Crack-free heat treatment method for additive manufacturing of nickel-based superalloy
By employing a rapid heating rate of no less than 40℃/min in the heat treatment of additive manufacturing nickel-based superalloys, the problem of cracking during heat treatment was solved, the pass rate of components was improved, and the process was simplified. This method is applicable to a variety of nickel-based superalloys.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-14
- Publication Date
- 2026-04-14
AI Technical Summary
Additive manufacturing of nickel-based superalloys is prone to cracking during subsequent heat treatment, leading to component scrapping, a problem that is difficult to solve effectively with existing technologies.
Heat treatment is carried out using a rapid heating rate of not less than 40℃/min, especially by rapidly crossing the temperature range of 500℃ to 850℃, to suppress the precipitation of carbide M23C6.
It effectively avoids cracks during heat treatment, significantly improves the pass rate of components, has a simple process and low cost, and is suitable for a variety of nickel-based high-temperature alloys.
Smart Images
Figure CN121847820A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of high-temperature alloy heat treatment technology, and specifically to a crack-free heat treatment method for additive manufacturing of nickel-based high-temperature alloys. Background Technology
[0002] Nickel-based superalloys are key materials for manufacturing hot-end components of high-end equipment such as aerospace engines and gas turbines. Additive manufacturing technologies, such as laser powder bed melting, have provided revolutionary means for forming complex components of these alloys. However, a serious problem generally exists in the subsequent heat treatment process, which is indispensable in additive manufacturing of nickel-based superalloys: intergranular cracks are easily generated during the heating stage of heat treatment, leading to the direct scrapping of components and low yield, which greatly restricts the industrial application of this technology.
[0003] Traditional heat treatment processes typically employ slow heating rates (e.g., 5–20 °C / min), leading to the precipitation of a large amount of second-phase during the heating process, which in turn causes component cracking. Existing technologies have attempted to adjust alloy composition and employ complex multi-stage heat treatment processes, but the effects have been limited and may introduce new problems. Therefore, there is an urgent need for a simple, universal method that can fundamentally suppress this type of heat treatment cracking. Summary of the Invention
[0004] The present invention aims to solve the technical problem that existing additive manufacturing nickel-based superalloys are prone to cracking during the subsequent heat treatment heating stage, leading to the direct scrapping of components, and provides a crack-free heat treatment method for additive manufacturing nickel-based superalloys.
[0005] The crack-free heat treatment method for additive manufacturing of nickel-based superalloys of the present invention is carried out according to the following steps:
[0006] The nickel-based superalloy workpiece obtained by additive manufacturing is placed in a heat treatment furnace and heated from room temperature to the target heat treatment temperature at a heating rate of 40℃ / min to 200℃ / min. The workpiece is then held at the target heat treatment temperature and subsequently cooled according to the process requirements.
[0007] The method of this invention effectively suppresses carbide formation during the heating process by increasing the heating rate of additively manufactured nickel-based superalloys to no less than 40°C / min in the initial stage of heat treatment. 23 The precipitation of C6 at grain boundaries fundamentally avoids the formation of cracks. This method is particularly suitable for precipitation-strengthened high-temperature alloys such as IN738LC alloy. The process is simple and reliable, providing an effective solution for defect-free heat treatment of additively manufactured high-temperature alloy components.
[0008] A heating rate of at least 40°C / min is crucial in the method of this invention. This rate is set to rapidly traverse a specific temperature range of 500°C to 850°C in the initial stage of heat treatment, thereby effectively suppressing the harmful carbide phase M that may cause cracking during this process. 23 C6 precipitation.
[0009] The beneficial effects of this invention are as follows:
[0010] 1. Effectively solves the cracking problem: This invention, by using a rapid heating rate of no less than 40℃ / min, can stably avoid cracking of additive manufacturing nickel-based superalloys during heat treatment, and significantly improve the qualification rate of components;
[0011] 2. Clear mechanism and significant effect: The method of this invention is based on a clear process-structure-property relationship. By controlling the key parameter of heating rate, it directly intervenes in the micro-process that leads to cracking. The technical effect is predictable and has good repeatability.
[0012] 3. The process of this invention is extremely simple and highly applicable. It only requires adjusting the heating program of existing heat treatment equipment without adding any additional processes or equipment. It is low in cost and easy to implement and promote in industrial settings. This method is particularly suitable for IN738LC alloy and has application potential for other nickel-based high-temperature alloys with similar properties.
[0013] 4. Excellent compatibility: The rapid heating step of this invention can be used as a pretreatment and can be seamlessly connected with subsequent heat treatment processes for various purposes (such as aging, solution treatment, homogenization, etc.), with a wide range of applications. Attached Figure Description
[0014] Figure 1 To obtain macroscopic surface morphology images of the samples for comparative experiments;
[0015] Figure 2 To obtain the surface macroscopic morphology image of the sample in Experiment 1;
[0016] Figure 3 To obtain backscattered electron (BSE) images of the samples for comparison experiments;
[0017] Figure 4 To obtain the backscattered electron (BSE) image of the sample in Experiment 1;
[0018] Figure 5 The surface macroscopic morphology of the sample obtained in Experiment 2;
[0019] Figure 6 The image shows the macroscopic surface morphology of the sample obtained in Experiment 3. Detailed Implementation
[0020] Specific Implementation Method 1: This implementation method is a crack-free heat treatment method for additive manufacturing of nickel-based superalloys, specifically carried out according to the following steps:
[0021] The nickel-based superalloy workpiece obtained by additive manufacturing is placed in a heat treatment furnace and heated from room temperature to the target heat treatment temperature at a heating rate of 40℃ / min to 200℃ / min. The workpiece is then held at the target heat treatment temperature and subsequently cooled according to the process requirements.
