Method for enhancing and improving comprehensive mechanical properties of laser additive manufacturing nickel-based superalloy through in-situ synergistic reaction of Si and N elements
Through Si3N4 in-situ collaborative reaction to regulate the laser absorption rate, a nickel-based high-temperature alloy composite with refined structure was prepared, which solved the problem of high precision and high performance in the manufacturing of nickel-based high-temperature alloy components by laser powder bed melting technology, achieving improvements in strength, hardness and ductility, while reducing the friction coefficient.
Patent Information
- Application Number
- CN202510417627.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2025-08-08
AI Technical Summary
The existing laser powder bed melting technology is difficult to meet the requirements of high precision and high performance when manufacturing nickel-based high-temperature alloy components. Especially in aerospace components with complex shapes and high dimensional accuracy, the nano-modification method has room for improvement, but there are problems of long production cycles and high cost.
Si3N4 is used as the reinforced phase, and through the in-situ synergistic reaction of Si and N elements, the laser absorption rate affects the laser forming temperature field, and a nickel-based high-temperature alloy composite material is prepared with a refined structure, which improves its strength, hardness, modulus and ductility, and reduces the friction coefficient.
The comprehensive mechanical properties of nickel-based high-temperature alloys are significantly improved, especially in structural parts such as aerospace combustion chambers and engine blades, which show excellent strength, hardness and ductility, while avoiding changes in other characteristics.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of laser powder bed fusion forming of metal components, and specifically relates to a method for enhancing the comprehensive mechanical properties of laser additively manufactured nickel-based high-temperature alloys through in-situ synergistic reaction of Si and N elements. Background Art
[0002] Nickel-based superalloy GH4169, due to its excellent high-temperature mechanical properties, corrosion resistance, and oxidation resistance, is widely used in the manufacture of aircraft engine combustion components and other components used in high-temperature environments. In practical applications, these nickel-based superalloy components often have complex shapes and high dimensional accuracy requirements, so achieving their precise forming presents certain challenges.
[0003] Laser Powder Bed Fusion (LPBF) technology uses a high-energy laser beam with a diameter of microns to build components layer by layer according to CAD models. It is an effective method for manufacturing high-precision and complex nickel-based components.
[0004] With the continuous advancement of science and technology, higher requirements have been placed on the performance of nickel-based superalloy components formed by LPBF. The academic community has conducted in-depth and detailed research on this, covering a variety of methods such as laser process optimization, post-heat treatment and nano-modification. Among them, laser process optimization has limited room for performance improvement, while post-heat treatment will extend the production cycle of LPBF nickel-based superalloy components and increase costs. In contrast, nano-modification provides an ideal way to improve the performance of LPBF-formed nickel-based superalloy components. By regulating the microstructure of nickel-based superalloys, their mechanical properties, corrosion resistance and oxidation resistance can be significantly enhanced. This method will play a key role in the widespread application of nickel-based superalloys through LPBF technology, and promote technological innovation and development in high-end manufacturing fields such as aerospace.
[0005] There are many studies on LPBF forming of nano-modified nickel-based high-temperature alloys. The reinforcing phases are mostly ceramic particles and metal elements, such as TiC, WC, ZrB2, SiC, Y, etc. Summary of the Invention
[0006] This invention proposes a method for enhancing the comprehensive mechanical properties of laser-additively manufactured nickel-based superalloys through in-situ synergistic reaction of Si and N elements. Using Si3N4 as the reinforcing phase of GH4169, the laser absorptivity is modulated by Si3N4, affecting the laser forming temperature field and guiding the in-situ synergistic reaction. This method results in a microstructured nickel-based superalloy composite material with significantly improved strength, hardness, modulus, and ductility, reduced friction coefficient, and enhanced overall mechanical properties.
[0007] To this end, the present invention provides a method for improving the comprehensive mechanical properties of laser additively manufactured nickel-based high-temperature alloys through in-situ synergistic reaction strengthening of Si and N elements, comprising the following steps:
[0008] Preparation of composite powder system:
[0009] The matrix of the composite powder system is a nickel-based high-temperature alloy, the strengthening phase is Si3N4, and the mass ratio of the strengthening phase Si3N4 in the composite powder system is 0.3%;
[0010] Laser Powder Bed Fusion:
[0011] The prepared composite powder system was subjected to laser powder bed fusion forming, and the laser energy density used was 62-93J / mm 3 .
