AR-hud adaptive azo / graphene composite gradient target and preparation method thereof

Abstract

The application relates to an AR-HUD adaptive AZO / graphene composite gradient target material and a preparation method thereof. The composite gradient target material is a three-layer composite structure, and from a bottom layer to a top layer, the three-layer composite structure is sequentially an AZO matrix layer, a graphene doped layer and a nano-silver reinforced layer, and a resistivity gradient is formed along the thickness direction of the target material. The graphene doped layer effectively improves the conductive stability of the target material and a plated film layer, the nano-silver reinforced layer optimizes the infrared blocking performance and the refractive index matching degree, and the problems of existing target material projection ghosting and glare are solved.

Description

Technical Field

[0001] This invention relates to the field of target technology, specifically to an AR-HUD compatible AZO / graphene composite gradient target and its preparation method. Background Technology

[0002] Augmented reality head-up display (AR-HUD) technology, as a core component of the intelligent upgrade of new energy vehicles, can project key information such as navigation and vehicle speed onto the windshield, achieving a fusion display of information and real-world scenery, greatly improving driving safety and convenience. Currently, the penetration rate of panoramic sunroofs and AR-HUDs has reached 28%. High-end new energy vehicles have increasingly stringent performance requirements for AR-HUD windshields, focusing on three key indicators: high light transmittance, low haze, and precise refractive index. Simultaneously, it must also consider electrical conductivity stability and infrared blocking performance to ensure projection clarity and driving comfort.

[0003] Currently, most targets used for AR-HUD windshield coatings are single AZO (aluminum-doped zinc oxide) targets or simple composite targets, which have several technical drawbacks: First, single AZO targets lack sufficient conductivity stability, and long-term use can easily lead to resistance drift, affecting the signal transmission performance of the coating layer and thus interfering with the AR-HUD projection accuracy. Second, the lack of targeted composite structure design results in poor matching between infrared blocking effect and refractive index, easily causing ghosting and glare in the projection, and the light transmittance is difficult to meet the requirements of high-end vehicles. Third, traditional targets are mostly of uniform performance structure, which cannot adapt to the differentiated performance requirements of the AR-HUD projection area and surrounding glass, limiting the improvement of display effect. Fourth, graphene, as a high-quality conductive reinforcing material, is prone to agglomeration in composite targets, resulting in insufficient target density, which in turn affects the uniformity and mechanical properties of the coating layer, and existing manufacturing processes cannot effectively solve this problem. Fifth, there is currently a lack of domestically produced targets specifically adapted for AR-HUD. The technology for specialized sputtering targets for windshields is monopolized by foreign countries, resulting in significant patent gaps and technological barriers that hinder the independent development of China's intelligent new energy vehicle industry. Therefore, it is crucial to develop a sputtering target that meets the core performance requirements of AR-HUD windshields and addresses technical challenges such as graphene agglomeration, performance gradient adaptation, and the balance between light transmittance and density. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide an AR-HUD-compatible AZO / graphene composite gradient target and its preparation method, thereby resolving the problems mentioned in the background section.

[0005] The present invention solves the technical problem by adopting the following technical solution: This invention provides an AR-HUD-compatible AZO / graphene composite gradient target. The composite gradient target has a three-layer composite structure, consisting of an AZO matrix layer, a graphene doped layer, and a silver nanoparticle reinforcement layer from bottom to top, forming a resistivity gradient along the target's thickness direction. The resistivity range is 1.5 × 10⁻⁶. -4 ~2.0×10 -4 Ω·cm; the component ratio of the composite gradient target material satisfies the following: the AZO matrix layer accounts for 85-90% of the total mass of the target material, the graphene doping amount in the graphene doped layer is 0.5%-1% of the total mass of the target material, and the thickness of the nano-silver reinforcement layer is 5-10μm; the density of the composite gradient target material is ≥96.5%, and the visible light transmittance of the coating layer prepared using the target material is ≥72%.

[0006] Furthermore, the AZO substrate layer is composed of zinc oxide (ZnO) and aluminum oxide, wherein the doping amount of Al2O3 is 2%-3% of the mass of ZnO. ZnO powder with a particle size of 50-100nm and Al2O3 powder with a particle size of 30-50nm are selected to ensure the basic light transmittance and conductivity of the AZO substrate, providing stable support for the subsequent composite layer.