[0022] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the nickel-based superalloy used is IN738LC alloy. Everything else is the same as in Specific Implementation Method One.
[0023] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that the additive manufacturing described herein is laser powder bed melting technology. Everything else is the same as in Specific Implementation Method One or Two.
[0024] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the target heat treatment temperature is 850℃~1250℃. Everything else is the same as in Specific Implementation Methods One to Three.
[0025] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method Four in that the target heat treatment temperature is 850℃. Everything else is the same as in Specific Implementation Method Four.
[0026] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method Five in that the target heat treatment temperature is 900℃. Everything else is the same as in Specific Implementation Method Five.
[0027] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method Six in that the target heat treatment temperature is 1120℃. Everything else is the same as in Specific Implementation Method Six.
[0028] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method Seven in that the target heat treatment temperature is 1250℃. Everything else is the same as in Specific Implementation Method Seven.
[0029] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method Eight in that the workpiece is heated from room temperature to the target heat treatment temperature at a heating rate of 40℃ / min. Everything else is the same as in Specific Implementation Method Eight.
[0030] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Method Nine in that it involves holding the sample at the target heat treatment temperature, followed by air cooling to room temperature. Everything else is the same as in Specific Implementation Method Nine.
[0031] The invention was verified using the following experiments:
[0032] Experiment 1: This experiment demonstrates a crack-free heat treatment method for additive manufacturing of nickel-based superalloys, specifically carried out according to the following steps:
[0033] The nickel-based superalloy workpiece (10mm×10mm×10mm) obtained by additive manufacturing was placed in a heat treatment furnace and heated from room temperature to the target heat treatment temperature of 850℃ at a heating rate of 40℃ / min. The workpiece was held at the target heat treatment temperature for 0h and then air-cooled to room temperature.
[0034] The nickel-based superalloy is IN738LC alloy;
[0035] The additive manufacturing described herein is laser powder bed melting technology.
[0036] Figure 2 The surface macroscopic morphology of the sample obtained in Experiment 1 is shown in the figure. The sample surface only showed uniform oxidation without any macroscopic cracks. Its backscattered electron (BSE) image is shown below. Figure 4 As shown, no continuous chain-like carbide precipitates were observed at the grain boundaries.
[0037] Experiment 2: This experiment differs from Experiment 1 in that the workpiece is heated from room temperature to the target heat treatment temperature of 1120℃ at a heating rate of 60℃ / min and held at that temperature for 2 hours. Everything else is the same as Experiment 1. Figure 5 The surface macroscopic morphology of the sample was obtained for Experiment 2. The result was that the sample was intact and had no cracks.
[0038] Experiment 3: This experiment differs from Experiment 1 in that the workpiece is heated from room temperature to the target heat treatment temperature of 1250℃ at a heating rate of 150℃ / min and held at that temperature for 2 hours. Everything else is the same as Experiment 1. Figure 6 The surface macroscopic morphology of the sample was obtained for Experiment 3. The result was that the sample was intact and had no cracks.
[0039] Comparative experiment: The difference between this experiment and Experiment 1 is that the heating rate is 5℃ / min. Everything else is the same as Experiment 1.
[0040] Figure 1 To compare the results, a macroscopic surface morphology image of the sample was obtained, as shown in the figure. The sample underwent severe cracking after heat treatment. Its backscattered electron (BSE) image is shown below. Figure 3 As shown, a large number of continuous chain-like precipitates M exist at the grain boundaries. 23 C6, the cracks are distributed along this precipitate phase.
[0041] The comparison between the above experiments and comparative experiments fully demonstrates that, for additively manufactured IN738LC alloys, increasing the initial heating rate of heat treatment to no less than 40℃ / min is a key and effective technical means to avoid heat treatment cracking. The method of this invention is simple and efficient, providing a reliable solution to a long-standing technical problem in this field.
Claims
1. A crack-free heat treatment method for additive manufacturing of nickel-based superalloys, characterized in that... The method is performed according to the following steps: The nickel-based superalloy workpiece obtained by additive manufacturing is placed in a heat treatment furnace and heated from room temperature to the target heat treatment temperature at a heating rate of 40℃ / min to 200℃ / min. The workpiece is then held at the target heat treatment temperature and subsequently cooled according to the process requirements.
2. The crack-free heat treatment method for additive manufacturing of nickel-based superalloys according to claim 1, characterized in that... The nickel-based superalloy is IN738LC alloy.
3. The crack-free heat treatment method for additive manufacturing of nickel-based superalloys according to claim 1, characterized in that... The additive manufacturing described herein is laser powder bed melting technology.
4. The crack-free heat treatment method for additive manufacturing of nickel-based superalloys according to claim 1, characterized in that... The target heat treatment temperature is 850℃~1250℃.
5. A crack-free heat treatment method for additive manufacturing of nickel-based superalloys according to claim 4, characterized in that... The target heat treatment temperature is 850℃.
6. A crack-free heat treatment method for additive manufacturing of nickel-based superalloys according to claim 4, characterized in that... The target heat treatment temperature is 900℃.
7. A crack-free heat treatment method for additive manufacturing of nickel-based superalloys according to claim 4, characterized in that... The target heat treatment temperature is 1120℃.
8. A crack-free heat treatment method for additive manufacturing of nickel-based superalloys according to claim 4, characterized in that... The target heat treatment temperature is 1250℃.
9. A crack-free heat treatment method for additive manufacturing of nickel-based superalloys according to claim 1, characterized in that... The workpiece is heated from room temperature to the target heat treatment temperature at a heating rate of 40℃ / min.
10. A crack-free heat treatment method for additive manufacturing of nickel-based superalloys according to claim 1, characterized in that... Hold at the target heat treatment temperature, then air cool to room temperature.