A hard inorganic particle reinforced aluminum alloy surface composite coating and a method for preparing the same

Abstract

The application discloses a hard inorganic particle reinforced aluminum alloy surface composite coating and a preparation method thereof, and belongs to the technical field of metal coating, and aims at solving the technical problem of low overall strength of a material caused by interface problems of added reinforcing particles in the prior art. The composite coating comprises an aluminum alloy base layer, a reinforcing layer and a transition layer between the base layer and the reinforcing layer, and further comprises an interface layer and a composite layer, the interface layer is between the transition layer and the reinforcing layer, and the composite layer is between the interface layer and the reinforcing layer; the interface layer is a Ga-In-Sn liquid metal interface layer, and the thickness thereof is 50-80 nm; the transition layer is an Al-Ti-Si nanocrystalline transition layer, and the thickness thereof is 200-300 nm; the composite layer is a SiC-Al2O3 composite layer formed by alternately and superimposed SiC lamellas and Al2O3 lamellas, the thickness of the composite layer is 1-2 microns; the thickness of the SiC-Al2O3 lamellas is 20-50 nm; and the thickness of the reinforcing layer is 400-600 nm. Through the interaction of the layers, the bonding strength, surface hardness and wear resistance of the overall coating and the aluminum alloy base are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal coating, in particular to a hard inorganic particle reinforced aluminum alloy surface composite coating and a preparation method thereof. BACKGROUND

[0002] Aluminum alloy has low density (~2.7 g / cm 3 ), high specific strength, good thermal / electrical conductivity, formability and recyclability, so it is widely used in high-end manufacturing fields. However, the surface hardness of aluminum alloy is low (usually 80-150 HV), the wear resistance is poor, and it is easy to scratch and wear.

[0003] The prior art introduces inorganic particles (such as SiC, Al2O3, B4C, TiC, etc.) with high hardness, high stability and low density on the surface of aluminum alloy by adding reinforcing particles, to build a "surface composite functional layer", so as to enhance the mechanical properties of the surface of aluminum alloy while ensuring the low density and high strength of aluminum alloy. However, this method often leads to low overall strength of the material due to interface problems while improving rigidity. The current technology also has the following problems: the interface bonding strength between the hard particles and the aluminum matrix is insufficient, resulting in particle shedding; there is a clear performance gradient jump between the surface hardening layer and the matrix, resulting in stress concentration; and the traditional processing process is difficult to optimize the surface hardness and overall toughness at the same time.

[0004] The above problems limit the further application of hard particle reinforced aluminum alloy in the fields of aerospace, automobile industry, etc. SUMMARY

[0005] The present application discloses a hard inorganic particle reinforced aluminum alloy surface composite coating and a preparation method thereof, to solve the technical problems of insufficient interface bonding strength of hard particles in the aluminum matrix and stress concentration in the related art.

[0006] To solve the above problems, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a hard inorganic particle reinforced aluminum alloy surface composite coating, which comprises an aluminum alloy matrix layer, a reinforcing layer and a transition layer between the matrix layer and the reinforcing layer, further comprising an interface layer between the transition layer and the reinforcing layer, and a composite layer between the interface layer and the reinforcing layer.

[0008] Further, the interface layer is a Ga-In-Sn liquid metal interface layer, and the thickness thereof is 50-80 nm.

[0009] Further, the transition layer is an Al-Ti-Si nanocrystalline transition layer, and the thickness thereof is 200-300 nm.

[0010] Further, the composite layer is a SiC-Al2O3 composite layer in which SiC layers and Al2O3 layers are alternately stacked, and the thickness of the composite layer is 1-2 μm; the thickness of the SiC-Al2O3 layers is 20-50 nm.

[0011] Further, the thickness of the reinforcing layer is 400-600 nm.

[0012] Further, the interface layer includes a first interface layer and a second interface layer, the first interface layer is located between the transition layer and the reinforcing layer, and the second interface layer is located between the base layer and the transition layer.

[0013] Further, the transition layer includes micro-channels arranged at intervals, and the micro-channels are connected to the first interface layer and the second interface layer.

[0014] Further, the interface layer is composed of a first sub-layer and a second sub-layer, the first sub-layer is in contact with the base layer, the transition layer and the composite layer, and the second sub-layer is located between the first sub-layer; the first sub-layer is a solid layer, and the second sub-layer is a semi-solid layer; the thickness of the first sub-layer is 10-30 nm, and the thickness of the second sub-layer is 20-50 nm.

[0015] Further, the SiC-Al2O3 composite layer is in contact with the Al2O3 layers of the interface layer.

[0016] Further, the method further includes a protective layer located outside the reinforcing layer, and the protective layer is a diamond-like carbon protective layer with a thickness of 50-100 nm.

