High-throughput experimental method for γ′ phase dissolution in nickel-based powder metallurgy superalloys

Abstract

The present invention discloses a high-throughput experimental method for the dissolution of γ′ phase in nickel-based powder high-temperature alloy, comprising the following steps: subjecting a nickel-based powder high-temperature alloy round rod sample to a solid solution treatment and then end-quenching cooling, thereby obtaining a sample with continuously changing γ′ phase size distribution and morphology in a high-throughput one-time manner; processing the round rod sample with continuously changing γ′ phase after end-quenching into a thin-sheet γ′ phase dissolution experimental sample; placing the thin-sheet sample in a vertical furnace that has reached a set solid solution temperature, rapidly heating it, and then rapidly cooling it after holding it for a period of time to retain the high-temperature structure; the present invention uses a high-throughput technology to quickly characterize and obtain dissolution data of γ′ phases of different sizes, distributions, and morphologies in nickel-based powder high-temperature alloys, thereby efficiently studying the dissolution behavior of the γ′ phase in the alloy and its influencing factors and dynamics; at the same time, the present invention is simple to operate, and experiments can be quickly carried out while ensuring test accuracy to obtain a large amount of continuous data; moreover, it can also reduce test time and cost and improve test efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of heat treatment technology in nickel-based powder high-temperature alloys, in particular to a high-throughput experimental method for dissolution of γ′ phase in nickel-based powder high-temperature alloys. Background Art

[0002] Nickel-based powder metallurgy superalloys (NMIs) possess excellent oxidation resistance, microstructure stability, and high-temperature mechanical properties, making them a key material of choice for hot-end components such as advanced aeroengine turbine disks. To meet the high-performance, high-thermal-efficiency, long-life, and high-reliability requirements of aeroengines, the alloying degree of NMIs has been continuously increased (to 40% to 50% by mass). However, this deteriorates the alloy's thermoplasticity during hot working, making microstructure control difficult and hindering the alloy's development towards higher performance. A high volume fraction (35% to 60%) of the ordered L12-type γ′ phase, coherent with the γ matrix, not only strengthens the alloy but also regulates its microstructure during hot working. During hot working, the γ′ phase dissolves or precipitates, altering its volume fraction, size, and distribution, thus affecting the alloy's hot-working properties and microstructural evolution. Understanding the dissolution and precipitation patterns of the γ′ phase during hot working is of great engineering significance for predicting and controlling the microstructure of powder metallurgy superalloys during hot working, optimizing hot working processes, and improving the alloy's hot working properties.

[0003] While much research has been conducted on γ′ phase precipitation, relatively little has been done on its dissolution during hot working. The dissolution behavior of γ′ phase can be highly complex, influenced by factors such as the initial γ′ phase content, type, size distribution, and hot working process. Currently, conventional homogenous specimens are primarily used to investigate the influence of these factors on the dissolution behavior and mechanism of high-volume-fraction γ′ phase. However, this approach is time-consuming, labor-intensive, inefficient, and produces disseminated data. Therefore, it is imperative to develop high-throughput experimental methods for studying γ′ phase dissolution in nickel-based powder metallurgy superalloys. Summary of the Invention

[0004] The problem solved by the present invention is to provide a high-throughput experimental method for the dissolution of γ′ phase in nickel-based powder high-temperature alloys. By using high-throughput technology, the dissolution data of γ′ phases of different sizes, distributions, and morphologies in nickel-based powder high-temperature alloys can be quickly characterized and obtained. The dissolution behavior of the γ′ phase in nickel-based powder high-temperature alloys and its influencing factors and dynamics can be efficiently studied, providing data and theoretical support for the organizational regulation and thermal processing process optimization design of nickel-based powder high-temperature alloys. At the same time, the present invention is simple to operate, and experiments can be carried out quickly while ensuring test accuracy to obtain a large amount of continuous data. Moreover, it can also reduce test time and cost and improve test efficiency.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A high-throughput experimental method for the dissolution of γ′ phase in nickel-based powder superalloys includes the following steps:

[0007] a. Ni-based powder high-temperature alloy round rod specimens were solution treated and then end-quenched to obtain samples with continuously changing γ′ phase size distribution and morphology in a high-throughput, one-time process.

[0008] b. Processing the round rod sample with continuously changing γ′ phase size distribution and morphology after end quenching into a thin sheet-like γ′ phase dissolution test sample;

[0009] c. The thin slice sample was subjected to a γ′ phase dissolution heat treatment experiment using a rapid heating and rapid cooling experimental device to obtain the γ′ phase structure during the high-temperature dissolution process;

[0010] d. Rapid characterization of end-quenched and heat-treated samples under high-throughput scanning electron microscopy;

[0011] e. Use computer vision and deep learning image analysis methods to quickly extract and process the characteristic parameters of the γ′ phase from the characterization images for analyzing the tissue evolution during the dissolution process.

