Gradient functional material of nickel-based superalloy and titanium alloy and preparation method of gradient functional material

Abstract

The invention provides a nickel-based superalloy and titanium alloy gradient functional material which comprises a titanium alloy, a gradient high-entropy alloy middle layer compounded on the surface of the titanium alloy and a nickel-based superalloy compounded on the gradient high-entropy alloy middle layer, and the adjacent alloy layers have metallurgical compatibility; the gradient high-entropy alloy middle layer comprises a plurality of high-entropy alloy layers with components changing in a gradient manner; the number of the high-entropy alloy layers is larger than or equal to two. The invention further provides a preparation method of the nickel-based superalloy and titanium alloy gradient functional material. According to the gradient functional material, the gradient high-entropy alloy middle layer is introduced, the solid solution forming tendency, the hysteresis diffusion effect and the strong solid solution strengthening effect of the high-entropy alloy are utilized, the bonding strength of a heterogeneous alloy interface is effectively improved, meanwhile, formation of intermetallic compounds is reduced, and the metallurgical compatibility and the mechanical property are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of heterogeneous alloys, and in particular to a functional gradient material of a nickel-based high-temperature alloy and a titanium alloy and a preparation method thereof. Background Art

[0002] With the continuous advancement and innovation of aerospace technology, the performance requirements for key components are increasing, requiring differentiated functional configurations for different parts, including but not limited to lightweight design, optimized wear resistance, corrosion resistance, and enhanced high-temperature tolerance. A single homogeneous material cannot simultaneously meet the comprehensive performance requirements of the complex aerospace service environment. The manufacture of heterogeneous alloy monolithic structures with multiple functions is increasingly becoming a bottleneck technology restricting the development of high-end equipment.

[0003] Titanium alloy is a lightweight structural material currently widely used in fields such as aerospace. It has a series of advantages such as low density, high specific strength and corrosion resistance. However, its high-temperature oxidation resistance and creep resistance are poor, its hardness is low, and it is easy to wear. At the same time, there is also the hidden danger of "titanium fire", which seriously limits the application of titanium alloy in high-temperature and wear environments. Nickel-based deformable high-temperature alloys have excellent high-temperature mechanical properties, oxidation resistance and creep resistance, and can maintain good structural stability and reliability at 600-800℃. However, its density is almost twice that of titanium alloy, and its large-scale use will inevitably greatly increase the weight of parts. The heterogeneous structure of titanium alloy / nickel-based high-temperature alloy can give full play to the respective advantages of the two materials and achieve complementary performance, thus obtaining a lightweight and multifunctional titanium alloy / nickel-based high-temperature alloy.

[0004] However, the following outstanding problems still exist in the preparation of titanium alloy / nickel-based high-temperature alloy heterostructures:

[0005] ①Ti and Ni can react to form a variety of Ti-Ni intermetallic compounds, which seriously deteriorate the mechanical properties of the heterogeneous alloy interface;

[0006] ②Ti and Ni heterogeneous metals have large differences in physical properties such as melting point, thermal expansion coefficient, and thermal conductivity, which makes it very easy to generate large internal stress at the interface of heterogeneous alloys. Long-term service or complex thermal cycle processes can easily lead to cracks or even macroscopic fractures in the structure. Currently, solid-phase welding (diffusion welding, explosion welding, friction welding) or high-energy beam welding (laser welding, electron beam welding) and other technologies are mainly used to reduce or avoid the formation of a melting zone during the connection process, thereby reducing the probability of the formation of Ti-Ni brittle intermetallic compounds. However, the effect is not good, the joint performance is poor, and it is difficult to obtain application.

[0007] Therefore, providing a preparation method of nickel-based high-temperature alloy and titanium alloy functional gradient material is of great significance for improving the bonding strength of the heterogeneous alloy interface between nickel-based high-temperature alloy and titanium alloy. Summary of the Invention

[0008] The technical problem solved by the present invention is to provide a gradient functional material of nickel-based high-temperature alloy and titanium alloy and a preparation method thereof. The gradient functional material provided by this application effectively improves the interface bonding strength of heterogeneous alloy titanium alloy and nickel-based high-temperature alloy, while reducing the formation of intermetallic compounds, thereby improving the metallurgical compatibility and mechanical properties of the gradient functional material.

[0009] The present application also provides a gradient functional material of a nickel-based high-temperature alloy and a titanium alloy, comprising: a titanium alloy, a gradient high-entropy alloy intermediate layer composited on the surface of the titanium alloy, and a nickel-based high-temperature alloy composited on the gradient high-entropy alloy intermediate layer, wherein adjacent alloy layers have metallurgical compatibility;

[0010] The gradient high entropy alloy intermediate layer includes several high entropy alloy layers with gradient composition changes; the number of the high entropy alloy layers is ≥2.