[0012] Preferably, during laser powder bed fusion forming, the laser power is 150-200 W, the scanning speed is 800-1100 mm / s, the scanning pitch is 80 μm, and the layer thickness is 30 μm.
[0013] Preferably, when preparing the composite powder system, the strengthening phase Si3N4 and the nickel-based high-temperature alloy are placed in a ceramic ball mill according to proportion, and then the composite powder system is prepared by mixing them evenly using a ball milling process.
[0014] Preferably, in the composite powder system, the nickel-based high-temperature alloy is GH4169 powder.
[0015] Preferably, the particle size of GH4169 powder is 40-50 μm, and the particle size of Si 3 N 4 powder is 1-10 μm.
[0016] Preferably, the parameters of the ball milling process are: ball-to-material ratio of 1:2, ball milling time of 4 hours, and ball milling speed of 250 r / min.
[0017] Preferably, before the laser powder bed fusion forming process, a substrate preheating mode is adopted to reduce stress, thereby improving the forming density and performance.
[0018] Preferably, high-purity argon is used as the protective atmosphere throughout the laser powder bed melting process.
[0019] Another technical purpose of the present invention is to provide a nickel-based high-temperature alloy strengthened by the in-situ synergistic reaction of Si and N elements, which is formed based on the above-mentioned method of improving the comprehensive mechanical properties of laser additively manufactured nickel-based high-temperature alloys by strengthening by the in-situ synergistic reaction of Si and N elements.
[0020] The advantages of the present invention are:
[0021] 1. This invention uses Si3N4 as a reinforcing phase for LPBF-formed nickel-based superalloys for the first time. The resulting composite material uses GH4169 as a matrix. By regulating the laser absorptivity to influence the laser forming temperature field and guide the in-situ synergistic reaction, a microstructured nickel-based superalloy composite material is obtained. This significantly improves the strength, hardness, modulus, and ductility of the nickel-based superalloy, reduces the friction coefficient, and enhances its overall mechanical properties.
[0022] 2. The present invention mentions a method for enhancing the comprehensive mechanical properties of nickel-based high-temperature alloys produced by laser additive manufacturing through the in-situ synergistic reaction of Si and N elements. It can be seen from the comparative example of GH4169 prepared under the same conditions that this method does not cause significant changes in grain morphology, stress distribution, texture strength and type, and avoids changes in other material properties while improving the overall performance.
[0023] 3. The nickel-based high-temperature alloy prepared in the present invention and strengthened by the in-situ synergistic reaction of Si and N elements is particularly suitable for combustion chambers and engine blades, and is also suitable for structural parts such as radiators. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 This is the GH4169 powder used in the examples and comparative examples.
[0025] Figure 2 It is the Si3N4 powder used in the examples and comparative examples.
[0026] Figure 3 This is the 0.3% Si3N4 / GH4169 powder used in the examples and comparative examples.
[0027] Figure 4 is the laser absorptivity of GH4169, Si3N4, and 0.3% Si3N4 / GH4169 powders used in the examples and comparative examples.
[0028] Figure 5 This is the microstructure of the LPBF-formed 0.3% Si3N4 / GH4169 sample in Example 1.
[0029] Figure 6 This is the grain morphology of the LPBF-formed 0.3% Si3N4 / GH4169 sample in Example 1.
[0030] Figure 7 This is the grain boundary distribution of the LPBF-formed 0.3% Si3N4 / GH4169 sample in Example 1.
[0031] Figure 8 This is the KAM diagram of the LPBF-formed 0.3% Si3N4 / GH4169 sample in Example 1.
[0032] Figure 9 This is the Taylor factor diagram of the LPBF-formed 0.3% Si3N4 / GH4169 sample in Example 1.
[0033] Figure 10 This is the pole figure of the LPBF-formed 0.3% Si3N4 / GH4169 sample in Example 1.