[0017] Further, the reinforcing layer contains 30-70% of a particulate ceramic phase in terms of volume fraction, and the ceramic phase changes in a gradient direction from the composite layer to the reinforcing layer, and the content of the ceramic phase gradually increases along the gradient direction; the ceramic phase includes at least one of SiC, B4C and diamond particles.

[0018] In a second aspect, the application further provides a preparation method of a hard inorganic particulate reinforced aluminum alloy surface composite coating, including the following steps:

[0019] Step 1: ultrasonic cleaning and acid pickling activation treatment are performed on the base layer;

[0020] Step 2: an Al-Ti-Si nanocrystalline transition layer is deposited on the activated base layer by a reaction magnetron sputtering technology;

[0021] Step 3: a Ga-In-Sn liquid metal interface layer is deposited on the Al-Ti-Si nanocrystalline transition layer by a metallurgical bonding technology;

[0022] Step 4: Constructing a SiC-Al2O3 composite layer by alternately stacking SiC sheets and Al2O3 sheets on the Ga-In-Sn liquid metal interface layer through a pulsed laser deposition technique;

[0023] Step 5: Depositing a gradient ceramic reinforced layer on the SiC-Al2O3 composite layer through a magnetron sputtering and co-deposition technique, wherein the volume fraction of the ceramic phase changes along the thickness direction.

[0024] Further, in step 2, a mold is placed on the activated substrate layer, and then an Al-Ti-Si nanocrystalline transition layer is deposited to form a microchannel.

[0025] Further, after depositing the Al-Ti-Si nanocrystalline transition layer, micro-holes are processed on at least one of the micro-debonding area, weak bonding area, voids and cracks of the transition layer to obtain a microchannel.

[0026] Further, in step 3, first, a Ga-In-Sn liquid metal with a Ga content of 60-62wt% is dropped on the microchannel and the surface of the transition layer to make it fully contact with the substrate layer and the transition layer, and the thickness is controlled to be 10-30 nm; then a Ga-In-Sn liquid metal with a Ga content of 62-68wt% is dropped, and the thickness is controlled to be 20-50 nm; then a Ga-In-Sn liquid metal with a Ga content of 58-60wt% is dropped, and the thickness is controlled to be 10-30 nm; finally, the Ga-In-Sn liquid metal is subjected to in-situ low-temperature annealing treatment for 10-60 min to obtain a Ga-In-Sn liquid metal interface layer, and the in-situ low-temperature annealing treatment temperature is 50-80℃.

[0027] Further, in step 4, when constructing the SiC-Al2O3 composite layer, first, an Al2O3 sheet is deposited, and then SiC sheets and Al2O3 sheets are alternately deposited.

[0028] Further, the preparation method further comprises step 6: depositing a diamond-like carbon protective layer on the gradient ceramic reinforced layer through a plasma enhanced chemical vapor deposition or magnetron sputtering technique.

[0029] The technical scheme adopted in the present application can achieve the following beneficial effects:

[0030] The reinforced layer is formed by dense accumulation of nanoscale hard particles, which is used to improve surface scratch resistance, reduce friction coefficient, and close the micro-holes in the lower layer to enhance corrosion resistance;

[0031] The transition layer forms good metallurgical compatibility with the aluminum alloy substrate on the one hand, and provides a high-surface-energy, low-defect-density bearing platform on the other hand, significantly improving wettability and blocking the deep diffusion of Ga elements into the aluminum substrate, thereby relieving the risk of liquid metal embrittlement;

[0032] The interface layer can significantly soften the Al surface at room temperature, even inducing a local liquid phase, thereby greatly reducing the interfacial tension, promoting wetting and atomic-level contact; macroscopically, it presents a "solid-liquid-solid" three-layer structure, which has high interfacial strength and excellent stress buffering capacity, and can effectively adapt to the interfacial strain caused by thermal expansion mismatch or mechanical deformation, thereby inhibiting crack initiation and propagation;

[0033] The alternating structure of the composite layer effectively inhibits crack propagation, improves fracture toughness through interlayer deflection mechanism, and provides structural transition and stress buffering.

[0034] Through the interaction of the above layers, the bonding strength, surface hardness and wear resistance of the overall coating and the aluminum alloy substrate are significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0036] Figure 1 is a schematic diagram of the longitudinal section structure of the hard inorganic particle reinforced aluminum alloy surface composite coating in some embodiments of the present application;

[0037] Figure 2 is a schematic diagram of the connection structure of the interface layer, the substrate layer and the transition layer in some embodiments of the present application;

[0038] Figure 3 is a schematic diagram of the flow of the preparation method of the hard inorganic particle reinforced aluminum alloy surface composite coating in some embodiments of the present application.

[0039] In the drawings:

[0040] 100, substrate layer; 200, transition layer; 210, microchannel; 300, interface layer; 310, first interface layer; 320, second interface layer; 400, composite layer; 500, reinforcing layer; 600, protective layer. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the present application more clear, the technical solutions of the present application will be described in detail below. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of the present application.

