A silver alloy target material and its preparation method and application

Abstract

The present invention belongs to the field of target material technology, and specifically discloses a silver alloy target material, its preparation method and application. The raw material components of the silver alloy target material include, by weight percentage: Ag 99.25-99.93%, Ce 0.05-0.55%, aluminum-copper alloy 0.01-0.05%, and manganese-copper alloy 0.01-0.15%. On the one hand, the present invention performs microalloying by adding a certain amount of Ce, Al-Cu alloy and Mn-Cu alloy to Ag; on the other hand, the microstructure morphology is regulated by combining forging and hot rolling treatments during the manufacturing process. Ultimately, without reducing the reflectivity, a significant improvement in anti-sulfurization and oxidation performance is achieved, and the target material has high hardness and is easy to process. The silver alloy target material starts to turn black and sulfurized in 8.0-11.2 hours, starts to turn black and oxidized in 7.5-10.6 hours, and has a Vickers hardness of 97-138.

Description

Technical Field

[0001] The present invention belongs to the technical field of target materials, and in particular relates to a silver alloy target material and a preparation method and application thereof. Background Art

[0002] Silver is often used as electrodes and reflective films in fields such as flat-panel displays and optical recording due to its high reflectivity, high thermal conductivity, low electrical resistance, and low extinction coefficient. However, pure silver has poor resistance to oxidation and sulfidation. This is primarily due to its tendency to react with O2 and H2S in air when exposed to air, forming an oxide film and Ag2S. This causes the silver film to lose its low resistance and high reflectivity properties, seriously impacting device reliability.

[0003] The resistance to sulfidation and oxidation of silver alloy targets and their films depends on the selection of alloying components and the target's microstructure, including grain size, crystal orientation, and density. Improving the oxidation and sulfidation resistance of silver films through alloying and microstructural manipulation is an effective development approach, and researchers have already conducted extensive research on this topic. However, there is still significant room for improvement in both sulfidation and oxidation resistance, as well as processing performance.

[0004] Therefore, there is an urgent need to develop a new silver alloy target material that can significantly improve its anti-sulfurization and anti-oxidation properties while also being easy to process. Summary of the Invention

[0005] The present invention aims to address at least one of the technical problems existing in the aforementioned prior art. To this end, the present invention provides a silver alloy target material, a preparation method, and applications thereof. The silver alloy target material utilizes a combination of alloying, plastic deformation, and heat treatment to control the microstructure, resulting in excellent anti-sulfurization and anti-oxidation properties and good processability.

[0006] The inventive concept of this invention is to, on the one hand, microalloy Ag by adding a certain amount of Ce, aluminum-copper (Al-Cu) alloy, and manganese-copper (Mn-Cu) alloy; on the other hand, to control the microstructure morphology by combining forging and rolling heat treatments during the preparation process. Ultimately, the result is a significant improvement in anti-sulfurization and anti-oxidation properties without reducing reflectivity, while also achieving high hardness and ease of processing.

[0007] To solve the above technical problems, the first aspect of the present invention provides a silver alloy target, whose raw material components include, by weight percentage: Ag 99.25-99.93%, Ce 0.05-0.55%, aluminum-copper alloy 0.01-0.05%, and manganese-copper alloy 0.01-0.15%.

[0008] Specifically, the present invention effectively improves the anti-sulfurization and anti-oxidation properties of the silver alloy target by adding a certain amount of Ce, Al-Cu alloy, and Mn-Cu alloy to the silver matrix. The interaction between these elements effectively improves the anti-sulfurization and anti-oxidation properties of the silver alloy target. Ce has a good anti-sulfurization effect, and its mechanism of action is as follows: Ce's electrode potential is between 1.44-1.60V, higher than Ag's electrode potential of 0.799V. Therefore, adding a small amount of Ce can increase the electrode potential of the Ag alloy target. Sulfurization reaction is a general electrochemical corrosion reaction, so it is obvious that the increase in electrode potential will inevitably lead to an increase in anti-sulfurization effect. At the same time, Ce acts as a deoxidizer during the smelting process, preferentially reacting with oxygen in the solid solution to form a dense protective film, reducing solid solution oxygen absorption and improving target purity. As a low-melting-point element, Ce can also lower the alloy's melting point, improve melt fluidity, reduce loose shrinkage defects in the alloy, and increase alloy density. Adding trace amounts of Ce can refine grains. Ce has a larger radius than Ag, which can cause compositional supercooling during solidification, acting as a heterogeneous nucleation agent and effectively preventing grain growth. Annealed alloying element Ce can achieve a relatively uniform distribution. Ce segregates at grain boundaries, acting as a pinning force, hindering grain boundary migration, thereby achieving grain refinement.

[0009] Al-Cu alloys have good anti-sulfurization properties while ensuring high reflectivity. On the one hand, Al, as one of the metals with the highest reflectivity except for precious metals, is the key to maintaining good reflectivity in the present invention; on the other hand, the electrode potential of Cu is 0.153V, which is lower than that of Ag, and Cu is also easy to generate black CuS with H2S, which protects Ag while reducing the reflectivity of silver. Therefore, the amount of Cu added should not be too much. In addition, Al-Cu alloys have strong dendritic solidification characteristics. The addition of an appropriate amount of Ce in the present invention reduces the alloy liquidus temperature and thus suppresses the alloy's dendritic tendency, refines the Al-Cu alloy structure, and promotes the uniform distribution of Al and Cu in the Ag matrix.