[0011] In some specific embodiments, the gradient high entropy alloy intermediate layer includes a first high entropy alloy layer, a second high entropy alloy layer and a third high entropy alloy layer compounded in sequence from the titanium alloy end to the nickel-based high-temperature alloy end; the first high entropy alloy layer has metallurgical compatibility with the titanium alloy, the first high entropy alloy layer and the second high entropy alloy layer have metallurgical compatibility, and the third high entropy alloy layer has metallurgical compatibility with the nickel-based high-temperature alloy.

[0012] In some specific embodiments, the titanium alloy is TC4 titanium alloy, the nickel-based high-temperature alloy is GH4169 nickel-based high-temperature alloy, and the gradient high-entropy alloy intermediate layer is composed of a Ti-V-Cu-Ni-Fe first high-entropy alloy layer, a Cu-Ni-V-Fe-Cr second high-entropy alloy layer and a Ni-Cu-Fe-Cr-Co third high-entropy alloy layer composited in sequence from the titanium alloy end to the nickel-based high-temperature alloy end.

[0013] In some specific embodiments, the content of Ti in the first high entropy alloy layer is 30-40 at%, the content of V is 20-40 at%, the content of Cu is 10-20 at%, the content of Ni is 5-15 at%, and the content of Fe is 5-15 at%;

[0014] The content of Cu in the second high entropy alloy layer is 20-40 at%, the content of Ni is 15-35 at%, the content of V is 10-30 at%, the content of Fe is 10-20 at%, and the content of Cr is 5-15 at%;

[0015] The third high entropy alloy layer has a Ni content of 25 to 45 at %, a Cu content of 10 to 30 at %, a Fe content of 10 to 30 at %, a Cr content of 5 to 20 at %, and a Co content of 5 to 15 at %.

[0016] In some specific embodiments, the titanium alloy is TA15 titanium alloy, the nickel-based high-temperature alloy is GH3536 nickel-based high-temperature alloy, and the gradient high-entropy alloy intermediate layer is composed of a Ti-V-Cr-Mn first high-entropy alloy layer, a Co-Cr-V-Mn-Ti second high-entropy alloy layer and a Fe-Co-Cr-Ni-Mn third high-entropy alloy layer composited in sequence from the titanium alloy end to the nickel-based high-temperature alloy end.

[0017] In some specific embodiments, the content of Ti in the first high entropy alloy layer is 30-50 at%, the content of V is 20-40 at%, the content of Cr is 20-40 at%, and the content of Mn is 5-20 at%.

[0018] The content of Co in the second high entropy alloy layer is 15-35at%, the content of Cr is 15-30at%, the content of V is 10-25wt%, the content of Mn is 15-35at%, and the content of Ti is 5-15at%;

[0019] The third high entropy alloy layer has an Fe content of 5 to 35 at %, a Co content of 5 to 35 at %, a Cr content of 5 to 35 at %, a Ni content of 5 to 35 at %, and a Mn content of 5 to 35 at %.

[0020] The present application also provides a method for preparing the functionally gradient material of the nickel-based high-temperature alloy and titanium alloy, comprising the following steps:

[0021] S1) selecting the elemental composition of each high entropy alloy layer in the gradient high entropy alloy intermediate layer based on the elemental composition and composition relationship of the titanium alloy and the nickel-based high-temperature alloy;

[0022] S2) determining the ratio of elements in each high entropy alloy layer to ensure metallurgical compatibility between adjacent alloy layers;

[0023] S3) preparing high entropy alloy powder for each high entropy alloy layer according to the ratio of elements in each high entropy alloy layer;

[0024] S4) Using laser melting deposition technology, high entropy alloy powder of each high entropy alloy layer is deposited layer by layer starting from the titanium alloy end, and finally the powder of the nickel-based high temperature alloy is deposited.

[0025] In some specific embodiments, in step S2), the method for determining the ratio of elements in each high entropy alloy layer is to use phase diagram thermodynamic calculation and experimental optimization.

[0026] In some specific embodiments, the laser power of the laser melting deposition technology is 800-1500 W, the scanning speed is 300-800 mm / min, and the powder feeding rate is 8-15 g / s.

[0027] In some specific embodiments, in the laser melting deposition technology, the cooling rate of the laser molten pool is 102-105° C. / s.