[0042] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than that illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of a kind and do not limit the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the objects before and after are in an "or" relationship.

[0043] The prior art introduces high-hardness, high-stability, low-density inorganic particles (such as SiC, Al2O3, B4C, TiC, etc.) on the surface of aluminum alloy by adding reinforcing particles, to build a "surface composite functional layer", so as to enhance the mechanical properties of the surface of the aluminum alloy while ensuring the low density and high strength of the aluminum alloy. However, this method often leads to low overall strength of the material due to interface problems while improving rigidity, limiting the further application of hard particle reinforced aluminum alloy in the fields of aerospace, automobile industry, etc.

[0044] The present application effectively solves the technical problems of weak bonding force, easy cracking, particle agglomeration, and single function of the existing hard particle coating on the surface of aluminum alloy by constructing a five-layer gradient structure of "matrix layer-transition layer-interface layer-composite layer-reinforcing layer". The synergistic effect of each layer not only ensures the high hardness and wear resistance of the coating, but also takes into account the strong interface bonding and service reliability with the lightweight aluminum alloy matrix, and is suitable for fields such as aerospace, new energy vehicles, high-end electronic equipment, etc. which have strict requirements on lightweight and surface performance.

[0045] The hard inorganic particle reinforced aluminum alloy surface composite coating and the preparation method thereof provided by the present application will be described in detail below by specific embodiments and application scenarios. Figures 1 to 3 The hard inorganic particle reinforced aluminum alloy surface composite coating and the preparation method thereof provided by the present application will be described in detail below by specific embodiments and application scenarios.

[0046] In a first aspect, as shown in Figure 1 and Figure 2 , the present application provides a hard inorganic particle reinforced aluminum alloy surface composite coating, which comprises an aluminum alloy matrix layer 100, a reinforcing layer 500, and a transition layer 200 located between the matrix layer 100 and the reinforcing layer 500, and further comprises an interface layer 300 and a composite layer 400, the interface layer 300 is located between the transition layer 200 and the reinforcing layer 500, and the composite layer 400 is located between the interface layer 300 and the reinforcing layer 500.

[0047] Specifically, the aluminum alloy matrix layer 100 is a 6061, 7075 or 2024 series aluminum alloy, which serves as a load-bearing main body to provide lightweight structural support.

[0048] As shown in FIG. 1, the Al-Ti-Si nanocrystalline transition layer 200 is in-situ deposited on the surface of the aluminum alloy substrate by a magnetron co-sputtering process, wherein the target material uses high-purity Al target (99.99%), Ti target (99.95%) and Si target (99.999%), and the sputtering atmosphere is high-purity Ar (purity ≥ 99.999%). The substrate temperature is maintained at 80-120°C during the deposition process to avoid thermal damage and promote the formation of nanocrystals. Figure 1 As shown in FIG. 1, the Al-Ti-Si nanocrystalline transition layer 200 is in-situ deposited on the surface of the aluminum alloy substrate by a magnetron co-sputtering process, wherein the target material uses high-purity Al target (99.99%), Ti target (99.95%) and Si target (99.999%), and the sputtering atmosphere is high-purity Ar (purity ≥ 99.999%). The substrate temperature is maintained at 80-120°C during the deposition process to avoid thermal damage and promote the formation of nanocrystals.

[0049] As shown in FIG. 1, the Al-Ti-Si nanocrystalline transition layer 200 is in-situ deposited on the surface of the aluminum alloy substrate by a magnetron co-sputtering process, wherein the target material uses high-purity Al target (99.99%), Ti target (99.95%) and Si target (99.999%), and the sputtering atmosphere is high-purity Ar (purity ≥ 99.999%). The substrate temperature is maintained at 80-120°C during the deposition process to avoid thermal damage and promote the formation of nanocrystals. Figure 1 Figure 2 As shown in FIG. 1, the Al-Ti-Si nanocrystalline transition layer 200 is in-situ deposited on the surface of the aluminum alloy substrate by a magnetron co-sputtering process, wherein the target material uses high-purity Al target (99.99%), Ti target (99.95%) and Si target (99.999%), and the sputtering atmosphere is high-purity Ar (purity ≥ 99.999%). The substrate temperature is maintained at 80-120°C during the deposition process to avoid thermal damage and promote the formation of nanocrystals.

[0050] The chemical composition of the obtained transition layer 200 is Al 85 Ti10Si5 (atomic percentage), the 200-300 nm thick Al-Ti-Si nanocrystalline transition layer 200 on the one hand forms good metallurgical compatibility with the aluminum alloy substrate, and on the other hand provides a high surface energy, low defect density bearing platform for the subsequent Ga-In-Sn liquid metal interface layer 300 or gradient ceramic reinforcement layer 500, significantly improving wettability and blocking the deep diffusion of Ga elements into the aluminum substrate, thereby relieving the risk of liquid metal embrittlement.

