Tungsten-based alloy target material and preparation method thereof

Abstract

The invention relates to the technical field of metal-based ceramic target material preparation, in particular to a tungsten-based alloy target material and a preparation method thereof. The method comprises the following steps: 1) pre-calcining Y2O3 powder and ZnO powder, and then carrying out ball milling and mixing on the calcined Y2O3 powder and ZnO powder and Al2O3 powder to obtain composite powder containing part of ZnAl2O4 phase; wherein the doping proportion of the Y2O3 powder is 13 wt% to 18 wt%, the doping proportion of the ZnO powder is 13 wt% to 18 wt%, and the doping proportion of the Al2O3 powder is 0.3 wt% to 2.0 wt%; the preparation method comprises 1) preparing composite powder, 2) carrying out ball milling mixing on the composite powder and tungsten powder to obtain uniformly distributed tungsten-based composite powder and carrying out shaping on the tungsten-based composite powder in a cold isostatic pressing or die pressing mode to obtain a green body, and 3) sintering the green body to obtain a tungsten-based alloy sintered blank and carrying out machining on the tungsten-based alloy sintered blank to obtain the tungsten-based alloy target material.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of metal-based ceramic target material preparation, in particular to a tungsten-based alloy target material and a preparation method thereof. BACKGROUND

[0002] COE technology (Color on Encapsulation) in the display field, also known as "color film formed on the thin film encapsulation", is a key innovation in current OLED display technology, and is developing rapidly especially in the field of foldable mobile phones and high-end straight-line mobile phones. The core is to remove the circular polarizer in the traditional OLED, and directly make a color filter (CF) and a black pixel definition layer (PDL) on the thin film encapsulation layer (TFE), thereby solving the light efficiency loss and thickness problem of the traditional structure. The tungsten-based alloy target material has important applications in the fields of OLED display, photovoltaic thin film, electric vacuum device and functional coating due to its high melting point, high density, excellent electrical conductivity and thermal stability.

[0003] In the prior art, the sintering activity of tungsten itself is poor, and a sintering temperature higher than 2000 DEG C is usually required to obtain a high-density product, which leads to high energy consumption, complex process, and easy occurrence of grain coarsening and internal stress problems. In order to improve the sintering performance, researchers often introduce rare earth oxides such as Y2O3 into the tungsten matrix. Y2O3 particles can play a role of dispersion strengthening and grain boundary pinning during the sintering process, effectively inhibit the grain growth, and improve the high-temperature stability and microstructure uniformity of the target material. However, when Y2O3 is doped alone, the densification effect is limited under low-temperature sintering conditions, and it is difficult to meet the requirement of the relative density of the target material being greater than or equal to 98% for high-end thin film preparation. SUMMARY

[0004] The application covers the following technical solutions:

[0005] One aspect of the application relates to a preparation method of a tungsten-based alloy target material, which comprises the following steps:

[0006] 1) Y2O3 powder and ZnO powder are pre-calcined and then ball-milled with Al2O3 powder to obtain a composite powder containing a part of ZnAl2O4 phase; wherein the doping proportions of the Y2O3 powder, the ZnO powder and the Al2O3 powder are 13 wt%-18 wt%, 13 wt%-18 wt% and 0.3 wt%-2.0 wt%, respectively;

[0007] 2) the composite powder is ball-milled with tungsten powder to obtain a tungsten-based composite powder uniformly distributed, and a green body is obtained by shaping the tungsten-based composite powder by cold isostatic pressing or die pressing;

[0008] 3) sintering the green body to obtain a tungsten-based alloy sintered body, and machining the tungsten-based alloy sintered body to obtain a tungsten-based alloy target material.

[0009] Still another aspect of the present application relates to a tungsten-based alloy target material, which is formed by sintering tungsten powder, Y2O3 powder, ZnO powder and Al2O3 powder;

[0010] wherein the content of Y2O3 is 13 wt% to 18 wt%, the content of ZnO is 13 wt% to 18 wt%, the content of Al2O3 is 0.3 wt% to 2.0 wt%, and the balance is tungsten.