[0034] Figure 11 This is the tensile fracture morphology of the LPBF-formed 0.3% Si3N4 / GH4169 sample in Example 1.
[0035] Figure 12 This is a laser confocal microscope image of the wear scar of the LPBF-formed 0.3% Si3N4 / GH4169 sample in Example 1.
[0036] Figure 13 This is the SEM image of the wear scar of the LPBF-formed 0.3% Si3N4 / GH4169 sample in Example 1.
[0037] Figure 14 This is the microstructure of the LPBF-formed GH4169 sample in Comparative Example 1.
[0038] Figure 15 This is the grain morphology of the LPBF-formed GH4169 sample in Comparative Example 1.
[0039] Figure 16 This is the grain boundary distribution of the LPBF-formed GH4169 sample in Comparative Example 1.
[0040] Figure 17 This is the KAM diagram of the LPBF-formed GH4169 sample in Comparative Example 1.
[0041] Figure 18 This is the Taylor factor diagram of the LPBF-formed GH4169 sample in Comparative Example 1.
[0042] Figure 19 This is the pole figure of the LPBF-formed 0.3% Si3N4 / GH4169 sample in Example 1.
[0043] Figure 20 This is the tensile fracture morphology of the LPBF-formed 0.3% Si3N4 / GH4169 sample in Example 1.
[0044] Figure 21 This is a laser confocal microscope image of the wear scar of the LPBF-formed 0.3% Si3N4 / GH4169 sample in Example 1.
[0045] Figure 22This is the SEM image of the wear scar of the LPBF-formed 0.3% Si3N4 / GH4169 sample in Example 1.
[0046] Figure 23 TEM comparison images of LPBF-formed GH4169 powder sample and LPBF-formed 0.3% Si3N4 / GH4169 sample, where: (a) shows the TEM image of the LPBF-formed GH4169 powder sample; (b) shows the TEM image of the LPBF-formed 0.3% Si3N4 / GH4169 sample;
[0047] Figure 24 yes Figure 23 TEM image and element distribution map of the particles in (b). DETAILED DESCRIPTION
[0048] The present invention is described in detail below with reference to the accompanying drawings and embodiments, but the scope of protection of the present invention is not limited thereto. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention fall within the scope of protection of the present invention.
[0049] In order to improve the comprehensive mechanical properties of existing nickel-based high-temperature alloys (such as GH4169 powder), such as strength, hardness, modulus, ductility and friction coefficient, the present invention adds Si3N4 powder to the existing nickel-based high-temperature alloy in proportion and adopts laser powder bed melting to form the formed specimens, so that the strength, hardness, modulus and ductility of the nickel-based high-temperature alloy are significantly improved, and the friction coefficient is reduced.
[0050] Si3N4 powder has excellent properties such as high strength, high toughness, good wear resistance, and low thermal expansion coefficient, making it suitable for use as a reinforcement phase in laser additive manufacturing of nickel-based high-temperature alloys. In particular, its lightweight properties make it have the potential to further achieve lightweighting of nickel-based high-temperature alloy components for aerospace. Experimental studies have found that the Si and N elements in Si3N4 powder can guide in-situ synergistic reactions during the laser powder bed fusion forming process, thereby strengthening the GH4169 powder and refining the microstructure (see Figure 23 、 Figure 24 ), forming dispersed alumina core-shell particles. These particles, while creating dispersion strengthening, also form a well-bonded matrix-reinforcement interface. This improves strength while preventing premature crack initiation at the interface under stress, thereby synergistically enhancing toughness.
[0051] In addition, according to previous experimental experience, when high-melting-point metals are nano-modified, mixing the matrix and the reinforcement phase at a certain molar ratio often yields the optimal composition of the material system. Therefore, the present invention sets the mass percentage of Si3N4 powder to 0.3%.
[0052] In order to illustrate the technical solutions involved in the present invention in detail, the present invention provides 16 embodiments and 2 comparative examples (see Table 1 below).
[0053] Table 1
[0054]
[0055]
[0056] The following is a more detailed description of some of the embodiments and comparative examples recorded in Table 1.