[0012] As a further solution of the present invention: in step a, the end quenching gradient cooling experimental device includes a computer terminal, a data acquisition instrument, a temperature measuring thermocouple, a temperature controlling thermocouple, an induction coil, an induction heating power supply, a temperature controller, a water tank and a water pump, an induction coil is provided on one side of the induction heating power supply, a temperature controlling thermocouple and a temperature measuring thermocouple are respectively provided on the outside of the induction coil, and a data acquisition instrument is provided at one end of the temperature measuring thermocouple, a computer terminal is provided on one side of the data acquisition instrument, a temperature controller is provided on one side of the temperature controlling thermocouple, and the induction heating power supply and the temperature controller are arranged, a water pump is provided below the bottom of the induction coil, and the bottom of the water pump is connected to the water tank;

[0013] The end-quenched standard specimen is heated and then kept warm using an end-quenching gradient cooling experimental device. The kept warm specimen is then kept in place and cooled from one end of the kept warm specimen. The cooling rate of the specimen gradually decreases from the cooling end to the non-cooling end, thereby achieving a series of continuously different cooling rates on one specimen, and thus obtaining γ′ phase structures with different sizes, distributions, and morphologies.

[0014] As a further solution of the present invention: in step b, in order to achieve rapid heating, a sample of appropriate size is selected, and at the same time, the surface free energy of the material does not affect the dissolution behavior of the alloy γ′ phase. The round rod sample with continuous change of γ′ phase after end quenching is machined into a thin sheet of γ′ phase dissolution experimental sample with a thickness of 0.5 mm for use in the next step of heat treatment dissolution experiment.

[0015] As a further embodiment of the present invention: in step c, the rapid heating and cooling experimental apparatus includes a vertical tube furnace and an ice water quenching tank, wherein the vertical tube furnace is disposed above the top of the ice water quenching tank; to minimize thermal fluctuations during the experiment, ceramic plugs are installed at the top and bottom of the vertical tube furnace, and sample through holes are provided in the ceramic plugs;

[0016] The thin slice sample was subjected to a heat treatment dissolution experiment using a rapid heating and cooling experimental device. The experimental steps are as follows:

[0017] 1) When the vertical tube furnace is heated to the set temperature, use a steel rod to place the thin sample into the furnace through the through-hole at the top of the tube furnace and position it in the heating zone of the furnace; at the same time, use a thin nickel wire to thermally isolate the sample from the steel rod;

[0018] The sample is fixed to the end of the steel rod about 5 mm with a thin nickel wire. One end of the nickel wire is fixed to the small ring at the end of the steel rod, and the other end is fixed to the circular hole at the upper end of the specimen.

[0019] 2) When the furnace temperature returns to the set temperature, start timing. After the set holding time is reached, open the positioning clamp on the upper end of the steel rod, and drop the sample directly into the ice water tank along with the steel rod to achieve rapid cooling, and obtain the γ′ phase high-temperature dissolved structure at the set dissolution temperature and time.

[0020] As a further solution of the present invention: in step d, the end-quenched sample and the heat-treated sample are ground, polished, and corroded, and then the sample tissue is photographed continuously at large scale and high magnification under a high-throughput, high-resolution scanning electron microscope.

[0021] As a further solution of the present invention: in step e, a deep learning image analysis method is used to quickly extract and process the γ′ phase characteristic data of the picture taken in d, so as to analyze the tissue evolution during the dissolution process.

[0022] The beneficial effect of the present invention is as follows: based on the influence of heat treatment technology on the microstructure of nickel-based high-temperature alloys, the present invention uses high-throughput preparation and high-throughput characterization as main technologies, that is, first, gradient cooling that can be achieved by end quenching is used to prepare alloy samples containing γ′ phases of different sizes, distributions and morphologies, and then rapid heating and cooling that can be achieved by a vertical tubular furnace and an ice water quenching tank device are used to obtain the phase dissolution structure of the alloy at different temperatures and times. Finally, a high-throughput scanning electron microscope is used to quickly and efficiently characterize the end-quenched samples and solution-treated samples, and a deep learning image analysis method is used to quickly extract and process the γ′ phase characteristic data, so as to more efficiently analyze the dissolution behavior and dynamics of γ′ phases of different sizes, distributions and morphologies in nickel-based high-temperature alloys, so as to analyze the evolution of the γ′ phase structure during the dissolution process, and provide data and theoretical support for structure regulation and process optimization design during heat treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the end-quenching gradient cooling experimental device of the present invention;

[0024] Figure 2 This is a diagram showing the sampling position of the dissolution sample and the size of the γ′ phase dissolution sample of the present invention;

[0025] Figure 3 Schematic diagram of the rapid heating and cooling experimental device of the present invention; DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] Specific examples are given below.