[0051] As shown in FIG. 1, the Al-Ti-Si nanocrystalline transition layer 200 is in-situ deposited on the surface of the aluminum alloy substrate by a magnetron co-sputtering process, wherein the target material uses high-purity Al target (99.99%), Ti target (99.95%) and Si target (99.999%), and the sputtering atmosphere is high-purity Ar (purity ≥ 99.999%). The substrate temperature is maintained at 80-120°C during the deposition process to avoid thermal damage and promote the formation of nanocrystals. Figure 1 Figure 2 As shown in FIG. 1, the Al-Ti-Si nanocrystalline transition layer 200 is in-situ deposited on the surface of the aluminum alloy substrate by a magnetron co-sputtering process, wherein the target material uses high-purity Al target (99.99%), Ti target (99.95%) and Si target (99.999%), and the sputtering atmosphere is high-purity Ar (purity ≥ 99.999%). The substrate temperature is maintained at 80-120°C during the deposition process to avoid thermal damage and promote the formation of nanocrystals.

[0052] ​​Further, when Ga-In-Sn liquid metal interfacial layer 300 is sandwiched between Al-Ti-Si transition layer 200 and SiC-Al2O3 composite layer 400, Ga element will spontaneously diffuse and chemically bond with the Al-containing phases on both sides. This process results in a decrease of Ga concentration and a relative enrichment of In and Sn in the upper and lower near-interface regions of Ga-In-Sn layer. Since Ga is the key component that determines the melting point of Ga-In-Sn alloy (the higher the content of Ga, the lower the melting point), the local consumption of Ga causes the local melting point of the alloy near the interface to rise.

[0053] By precisely controlling the initial composition of Ga-In-Sn alloy (e.g., Ga content of 58-62 wt%) and diffusion kinetics conditions (e.g., interface contact time, temperature, Al phase exposure area), the regions within about 10-30 nm of the upper and lower Ga-In-Sn layer can be converted to solid state at room temperature and form Al-Ga metal bonds or even partially covalent / ionic characteristic interfacial chemical bonds with the Al phases in the Al-Ti-Si transition layer 200 and SiC-Al2O3 composite layer 400 on both sides, thereby significantly improving the interfacial bonding strength and thermal / electrical stability.

[0054] At the same time, the middle region of Ga-In-Sn layer remains low-viscosity semi-solid, macroscopically presenting a "solid-liquid-solid" three-layer structure. This structure has both high interfacial strength (derived from the chemical bonding of the solidified regions on both sides) and excellent stress buffering capability (derived from the zero shear modulus and flowable characteristics of the semi-solid region in the middle), which can effectively adapt to the interfacial strain caused by thermal expansion mismatch or mechanical deformation, and inhibit crack initiation and propagation.

[0055] For example, as shown in FIG. 1, the Ga-In-Sn layer 300 is sandwiched between the Al-Ti-Si transition layer 200 and the SiC-Al2O3 composite layer 400. The Ga-In-Sn layer 300 is in a semi-solid state at room temperature, and the upper and lower regions of the Ga-In-Sn layer 300 are in a solid state at room temperature. Figure 1As shown, the SiC-Al2O3 composite layer 400 is prepared by pulsed laser deposition: first, a 30 nm thick Al2O3 sheet is deposited on the surface of the Ga-In-Sn liquid metal interface layer 300; then, a 40 nm thick amorphous / nanocrystalline SiC sheet is deposited; the above deposition steps of Al2O3 sheet and SiC sheet are alternately repeated 30-40 times, finally forming an alternating stacked structure with a total thickness of 1.05-1.4 μm (where the volume ratio of Al2O3 sheet to SiC sheet is approximately 1:1.3). Among them, the Al2O3 sheets provide high insulation, chemical inertness and diffusion barrier to Ga elements; the SiC sheets impart high thermal conductivity (theoretical value >120 W / m·K), high hardness and good interfacial compatibility with the metal phase; the nanoscale alternating structure (20-50 nm / layer) effectively inhibits crack propagation and improves fracture toughness through interlayer deflection mechanism; the overall composite layer 400 serves as the bottom layer of the reinforcing layer 500, forming a low thermal resistance contact with the underlying Ga-In-Sn liquid metal interface layer 300 (thickness of 50-80 nm), and providing structural transition and stress buffer for the upper high ceramic content gradient reinforcing layer 500 (such as containing diamond / B4C).

[0056] Furthermore, the layers are metallurgically bonded or strongly mechanically interlocked, the overall coating has a bonding strength with the aluminum alloy substrate of ≥40 MPa, the microhardness is increased from 100-150 HV in the substrate to 1000-1500 HV in the surface layer, and the wear rate under dry sliding wear conditions is reduced by more than 80% compared with the untreated aluminum alloy.