[0011] The present application realizes high purity, high density and composition stability of traditional tungsten-based target material by introducing Y2O3, ZnO and Al2O3 synergistic doping in tungsten matrix and combining with low-temperature hot isostatic pressing sintering process. Y2O3 dispersion phase can effectively inhibit grain growth, ZnO helps low-temperature densification, and Al2O3 and ZnO partially react to form ZnAl2O4, which is relatively thermodynamically stable and can significantly inhibit ZnO evaporation and maintain alloy composition balance. Through this synergistic mechanism, the target material of the present application can reach a relative density of ≥98%, a purity of ≥3N6, fine and uniform grain distribution at 1050℃ to 1200℃, avoiding the problems of high energy consumption and grain coarsening caused by high-temperature sintering. At the same time, the hot isostatic pressing process reduces internal stress, prevents the generation of cracks and surface defects, thereby improving the processing performance and service life of the target material. The present application not only optimizes the microstructure and macroscopic performance of the material, but also is suitable for stable preparation of small and large size target materials, and can meet the demand for high-density and high-purity tungsten-based target material for OLED display and other high-end thin film devices. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0013] Figure 1 : The actual picture of the tungsten-based alloy target material prepared in Example 2.

[0014] Figure 2 : EBSD grain size distribution histogram, the grain distribution of the control group is wide and coarsened, and the grain distribution of the experimental group is relatively narrow, with an average size of about 22 μm.

[0015] Figure 3SEM cross-section of Example 2 group, showing ZnAl2O4 dispersoids uniformly distributed at grain boundaries.

[0016] Figure 4 TG-MS curve showing obvious Zn evaporation peak in the control group, and the Zn evaporation peak intensity of the experimental group is significantly weakened.

[0017] Figure 5 XRD pattern, the characteristic diffraction peaks (311), (440) of ZnAl2O4 are marked, indicating that ZnAl2O4 phase is generated in the experimental group.

[0018] Figure 6 Surface defect comparison histogram, showing that the number of surface defects in the experimental group is significantly lower than that in the control group. Note: "*" indicates P<0.05, the difference between the experimental group and the control group is significant.

[0019] Figure 7 Thin film transmittance curve with wavelength change. DETAILED DESCRIPTION

[0020] Reference will now be made in detail to the embodiments of the present application, one or more examples of which are set forth below. Each example is provided by way of explanation of the present application, not limitation of the present application. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present application without departing from the scope or spirit of the present application. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment.

[0021] Unless otherwise defined, all terms (including technical and scientific terms) used herein in the present disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this present disclosure belongs. By further guidance, the following definitions are used for better understanding the teachings of the present disclosure. The terms used in the specification of the present disclosure herein are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0022] In the present disclosure, unless otherwise specified, the scientific and technical terms used herein have the meanings commonly understood by those skilled in the art.

[0023] The terms "containing", "including" and "comprising" used in the present disclosure are synonymous and are inclusive or open-ended and do not exclude additional, unrecited members, elements or method steps.

[0024] The numerical ranges in the present disclosure expressed in endpoints include all numbers and fractions subsumed within the range, as well as the recited endpoints.

[0025] The term "about" or "approximately" as used herein means within 20%, preferably within 10%, and more preferably within 5% of a given value or range. It is also meant to include the specific number, e.g., about 20 includes 20.

[0026] Furthermore, in describing representative embodiments of the present application, the specification can have presented the method and / or process of the present application as a particular sequence of steps. However, to the extent that the method or process depends on the performance of such steps, the method or process should not be limited to the

[0027] In the present application, the concentration values are intended to include fluctuations within a certain range. For example, there can be fluctuations within a corresponding accuracy range. For example, 2%, fluctuations within a range of ±0.1% can be allowed.

[0028] As used in the present application, the singular forms "a", "an" and "the" include plural referents unless otherwise stated.

[0029] In the present application, the descriptions such as "a plurality of", "a plurality of kinds" and the like, if not particularly limited, refer to greater than or equal to 2 in number.

[0030] In the present application, in the technical features described in an open-ended manner, both a closed technical solution consisting of the listed features and an open technical solution including the listed features are included.

[0031] In the present application, "preferably", "more preferably", "even more preferably", "suitably" are only used to describe embodiments or examples with better effects, and should be understood as not constituting a limitation on the protection scope of the present application. In the present application, "optionally", "optional", "alternatively" means that it can or can not be present, i.e., it means to be selected from either of the two parallel schemes "yes" or "no". If there are multiple "optionally" in a technical solution, and there is no special description, and there is no contradictory relationship or mutual restriction, each "optionally" is independent of each other.