[0007] Furthermore, the graphene in the graphene-doped layer undergoes modification treatment. The modifying raw materials include yttrium oxide, a 5% (w / w) chitosan solution, and hydroxyapatite. During the modification process, the mass ratio of graphene, yttrium oxide, and hydroxyapatite is 10:1:2, and the amount of chitosan solution used is 8-12 times the mass of graphene. The modified graphene exhibits significantly improved dispersibility, effectively preventing agglomeration during the composite process. It also enhances the bonding force with the AZO matrix layer and the nano-silver reinforcement layer, thereby improving the overall stability of the target material.

[0008] Furthermore, the nano-silver reinforcing layer is prepared using nano-silver powder with a particle size of 10-20 nm. The surface of the nano-silver powder is modified with a silane coupling agent, the amount of which is 0.3%-0.5% of the mass of the nano-silver powder. This modification is used to optimize the dispersibility of the nano-silver, improve the infrared blocking performance and refractive index matching, and at the same time enhance the tightness of the bonding with the graphene doped layer, thus preventing delamination.

[0009] Furthermore, the total thickness of the composite gradient target is 5-15 mm, of which the AZO matrix layer accounts for 70%-80% of the total thickness, the graphene doped layer accounts for 10%-20% of the total thickness, and the nano-silver reinforcement layer is strictly controlled at 5-10 μm. Through thickness ratio and gradient design, the resistivity is precisely controlled to meet the differentiated performance requirements of the AR-HUD projection area and the surrounding glass.

[0010] The above-mentioned preparation method of AR-HUD adapted AZO / graphene composite gradient target The preparation method includes five steps: graphene modification, segmented ball milling, layered molding, low-temperature sintering and plasma activation, and post-treatment, as detailed below: Graphene modification: Graphene powder, yttrium oxide powder, and hydroxyapatite powder were mixed in a mass ratio of 10:1:2, and a 5% (w / w) chitosan solution was added. The mixture was stirred and dispersed for 2-3 hours at a stirring speed of 800-1000 r / min. Subsequently, the mixture was treated by spray drying at a temperature of 120-150℃ to obtain modified graphene powder. This step improves the dispersibility of graphene through multi-component synergistic modification, laying the foundation for subsequent composite preparation.

[0011] Segmented ball milling: Preparation of AZO matrix slurry: ZnO powder and Al2O3 powder were mixed in a certain proportion, and anhydrous ethanol was added as a dispersant. The amount of dispersant was 30%-40% of the mass of the mixed powder. The mixture was then placed in a planetary ball mill and ball-milled for 4-6 hours at a speed of 300-400 r / min and a ball-to-powder ratio of 10:1 to obtain AZO matrix slurry. Preparation of graphene-doped slurry: Modified graphene powder is mixed with a portion of AZO matrix slurry and ball-milled for 2-3 hours at a speed of 400-500 r / min to obtain graphene-doped slurry, ensuring that graphene is uniformly dispersed in the AZO system; Preparation of nano-silver reinforced slurry: The modified nano-silver powder was added to anhydrous ethanol and ultrasonically dispersed for 1-2 hours with an ultrasonic power of 300-400W. Then it was mixed with the remaining AZO matrix slurry and stirred evenly to obtain nano-silver reinforced slurry. The three slurries were processed using a vacuum drying process at a temperature of 80-100℃ for 6-8 hours to remove the dispersant and obtain the corresponding dried powder for each layer.

[0012] Layered molding: A special mold is used to load the powder in layers in the following order: bottom layer of AZO matrix dry powder, middle layer of graphene doped dry powder, and top layer of nano-silver reinforced dry powder. Each layer of powder is evenly spread and pre-pressed using a gradient pressure method. The pre-pressing pressure is 20-30 MPa, the holding time is 10-15 min, and the pre-pressing temperature is 25-30℃. The amount of powder used in each layer is precisely controlled according to the target material composition ratio and thickness requirements to ensure the stability of the gradient structure.