[0028] The present application provides a gradient functional material of nickel-based high-temperature alloy and titanium alloy, which includes a titanium alloy, a gradient high-entropy alloy intermediate layer compounded on the surface of the titanium alloy, and a nickel-based high-temperature alloy compounded on the gradient high-entropy alloy intermediate layer, and adjacent alloy layers have metallurgical compatibility, and the gradient high-entropy alloy intermediate layer includes several layers of high-entropy alloy layers with gradient composition changes; in the gradient functional material of nickel-based high-temperature alloy and titanium alloy provided in the present application, from the titanium alloy end to the nickel-based high-temperature alloy end, the composite several layers of high-entropy alloy intermediate layers make the high-entropy alloy composition gradually change in sequence, so that the composition gradient transition between the titanium alloy, each high-entropy alloy layer and the nickel-based high-temperature alloy is conducive to forming a good interface metallurgical bonding, and effectively blocks the mutual diffusion of Ti elements and Ni elements, reducing the formation of brittle intermetallic compounds.

[0029] Furthermore, the present application provides a method for preparing gradient functional materials of nickel-based high-temperature alloys and titanium alloys, which adopts laser melting deposition technology. Starting from a titanium alloy substrate, high-entropy alloy powders with different compositions and gradient changes are deposited layer by layer in a layer-by-layer manner, and finally nickel-based high-temperature alloy powder is deposited. This deposition technology uses a high-energy laser beam as a heat source and powder as a raw material. Through layer-by-layer deposition, the preparation of gradient functional materials can be quickly completed, and the tiny laser molten pool has an extremely fast cooling rate, which can effectively inhibit atomic diffusion and the generation of complex intermediate layer compound phases in high-entropy alloys, promote the formation of a multi-component solid solution structure with fine grains, improve the metallurgical compatibility of the heterogeneous alloy interface, and enhance the bonding strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is an SEM photograph of the functionally gradient material of nickel-based high-temperature alloy and titanium alloy prepared in Example 3 of the present invention;

[0031] Figure 2 This is an SEM photograph of the functionally gradient material of titanium alloy and nickel-based high-temperature alloy prepared in Example 4 of the present invention;

[0032] Figure 3This is an SEM photograph of the functionally gradient material of titanium alloy and nickel-based high-temperature alloy prepared in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0033] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0034] In view of the problem in the prior art that nickel-based high-temperature alloys and titanium alloys with heterogeneous structures react to form intermetallic compounds, deteriorating the mechanical properties of the heterogeneous alloy interface and causing cracks after long-term service, the present application provides a gradient functional material of nickel-based high-temperature alloys and titanium alloys and a preparation method thereof. By introducing several layers of high-entropy alloy layers with gradient composition between the nickel-based high-temperature alloy and the titanium alloy, a smooth transition at the interface of the titanium alloy and the nickel-based high-temperature alloy heterogeneous alloy is achieved, metallurgical compatibility is improved, and the mutual diffusion of Ti and Ni elements is effectively blocked, the probability of forming brittle intermetallic compounds is reduced, and the bonding strength of the gradient functional material is ensured. Specifically, an embodiment of the present invention first discloses a gradient functional material of nickel-based high-temperature alloy and titanium alloy, comprising: a titanium alloy, a gradient high-entropy alloy intermediate layer compounded on the surface of the titanium alloy, and a nickel-based high-temperature alloy compounded on the gradient high-entropy alloy intermediate layer, wherein adjacent alloy layers have metallurgical compatibility;

[0035] The gradient high entropy alloy intermediate layer includes several high entropy alloy layers with gradient composition changes; the number of the high entropy alloy layers is ≥2.

[0036] In the gradient functional materials of nickel-based high-temperature alloy and titanium alloy provided in the present application, the titanium alloy and the nickel-based high-temperature alloy are titanium alloy and nickel-based high-temperature alloy well known to those skilled in the art, and the present application has no special restrictions on this.

[0037] The gradient high entropy alloy intermediate layer between the titanium alloy and the nickel-based high-temperature alloy includes several layers of high entropy alloy layers with gradient composition changes. In the present application, the several high entropy alloy layers with gradient composition changes refer to the first high entropy alloy layer, the second high entropy alloy layer, the third high entropy alloy layer...the N-1 high entropy alloy layer and the N high entropy alloy layer from the titanium alloy end to the nickel-based high-temperature alloy end, wherein the gradient composition change indicates that the composition of the first high entropy alloy layer presents a gradient change relative to the composition of the titanium alloy and combined with the nickel-based high-temperature alloy composition, the composition of the second high entropy alloy layer presents a gradient change relative to the composition of the first high entropy alloy layer, the composition of the third high entropy alloy layer presents a gradient change relative to the composition of the second high entropy alloy layer...the composition of the N-1 high entropy alloy layer presents a gradient change relative to the composition of the N-2 high entropy alloy layer, and the composition of the N high entropy alloy layer presents a gradient change relative to the composition of the N-1 high entropy alloy layer; the gradient composition change of the above-mentioned high entropy alloy layers is based on the metallurgical compatibility of the adjacent alloy layers and the formation of good metallurgical bonding.