[0032] A first aspect of the present application relates to a method for producing a tungsten-based alloy target material, comprising the following steps:

[0033] 1) Y2O3 powder and ZnO powder are pre-calcined and then ball-milled with Al2O3 powder to obtain a composite powder containing a part of ZnAl2O4 phase; wherein the doping proportions of the Y2O3 powder, the ZnO powder and the Al2O3 powder are 13 wt% to 18 wt%, 13 wt% to 18 wt%, and 0.3 wt% to 2.0 wt%, respectively;

[0034] 2) the composite powder is ball-milled with tungsten powder to obtain a tungsten-based composite powder with uniform distribution, and the tungsten-based composite powder is shaped into a green body by cold isostatic pressing or die pressing;

[0035] 3) the green body is sintered to obtain a tungsten-based alloy sintered body, and the tungsten-based alloy sintered body is machined to obtain a tungsten-based alloy target material.

[0036] In some embodiments, the particle size of the Al2O3 powder is 20 nm to 200 nm, for example, 50 nm, 100 nm, or 150 nm; and the purity is not less than 4N.

[0037] The nano-sized Al2O3 has a small particle size and a large specific surface area, and can react with ZnO more thoroughly in solid phase to form a stable ZnAl2O4 dispersion phase at a lower temperature, thereby effectively "locking" Zn element and reducing the volatilization loss of ZnO. In addition, the nano Al2O3 can enter the grain boundary and form a dispersion distribution during sintering, play a role of grain boundary pinning, inhibit the growth of tungsten grains, make the sintered body grain size more uniform, and improve the overall relative density.

[0038] Limiting the purity of Al2O3 to be ≥4N can avoid the introduction of impurity elements (Na, K, Fe, etc.), prevent abnormal discharge and film defects in the sputtering process, and thereby improve the electrical performance stability of the target material and the optical quality of the deposited film.

[0039] In some embodiments, the purity of the Y2O3 powder, the ZnO powder and the tungsten powder is not less than 4N, and the particle size ratio is 1 μm to 3 μm: 0.5 μm to 1.5 μm: 0.5 μm to 1.5 μm.

[0040] Y2O3 and ZnO maintain a small particle size, which makes them uniformly distributed after ball milling, and is conducive to the rapid reaction of generating ZnAl2O4 dispersion phase at a low temperature; the tungsten powder is refined, has a large specific surface area, and is conducive to the uniform combination with the composite oxide and the reduction of pore generation. The particle size ratio of the three is matched, which is conducive to the formation of a close-packed structure during ball milling, improves the sintering driving force, and thereby promotes high densification. In summary, by controlling the particle size range of different raw material powders, the dispersion phase is uniformly distributed in the tungsten grain boundary and inside the grain, and segregation or agglomeration of large particles is avoided.

[0041] In some embodiments, the pre-calcination condition is 400-700℃ for 4-6 hours.

[0042] Pre-calcination at 400-700℃ can make ZnO and Al2O3 partially react to form ZnAl2O4 dispersion phase at a lower temperature, which can act as "grain pinning points" in the subsequent sintering process to inhibit grain coarsening and effectively "lock" Zn elements to avoid ZnO evaporation. Since the pre-calcination has formed a partially stable phase, the sintering kinetics barrier can be reduced during the HIP (hot isostatic pressing) stage.

[0043] In some embodiments, the composite powder is subjected to spray drying granulation treatment before being ball-milled with the tungsten powder.

[0044] In some embodiments, each ball-milling in the method is independently selected from dry milling or wet milling; the material of the milling balls is preferably WC or zirconia balls; and the material of the ball jar is preferably WC or polyurethane.

[0045] In some embodiments, the pressure for cold isostatic pressing is 210-250MPa, and the pressure holding time is 10-20min.

[0046] In some embodiments, the method for sintering the green body is to vacuumize the green body after welding a package, and then to sinter the green body by hot isostatic pressing.

[0047] In some embodiments, the temperature for hot isostatic pressing is 1050-1200℃, the pressure is 130-150MPa, and the holding time is 4-10h.

[0048] According to the second aspect of the present application, the tungsten-based alloy target is sintered from tungsten powder, Y2O3 powder, ZnO powder and Al2O3 powder.

