded into a pouch. The pouch filled with powder is connected to the equipment, and a vacuum is evacuated at room temperature (25°C), with the vacuum level less than 1×10⁻⁶. -3 Pa is followed by a time t1, where t1 is 1 hour.

[0060] S13: Connect the powder-filled package to the equipment and begin vacuuming at room temperature (25°C), with the vacuum level less than 1×10⁻⁶. -3 Pa is followed by a time t4, where t4 is 1 hour.

[0061] S14: Set the heater temperature to 130–150°C, start heating, and heat until the temperature reaches 130–150°C and the vacuum is less than 1×10⁻⁶. -3 Pa, automatic heat preservation begins, heat preservation time is t5, heat preservation temperature is S6, the low temperature peak of water vapor double peak in the degassing kinetic curve of fine powder in narrow particle size range, where t5 is 3 hours;

[0062] S15: Adjust the heater set temperature to 280–310℃, and heat the jacket along with the furnace until the temperature reaches 280–310℃ and the vacuum is less than 1×10⁻⁶. -3 Pa, automatic heat preservation begins, heat preservation time is t6, heat preservation temperature is S6, the water vapor double peak position and carbon dioxide peak position in the narrow particle size range fine powder degassing kinetic curve, where t6 is 3 hours;

[0063] S16: Adjust the heater set temperature to 410–480℃, and heat the jacket along with the furnace until the temperature reaches 410–480℃ and the vacuum is less than 1×10⁻⁶. -3 Pa, start heat preservation, heat preservation time is t7, heat preservation temperature value is S6, the high temperature peak of carbon monoxide in the degassing kinetic curve of fine powder in narrow particle size range, where t7 is 3 hours;

[0064] S17: Adjust the heater setting temperature to the upper limit temperature of the degassing furnace (<600℃), and maintain the furnace temperature as it heats up, with a vacuum of less than 1×10⁻⁶. -3 Pa (Multi-stage degassing at medium, low, and high temperatures);

[0065] S18: Turn off the heating and keep the vacuum state for cooling for more than t8 hours, then remove the sleeve and perform sleeve sealing welding, where t8 is 1 hour.

[0066] In S18, the high-temperature alloy powder in the package is used to prepare high-temperature alloy ingots by hot isostatic pressing, or the high-temperature alloy powder is taken out of the package and stored in a vacuum. The high-temperature alloy powder can be used for powder metallurgy or additive manufacturing.

[0067] For comparison, conventional single-stage degassing can also be performed. Specific methods include: adjusting the heater set temperature to 300–360°C, heating the jacket along with the furnace, and raising the temperature to the specified level while maintaining a vacuum of less than 1×10⁻⁶. -3 Pa, heat preservation time t2, turn off heating and keep in vacuum state for cooling time t3 or more, remove the sleeve and perform sleeve sealing welding (single-stage degassing), where t2 is 9 hours and t3 is half an hour.

[0068] The method for testing the gas content in ingots or powders includes: using an oxygen and nitrogen gas analyzer, and determining the gas content according to the pulse heating-infrared thermal conductivity method (HB5220.49-2008). It should be noted that t2 = t5 + t6 + t7, and in this application, t2 is 9 hours, while t5, t6, and t7 are all 3 hours, satisfying the above equation.

[0069] Example 2

[0070] Reference Appendix Figure 1-5 This embodiment proposes a precise, customized processing technology to reduce the oxygen content of moist high-temperature alloy powder.

[0071] The method for obtaining the degassing temperature includes the following steps:

[0072] S1: Ni-Cr-Mo-Ti-Al-Hf-Ta-WBC nickel-based superalloy (1#) powder is sieved into narrow particle size ranges of different particle size grades for later use. The narrow particle size range is 15-25μm and 75-100μm.

[0073] S2: Using an oxygen and nitrogen gas analyzer, the gas content of the powders in the above particle size range was determined according to HB5220.49-2008 pulse heating-infrared thermal conductivity method. The oxygen content of the 15-25μm powder was 130ppm, and the oxygen content of the 75-100μm powder was 56ppm. The high-temperature alloy powder with a narrow particle size range and high oxygen content was selected.