[0013] Low-temperature sintering and plasma activation: The pre-pressed green body is placed in a sintering furnace. An inert gas (argon or nitrogen) is first introduced for atmosphere protection at a flow rate of 50-100 mL / min to remove air from the furnace. Then, the temperature is raised to 1250℃ for low-temperature sintering at a rate of 5-8℃ / min and a holding time of 3-4 hours. During the sintering process, plasma activation is performed simultaneously with a plasma power of 500-600W, an activation time of 30-60 minutes, and an activation frequency of 13.56MHz. Through the synergistic effect of low-temperature sintering and plasma activation, the sintering temperature is reduced, energy consumption is saved, and the graphene agglomeration problem is effectively solved, thereby improving the density of the target material. After sintering, the green body is cooled to room temperature in the furnace to obtain the sintered green body.

[0014] Post-processing: The sintered blank is removed and the surface is ground using precision grinding equipment to remove surface impurities and burrs, and the surface roughness Ra of the target material is controlled to be ≤0.8μm. Then, it is cleaned and dried to obtain AR-HUD adapted AZO / graphene composite gradient target material. The cleaning is carried out by ultrasonic cleaning with deionized water for 20-30 minutes, and the drying temperature is 80-100℃ for 2-3 hours.

[0015] Furthermore, in step 2, a small amount of dispersant (such as polyethylene glycol) can be added during planetary ball milling, with the amount being 0.5%-1% of the mass of the mixed powder, to further improve the uniformity of powder dispersion and avoid agglomeration during ball milling.

[0016] Furthermore, in step 4, the purity of the inert gas is ≥99.99% to ensure that the green body is not oxidized during sintering and to guarantee the conductivity and density of the target material. The plasma activation treatment can destroy the inert groups on the surface of graphene, enhance the interfacial bonding force between graphene and AZO matrix and nano silver, and further optimize the gradient properties of the target material.

[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention designs a three-layer composite structure of "AZO matrix + graphene doped layer + nano-silver reinforcement layer". The graphene doped layer effectively improves the conductivity stability of the target material and the coating layer, while the nano-silver reinforcement layer optimizes the infrared blocking performance and refractive index matching, solving the problems of projection ghosting and glare in existing target materials. At the same time, through a gradient doping process, the target material forms a thickness of 1.5 × 10⁻⁶ Å. -4 ~2.0×10 -4 The resistivity gradient of Ω·cm precisely matches the different performance requirements of the AR-HUD projection area and the surrounding glass, significantly improving the display effect.

[0018] Solving core technical challenges and improving product quality: Graphene is synergistically modified with yttrium oxide, 5% chitosan solution, and hydroxyapatite, combined with low-temperature sintering (1250℃) and plasma activation composite processes. This effectively solves the graphene agglomeration problem, ensuring that the target material density is ≥96.5%. The visible light transmittance of the coating layer prepared using this target material is ≥72%, balancing light transmittance and mechanical properties, and meeting the core requirements of "high light transmittance and low haze" for AR-HUD windshields.

[0019] By defining precise component ratios and thickness ranges for AZO matrix, graphene, and nano-silver, and optimizing key process parameters such as segmented ball milling, layered molding, and sintering, the preparation process becomes controllable, product performance is stable, and industrial mass production is facilitated. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to specific examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1 An AR-HUD-adaptive AZO / graphene composite gradient target material has a three-layer composite structure. The AZO matrix layer accounts for 85% of the total mass of the target material, the graphene doping amount is 1% of the total mass of the target material, the nano-silver reinforcement layer has a thickness of 5μm, and the total thickness of the target material is 5mm. The AZO matrix layer accounts for 80% of the total thickness, and the graphene doped layer accounts for 20% of the total thickness.