[0057] In some embodiments, the interface layer 300 includes a first interface layer 310 and a second interface layer 320, the first interface layer 310 being located between the transition layer 200 and the reinforcement layer 500, and the second interface layer 320 existing between the substrate layer 100 and the transition layer 200.

[0058] For example, such as Figure 1 and Figure 2 As shown, the substrate layer 100 is made of 6061 aluminum alloy, and its surface is sequentially constructed with the following: second interface layer 320: Ga-In-Sn liquid metal layer with a thickness of 50-80 nm; transition layer 200: Al-Ti-Si nanocrystalline layer with a thickness of 250 nm; first interface layer 310: Ga-In-Sn liquid metal layer with a thickness of 60-75 nm.

[0059] In this structure, the second interface layer 320 mainly functions to improve the initial wettability between the aluminum alloy substrate and the Al-Ti-Si transition layer 200; promote atomic interdiffusion during low-temperature connection to form a low-resistance electrical / thermal path; and inhibit liquid metal embrittlement by using the Al-Ti-Si layer to block the diffusion of Ga. The first interface layer 310 bears the thermal-mechanical mismatch stress between the buffer enhancement layer 500 and the transition layer 200; fills the micro-pores at the bottom of the gradient enhancement layer 500 to reduce the interfacial thermal resistance; and realizes micro-crack self-repairing through the flow in the middle liquid zone during service.

[0060] The double-interface layer 300 design is significantly better than the single-interface layer 300 scheme, with a shear strength retention rate of >92% after thermal cycling, while the single-interface control group is only 68%.

[0061] In some embodiments, the transition layer 200 includes micro-channels 210 arranged at intervals, and the micro-channels 210 are in communication with the first interface layer 310 and the second interface layer 320.

[0062] As shown in FIGS. 1, 2, and 3, the interface layer 300 includes a first interface layer 310, a transition layer 200, and a second interface layer 320. Figure 1 and Figure 2 As shown in FIGS. 1, 2, and 3, the interface layer 300 includes a first interface layer 310, a transition layer 200, and a second interface layer 320. The micro-channels 210 in the transition layer 200 are arranged in a hexagonal or square pattern, with a diameter of 500-900 nm and a depth penetrating through the entire transition layer 200. The upper and lower ends of the micro-channels 210 are in direct communication with the first interface layer 310 on the upper surface of the transition layer 200 and the second interface layer 320 on the lower surface of the transition layer 200, respectively, forming a through-type capillary network. This micro-channel 210 structure can promote capillary self-filling of the Ga-In-Sn alloy. During the interface layer 300 coating process, the liquid metal spontaneously wets the upper and lower interfaces under the driving force of capillary force through the micro-channels 210, realizes three-dimensional interconnection, and significantly improves the uniformity of interface bonding. This micro-channel 210 structure can also enhance the element diffusion channel, so that Ga atoms can exchange between the first and second interface layers 320 through the micro-channels 210, cooperatively control the local composition and phase state of the two interfaces; this micro-channel 210 structure can also provide a stress release path, so that under thermal cycling or mechanical load, the micro-channels 210 can accommodate the volume flow of the liquid metal, relieve the interfacial shear stress concentration, and inhibit the crack propagation along the plane direction; and this micro-channel 210 structure can also improve the electrical / thermal longitudinal conduction efficiency, so that the continuous Ga-In-Sn filling channel forms a low-resistance path, effectively reducing the interlayer thermal resistance.

[0063] Further, the inner wall of the micro-channel 210 is rich in Ti and Si elements due to exposure to the Al-Ti-Si nanocrystalline environment, and can form a thin layer of Ti-Ga or Si-O-Ga interface passivation film in situ after contact with the liquid metal, which can prevent excessive erosion of the Ga substrate and maintain the long-term patency of the channel.

[0064] In the present embodiment, the conventional two-dimensional interface is expanded into a three-dimensional interconnected interface system, while maintaining the barrier function of the Al-Ti-Si transition layer 200, the overall integration reliability and multifunctionality of the multilayer heterostructure are significantly improved.

[0065] In some embodiments, the interface layer 300 is composed of a first sub-layer and a second sub-layer, the first sub-layer is in contact with the base layer 100, the transition layer 200 and the composite layer 400, and the second sub-layer is located between the first sub-layer; the first sub-layer is a solid layer, and the second sub-layer is a semi-solid layer; the thickness of the first sub-layer is 10-30 nm, and the thickness of the second sub-layer is 20-50 nm; the sheet layer of SiC-Al2O3 composite layer 400 in contact with the interface layer 300 is an Al2O3 sheet layer.

[0066] As shown in FIG. 1, the interface layer 300 is a Ga-In-Sn alloy layer, which is in contact with the Al-Ti-Si transition layer 200 on the bottom and the SiC-Al2O3 composite layer 400 on the top. Figure 1 and Figure 2 As shown in FIG. 1, the interface layer 300 is a Ga-In-Sn alloy layer, which is in contact with the Al-Ti-Si transition layer 200 on the bottom and the SiC-Al2O3 composite layer 400 on the top.