[0074] S3: The selected powder with the preferred narrow particle size range is placed in a protective atmosphere programmed temperature rise desorption device and heated at a rate of 10℃ / min to 1000℃ below the solidus line of the alloy powder.

[0075] S4: Gas escape curve of high-temperature alloy (1#) powder during heating was recorded by mass spectrometry. Figure 1 The water vapor exhibits two peaks, with the peak positions corresponding to temperatures of 150℃ and 300℃, respectively.

[0076] S5: Observe the water vapor (H2O) detachment peak in the gas detachment curve. By observing the existence of a double peak structure, read the temperatures corresponding to the maximum values ​​of the low temperature range peak and the medium temperature range peak, which are 150℃ and 300℃ respectively. Use the temperatures corresponding to the two peaks as the alternative heat preservation temperatures for the medium and low temperature ranges of the actual vacuum degassing of powder in the full particle size range.

[0077] S6: Observe the extraction peaks of other oxygen-containing gases (such as carbon monoxide and carbon dioxide) in the gas extraction curve, and read their corresponding peak temperatures. Carbon dioxide is 310℃ and carbon monoxide is 470℃. Compare the double peak temperatures of water vapor to see if there is any overlap. Under the principle of the simplest number of process parameters, select the temperature corresponding to the peak as the degassing and heat preservation temperature in the medium and high temperature range. The degassing process temperature parameter combination for this alloy is 150℃ + 310℃ + 470℃.

[0078] S7: The actual heating rate during the degassing process is 10℃ / min.

[0079] The degassing process includes the following steps:

[0080] S11: Sieve the high-temperature alloy powder into a wide range of actual particle sizes for later use, with a particle size range of ≤53μm;

[0081] S12: While the powder is continuously compacted on the vibrating table, it is loaded into the packaging sleeve. The powder-filled sleeve is then connected to the equipment. Vacuuming begins at room temperature, with the vacuum level less than 1×10⁻⁶. -3 Keep it for 1 hour after Pa;

[0082] S13: Adjust the heater setting temperature to 300-360℃, and allow the jacket to heat up with the furnace until the temperature is reached and the vacuum is less than 1×10⁻⁶℃. -3 Pa, heat for 9 hours, turn off heating and keep in vacuum state for more than half an hour to cool, remove the sleeve and perform sleeve sealing welding (single-stage degassing);

[0083] S14: Connect the powder-filled package to the equipment and begin evacuation at room temperature (25°C), with the vacuum level less than 1×10⁻⁶. -3 Keep it for 1 hour after Pa;

[0084] S15: Set the heater temperature to 150℃ and start heating. Heat until the temperature reaches 130-150℃ and the vacuum is less than 1×10⁻⁶. -3 Pa, automatic heat preservation begins, heat preservation time is 3 hours, heat preservation temperature value is based on S6, preferably the low temperature peak position of water vapor double peak in the degassing kinetic curve of fine powder with narrow particle size range;

[0085] S16: Adjust the heater set temperature to 310℃, and heat the jacket along with the furnace until the temperature reaches 310℃ and the vacuum is less than 1×10⁻⁶. -3 Pa, automatic heat preservation begins, heat preservation time is 3 hours, heat preservation temperature value is based on S6, preferably the water vapor double peak position and carbon dioxide peak position in the narrow particle size range fine powder degassing kinetic curve;

[0086] S17: Adjust the heater set temperature to 470℃, and heat the jacket along with the furnace until the temperature reaches 470℃ and the vacuum is less than 1×10⁻⁶. -3Pa, automatic heat preservation begins, heat preservation time is 3 hours, heat preservation temperature value is based on S6, preferably the high temperature peak position of carbon monoxide in the degassing kinetic curve of fine powder with narrow particle size range;

[0087] S18: Adjust the heater set temperature to the upper limit temperature of the degassing furnace, and maintain the temperature of the jacket as the furnace heats up, with a vacuum of less than 1×10⁻⁶. -3 Pa.

[0088] S19: Turn off the heating and keep the vacuum state for more than 1 hour to cool. Then remove the sleeve and perform sleeve sealing welding.