[0022] The preparation method is as follows: Graphene modification: Mix 10g graphene powder, 1g yttrium oxide powder, and 2g hydroxyapatite powder, add 120g of 5% chitosan solution, stir and disperse for 3h at a stirring speed of 800r / min, and spray dry (120℃) to obtain modified graphene powder. Segmented ball milling: ZnO powder and Al2O3 powder (Al2O3 being 2% of ZnO by mass) were mixed, 30% anhydrous ethanol was added, and the mixture was ball-milled for 6 hours (300 r / min, ball-to-powder ratio 10:1) to obtain an AZO matrix slurry; 85% of the AZO matrix slurry was mixed with modified graphene powder and ball-milled for another 3 hours (400 r / min), and dried to obtain graphene-doped powder; modified nano-silver powder (0.3% silane coupling agent) was added to anhydrous ethanol, ultrasonically dispersed for 2 hours (300 W), mixed with the remaining 15% AZO matrix slurry, and dried to obtain nano-silver reinforced powder; Layered molding: The AZO matrix powder, graphene doped powder, and nano silver reinforced powder are layered and molded in that order, and pre-pressed at 20MPa for 15min (25℃). Low-temperature sintering and plasma activation: Argon gas was introduced (50 mL / min), the temperature was raised to 1250℃ (heating rate 5℃ / min), held for 4 h, and plasma activation was performed simultaneously for 60 min (power 500 W, frequency 13.56 MHz), followed by furnace cooling; the plasma activation used radio frequency plasma with a power of 500-600 W, an activation time of 30-60 min, and an activation frequency of 13.56 MHz. Post-processing: Precision grinding (Ra≤0.8μm, precision grinding (using a five-axis linkage grinding machine, surface roughness Ra≤0.8μm, test according to GB / T 1031-2009)), ultrasonic cleaning with deionized water for 30 min, drying at 80℃ for 3 h to obtain the finished product, with coating haze ≤1.2%, infrared blocking rate ≥85% (800-2500nm band), and no ghosting or glare in the projection.

[0023] Example 2 An AR-HUD-adaptive AZO / graphene composite gradient target material has a three-layer composite structure. The AZO matrix layer accounts for 90% of the total mass of the target material, the graphene doping amount is 0.5% of the total mass of the target material, the nano-silver reinforcement layer has a thickness of 10 μm, and the total thickness of the target material is 15 mm. The AZO matrix layer accounts for 70% of the total thickness, and the graphene doped layer accounts for 20% of the total thickness.

[0024] The preparation method is as follows: Graphene modification: Mix 10g graphene powder, 1g yttrium oxide powder, and 2g hydroxyapatite powder, add 80g of 5% chitosan solution, stir and disperse for 2h at a stirring speed of 1000r / min, and spray dry (150℃) to obtain modified graphene powder. Segmented ball milling: ZnO powder and Al2O3 powder (Al2O3 being 3% of ZnO by mass) were mixed, 40% anhydrous ethanol was added, and the mixture was ball-milled for 4 hours (400 r / min, ball-to-powder ratio 10:1) to obtain an AZO matrix slurry; 90% of the AZO matrix slurry was mixed with modified graphene powder and ball-milled for another 2 hours (500 r / min), and dried to obtain graphene-doped powder; modified nano-silver powder (0.5% silane coupling agent) was added to anhydrous ethanol, ultrasonically dispersed for 1 hour (400 W), mixed with the remaining 10% AZO matrix slurry, and dried to obtain nano-silver reinforced powder; Layered molding: The AZO matrix powder, graphene doped powder, and nano silver reinforced powder are layered and molded in that order, and pre-pressed at 30MPa for 10min (30℃). Low-temperature sintering and plasma activation: Nitrogen gas was introduced (100 mL / min), the temperature was raised to 1250℃ (heating rate 8℃ / min), held for 3 h, and plasma activation was performed simultaneously for 30 min (power 600 W, frequency 13.56 MHz), followed by furnace cooling. Post-processing: Precision grinding (Ra≤0.8μm, precision grinding (using a five-axis linkage grinding machine, surface roughness Ra≤0.8μm, test according to GB / T 1031-2009)), ultrasonic cleaning with deionized water for 20 min, drying at 100℃ for 2 h to obtain the finished product, with coating haze ≤1.2%, infrared blocking rate ≥85% (800-2500nm band), and no ghosting or glare in the projection.

[0025] Example 3 An AR-HUD-adaptive AZO / graphene composite gradient target material has a three-layer composite structure. The AZO matrix layer accounts for 88% of the total mass of the target material, the graphene doping amount is 0.8% of the total mass of the target material, the nano-silver reinforcement layer has a thickness of 8μm, and the total thickness of the target material is 10mm. The AZO matrix layer accounts for 75% of the total thickness, the graphene doped layer accounts for 15% of the total thickness, the coating haze is ≤1.2%, the infrared blocking rate is ≥85% (800-2500nm band), and there is no ghosting or glare phenomenon in the projection.

[0026] Comparative Example 1 (Unmodified Graphene) The difference from the example is that no modification was performed on the graphene, and the proportions of the other components and the preparation process are the same as in the example.