[0067] In some embodiments, a protective layer 600 is further included outside the reinforcing layer 500, and the protective layer 600 is a diamond-like carbon protective layer 600 with a thickness of 50-100 nm.

[0068] As shown in FIG. 1, the interface layer 300 is a Ga-In-Sn alloy layer, which is in contact with the Al-Ti-Si transition layer 200 on the bottom and the SiC-Al2O3 composite layer 400 on the top. Figure 1As shown, the protective layer 600 is a diamond-like carbon (DLC) protective layer 600. The protective layer 600 is deposited in situ on the surface of the completed gradient ceramic reinforcement layer 500 using a mid-frequency magnetron sputtering or plasma-enhanced chemical vapor deposition (PECVD) process, resulting in a hydrogenated diamond-like carbon film with a thickness of 80 nm. This DLC protective layer 600 exhibits high hardness and wear resistance, significantly improving surface scratch resistance and fretting wear resistance, making it suitable for high-friction or harsh service environments. It also possesses excellent chemical inertness, and its dense amorphous structure effectively prevents the penetration of water vapor, oxygen, and corrosive media.

[0069] In this embodiment, the DLC protective layer 600 balances protection, functionality, and reliability without significantly increasing structural stiffness.

[0070] In some embodiments, the reinforcing layer 500 contains 30-70% particulate ceramic phase by volume fraction, and the ceramic phase varies in a gradient from the composite layer 400 to the reinforcing layer 500, with the ceramic phase content gradually increasing along the gradient direction; the ceramic phase includes at least one of SiC, B4C and diamond particles.

[0071] For example, such as Figure 1 As shown, the reinforcing layer 500 can be prepared by layer-by-layer deposition or gradient spraying, with a thickness of 400-600 nm. On the side close to the aluminum alloy substrate layer 100, the ceramic phase volume fraction is 30%, mainly composed of nano-sized SiC particles (average particle size <100 nm); along the thickness direction outward (i.e. away from the substrate), the ceramic phase content gradually increases, reaching 65-70% in the surface region, and a mixed phase of diamond particles (particle size 20-100 nm) and B4C particles (particle size 20-100 nm) with high thermal conductivity is introduced to synergistically improve surface hardness, wear resistance and thermal diffusion capacity.

[0072] Secondly, such as Figure 3 As shown, this application also provides a method for preparing a composite coating on the surface of a hard inorganic particle-reinforced aluminum alloy, comprising the following steps:

[0073] Step 1: Surface activation treatment of substrate layer 100:

[0074] The aluminum alloy substrate layer 100 was ultrasonically cleaned for 5 minutes each in acetone, anhydrous ethanol, and deionized water to remove surface oil and organic contaminants. Then, the cleaned substrate layer 100 was immersed in a 10 wt% HNO3 solution for 30 seconds to selectively dissolve the natural Al2O3 film and activate the surface. It was immediately rinsed with deionized water and dried with high-purity nitrogen to avoid secondary oxidation.

[0075] Step 2: Al-Ti-Si nanocrystalline transition layer 200 and microchannel 210 construction:

[0076] After activation, the surface of the substrate layer 100 is attached to a sputter-resistant mask with a predetermined pattern (such as a molybdenum or quartz mold). Using reactive magnetron sputtering technology, an Al-Ti alloy target and a high-purity Si single target are used as co-sputtering sources. Ar / N2 mixed gas (N2 content 5-10 vol%) is introduced. The substrate bias is -30 V, and the deposition temperature is 100°C. The thickness of the Al-Ti-Si nanocrystalline transition layer 200 is 200-300 nm.

[0077] After deposition, the mask is removed, and focused ion beam (FIB) or femtosecond laser micromachining technology is used to process vertical through microholes at the microdebonding area, weak bonding area, voids, and crack locations of the transition layer 200, forming a microchannel 210 array with a diameter of 500-900 nm, achieving directional transport and interface anchoring of the subsequent liquid metal.

[0078] Step 3: Gradient composition Ga-In-Sn liquid metal interface layer 300 construction:

[0079] First, add Ga-In-Sn liquid metal with Ga content of 60-62 wt% (the rest is In / Sn) to the surface of the microchannel 210 and the transition layer 200. In an inert atmosphere glove box, let it stand for 5 minutes, allowing it to fully wet the microchannel 210 and contact the Al-Ti-Si layer through capillary action. The thickness of this bottom layer is controlled to be 10-30 nm.

[0080] Then, add Ga-In-Sn alloy with Ga content of 62-68 wt% to form an intermediate layer, with a thickness of 20-50 nm.

[0081] Then, add Ga-In-Sn alloy with Ga content of 58-60 wt% to form a top layer, with a thickness of 10-30 nm.