[0089] S13 is a single-stage degassing process, while S14-S19 are multi-stage degassing processes, which facilitates control experiments.

[0090] Actual oxygen content test after degassing:

[0091] The oxygen content of the powdered high-temperature alloy ingot, which was formed by standard hot isostatic pressing, was analyzed using an oxygen and nitrogen gas analyzer. According to the pulse heating-infrared thermal conductivity method of HB5220.49-2008, the oxygen content after single-stage degassing was 113 ppm when the total degassing time was aligned. After multi-stage degassing optimized by water vapor bimodal peaks, the oxygen content was 96 ppm. The oxygen reduction treatment of the moist high-temperature alloy powder was achieved. The above results are summarized in Table 1, Experiment No. 1.

[0092] Example 3

[0093] Reference Appendix Figure 1-5 This embodiment proposes a precise, customized processing technology to reduce the oxygen content of moist high-temperature alloy powder.

[0094] S1: Ni-Cr-Mo-Ti-Al-Hf-Ta-WBC nickel-based superalloy (1#) powder is sieved into narrow particle size ranges of different particle size grades for later use. The narrow particle size range is 15-25μm and 75-100μm.

[0095] S2: Using an oxygen and nitrogen gas analyzer, the gas content of the powders in the above particle size range was determined according to HB5220.49-2008 pulse heating-infrared thermal conductivity method. The oxygen content of the 15-25μm powder was 130ppm, and the oxygen content of the 75-100μm powder was 56ppm. The coarse powder in the narrow particle size range of 75-100μm was used as a comparison with the preferred narrow particle size range high temperature alloy powder.

[0096] S3: Place the narrow particle size range powder into a protective atmosphere programmed temperature rise desorption device and heat it at a rate of 10℃ / min to 1000℃ below the solidus line of the alloy powder;

[0097] S4: Gas escape curve of coarse-grained powder of high-temperature alloy (1#) during the heating process was recorded by mass spectrometry. Figure 2 No obvious water vapor peak was observed, so the peak temperature could not be obtained. No double water vapor peak was found, so the temperature of the low-temperature peak could not be read. Therefore, it could not be used as a candidate insulation temperature for the low-temperature section of actual vacuum degassing. The above results are summarized in Table 1, Experiment No. 2.

[0098] Example 4

[0099] Reference Appendix Figure 1-5 This embodiment proposes a method for reducing the oxygen content of high-temperature alloy powder.

[0100] S1: Ni-Co-Cr-W-Mo-Nb-Al-Ti-BC nickel-based superalloy (2#) powder is sieved into a wide range of actual particle sizes for later use, with a particle size range of ≤53μm;

[0101] S2: Place the powder in a protective atmosphere programmed heating desorption equipment for heating to 1000°C below the solidus line of the alloy powder;

[0102] S3: Gas escape curve of high-temperature alloy (2#) powder during heating process was recorded by mass spectrometry. Figure 3 A water vapor peak appears, but no obvious bimodal structure is observed, making it impossible to distinguish the water vapor degassing characteristic sensitive temperature at medium and low temperatures (this is an existing technology with certain limitations).

[0103] S4: Observe the water vapor (H2O) detachment peak in the gas detachment curve. No double peak structure appears, and the temperature of the low temperature range peak cannot be read. It cannot be used as the alternative insulation temperature for the low temperature range of actual vacuum degassing. The above results are summarized in Table 1, Experiment No. 3.

[0104] Example 5

[0105] Reference Appendix Figure 1-5 This embodiment proposes a precise customized treatment process to reduce the oxygen content of moist superalloy powder. Ni-Cr-Mo-Ti-Al-Hf-Ta-WBC nickel-based superalloy (3#) powder was selected, and the remaining steps were the same as in Embodiment 2. The results are summarized in Table 1, under Experiment No. 4 and... Figure 4 (Two peaks of water vapor appear).