[0010] The addition of Mn-Cu alloy can effectively improve the oxidation resistance and anti-sulfurization properties of silver alloy targets. Its mechanism of action is similar to that of Al-Cu alloy, both of which come from the increase in Cu counter electrode potential and its reaction with H2S. At the same time, the addition of Mn-Cu alloy can also inhibit the migration of silver elements, thereby suppressing bulges. This is mainly because the Mn-Cu alloy is more evenly dispersed with silver and Ce during smelting, which can effectively inhibit the migration of silver elements.

[0011] Preferably, the raw material components of the silver alloy target include, by weight percentage: Ag 99.25-99.56%, Ce 0.35-0.55%, aluminum-copper alloy 0.02-0.05%, and manganese-copper alloy 0.01-0.15%.

[0012] Preferably, the purity of Ag and Ce is not less than 99.99%.

[0013] Preferably, the Ag is in a spherical shape.

[0014] Preferably, the mass ratio of aluminum to copper in the Al-Cu alloy is (1-3):1.

[0015] Preferably, the purity of the Al-Cu alloy is not less than 99.95%, and the alloy is in the form of a massive ingot.

[0016] Preferably, the mass ratio of manganese to copper in the Mn-Cu alloy is (2.5-5):1.

[0017] Preferably, the purity of the Mn-Cu alloy is not less than 99.95%, and the form is a massive ingot.

[0018] A second aspect of the present invention provides a method for preparing the above-mentioned silver alloy target, comprising the following steps:

[0019] Ag, Ce, aluminum-copper alloy and manganese-copper alloy are mixed and smelted; the smelted alloy solution is then cast into an ingot; and the silver alloy target is obtained through forging, rolling, processing and binding.

[0020] Preferably, the smelting temperature condition is: smelting at 1250-1350° C. for 4-6 hours.

[0021] Preferably, after the Ag, Ce, aluminum-copper alloy and manganese-copper alloy are mixed, a layer of charcoal is laid on the surface thereof.

[0022] Preferably, the charcoal is oak charcoal.

[0023] Preferably, the smelting is carried out under inert atmosphere conditions.

[0024] Preferably, the inert atmosphere is an argon atmosphere.

[0025] Preferably, the casting process is: pouring the smelted alloy solution into a mold, then placing an ignition agent above the alloy solution, the main component of the ignition agent being a mixture of Fe2O3, Al and Al2O3, for isolating oxygen, and then water cooling.

[0026] Preferably, the forging step also includes a step of performing forging heat treatment on the ingot before and after the forging, and the temperature condition of the forging heat treatment is: performing heat treatment at 700-750° C. for 45-50 minutes.

[0027] Preferably, before and after the rolling, the forged billet is further subjected to a rolling heat treatment step, and the temperature condition of the rolling heat treatment is: heat treatment at 500-550° C. for 1-2 hours.

[0028] The present invention achieves the regulation of the microstructure of the silver alloy target material by performing forging and rolling heat treatment under specific conditions, so that the precipitated phase is distributed in a uniform manner, and while further improving the anti-sulfurization and anti-oxidation properties of the target material, the hardness of the target material is increased, thereby improving the processing performance.

[0029] A third aspect of the present invention provides an electrode, which includes the above-mentioned silver alloy target.

[0030] A fourth aspect of the present invention provides a reflective film, which includes the above-mentioned silver alloy target.

[0031] Compared with the prior art, the above technical solution of the present invention has at least the following technical effects or advantages:

[0032] (1) The silver alloy target material of the present invention contains a certain amount of Ce, Al-Cu alloy, and Mn-Cu alloy. The elements interact with each other to effectively improve the anti-sulfurization and anti-oxidation properties of the silver alloy target material. Among them: Ce not only has a good anti-sulfurization effect, but also helps to improve the density of the alloy and refine the grains; Al-Cu alloy can ensure high reflectivity while having good anti-sulfurization performance, and at the same time promote the uniform distribution of Al and Cu in the Ag matrix; Mn-Cu alloy can simultaneously improve the anti-oxidation and anti-sulfurization properties of the silver alloy target material and inhibit the migration of silver elements.