[0038] Among the several high-entropy alloy layers of the gradient high-entropy alloy intermediate layer, the number of high-entropy alloy layers is ≥2 layers. Specifically, the number of high-entropy alloy layers is 2 to 10 layers. More specifically, the number of high-entropy alloy layers is 3 to 8 layers. More specifically, the number of high-entropy alloy layers is 4 to 7 layers. In a specific embodiment, the number of high-entropy alloy layers is 3 layers.

[0039] In some specific embodiments, the gradient high entropy alloy intermediate layer includes a first high entropy alloy layer, a second high entropy alloy layer and a third high entropy alloy layer compounded in sequence from the titanium alloy end to the nickel-based high-temperature alloy end; the first high entropy alloy layer has metallurgical compatibility with the titanium alloy, the first high entropy alloy layer and the second high entropy alloy layer have metallurgical compatibility, and the third high entropy alloy layer has metallurgical compatibility with the nickel-based high-temperature alloy.

[0040] In some specific embodiments, the titanium alloy is TC titanium alloy, the nickel-based high-temperature alloy is GH4169 nickel-based high-temperature alloy, and the gradient high-entropy alloy intermediate layer is composed of a composite Ti-V-Cu-Ni-Fe first high-entropy alloy layer, a Cu-Ni-V-Fe-Cr second high-entropy alloy layer and a Ni-Cu-Fe-Cr-Co third high-entropy alloy layer from the titanium alloy end to the nickel-based high-temperature alloy end; further, the Ti content in the first high-entropy alloy layer is 30-40at%, the V content is 20-40at%, the Cu content is 10-20at%, the Ni content is 5-15at%, and the Fe content is 5-15at%; specifically, the Ti content in the first high-entropy alloy layer is 32-38at%, the V content is 22-37at%, the Cu content is 12-17at%, the Ni content is 6-13at%, and the Fe content is 6-13at%.

[0041] The Cu content in the second high-entropy alloy layer is 20-40at%, the Ni content is 15-35at%, the V content is 10-30at%, the Fe content is 10-20at%, and the Cr content is 5-15at%; specifically, the Cu content in the second high-entropy alloy layer is 22-38at%, the Ni content is 18-32at%, the V content is 13-26at%, the Fe content is 12-18at%, and the Cr content is 7-12at%.

[0042] The Ni content in the third high-entropy alloy layer is 25-45at%, the Cu content is 10-30at%, the Fe content is 10-30at%, the Cr content is 5-20at%, and the Co content is 5-15wt%; specifically, the Ni content is 28-42at%, the Cu content is 13-26wt%, the Fe content is 14-26at%, the Cr content is 8-17at%, and the Co content is 8-12at%.

[0043] More specifically, the first high entropy alloy layer is Ti35V30Cu15Ni10Fe10, the second high entropy alloy layer is Cu30Ni25V20Fe15Cr10, and the third high entropy alloy layer is Ni35Cu20Fe20Cr15Co10, or the first high entropy alloy layer is Ti30V35Cu20Ni10Fe15, the second high entropy alloy layer is Cu30Ni25V25Fe15Cr15, and the third high entropy alloy layer is Ni40Cu15Fe15Cr15Co15.

[0044] In some specific embodiments, the titanium alloy is TA15 titanium alloy, the nickel-based high-temperature alloy is GH3536 nickel-based high-temperature alloy, and the gradient high-entropy alloy intermediate layer is composed of a Ti-V-Cr-Mn first high-entropy alloy layer, a Co-Cr-V-Mn-Ti second high-entropy alloy layer and a Fe-Co-Cr-Ni-Mn third high-entropy alloy layer composited in sequence from the titanium alloy end to the nickel-based high-temperature alloy end.

[0045] Specifically, the Ti content in the first high entropy alloy layer is 30-50at%, the V content is 20-40at%, the Cr content is 20-40at%, and the Mn content is 5-20at%; specifically, the Ti content in the first high entropy alloy layer is 32-47at%, the V content is 23-36at%, the Cr content is 23-37at%, and the Mn content is 8-17at%; more specifically, the Ti content in the first high entropy alloy layer is 34-42at%, the V content is 26-30at%, the Cr content is 27-32at%, and the Mn content is 12-14at%.

[0046] The content of Co in the second high entropy alloy layer is 15-35at%, the content of Cr is 15-30at%, the content of V is 10-25wt%, the content of Mn is 15-35at%, and the content of Ti is 5-15at%; specifically, the content of Co in the second high entropy alloy layer is 18-30at%, the content of Cr is 19-27at%, the content of V is 14-22wt%, the content of Mn is 19-32at%, and the content of Ti is 8-13at%; in some specific embodiments, the second high entropy alloy layer is.