[0028] See also Figure 1-3 A high-throughput experimental method for the dissolution of γ′ phase in nickel-based powder superalloys comprises the following steps:

[0029] a. Ni-based powder high-temperature alloy round rod specimens were solution treated and then end-quenched to obtain samples with continuously changing γ′ phase size distribution and morphology in a high-throughput, one-time process.

[0030] The end quenching gradient cooling experimental device includes a computer terminal, a data acquisition instrument, a temperature measuring thermocouple, a temperature controlling thermocouple, an induction coil, an induction heating power supply, a temperature controller, a water tank and a water pump. An induction coil is provided on one side of the induction heating power supply, and a temperature controlling thermocouple and a temperature measuring thermocouple are provided on the outside of the induction coil respectively. A data acquisition instrument is provided at one end of the temperature measuring thermocouple, a computer terminal is provided on one side of the data acquisition instrument, a temperature controller is provided on one side of the temperature controlling thermocouple, and the induction heating power supply and the temperature controller are provided. A water pump is provided under the bottom of the induction coil, and the bottom of the water pump is connected to the water tank.

[0031] During operation, after placing the sample inside the induction coil, the induction heating power supply starts working, so that the induction coil can heat the sample. During the heating process, the temperature can be easily controlled through the temperature-controlling thermocouple and the temperature controller, and the temperature measuring thermocouple facilitates data acquisition by the data acquisition instrument, and the computer terminal facilitates electronic control, thereby facilitating temperature control. During cooling, the water pump works to cool the sample with the cooling water inside the water tank.

[0032] The end-quenched standard specimen is heated and then held in temperature using an end-quenched gradient cooling experimental device. The held-temperature specimen is then kept in place and cooled from one end. The cooling rate of the specimen gradually decreases from the cooled end to the uncooled end, thereby achieving a series of continuously different cooling rates on the same specimen, thereby obtaining γ′ phase structures with different size distributions and morphologies.

[0033] b. Processing the round rod sample with continuously changing γ′ phase size distribution and morphology after end quenching into a thin sheet-like γ′ phase dissolution test sample;

[0034] In order to achieve rapid heating, a sample of appropriate size was selected, and at the same time, the surface free energy of the material did not affect the dissolution behavior of the alloy γ′ phase. The round rod sample with continuously changing γ′ phase size distribution and morphology after end quenching was machined into a thin sheet-shaped γ′ phase dissolution test sample with a thickness of 0.5 mm for the next heat treatment dissolution experiment.

[0035] c. The thin slice sample is subjected to a heat treatment experiment using a rapid heating and cooling device to obtain a γ′ phase high-temperature dissolved structure at a set temperature and time;

[0036] The rapid heating and cooling experimental apparatus consists of a vertical tube furnace and an ice-water quenching tank. The vertical tube furnace is located above the top of the ice-water quenching tank. To minimize thermal fluctuations during the experiment, ceramic plugs with sample holes are installed at the top and bottom of the vertical tube furnace.

[0037] When the vertical tube furnace is heated to the set temperature, a steel rod is used to place the thin sample into the furnace through the through-hole at the top of the tube furnace and position it in the heating zone of the furnace. At the same time, a thin nickel wire is used to thermally isolate the sample from the steel rod.

[0038] The sample is fixed to the end of the steel rod about 5 mm with a thin nickel wire. One end of the nickel wire is fixed to the small ring at the end of the steel rod, and the other end is fixed to the circular hole at the upper end of the specimen.

[0039] When the furnace temperature returns to the set temperature, the timing starts. After the set holding time is reached, the positioning clamp on the upper end of the steel rod is opened, and the sample and the steel rod are directly dropped into the ice water tank to achieve rapid cooling and retain the high-temperature dissolved structure of the γ′ phase;

[0040] d. Rapid characterization of end-quenched and heat-treated samples under high-throughput scanning electron microscopy;

[0041] The end-quenched and heat-treated samples were ground, polished, and etched, and then large-scale, continuous, high-magnification photographs of the sample structures were taken under a high-throughput, high-resolution scanning electron microscope.

[0042] e. Using computer vision and deep learning image analysis methods to rapidly extract and process γ′ phase characteristic parameters from characterization images for analysis of microstructure evolution during dissolution;

[0043] A deep learning image analysis method is used to quickly extract and process the γ′ phase characteristic data from the image taken in d for analyzing the tissue evolution during the dissolution process.