[0049] In the tungsten-based alloy target, the content of Y2O3 is 13-18 wt%, the content of ZnO is 13-18 wt%, the content of Al2O3 is 0.3-2.0 wt%, and the balance is tungsten.

[0050] The present application limits the component ratio and microstructure comprehensively, so that the obtained tungsten-based alloy target has high density, low defect rate, stable composition and excellent sputtering performance, and can effectively improve the consistency and reliability of thin film preparation.

[0051] In some embodiments, the particle size of the Al2O3 powder is 20-200nm, and the target contains ZnAl2O4 dispersion phase.

[0052] In some embodiments, the tungsten-based alloy target has a relative density of not less than 98%, and the Y2O3, ZnO and ZnAl2O4 are uniformly dispersed in the microstructure, and the grain size is 15-30 μm.

[0053] Embodiments of the present application will be described in detail below with reference to examples. It should be understood that these examples are only used to illustrate the present application and not intended to limit the scope of the present application. In the following examples, the experimental methods without specific conditions are preferred to refer to the guidance given in the present application, and can also be performed according to the experimental manuals or conventional conditions in the art, or according to the conditions suggested by the manufacturers.

[0054] In the following specific examples, the measurement parameters of the raw material components may have slight deviations within the weighing accuracy range, unless otherwise specified. With respect to temperature and time parameters, acceptable deviations caused by instrument testing accuracy or operation accuracy are allowed.

[0055] Example 1

[0056] 1. Powder preparation: 1.4 kg of tungsten powder with purity ≥4N and particle size 1 μm, 0.3 kg of Y2O3 powder with purity ≥4N and particle size 1 μm, 0.3 kg of ZnO powder with purity ≥4N and particle size 1 μm, and 0.01 kg of Al2O3 powder with purity ≥4N and particle size 50 nm were weighed.

[0057] 2. Calcination treatment: the mixed Y2O3 and ZnO were placed in a tube furnace and heat-treated at 500 ℃ for 5 h, and then cooled with the furnace.

[0058] 3. Composite powder preparation: the calcined Y2O3+ZnO powder and Al2O3 powder were mixed and ball-milled for 8 h with a ball-to-material ratio of 2:1 and φ3 mm WC balls as the medium to obtain a composite powder containing ZnAl2O4 phase.

[0059] 4. Mixing and granulation: the above composite powder and tungsten powder with purity ≥4N were wet ball-milled for 10 h with a polyurethane ball tank as the medium, and then spray-dried and granulated to obtain a tungsten-based composite powder with good flowability.

[0060] 5. Pressing forming: mold pre-pressing was performed at a pressure of 30 MPa, followed by cold isostatic pressing at a pressure of 220 MPa for 15 min to obtain a φ103×28 mm green body.

[0061] 6. Hot isostatic pressing sintering: the green body was sleeved and vacuumized, and then hot isostatic pressed at 1100 ℃ and 140 MPa for 6 h to obtain a sintered body.

[0062] 7. Machining: removing the package, wire cutting to obtain φ80x6 mm single tungsten alloy target material.

[0063] Test results: target material relative density 98.2%, purity 3N7, grain size about 18 μm, uniform microstructure, no cracks and peeling on the surface.

[0064] Example 2

[0065] A large-size tungsten alloy target material with a composition ratio of W: Y2O3: ZnO: Al2O3 = 74:13:13:1.0 (wt%) was prepared, with a size of 440x200x18 mm.

[0066] Steps:

[0067] 1. Powder preparation: weighing 133.2 kg of tungsten powder with a purity of ≥4N and a particle size of 1 μm, 23.4 kg of Y2O3 powder with a purity of ≥4N and a particle size of 3 μm, 23.4 kg of ZnO powder with a purity of ≥4N and a particle size of 1 μm, and 1.8 kg of Al2O3 powder with a purity of ≥4N and a particle size of 100 nm.

[0068] 2. Calcination treatment: mixing Y2O3 and ZnO, and cooling after holding at 650 ℃ for 6 h.

[0069] 3. Composite powder preparation: ball milling the calcined Y2O3+ZnO powder and Al2O3 powder in a polyurethane ball mill jar for 16 h to form a composite powder containing ZnAl2O4 phase.

[0070] 4. Mixing and granulation: placing the composite powder and tungsten powder with a purity of ≥4N in a V-type mixer and mixing under inert atmosphere for 12 h.