[0057] Example 6
[0058] This embodiment is a method for enhancing the comprehensive mechanical properties of a nickel-based high-temperature alloy manufactured by laser additive manufacturing through in-situ synergistic reaction of Si and N elements.
[0059] The composite material composition involved is 0.3% Si3N4 / GH4169, the particle size of the GH4169 powder involved is 40-50 μm, and the particle size of the Si3N4 powder is 1-10 μm.
[0060] The preparation method of this embodiment specifically comprises the following steps:
[0061] Step (1): GH4169 powder ( Figure 1 ) and Si3N4 powder ( Figure 2 ) were placed in a ceramic ball mill according to the designed ratio for ball milling and mixing. The grinding balls used were ceramic grinding balls, the ball-to-material ratio was 1:2, and high-purity argon was filled into the ball mill as a protective atmosphere. The ball milling time was 6 hours and the rotation speed was 250 r / min to obtain a composite powder ( Figure 3 ), the laser reflectivity of the composite powder is significantly lower than that of GH4169 powder ( Figure 4 ), the laser absorption rate is significantly improved.
[0062] Step (2): The obtained composite powder is subjected to laser powder bed fusion forming. The laser power used is 150W, the scanning speed is 1000mm / s, the scanning pitch is 80μm, and the layer thickness is 30μm. High-purity argon is used as the protective atmosphere throughout the forming process. After the laser forming is completed and cooled, the sample is separated from the substrate by electric spark cutting to obtain the 0.3% Si3N4 / GH4169 composite material. The microstructure of the obtained composite material is as follows Figure 5 As shown in Figure 2, it can be seen that the sample has a finer microstructure. The grain morphology, grain boundary distribution, dislocation distribution, texture strength, and texture type of the sample are shown in Figure 2. Figures 6-10 As shown. The room temperature tensile strength is 1166.20MPa, the elongation is 24.49%, and there are obvious dimples on the fracture surface ( Figure 11). The room temperature Vickers hardness is 346.28HV5, the nanohardness is 262.69GPa, and the modulus is 4.61GPa. The room temperature friction coefficient is 0.49 and the wear volume is 0.10mm 3 ( Figure 12 ), wear marks without obvious peeling or cracks ( Figure 13 This can be attributed to the fact that the addition of 0.3wt.% Si3N4 increases the laser absorption rate, thereby increasing the molten pool temperature, increasing the liquid phase existence time of the molten pool, promoting the microstructure refinement and in-situ reaction of the matrix, and forming dispersed alumina core-shell structure particles. The core-shell structure particles form a matrix and reinforcement phase interface with good bonding while forming dispersion strengthening ( Figure 23 、 Figure 24 ) precipitate, thereby forming a strengthening effect, which synergistically improves the mechanical properties of the sample, such as strength and ductility.
[0063] Example 11
[0064] The implementation steps were similar to those in Example 6. This example differed from Example 1 only in the laser power and scanning speed used in step (2) of laser powder bed fusion. In this example, the laser power was 200 W and the scanning speed was 900 mm / s. The resulting composite material had a room temperature tensile strength of 1060.39 MPa and an elongation of 20.56%.
[0065] Comparative Example 1
[0066] Refer to the implementation of Example 6. The only difference between Comparative Example 1 and Example 6 is that the GH4169 material involved in Comparative Example 1 does not contain Si3N4, and is only a pure GH4169 material formed by laser powder bed melting. The microstructure of the obtained GH4169 material is as follows Figure 14 As shown in Figure 2, it can be seen that the sample structure is relatively coarse. The grain morphology, grain boundary distribution, dislocation distribution, texture strength, and texture type of the sample are shown in Figure 2. Figures 15-19 As shown. The room temperature tensile strength is 1048.90MPa, the elongation is 20.50%, and there are obvious cracks on the fracture ( Figure 20 ). The room temperature Vickers hardness is 316.34HV5, the nanohardness is 241.47GPa, and the modulus is 4.30GPa. The room temperature friction coefficient is 0.55 and the wear volume is 0.14mm 3 ( Figure 21 ), there are obvious cracks in the wear marks ( Figure 22 ).