[0106] Example 6

[0107] Reference Appendix Figure 1-5 This embodiment proposes a precise customized treatment process to reduce the oxygen content of moist high-temperature alloy powder. Ni-Cr-Mo-Ti-Al-Hf-Ta-WBC nickel-based high-temperature alloy (3#) powder is selected, and the remaining steps are the same as in Example 3. The results are summarized in Experiment No. 5 in Table 1.

[0108] Example 7

[0109] Reference Appendix Figure 1-5 This embodiment proposes a precise customized treatment process to reduce the oxygen content of moist superalloy powder. Ni-Cr-Mo-Ti-Al-Hf-Ta-WBC nickel-based superalloy (4#) powder was selected, and the remaining steps were the same as in Example 2. The results are summarized in Table 1, Experiment No. 6 and... Figure 5 (Two peaks of water vapor appear).

[0110] Example 8

[0111] Reference Appendix Figure 1-5 This embodiment proposes a precise customized processing technology to reduce the oxygen content of moist high-temperature alloy powder. A nickel-based high-temperature alloy (4#) of Ni-Cr-Mo-Ti-Al-Hf-Ta-WBC is selected. The remaining steps are the same as in Embodiment 3. The results are summarized in Experiment No. 7 in Table 1.

[0112] Table 1: Selection of degassing process parameters for the highest peak position of oxygen-containing gases (water vapor, carbon dioxide, carbon monoxide) in Ni-based superalloy powders with different compositions, and oxygen content of the powder superalloys after degassing treatment.

[0113]

[0114] In the table above, the percentages of alloying elements in nickel-based superalloys (1#), (2#), (3#), and (4#) are different.

[0115] In summary, the method of narrow particle size sieving of fine powder can obtain a bimodal curve of water vapor, while the methods of Examples 3, 4, 6 and 8 cannot obtain a bimodal curve. Therefore, the sensitive temperature range of gas release of 130-150°C will be missed, and thus one of the optimized process parameters will be missed.

[0116] Example 2 (Experiment No. 1 in Table 1) compares the actual degassing parameters (including the 150°C degassing process) determined by the bimodal method with a single degassing temperature. The actual multi-stage degassing (including 150°C) determined by the bimodal method resulted in a lower oxygen content, which could be controlled below 100 ppm. The single-peaked sample was a comparative example of a nickel-based superalloy (2#) (Experiment No. 3 in Table 1).

[0117] In summary, the multi-stage degassing process (optimally selected at 25+150+300+470℃) optimized using a bimodal steam removal curve resulted in oxygen content of powdered high-temperature alloys (0–53 μm particle size range) with different compositions within the range of 87–96 ppm after degassing. This achieved the goal of controlling the oxygen content of high-temperature alloy powders stored under conventional air storage conditions to <100 ppm after degassing. Figure 6 ).

[0118] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A precise, customized processing technology for reducing the oxygen content of moist high-temperature alloy powder, characterized in that, The process involves screening high-temperature alloy powders of different particle sizes, selecting those sensitive to water vapor removal, and placing the high-temperature alloy powders into a protective atmosphere programmed temperature rise desorption device to obtain a double peak of water removal. The sensitive temperatures of water vapor removal in the low-temperature and medium-temperature sections are used as the water vapor degassing and heat preservation temperatures, respectively. Combined with the removal temperatures of other oxygen-containing gases tracked during the heating process, this is used as the basis to obtain a low, medium, and high-temperature multi-stage degassing process. The method for obtaining the degassing temperature includes the following steps: S1: The high-temperature alloy powder is sieved into narrow particle size ranges of different particle size grades for later use; wherein, the narrow particle size range includes: ≤15μm, 15~25μm excluding 15μm, 25~32μm excluding 25μm, 32~45μm excluding 32μm, 45~53μm excluding 45μm, 53~63μm excluding 53μm, 63~75μm excluding 63μm, 75~100μm excluding 75μm, 100~120μm excluding 100μm, and 120~150μm excluding 120μm; S2: Using an oxygen and nitrogen gas analyzer, the gas content of the powder in the above particle size range is determined by pulse heating-infrared thermal conductivity method, and high-temperature alloy powder with high oxygen content in a narrow particle size range is selected. S3: The selected high-oxygen-content, narrow-particle-size high-temperature alloy powder is placed in a protective atmosphere programmed heating desorption equipment and heated at a specified heating rate to a temperature below the solidus of the high-temperature alloy powder. S4: Gas release curve of high-temperature alloy powder during heating at the heating rate of S3 was recorded by mass spectrometry; S5: Observe the water vapor release peak in the gas release curve and observe whether there is a double peak structure. If there is a double peak structure, read the temperature corresponding to the maximum value of the low temperature peak and the medium temperature peak. Use the temperature corresponding to the two peaks as the alternative heat preservation temperature for the medium and low temperature sections of the actual vacuum degassing of powder in the subsequent full particle size range. S6: Observe the extraction peaks of other oxygen-containing gases in the gas extraction curve, read their corresponding peak temperatures, and compare them with the double peak temperatures of water vapor to see if there is any overlap. If there is an overlap, select the temperature corresponding to the peak as the degassing and heat preservation temperature in the medium and low temperature range under the principle of the simplest number of process parameters. The other oxygen-containing gases include oxygen, carbon dioxide and carbon monoxide. S7: The actual degassing heating rate is selected to be the same as the heating rate used when the gas removal curve is obtained by the programmed temperature rise desorption equipment.