[0044] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A high-throughput experimental method for the dissolution of γ′ phase in nickel-based powder superalloys, characterized in that: The following steps are involved: a. Ni-based powder high-temperature alloy round rod specimens were solution treated and then end-quenched to obtain samples with continuously changing γ′ phase size distribution and morphology in a high-throughput, one-time process. b. Processing the round rod sample with continuously changing γ′ phase size distribution and morphology after end quenching into a thin sheet-like γ′ phase dissolution test sample; c. The thin-section specimens were subjected to a γ′ phase dissolution heat treatment experiment using a rapid heating and cooling experimental apparatus to obtain a γ′ phase structure during the high-temperature dissolution process. In step c, the rapid heating and cooling experimental apparatus comprised a vertical tube furnace and an ice-water quenching tank, with the vertical tube furnace positioned above the ice-water quenching tank. To minimize thermal fluctuations during the experiment, ceramic plugs with sample access holes were installed at the top and bottom of the vertical tube furnace. The thin slice sample was subjected to a heat treatment dissolution experiment using a rapid heating and cooling experimental device. The experimental steps are as follows: 1) When the vertical tube furnace is heated to the set temperature, use a steel rod to place the thin sample into the furnace through the through-hole at the top of the tube furnace and position it in the heating zone of the furnace; at the same time, use a thin nickel wire to thermally isolate the sample from the steel rod; The sample is fixed to the end of the steel rod about 5 mm with a thin nickel wire. One end of the nickel wire is fixed to the small ring at the end of the steel rod, and the other end is fixed to the circular hole at the upper end of the specimen. 2) When the furnace temperature returns to the set temperature, the timing starts. After the set holding time is reached, the positioning clamp on the upper end of the steel rod is opened, and the sample and the steel rod are directly dropped into the ice water tank to achieve rapid cooling, and the γ′ phase high temperature dissolved structure at the set dissolution temperature and time is obtained; d. Rapid characterization of end-quenched and heat-treated samples under high-throughput scanning electron microscopy; e. Use computer vision and deep learning image analysis methods to quickly extract and process the characteristic parameters of the γ′ phase from the characterization images for analyzing the tissue evolution during the dissolution process.

2. The high-throughput experimental method for γ′ phase dissolution in nickel-based powder superalloy according to claim 1, characterized in that: In step a, the end-quenching gradient cooling experimental device includes a computer terminal, a data acquisition instrument, a temperature measuring thermocouple, a temperature controlling thermocouple, an induction coil, an induction heating power supply, a temperature controller, a water tank and a water pump. An induction coil is provided on one side of the induction heating power supply, and a temperature controlling thermocouple and a temperature measuring thermocouple are respectively provided on the outside of the induction coil. A data acquisition instrument is provided at one end of the temperature measuring thermocouple, a computer terminal is provided on one side of the data acquisition instrument, a temperature controller is provided on one side of the temperature controlling thermocouple, and the induction heating power supply and the temperature controller are provided. A water pump is provided below the bottom of the induction coil, and the bottom of the water pump is connected to the water tank; The end-quenched standard specimen is heated and then kept warm using an end-quenching gradient cooling experimental device. The kept warm specimen is then kept in place and cooled from one end of the kept warm specimen. The cooling rate of the specimen gradually decreases from the cooling end to the non-cooling end, thereby achieving a series of continuously different cooling rates on one specimen, and thus obtaining γ′ phase structures with different sizes, distributions, and morphologies.

3. The high-throughput experimental method for γ′ phase dissolution in nickel-based powder superalloy according to claim 1, characterized in that: In step b, in order to achieve rapid heating, a sample of appropriate size is selected. At the same time, the surface free energy of the material does not affect the dissolution behavior of the alloy γ′ phase. The round rod sample with continuously changing γ′ phase size distribution after end quenching is machined into a thin sheet of γ′ phase dissolution experimental sample with a thickness of 0.5 mm for the next heat treatment dissolution experiment.

4. The high-throughput experimental method for γ′ phase dissolution in nickel-based powder superalloy according to claim 1, characterized in that: In step d, the end-quenched sample and the heat-treated sample are ground, polished, and etched, and then the sample tissue is photographed continuously at large scale and high magnification under a high-throughput, high-resolution scanning electron microscope.

5. The high-throughput experimental method for γ′ phase dissolution in nickel-based powder superalloy according to claim 1, characterized in that: In step e, a deep learning image analysis method is used to quickly extract and process the γ′ phase characteristic data of the image taken in step d for analyzing the tissue evolution during the dissolution process.

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