[0047] The content of Fe in the third high entropy alloy layer is 5-35at%, the content of Co is 5-35at%, the content of Cr is 5-35at%, the content of Ni is 5-35at%, and the content of Mn is 5-35at%; specifically, the content of Fe is 9-26at%, the content of Co is 12-25at%, the content of Cr is 15-26at%, the content of Ni is 16-25at%, and the content of Mn is 18-25at%; in some specific embodiments, the third high entropy alloy layer is.

[0048] In some specific embodiments, the first high entropy alloy layer is Ti40V25Cr25Mn10, the second high entropy alloy layer is Co35Cr20V15Mn20Ti10, and the third alloy layer is Fe20Co20Cr20Ni20Mn20; or, in some specific embodiments, the first high entropy alloy layer is Ti40V30Cr20Mn10, the second high entropy alloy layer is Co30Cr15V20Mn15Ti10, and the third high entropy alloy layer is Fe15Co15Cr20Ni30Mn20.

[0049] The present application also provides a method for preparing a functionally gradient material of a nickel-based high-temperature alloy and a titanium alloy, comprising the following steps:

[0050] S1) selecting the elemental composition of each high entropy alloy layer in the gradient high entropy alloy intermediate layer according to the elemental composition of the titanium alloy and the nickel-based high-temperature alloy;

[0051] S2) determining the ratio of elements in each high entropy alloy layer to ensure metallurgical compatibility between adjacent alloy layers;

[0052] S3) preparing high entropy alloy powder for each high entropy alloy layer according to the ratio of elements in each high entropy alloy layer;

[0053] S4) Using laser melting deposition technology, high entropy alloy powder of each high entropy alloy layer is deposited layer by layer starting from the titanium alloy end, and finally the nickel-based high temperature alloy is deposited.

[0054] In the preparation method of the gradient functional material of nickel-based high-temperature alloy and titanium alloy provided in this application, the elemental composition of each high-entropy alloy layer in the gradient high-entropy alloy intermediate layer is first selected based on the elemental composition and content relationship of titanium alloy and nickel-based high-temperature alloy.

[0055] According to the present invention, the proportional relationship of the elements in each high entropy alloy layer is determined to ensure that adjacent alloy layers have metallurgical compatibility; in some specific embodiments, the proportional relationship of the elements in each high entropy alloy layer is determined through phase diagram thermodynamic calculation and experimental optimization to obtain each high entropy alloy layer with a gradual composition gradient.

[0056] The present application then prepares high entropy alloy powder for each high entropy alloy layer according to the ratio of elements in each high entropy alloy layer; the preparation method of the high entropy alloy powder is not particularly limited and can be prepared according to methods familiar to those skilled in the art.

[0057] According to the present invention, laser melting deposition technology is finally used to deposit high entropy alloy powder of each high entropy alloy layer layer by layer starting from the titanium alloy end, and finally the powder of the nickel-based high-temperature alloy is deposited. The laser melting deposition (LMD) technology is a metal additive manufacturing method based on a high-energy laser beam, which forms a solid material by melting metal powder layer by layer. In some specific embodiments, the laser power of the LMD technology is 800-1500W, the scanning speed is 300-800mm / min, and the powder feeding rate is 8-15g / s; specifically, the laser power of the LMD technology is 900-1300W, the scanning speed is 400-700mm / min, and the powder feeding rate is 10-14g / s; more specifically, the laser power of the LMD technology is 1000-1200W, the scanning speed is 400-600mm / min, and the powder feeding rate is 11-12g / s.

[0058] In some specific embodiments, the cooling rate of the laser molten pool of the LMD technology is 10 2 ~10 5 ℃ / s, specifically, the cooling rate is 10 3 ~10 4 The rapid cooling rate of the laser melt pool suppresses atomic diffusion and the formation of complex intermetallic compound phases in the high-entropy alloy layer, promoting the formation of a multicomponent solid solution structure with fine grains. The high-entropy alloy layer's solid solution formation tendency, delayed diffusion effect, and strong solid solution strengthening effect suppress the formation of brittle intermetallic compounds, thereby significantly improving the interfacial properties of the heterogeneous alloy. The specific implementation methods of the LMD technology are not particularly limited in this application and can be carried out according to methods familiar to those skilled in the art.

[0059] At the titanium alloy / nickel-based superalloy heterojunction, where intermetallic compounds are prone to forming, adding a high-entropy alloy layer as an intermediate transition layer can effectively prevent the formation of intermetallic compounds. The high degree of disorder and large lattice distortion of the high-entropy alloy in the gradient high-entropy alloy intermediate layer have a significant hysteresis effect on element diffusion, effectively blocking the mutual diffusion of Ti and Ni elements, further reducing the probability of intermetallic compound formation at the heterojunction interface.