[0071] 5. Pressing: cold isostatic pressing at a pressure of 230 MPa for 20 min to obtain a large-size green body of 185x275x565 mm.

[0072] 6. Hot isostatic pressing sintering: vacuum packaging of the green body, sintering at 1200 ℃ and 150 MPa for 10 h to obtain a large-size sintered body.

[0073] 7. Machining: removing the package, wire cutting to obtain a 440x200x18 mm tungsten alloy target material.

[0074] The detection result is that the relative density of the target material is 98.6%, the purity is 3N8, the grain size is about 22 μm, ZnAl2O4 is dispersedly distributed in the microstructure, and the whole is uniform without stratification.

[0075] The tungsten-based alloy target material prepared in Example 2 is shown in the actual figure as Figure 1 indicated.

[0076] Example 3

[0077] A tungsten-based alloy target material with the component ratio of W:Y2O3:ZnO:Al2O3 = 69:13:18:2.0 (wt%) is prepared, and the specification is φ80x6 mm.

[0078] Steps:

[0079] 1. Powder preparation: 1.38 kg of tungsten powder with purity ≥4N and particle size 1 μm, 0.26 kg of Y2O3 powder with purity ≥4N and particle size 1 μm, 0.36 kg of ZnO powder with purity ≥4N and particle size 1 μm, and 0.04 kg of Al2O3 powder with purity ≥4N and particle size 80 nm are weighed.

[0080] 2. Calcination treatment: Y2O3 and ZnO are cooled after being kept at 500 ℃ for 4 h.

[0081] 3. Composite powder preparation: after mixing with Al2O3 powder, wet ball milling is performed for 6 h, and the medium is φ1-3 mm zirconia ball, to obtain a composite powder containing part of ZnAl2O4.

[0082] 4. Mixing and granulation: the composite powder is spray-dried into spherical particles, and then mixed with tungsten powder for 10 h to obtain uniform tungsten-based composite powder.

[0083] 5. Pressing forming: after die pressing, cold isostatic pressing is performed at a pressure of 210 MPa for 10 min to obtain a green body.

[0084] 6. Hot isostatic pressing sintering: hot isostatic pressing is performed at 1150 ℃ and 135 MPa for 5 h to obtain a sintered body.

[0085] 7. Machining: after debinding and cutting, a φ80x6 mm tungsten-based alloy target material is obtained.

[0086] The detection result is that the relative density of the target material is 98.9%, the grain size is about 25 μm, the purity is 3N7, Y2O3, ZnO and ZnAl2O4 are uniformly distributed, and the surface quality is good.

[0087] Experimental example

[0088] I. Purpose of the experiment

[0089] The present study found that Y2O3 doping can inhibit grain growth, and ZnO doping is helpful for low-temperature densification, but ZnO has serious volatilization above 1200 ℃, causing fluctuations in target composition and purity reduction. In this study, Example 2 (W:Y2O3:ZnO:Al2O3 = 74:13:13:1.0, wt%) was the best implementation scheme, and by introducing a small amount of nano-Al2O3 and forming ZnAl2O4 dispersion phase after calcination pretreatment, the volatilization of ZnO was effectively inhibited, and the grain boundary pinning and low-temperature densification were promoted.

[0090] II. Experimental methods

[0091] 2.1 Grouping and sample preparation

[0092] The experimental group and the control group both used W, Y2O3, ZnO powders with a purity of ≥4N (particle sizes were 1 μm, 1~3 μm, and 1 μm, respectively). The Al2O3 powder was nano-sized (particle size about 100 nm) with a purity of ≥4N.

[0093] Experimental group (Example 2; Experiment): After Y2O3 and ZnO were calcined at 650 ℃ for 6 h, they were mixed with Al2O3 powder and wet ball-milled for 16 h to obtain a composite powder containing part of ZnAl2O4. Then, the W powder was mixed for 12 h, cold isostatic pressing (230 MPa, 20 min) was performed, and finally hot isostatic pressing sintering was performed at 1200 ℃, 150 MPa, and 10 h. The target material with a size of 440×200×18 mm was machined.

[0094] Control 1 (Control1): No Al2O3 was added, and the rest of the steps were the same as the experimental group.