[0027] Comparative Example 2 The difference from the example is that the component ratio is exactly the same as in Example 1, and a uniform structure (without a three-layer layered design) is adopted, with graphene and silver nanoparticles uniformly dispersed in the AZO matrix.

[0028] Comparative Example 3 The difference from the example is that the traditional high-temperature sintering process (sintering temperature of 1400℃) is used, and no plasma activation treatment is performed. The proportions of other components and the preparation process are the same as those in the example.

[0029] Comparative Example 4 (Graphene modified with yttrium oxide only) The difference from the example is that the graphene is modified with only yttrium oxide (without chitosan solution or hydroxyapatite), and the amount of yttrium oxide used during modification is the same as in the example (graphene to yttrium oxide mass ratio 10:1). The proportions of other components and the preparation process are the same as in the example.

[0030] Comparative Example 5 (Graphene modified with chitosan solution only) The difference from the example is that the graphene is modified only by a single chitosan solution with a mass fraction of 5% (without yttrium oxide and hydroxyapatite), the amount of chitosan solution used is the same as in the example (10 times the mass of graphene), and the proportions of other components and the preparation process are the same as in the example.

[0031] Comparative Example 6 (deviation in the proportion of modified components) The difference from the example is that when the graphene is modified, the mass ratio of graphene, yttrium oxide and hydroxyapatite is 10:2:3 (deviating from the 10:1:2 ratio of the present invention), while the proportions of the other components and the preparation process are the same as those in the example.

[0032] Comparative Example 7 (insufficient chitosan solution) The difference from the example is that when modifying graphene, the amount of chitosan solution used is 5 times the mass of graphene (lower than the range of 8-12 times in this invention), while the proportions of other components and the preparation process are the same as in the example.

[0033] The difference from the example is that the graphene was not modified, and the proportions of the other components and the preparation process are the same as in the example.

[0034] Performance tests were conducted on the products of Examples 1-3 and Comparative Examples 1-7, and the test results are as follows:

[0035]

[0036] The composite gradient targets prepared in Examples 1-3 of this invention outperform all comparative examples in terms of density, resistivity gradient control, graphene dispersion, coating transmittance, and conductivity stability. This particularly highlights the crucial role of graphene optimization and modification, and the performance degradation trend under different graphene modification conditions is clear. Without graphene modification (Comparative Example 1), graphene agglomeration was most severe, the target material density and transmittance decreased most significantly, and the conductivity stability deteriorated significantly. It was the worst performing group among all the modified comparative examples, which confirms the necessity of graphene modification. Compared with the multi-component synergistic modification in the examples, the single modification (Comparative Examples 4 and 5) resulted in insufficient graphene dispersion and local agglomeration, and all properties declined significantly. Moreover, the effect of chitosan modification alone was worse than that of yttrium oxide modification alone, indicating that multi-component synergistic modification can achieve complementary performance, while single modification cannot achieve the optimal effect. When the modification parameters deviate from the limits of this invention (Comparative Examples 6 and 7), even with multi-component modification or single modification, the performance still declines. Among them, the performance deterioration of insufficient chitosan content (Comparative Example 7) is close to that of the unmodified group, while the performance decline of deviation in the proportion of modified components (Comparative Example 6) is relatively mild, which confirms the rationality of the graphene modification component proportion and modifier content limits of this invention. Comparative Example 2, with its gradient-free design, while exhibiting uniform graphene dispersion, fails to meet the differentiated requirements of the AR-HUD projection area and surrounding glass. Comparative Example 3, employing traditional high-temperature sintering without plasma activation, results in localized graphene agglomeration, leading to lower target density and transmittance compared to the embodiments of this invention. Example 2, compared to Examples 1 and 3, demonstrates optimal density, transmittance, and electrical conductivity stability due to optimized component ratios and process parameters, further validating the rationality of the component and process limitations of this invention. In summary, the multi-component synergistic graphene modification process and precise parameter limitations of this invention are key to resolving graphene agglomeration and ensuring the comprehensive performance of the target material. Combined with a composite structure design and a low-temperature sintering-plasma activation synergistic process, it effectively improves target material performance, meeting the core usage requirements of AR-HUD windshields.