[0060] In the gradient functional materials of nickel-based superalloys and titanium alloys provided in this application, a high-entropy alloy gradient composite structure with a gradually varying composition is designed in a high-entropy alloy system with similar components, thereby solving the metallurgical compatibility problem of a single-component intermediate layer and achieving a smooth transition at the titanium alloy / nickel-based superalloy heterogeneous interface. The high-entropy alloy lattice structure exhibits severe distortion and deformation due to the chemical disorder of atomic occupancy, and has a strong solid solution strengthening effect. Using a high-entropy alloy as an intermediate layer can fully utilize the performance characteristics and advantages of the alloy and effectively improve the mechanical properties of the intermediate layer itself.

[0061] Furthermore, in the preparation process of functionally gradient materials, laser melting deposition (LMD) uses a high-energy laser beam as a heat source and powder as a raw material. Through layer-by-layer accumulation, it can quickly complete the "near-net-shape" manufacturing of complex components from the CAD model. By changing the delivered powder material in real time, it can directly realize the combination manufacturing of different materials. Compared with traditional processes, LMD has a unique forming principle advantage in the preparation of gradient material components. In addition, in the LMD process, the tiny laser molten pool has an extremely fast cooling rate (10 2 ~10 5 ℃ / s), which can effectively inhibit atomic diffusion and the generation of complex intermetallic compound phases in high entropy alloys, promote the formation of a multi-component solid solution structure with fine grains, improve the metallurgical compatibility of heterogeneous alloy interfaces, and enhance bonding strength.

[0062] In order to further understand the present invention, the gradient functional material of nickel-based high-temperature alloy and titanium alloy provided by the present invention and the preparation method thereof are described in detail below in combination with the embodiments. The protection scope of the present invention is not limited by the following embodiments.

[0063] Example 1

[0064] A) preparing a TC4 titanium alloy substrate;

[0065] B) Using a laser melting deposition system, set the laser power to 1000 W, the scanning speed to 600 mm / min, and the powder feeding rate to 10 g / s;

[0066] C) adding a first layer of high entropy alloy powder (Ti35V30Cu15Ni10Fe10) on the surface of the TC4 titanium alloy substrate to form a first high entropy alloy gradient layer;

[0067] D) adding a second layer of high entropy alloy powder (Cu30Ni25V20Fe15Cr10) on the surface of the first high entropy alloy gradient layer to form a second high entropy alloy gradient layer;

[0068] E) Finally, a third layer of high entropy alloy powder (Ni35Cu20Fe20Cr15Co10) is added to the surface of the second high entropy alloy gradient layer to complete the preparation of the gradient layer;

[0069] F) Depositing GH4169 high-temperature alloy on the basis of the gradient layer to obtain a gradient functional material of titanium alloy and nickel-based high-temperature alloy.

[0070] The shear strength test results of the titanium alloy itself and the gradient functional material in this embodiment are shown in Table 1.

[0071] Table 1 Shear strength performance data of titanium alloy and functionally gradient materials

[0072]

[0073]

[0074] As shown in Table 1, the shear strength of the gradient functional material of titanium alloy and nickel-based high-temperature alloy prepared in this embodiment reaches more than 60% of the titanium alloy parent material, thereby improving the bonding strength of titanium alloy TC4 and GH4169 high-temperature alloy.

[0075] Example 2

[0076] A) preparing a TC4 titanium alloy substrate;

[0077] B) Using a laser melting deposition system, set the laser power to 1000 W, the scanning speed to 600 mm / min, and the powder feeding rate to 10 g / s;

[0078] C) adding a first layer of high entropy alloy powder (Ti30V35Cu20Ni10Fe15) on the surface of the TC4 titanium alloy substrate to form a first high entropy alloy gradient layer;

[0079] D) adding a second layer of high entropy alloy powder (Cu30Ni25V25Fe15Cr15) on the surface of the first high entropy alloy gradient layer to form a second high entropy alloy gradient layer;

[0080] E) Finally, a third layer of high entropy alloy powder (Ni40Cu15Fe15Cr15Co15) is added to the surface of the second high entropy alloy gradient layer to complete the preparation of the gradient layer;

[0081] Table 2 Shear strength performance data of titanium alloy and gradient functional material in Example 2

[0082]

[0083]

[0084] As shown in Table 2, the shear strength of the gradient functional material of titanium alloy and nickel-based high-temperature alloy prepared in this embodiment reaches more than 60% of the titanium alloy parent material, thereby improving the bonding strength of titanium alloy TC4 and GH4169 high-temperature alloy.