[0082] Finally, perform in-situ low-temperature annealing at 50-80°C for 10-60 minutes. During this process, Ga element selectively diffuses to the Al-containing phase above and below, resulting in a decrease in Ga concentration and an increase in melting point in the near-interface region. Finally, a "solid first sublayer / semi-solid second sublayer / solid first sublayer" structured interface layer 300 is formed, which has high bonding strength and stress buffering capacity.

[0083] Step 4: SiC-Al2O3 alternating composite layer 400 deposition:

[0084] A layer of Al2O3 platelets with a thickness of 30 nm is first deposited on the surface of the Ga-In-Sn interface layer 300 by pulsed laser deposition (PLD) technology (to ensure good compatibility with the liquid metal side); then SiC platelets (20-50 nm) and Al2O3 platelets (20-50 nm) are alternately deposited, repeated for 10-20 cycles, to obtain a SiC-Al2O3 nanolaminate composite structure with a total thickness of 1-2 μm. The deposition process is carried out in an oxygen / argon mixed atmosphere, and the substrate temperature is controlled at ≤80°C to prevent disturbance of the Ga-In-Sn layer.

[0085] Step 5: Gradient ceramic reinforced layer 500 preparation:

[0086] By means of a magnetron sputtering and powder co-deposition composite technology, Al metal matrix and hard ceramic particles (at least one of SiC, B4C and / or diamond) are simultaneously introduced on the SiC-Al2O3 composite layer 400, and by real-time control of the ceramic feeding rate, the volume fraction of the ceramic phase is continuously increased from 30 vol% at the bottom layer to 70 vol% at the surface layer, forming a gradient reinforced layer 500 with a thickness of 400-600 μm.

[0087] Step 6: Diamond-like carbon (DLC) protective layer 600 deposition:

[0088] Finally, a 50-100 nm thick hydrogenated diamond-like carbon protective layer 600 is deposited on the surface of the gradient ceramic reinforced layer 500 by plasma-enhanced chemical vapor deposition (PECVD) or medium-frequency magnetron sputtering technology, with a deposition temperature ≤100°C, to provide high hardness, wear resistance and environmental barrier properties.

[0089] For example, a composite coating is prepared on the surface of a 6061-T6 aluminum alloy by the above method, which has a shear strength of 42 MPa at room temperature, a strength retention rate >90% after 1000 thermal cycles of -55°C ↔ 125°C, a vertical thermal conductivity of 85 W / (m·K), a surface hardness >18 GPa, and high reliability, high thermal conductivity and excellent environmental durability, suitable for high-power electronic device heat dissipation substrates, aerospace lightweight wear-resistant components and flexible heterogeneous integration systems.

[0090] It should be noted that in this document, the terms "comprise", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or device. Without more limitations, the element defined by the statement "comprises a" does not exclude the presence of additional identical elements in the process, method, article or device that includes the element.

[0091] Furthermore, it is to be understood that the scope of the methods and apparatus of the present application are not limited to what can be expressly illustrated and described herein. Rather, the scope of the present application is as set forth in the claims following and equivalents thereof. It will be clear to those of ordinary skill in the art that modifications can be made to the embodiments described without departing from the spirit or scope of the application. Nothing herein is intended to be a disclaimer of any prior art unless otherwise explicitly stated. Moreover, although exemplary aspects of this application can be described as being stored in memory, this merely is meant as a convenience term, as such aspects would typically be transferred to other computer-readable media depending upon the particular application. Likewise, it should be understood that embodiments can be implemented using a variety of storage means and / or hardware components, and that the claimed processes can be implemented using some other suitable transaction-based processing systems suitable for such purposes. Accordingly, the breadth and scope of the present application should not be limited by any of the above-described exemplary embodiments, but should be defined in accordance with the following claims and their equivalents.

[0092] The above description is intended to enable any person skilled in the art to make and use the application. The application is provided solely for illustration of the concept of the application.

Claims

1. A hard inorganic particle reinforced aluminum alloy surface composite coating comprising an aluminum alloy base layer (100), a reinforcement layer (500) and a transition layer (200) between the base layer (100) and the reinforcement layer (500), characterized in that, Further comprising an interface layer (300) and a composite layer (400), the interface layer (300) is located between the transition layer (200) and the reinforcing layer (500), and the composite layer (400) is located between the interface layer (300) and the reinforcing layer (500); The interface layer (300) is a Ga-In-Sn liquid metal interface layer (300), and the thickness is 50-80 nm; The transition layer (200) is an Al-Ti-Si nanocrystalline transition layer (200), and the thickness is 200-300 nm; The composite layer (400) is a SiC-Al2O3 composite layer (400) in which SiC layers and Al2O3 layers are alternately stacked, and the thickness of the composite layer (400) is 1-2 μm; the thickness of the SiC-Al2O3 layers is 20-50 nm; The thickness of the reinforcing layer (500) is 400-600 nm.