[0037] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0038] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An AR-HUD-adaptive AZO / graphene composite gradient target, characterized in that, The composite gradient target material has a three-layer composite structure, consisting of an AZO matrix layer, a graphene doped layer, and a silver nanoparticle reinforcement layer from bottom to top, forming a resistivity gradient along the thickness direction of the target material, with a resistivity range of 1.5 × 10⁻⁶. -4 ~2.0×10 -4 ; The composition ratio of the composite gradient target material satisfies the following: the AZO matrix layer accounts for 85%-90% of the total mass of the target material, the graphene doping amount in the graphene doped layer is 0.5%-1% of the total mass of the target material, and the thickness of the nano-silver reinforcement layer is 5-10 μm.

2. The AR-HUD-adaptive AZO / graphene composite gradient target material according to claim 1, characterized in that, The AZO substrate layer is composed of ZnO and Al2O3, with the Al2O3 doping amount being 2%-3% of the ZnO mass. The ZnO powder particle size is 50-100nm, and the Al2O3 powder particle size is 30-50nm.

3. The AR-HUD-adaptive AZO / graphene composite gradient target according to claim 1, characterized in that, The graphene in the graphene-doped layer is modified by means of yttrium oxide, 5% chitosan solution, and hydroxyapatite. The mass ratio of graphene, yttrium oxide, and hydroxyapatite is 10:1:2, and the amount of chitosan solution used is 8-12 times the mass of graphene.

4. The AR-HUD-adaptive AZO / graphene composite gradient target material according to claim 1, characterized in that, The nano-silver reinforcing layer is prepared using nano-silver powder with a particle size of 10-20 nm. The surface of the nano-silver powder is modified with a silane coupling agent, and the amount of the modifier is 0.3%-0.5% of the mass of the nano-silver powder.

5. The AR-HUD-adaptive AZO / graphene composite gradient target according to claim 1, characterized in that, The total thickness of the composite gradient target is 5-15 mm, the thickness of the AZO matrix layer accounts for 70%-80% of the total thickness, and the thickness of the graphene doped layer accounts for 10%-20% of the total thickness.

6. A method for preparing an AR-HUD-adaptive AZO / graphene composite gradient target as described in any one of claims 1-5, characterized in that, The process includes five steps: graphene modification, segmented ball milling, layered molding, low-temperature sintering and plasma activation, and post-treatment, as detailed below: (1) Graphene modification: Graphene, yttrium oxide and hydroxyapatite are mixed in a mass ratio of 10:1:2, and a 5% chitosan solution is added. The mixture is stirred and dispersed for 2-3 hours, and then spray-dried to obtain modified graphene powder. (2) Segmented ball milling: AZO matrix slurry, graphene doped slurry and nano silver reinforced slurry were prepared respectively, and each slurry was dried under vacuum to obtain the corresponding dry powder; (3) Layered molding: The AZO matrix dry powder, graphene doped dry powder, and nano silver reinforced dry powder are layered and molded in the order of layered molding, and gradient pressure is applied for pre-pressing. (4) Low-temperature sintering and plasma activation: Inert gas is introduced for protection, the temperature is raised to 1250℃ for sintering, and plasma activation is carried out simultaneously. After sintering, the furnace is cooled. (5) Post-processing: Grinding, cleaning and drying the sintered blank to obtain the finished product.

7. The preparation method according to claim 6, characterized in that, In step (2), the ball milling time of the AZO matrix slurry is 4-6h, the ball milling speed is 300-400r / min, and the ball-to-material ratio is 10:1; the ball milling time of the graphene doped slurry is 2-3h, and the ball milling speed is 400-500r / min; the ultrasonic dispersion time of the nano-silver reinforced slurry is 1-2h, and the ultrasonic power is 300-400W.

8. The preparation method according to claim 6, characterized in that, In step (3), the pre-compression pressure is 20-30 MPa, the pressure holding time is 10-15 min, and the pre-compression temperature is 25-30℃.

9. The preparation method according to claim 6, characterized in that, In step (4), the inert gas is argon or nitrogen, the gas flow rate is 50-100 mL / min, the heating rate is 5-8 °C / min, the sintering holding time is 3-4 h, the plasma activation power is 500-600 W, the activation time is 30-60 min, and the activation frequency is 13.56 MHz.

10. The AR-HUD-adaptive AZO / graphene composite gradient target according to any one of claims 1-5, characterized in that, The target material is used in the magnetron sputtering coating process of AR-HUD windshields for new energy vehicles, and is compatible with continuous and intermittent coating production lines.

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