[0085] Example 3

[0086] A) Prepare TA15 titanium alloy substrate;

[0087] B) Using a laser melting deposition system, set the laser power to 1000 W, the scanning speed to 600 mm / min, and the powder feeding rate to 10 g / s;

[0088] C) adding a first layer of high entropy alloy powder (Ti40V25Cr25Mn10) on the surface of the TA15 titanium alloy substrate to form a first high entropy alloy layer;

[0089] D) adding a second layer of high entropy alloy powder (Co35Cr20V15Mn20Ti10) on the surface of the first high entropy alloy layer to form a second high entropy alloy layer;

[0090] E) Finally, a third layer of high entropy alloy powder (Fe20Co20Cr20Ni20Mn20) is added on the surface of the second high entropy alloy layer to complete the preparation of the gradient layer;

[0091] F) Depositing GH3536 high-temperature alloy on the basis of the gradient layer to obtain a gradient functional material of titanium alloy and nickel-based high-temperature alloy.

[0092] Figure 1 This is an SEM photograph of the gradient functional material of titanium alloy and nickel-based high-temperature alloy prepared in this embodiment. From bottom to top in the figure, they are: GH3536 nickel-based high-temperature alloy, third high-entropy alloy layer, second high-entropy alloy layer, first high-entropy alloy layer and TA15 titanium alloy; it can be seen from the figure that the gradient high-entropy alloy layer can realize the connection of GH3536 high-temperature alloy and TA15 titanium alloy, and the interface of the connection layer is metallurgical bonding, without obvious defects and obvious intermetallic compounds.

[0093] Example 4

[0094] A) Preparation of TA15 titanium alloy substrate;

[0095] B) Using a laser melting deposition system, set the laser power to 1000 W, the scanning speed to 600 mm / min, and the powder feeding rate to 10 g / s;

[0096] C) adding a first layer of high entropy alloy powder (Ti40V30Cr20Mn10) on the surface of the TA15 titanium alloy substrate to form a first high entropy alloy layer;

[0097] D) adding a second layer of high entropy alloy powder (Co30Cr15V20Mn15Ti10) on the surface of the first high entropy alloy layer to form a second high entropy alloy layer;

[0098] E) Finally, a third layer of high entropy alloy powder (Fe15Co15Cr20Ni30Mn20) is added on the surface of the second high entropy alloy layer to complete the preparation of the gradient layer;

[0099] F) Depositing GH3536 high-temperature alloy on the basis of the gradient layer to obtain a gradient functional material of titanium alloy and nickel-based high-temperature alloy.

[0100] Figure 2 This is an SEM photograph of the gradient functional material of the titanium alloy and nickel-based high-temperature alloy prepared in this embodiment. From bottom to top in the figure, they are: GH3536 nickel-based high-temperature alloy, the third high-entropy alloy layer (Fe15Co15Cr20Ni30Mn20), the second high-entropy alloy layer (Co30Cr15V20Mn15Ti10), the first high-entropy alloy layer (Ti40V30Cr20Mn10) and TA15 titanium alloy; it can be seen from the figure that the gradient high-entropy alloy layer can realize the connection of GH3536 high-temperature alloy and TA15 titanium alloy, and the interface of the connecting layer is metallurgical bonding, without obvious defects and obvious intermetallic compounds.

[0101] Comparative Example 1

[0102] A) preparing a TC4 titanium alloy substrate;

[0103] B) Using a laser melting deposition system, set the laser power to 1000 W, the scanning speed to 600 mm / min, and the powder feeding rate to 10 g / s;

[0104] C) adding a first layer of alloy powder (Ti50V50 alloy) on the surface of the TC4 titanium alloy substrate to form a first transition layer;

[0105] D) adding a second layer of alloy powder (V80Cr20) on the surface of the first transition layer to form a second transition layer;

[0106] E) Finally, a third layer of alloy powder (Ni60Cr40) is added on the surface of the second transition layer to complete the preparation of the gradient layer;

[0107] F) Depositing GH4169 high-temperature alloy on the basis of the gradient layer to obtain a gradient functional material of titanium alloy and nickel-based high-temperature alloy.

[0108] Figure 3This is an SEM photograph of the gradient functional material of titanium alloy and nickel-based high-temperature alloy prepared in this comparative example. From bottom to top in the figure, they are: TC4 titanium alloy, first alloy layer (Ti50V50), second alloy layer (V80Cr20), third alloy layer (Ni60Cr40) and GH4169 high-temperature alloy; it can be seen from the figure that the use of a binary alloy transition layer cannot achieve the connection between GH419 high-temperature alloy and TC4 titanium alloy, there are many intermetallic compounds at the interface of the connection layer, there are obvious interface cracks, and the connection strength is extremely low.