[0095] Control 2 (Control2): No Y2O3+ZnO calcination was performed, and the rest of the steps were the same as the experimental group.

[0096] Each group of samples was prepared in n=4 replicates to ensure statistical significance.

[0097] 2.2 Testing and characterization

[0098] Densification and Microstructure: Relative density was measured using the Archimedes method; porosity was quantified using metallographic imaging; grain size and texture were analyzed using SEM / EBSD; and the cross-section of the sintered target was observed using scanning electron microscopy (SEM). Microstructure homogeneity information was obtained through backscattered electron imaging (BSE), and elemental qualitative analysis was performed using energy dispersive spectroscopy (EDS) to identify Zn and Al enriched regions and confirm the presence and distribution of the ZnAl2O4 dispersed phase.

[0099] Composition stability: TG-MS was used to simulate the HIP temperature range and monitor the Zn volatilization signal; ICP-OES was used to determine the Zn retention rate and batch-to-batch consistency; EPMA was used to scan the elemental distribution of Zn, Al, and Y; XRD / Rietveld was used to quantify the ZnAl2O4 content.

[0100] Surface quality inspection: After polishing the sample, select multiple random areas (no less than 5 areas per sample) under an optical microscope or SEM, manually count the number of surface defects such as pinholes, cracks, and peeling, and convert them into defect density per unit area (defects / cm²). 2 For each group, n=4, take the average and calculate the standard error.

[0101] Sputtering and film performance: testing discharge voltage fluctuations, abnormal discharge frequency, and target lifetime; refractive index n, transmittance, film thickness uniformity, and defect rate of the deposited film.

[0102] Statistical analysis was performed using t-tests and one-way ANOVA, with a significance level set at *P<0.05.

[0103] III. Results and Discussion

[0104] 3.1 Densification and Microstructure

[0105] The relative compactness of the experimental group reached 98.6% ± 0.3%, which was significantly higher than that of control 1 (96.9% ± 0.5%) and control 2 (97.1% ± 0.4%), and the porosity was reduced by about 30%.

[0106] EBSD showed a median grain size of approximately 22 μm with a concentrated distribution, while the control group exhibited significant grain coarsening. Figure 2 ). Figure 3 SEM cross-sectional images of the experimental group are shown. The average grain size of the experimental group samples is approximately 22 μm, with uniform distribution and fine bright spots visible near the grain boundaries. Energy dispersive spectroscopy (EDS) analysis confirmed these as Zn and Al enriched regions, corresponding to the ZnAl2O4 dispersed phase. These results indicate that the introduction of Al2O3 and the pre-calcination process effectively promoted the formation of the ZnAl2O4 dispersed phase, thereby achieving grain boundary pinning and low-temperature densification.

[0107] 3.2 ZnO volatility and component stability

[0108] TG-MS tests showed that controls 1 and 2 exhibited significant ZnO volatilization peaks at 1100℃–1150℃, while the peak intensity of the experimental group decreased by more than 40%. Figure 4 ICP-OES analysis showed that the Zn retention rate in the experimental group was ≥92%, while that in control 1 was only 68% and control 2 was 74%. EPMA surface scanning showed that the Zn distribution in the experimental group was uniform, and the pixel-level coefficient of variation was reduced by 35%. Figure 5 The XRD pattern further confirmed the presence of the ZnAl2O4 dispersed phase in the experimental group, indicating that the introduction of Al2O3 effectively "locked" Zn.

[0109] 3.3 Surface quality inspection

[0110] Figure 6 The surface defect density statistics for the experimental and control groups are shown. The number of surface defects in Control 1 and Control 2 were 18 per cm³. 2 With 15 per cm 2 The experimental group showed more severe peeling and pinholes; while the experimental group had a significantly reduced number of defects, only 5 per cm. 2 (P<0.05). This result indicates that the introduction of Al2O3 and the use of a pre-calcination process can effectively improve the surface quality of the target material and reduce the risk of surface failure during processing and use.

[0111] 3.4 Sputtering performance and film quality

[0112] Under DC sputtering conditions, the discharge voltage fluctuation in the experimental group was ±2%, significantly better than control 1 (±5%) and control 2 (±4%); the frequency of abnormal discharges decreased by 40%, and the target lifetime was extended by approximately 15%. The transmittance of the deposited film at 550 nm wavelength increased by 3%, the film thickness uniformity remained at ±2%, and the pinhole rate decreased by 25%. Figure 7 ).