2. The precise customized processing technology for reducing the oxygen content of moisture-containing high-temperature alloy powder according to claim 1, characterized in that, The degassing process includes the following steps: S11: Sieve the high-temperature alloy powder into a wide range of actual particle sizes for later use. The wide range of actual particle sizes includes: ≤53μm, ≤63μm, 15~53μm, 53~150μm, and 75~150μm. S12: High-temperature alloy powder is continuously compacted on a vibrating table and then loaded into a pouch. The pouch filled with powder is connected to the equipment, and a vacuum is started at room temperature, with the vacuum level less than 1×10⁻⁶. -3 Pa followed by a hold time t1; S13: Connect the powder-filled package to the equipment and begin evacuation at room temperature, with a vacuum level less than 1 × 10⁻⁶. -3 Pa followed by t4 time; S14: Set the heater temperature to 130~150℃, start heating, and heat until the temperature reaches 130~150℃ and the vacuum is less than 1×10⁻⁶. -3 Pa, automatic heat preservation begins, heat preservation time is t5 time, heat preservation temperature value is the low temperature peak of the water vapor double peak in the degassing kinetic curve of the high oxygen content narrow particle size range high-temperature alloy powder in S6. S15: Adjust the heater set temperature to 280~310℃, and heat the jacket along with the furnace until the temperature reaches 280~310℃ and the vacuum is less than 1×10⁻⁶. -3 Pa, automatic heat preservation begins, heat preservation time is t6, and heat preservation temperature value is the mid-temperature peak position of water vapor double peak and carbon dioxide peak position in the degassing kinetic curve of high oxygen content narrow particle size range high temperature alloy powder in S6. S16: Adjust the heater set temperature to 410~480℃, and heat the jacket along with the furnace until the temperature reaches 410~480℃ and the vacuum is less than 1×10⁻⁶. -3 Pa, start heat preservation, heat preservation time is t7 time, heat preservation temperature value is the high temperature peak position of carbon monoxide in the narrow particle size range fine powder degassing kinetic curve in S6. S17: Adjust the heater set temperature to the upper limit temperature of the degassing furnace, and maintain the furnace temperature as it heats up, with a vacuum of less than 1×10⁻⁶. - 3 Pa; S18: Turn off the heating, maintain the vacuum state and cool for more than t8 hours, then remove the sleeve and perform sleeve sealing welding.

3. The precise customized processing technology for reducing the oxygen content of moist high-temperature alloy powder according to claim 2, characterized in that, In step S18, the high-temperature alloy powder in the cladding is used to prepare a high-temperature alloy ingot using hot isostatic pressing.

4. The precise customized processing technology for reducing the oxygen content of moisture-containing high-temperature alloy powder according to claim 3, characterized in that, Methods for testing the gas content in ingots or powders include: using an oxygen and nitrogen gas analyzer and determining it according to the pulse heating-infrared thermal conductivity method.

Images