[0109] The above embodiments are only intended to help understand the method and core concept of the present invention. It should be noted that, without departing from the principles of the present invention, a number of improvements and modifications may be made to the present invention by those skilled in the art, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0110] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A functional gradient material of nickel-based high-temperature alloy and titanium alloy, characterized in that: include: A titanium alloy, a gradient high entropy alloy intermediate layer composited on the surface of the titanium alloy, and a nickel-based high-temperature alloy composited on the gradient high entropy alloy intermediate layer, wherein adjacent alloy layers have metallurgical compatibility; The gradient high entropy alloy intermediate layer includes several layers of high entropy alloy layers with gradient composition changes; the number of the high entropy alloy layers is ≥2 layers.

2. The functionally gradient material according to claim 1, characterized in that The gradient high entropy alloy intermediate layer includes a first high entropy alloy layer, a second high entropy alloy layer and a third high entropy alloy layer compounded in sequence from the titanium alloy end to the nickel-based high-temperature alloy end; the first high entropy alloy layer has metallurgical compatibility with the titanium alloy, the first high entropy alloy layer and the second high entropy alloy layer have metallurgical compatibility, and the third high entropy alloy layer has metallurgical compatibility with the nickel-based high-temperature alloy.

3. The functionally gradient material according to claim 1 or 2, characterized in that: The titanium alloy is TC4 titanium alloy, the nickel-based high-temperature alloy is GH4169 nickel-based high-temperature alloy, and the gradient high-entropy alloy intermediate layer is composed of a Ti-V-Cu-Ni-Fe first high-entropy alloy layer, a Cu-Ni-V-Fe-Cr second high-entropy alloy layer and a Ni-Cu-Fe-Cr-Co third high-entropy alloy layer composited in sequence from the titanium alloy end to the nickel-based high-temperature alloy end.

4. The functionally gradient material according to claim 3, characterized in that: The first high entropy alloy layer has a Ti content of 30 to 40 at%, a V content of 20 to 40 at%, a Cu content of 10 to 20 at%, a Ni content of 5 to 15 at%, and a Fe content of 5 to 15 at%; The content of Cu in the second high entropy alloy layer is 20-40 at%, the content of Ni is 15-35 at%, the content of V is 10-30 at%, the content of Fe is 10-20 at%, and the content of Cr is 5-15 at%; The third high entropy alloy layer has a Ni content of 25 to 45 at %, a Cu content of 10 to 30 at %, a Fe content of 10 to 30 at %, a Cr content of 5 to 20 at %, and a Co content of 5 to 15 at %.

5. The functionally gradient material according to claim 1 or 2, characterized in that: The titanium alloy is TA15 titanium alloy, the nickel-based high-temperature alloy is GH3536 nickel-based high-temperature alloy, and the gradient high-entropy alloy intermediate layer is composed of a Ti-V-Cr-Mn first high-entropy alloy layer, a Co-Cr-V-Mn-Ti second high-entropy alloy layer and a Fe-Co-Cr-Ni-Mn third high-entropy alloy layer, which are composited in sequence from the titanium alloy end to the nickel-based high-temperature alloy end.

6. The functionally gradient material according to claim 5, characterized in that: The first high entropy alloy layer has a Ti content of 30 to 50 at%, a V content of 20 to 40 at%, a Cr content of 20 to 40 at%, and a Mn content of 5 to 20 at%. The content of Co in the second high entropy alloy layer is 15-35at%, the content of Cr is 15-30at%, the content of V is 10-25wt%, the content of Mn is 15-35at%, and the content of Ti is 5-15at%; The third high entropy alloy layer has an Fe content of 5 to 35 at %, a Co content of 5 to 35 at %, a Cr content of 5 to 35 at %, a Ni content of 5 to 35 at %, and a Mn content of 5 to 35 at %.

7. The method for preparing the functionally gradient material of nickel-based high-temperature alloy and titanium alloy according to claim 1, comprising the following steps: S1) selecting the elemental composition of each high entropy alloy layer in the gradient high entropy alloy intermediate layer based on the elemental composition and composition relationship of the titanium alloy and the nickel-based high-temperature alloy; S2) determining the ratio of elements in each high entropy alloy layer to ensure metallurgical compatibility between adjacent alloy layers; S3) preparing high entropy alloy powder for each high entropy alloy layer according to the ratio of elements in each high entropy alloy layer; S4) Using laser melting deposition technology, high entropy alloy powder of each high entropy alloy layer is deposited layer by layer starting from the titanium alloy end, and finally the powder of the nickel-based high temperature alloy is deposited.

8. The preparation method according to claim 7, characterized in that In step S2), the method for determining the ratio of elements in each high entropy alloy layer is to use phase diagram thermodynamic calculation and experimental optimization.

9. The preparation method according to claim 7, characterized in that The laser power of the laser melting deposition technology is 800-1500W, the scanning speed is 300-800mm / min, and the powder feeding rate is 8-15g / s.

10. The preparation method according to claim 7, characterized in that In the laser melting deposition technology, the cooling rate of the laser molten pool is 102-105°C / s.

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