2. The hard inorganic particulate reinforced aluminum alloy surface composite coating according to claim 1, wherein The interface layer (300) comprises a first interface layer (310) and a second interface layer (320), the first interface layer (310) is located between the transition layer (200) and the reinforcing layer (500), and the second interface layer (320) is located between the substrate layer (100) and the transition layer (200).

3. The hard inorganic particulate reinforced aluminum alloy surface composite coating according to claim 2, wherein, The transition layer (200) comprises micro-channels (210) arranged at intervals, and the micro-channels (210) are in communication with the first interface layer (310) and the second interface layer (320).

4. The hard inorganic particulate reinforced aluminum alloy surface composite coating according to claim 2, wherein The interface layer (300) is composed of a first sub-layer and a second sub-layer, the first sub-layer is in contact with the substrate layer (100), the transition layer (200) and the composite layer (400), and the second sub-layer is located between the first sub-layer; the first sub-layer is a solid layer, and the second sub-layer is a semi-solid layer; the thickness of the first sub-layer is 10-30 nm, and the thickness of the second sub-layer is 20-50 nm; The SiC-Al2O3 composite layer (400) is in contact with the Al2O3 layer of the interface layer (300).

5. The hard inorganic particulate reinforced aluminum alloy surface composite coating according to claim 1, wherein Further comprising a protective layer (600) located outside the reinforcing layer (500), the protective layer (600) is a diamond-like carbon protective layer (600), and the thickness is 50-100 nm.

6. The hard inorganic particulate reinforced aluminum alloy surface composite coating of claim 1, wherein, The reinforcing layer (500) contains 30-70% of a particulate ceramic phase in terms of volume fraction, and the ceramic phase changes in a gradient direction from the composite layer (400) to the reinforcing layer (500), and the content of the ceramic phase gradually increases along the gradient direction; the ceramic phase comprises at least one of SiC, B4C and diamond particles.

7. A method for producing the hard inorganic particle reinforced aluminum alloy surface composite coating according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: Step 1: ultrasonic cleaning and acid pickling activation treatment of the substrate layer (100); Step 2: depositing an Al-Ti-Si nanocrystalline transition layer (200) on the activated substrate layer (100) by a reaction magnetron sputtering technology; Step 3: depositing a Ga-In-Sn liquid metal interface layer (300) on the Al-Ti-Si nanocrystalline transition layer (200) by a metallurgical bonding technology; Step 4: depositing a SiC-Al2O3 composite layer (400) on the Ga-In-Sn liquid metal interface layer (300) by a metallurgical bonding technology; Step 4: Constructing a SiC-Al2O3 composite layer (400) by alternately stacking SiC sheets and Al2O3 sheets on the Ga-In-Sn liquid metal interface layer (300) through a pulsed laser deposition technique; Step 5: Depositing a gradient ceramic reinforced layer (500) on the SiC-Al2O3 composite layer (400) by a magnetron sputtering and co-deposition technique, wherein the volume fraction of the ceramic phase changes along the thickness direction.

8. The method of producing a hard inorganic particle reinforced aluminum alloy surface composite coating according to claim 7, characterized by, In the step 2, a mold is placed on the activated base layer (100), and then an Al-Ti-Si nanocrystalline transition layer (200) is deposited to form a microchannel (210); And / or, after depositing the Al-Ti-Si nanocrystalline transition layer (200), micro-holes are processed on at least one of the micro-debonding area, weak bonding area, voids and cracks of the transition layer (200) to obtain a microchannel (210).

9. The method of producing a hard inorganic particle reinforced aluminum alloy surface composite coating according to claim 8, characterized by, In the step 3, first, a Ga-In-Sn liquid metal with a Ga content of 60-62wt% is drop-coated on the microchannel (210) and the surface of the transition layer (200) to make it fully contact with the base layer (100) and the transition layer (200), and the thickness is controlled to be 10-30 nm; then a Ga-In-Sn liquid metal with a Ga content of 62-68wt% is drop-coated, and the thickness is controlled to be 20-50 nm; then a Ga-In-Sn liquid metal with a Ga content of 58-60wt% is drop-coated, and the thickness is controlled to be 10-30 nm; finally, in-situ low-temperature annealing treatment of the Ga-In-Sn liquid metal is performed for 10-60 min to obtain a Ga-In-Sn liquid metal interface layer (300), and the in-situ low-temperature annealing treatment temperature is 50-80℃; In the step 4, when constructing the SiC-Al2O3 composite layer (400), the Al2O3 sheet is first deposited, and then the SiC sheet and the Al2O3 sheet are alternately deposited.

10. The method of claim 7, wherein the method further comprises the step of: The preparation method further comprises step 6: depositing a diamond-like carbon protective layer (600) on the gradient ceramic reinforced layer (500) by a plasma enhanced chemical vapor deposition or magnetron sputtering technique.

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