[0113] By setting up a control experiment, this study systematically demonstrated that in the Y2O3–ZnO–Al2O3 co-doping system, the pre-calcination step of nano-Al2O3 and Y2O3+ZnO can effectively suppress ZnO volatilization under low-temperature HIP conditions, forming a ZnAl2O4 dispersed phase, which significantly improves the density, purity, and microstructure uniformity of tungsten-based sputtering targets. Compared with the control group, the experimental group showed statistically significant advantages in relative density, Zn retention rate, surface defect density, and sputtering performance. This method provides a feasible technical route for the low-temperature preparation of high-performance tungsten-based targets and is suitable for application in high-end fields such as OLED displays.

[0114] In summary, the present application not only overcomes the problem of insufficient densification of the existing W-Y2O3 system under low-temperature HIP, but also solves the volatilization problem of ZnO for the first time by using the "zinc locking" mechanism of ZnAl2O4, and the multiple synergistic effects of microstructure refinement, composition stability and surface defect reduction verified by the experimental examples.

[0115] The above-described embodiments only express several embodiments of the present application, which are described in detail and specifically, but should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims, and the description and drawings can be used to explain the content of the claims.

Claims

1. A method for producing a tungsten-based alloy target material, characterized by, The method comprises the following steps: 1) mixing Y2O3 powder and ZnO powder after pre-calcination with Al2O3 powder by ball milling to obtain a composite powder containing a part of ZnAl2O4 phase; wherein the doping ratio of the Y2O3 powder, the ZnO powder and the Al2O3 powder is 13 wt%-18 wt%, 13 wt%-18 wt%, 0.3 wt%-2.0 wt% respectively; 2) mixing the composite powder with tungsten powder by ball milling to obtain a uniformly distributed tungsten-based composite powder, and shaping the tungsten-based composite powder by cold isostatic pressing or die pressing to obtain a green body; 3) sintering the green body to obtain a tungsten-based alloy sintered body, and machining the tungsten-based alloy sintered body to obtain a tungsten-based alloy target material.

2. The production method according to claim 1, characterized by, The particle size of the Al2O3 powder is 20 nm-200 nm, and the purity is not less than 4N.

3. The production method according to claim 1, characterized by, The purity of the Y2O3 powder, the ZnO powder and the tungsten powder is not less than 4N, and the particle size ratio is 1 μm-3 μm: 0.5 μm-1.5 μm: 0.5 μm-1.5 μm.

4. The method of claim 1, wherein, The pre-calcination condition is calcination at 400°C-700°C for 4-6 hours.

5. The process according to any one of claims 1 to 4, characterized in that, The composite powder is subjected to spray drying and granulation treatment before being mixed with the tungsten powder by ball milling.

6. The method of any one of claims 1 to 4, wherein the method further comprises, Each ball milling in the method is independently selected from dry milling or wet milling; the material of the milling ball is preferably WC or zirconia ball; and the material of the ball tank is preferably WC or polyurethane.

7. The method of any one of claims 1 to 4, wherein the method further comprises the step of: The pressure of the cold isostatic pressing is 210 MPa-250 MPa, and the pressure holding time is 10 min-20 min.

8. The method of any one of claims 1 to 4, wherein, The method of sintering the sintered body is vacuumizing after welding a package of the green body, and sintering the sintered body by hot isostatic pressing.

9. The production method according to claim 8, characterized by, The temperature of the hot isostatic pressing is 1050°C-1200°C, the pressure is 130 MPa-150 MPa, and the holding time is 4 h-10 h.

10. A tungsten-based alloy target material, characterized by, The target material is sintered from tungsten powder, Y2O3 powder, ZnO powder and Al2O3 powder; wherein the content of Y2O3 is 13 wt%-18 wt%, the content of ZnO is 13 wt%-18 wt%, the content of Al2O3 is 0.3 wt%-2.0 wt%, and the balance is tungsten; Optionally, the particle size of the Al2O3 powder is 20 nm-200 nm, and there is a ZnAl2O4 dispersed phase in the target material; Optionally, the relative density of the tungsten-based alloy target material is not less than 98%, and Y2O3, ZnO and ZnAl2O4 are uniformly dispersed in the microstructure, and the grain size is 15 μm-30 μm.

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