[0067] In summary, Si3N4 can influence the laser forming temperature field and guide the in-situ synergistic reaction by regulating the laser absorption rate, thereby obtaining a nickel-based high-temperature alloy composite material with refined structure, significantly improving the strength, hardness, modulus and ductility of the nickel-based high-temperature alloy, reducing the friction coefficient, and improving its comprehensive mechanical properties. The laser energy density is 62-93J / mm 3 When the laser energy density is within this range, the tensile properties of the composite material show a synergistic improvement in strength and toughness compared to GH4169. Lower tensile properties may be achieved when the laser energy density is too low or too high. Notably, compared to GH4169 samples prepared under the same conditions, the composite material shows no significant changes in grain morphology, stress distribution, or texture strength and type, thus improving overall performance without altering other material properties.
Claims
1. A method for improving the comprehensive mechanical properties of nickel-based high-temperature alloys manufactured by laser additive manufacturing through in-situ synergistic reaction of Si and N elements, characterized in that: The steps include: Preparation of composite powder system: The matrix of the composite powder system is a nickel-based high-temperature alloy, the strengthening phase is Si3N4, and the mass ratio of the strengthening phase Si3N4 in the composite powder system is 0.3%; Laser Powder Bed Fusion: The prepared composite powder system was subjected to laser powder bed fusion forming, and the laser energy density used was 62-93J / mm 3 .
2. The method of enhancing the comprehensive mechanical properties of nickel-based high-temperature alloys manufactured by laser additive manufacturing through in-situ synergistic reaction of Si and N elements according to claim 1, characterized in that: During laser powder bed fusion forming, the laser power is 150-200W, the scanning speed is 800-1100mm / s, the scanning spacing is 80μm, and the layer thickness is 30μm.
3. The method of enhancing the comprehensive mechanical properties of nickel-based high-temperature alloys manufactured by laser additive manufacturing through in-situ synergistic reaction of Si and N elements according to claim 2, characterized in that: When preparing the composite powder system, the strengthening phase Si3N4 and the nickel-based high-temperature alloy are placed in a ceramic ball mill according to proportion, and then the composite powder system is prepared by mixing them evenly using a ball milling process.
4. The method of enhancing the comprehensive mechanical properties of nickel-based high-temperature alloys manufactured by laser additive manufacturing through in-situ synergistic reaction of Si and N elements according to claim 2, characterized in that: In the composite powder system, the nickel-based high-temperature alloy is GH4169 powder.
5. The method of enhancing the comprehensive mechanical properties of nickel-based high-temperature alloys manufactured by laser additive manufacturing through in-situ synergistic reaction of Si and N elements according to claim 3, characterized in that: The particle size of GH4169 powder is 40-50 μm, and the particle size of Si3N4 powder is 1-10 μm.
6. The method of enhancing the comprehensive mechanical properties of nickel-based high-temperature alloys manufactured by laser additive manufacturing through in-situ synergistic reaction of Si and N elements according to claim 2, characterized in that: The parameters of the ball milling process are: ball-to-material ratio of 1:2, ball milling time of 4 h, and ball milling speed of 250 r / min.
7. The method of enhancing the comprehensive mechanical properties of nickel-based high-temperature alloys manufactured by laser additive manufacturing through in-situ synergistic reaction of Si and N elements according to claim 1, characterized in that: Before the laser powder bed fusion forming process, a substrate preheating mode was adopted to reduce stress and thereby improve the forming density and performance.
8. The method of enhancing the comprehensive mechanical properties of nickel-based high-temperature alloys manufactured by laser additive manufacturing through in-situ synergistic reaction of Si and N elements according to claim 1, characterized in that: High-purity argon is used as the protective atmosphere throughout the laser powder bed melting process.
9. A nickel-based high-temperature alloy strengthened by in-situ synergistic reaction of Si and N elements, characterized in that: The method for enhancing the comprehensive mechanical properties of nickel-based high-temperature alloys manufactured by laser additive manufacturing through in-situ synergistic reaction of Si and N elements as described in any one of claims 2 to 8 is formed.