[0033] (2) During the preparation of the silver alloy target material of the present invention, the microstructure morphology is regulated through forging and rolling heat treatment, thereby further improving the target material's anti-sulfurization and anti-oxidation properties while increasing the target material's hardness, thereby enhancing processing performance. The prepared silver alloy target material begins to blacken due to sulfurization in 8.0-11.2 hours and begins to blacken due to oxidation in 7.5-10.6 hours, with a Vickers hardness of 97-138. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The microstructure diagrams of the silver alloy targets prepared in Comparative Examples 1-3 and Examples 1-9;

[0035] Figure 2 The grain size diagram of the silver alloy targets prepared in Comparative Examples 1-3 and Examples 1-9;

[0036] Figure 3 Graphs showing the resistivity of the silver alloy targets prepared in Comparative Examples 1-3 and Examples 1-9;

[0037] Figure 4 The Vickers hardness diagram of the silver alloy targets prepared in Comparative Examples 1-3 and Examples 1-9. DETAILED DESCRIPTION

[0038] The present invention is described in detail below with reference to the examples to facilitate understanding of the present invention by those skilled in the art. It is necessary to point out that the examples are only used to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made to the present invention by those skilled in the art based on the above-mentioned invention should still fall within the scope of protection of the present invention. At the same time, the raw materials mentioned below that are not described in detail are all commercially available products; the process steps or preparation methods that are not mentioned in detail are all process steps or preparation methods known to those skilled in the art.

[0039] Example 1

[0040] A silver alloy target material, whose raw material components, by weight percentage, are: Ag 99.85%, Ce 0.05%, Al-Cu alloy 0.05%, and manganese-copper alloy 0.05%. Among them, the Ag has a purity of not less than 99.99% and is in a spherical shape; the Ce has a purity of not less than 99.99%; the Al-Cu alloy (aluminum to copper ratio of 3:1 by mass) and the Mn-Cu alloy (manganese to copper ratio of 5:1 by mass) have a purity of not less than 99.95% and are in the form of a massive ingot.

[0041] A method for preparing a silver alloy target comprises the following steps:

[0042] (1) Melting: Weigh Ag, Ce, Al-Cu alloy and Mn-Cu alloy according to weight percentage, put them into a melting crucible, heat to 1320°C and hold for 4.5 hours; introduce Ar gas for 45 minutes; reduce the temperature to 1260°C, add oak charcoal and hold for 30 minutes;

[0043] (2) Casting: Apply a release agent to the inner wall of the mold, then pour the smelted alloy solution into the mold, and place an ignition agent on top of the alloy solution. The ignition agent is mainly composed of a mixture of Fe2O3, Al and Al2O3 to isolate oxygen; after the ignition agent is completely burned, the alloy ingot is taken out of the mold; and water cooling is used to obtain the ingot;

[0044] (3) Forging: The ingot was heat treated before and after forging at a temperature of 720°C for 50 minutes.

[0045] (4) Rolling: The forged billet was heat treated before and after rolling at a temperature of 550°C for 1 hour.

[0046] (5) Processing: The rolled blank is processed into a circular target sample with a diameter of 80 mm and a thickness of 6 mm by wire cutting and grinding;

[0047] (6) Binding: Place the copper backing plate and the circular target sample on a heating platform and keep them at 220°C for 5 hours. After keeping warm, apply liquid In to the copper backing plate and the sample surface. After applying it evenly, bond the sample to the copper backing plate to obtain the silver alloy target of this embodiment.

[0048] Examples 2-9

[0049] With reference to the components of the silver alloy target in Example 1, the difference between Examples 2-9 and Example 1 is only that the amounts of the raw materials of the silver alloy target are changed, as shown in Table 1.

[0050] Table 1:

[0051] Components Ag (wt%) Ce (wt%) Al-Cu alloy (wt%) Mn-Cu alloy (wt%) Example 2 99.87 0.05 0.05 0.03 Example 3 99.56 0.35 0.04 0.05 Example 4 99.34 0.52 0.02 0.12 Example 5 99.87 0.10 0.01 0.02 Example 6 99.93 0.05 0.01 0.01 Example 7 99.55 0.35 0.05 0.05 Example 8 99.25 0.55 0.05 0.15 Example 9 99.32 0.53 0.03 0.12

[0052] Comparative Examples 1-3

[0053] With reference to the components of the silver alloy target in Example 1, the difference between Comparative Examples 1-3 and Example 1 is only that the types and amounts of the raw materials of the silver alloy target are changed, as shown in Table 2.

[0054] Table 2:

[0055]

[0056] Performance Testing

[0057] 1. Microstructure

[0058] The silver alloy targets prepared in Examples 1-9 and Comparative Examples 1-3 were cut into 10 mm × 10 mm × 5 mm samples, and then polished and etched with 400#-7000# sandpaper. The target morphology was observed under an optical microscope at 1000 times magnification. The microscopic results are as follows: Figure 1 As shown, the grain size is Figure 2 shown.

[0059] Figure 1 Figures (a)-(I) correspond to the silver alloy targets prepared in Comparative Examples 1-3 and Examples 1-9, respectively. Figure 1 It can be seen that there is no significant difference in the microstructure in each comparative example and embodiment. It can be seen that compared with the traditional addition of In, the introduction of Ce, Al-Cu alloy and Mn-Cu alloy does not produce significant changes in the microstructure.

[0060] Figure 2 D1-D3 correspond to the silver alloy targets prepared in Comparative Examples 1-3, and S1-S9 correspond to the silver alloy targets prepared in Examples 1-9. Figure 2It can be seen that the silver alloy targets prepared in the comparative examples and embodiments have large differences in grain size. Compared with the addition of In, the grains are finer after adding Ce, Al-Cu alloy and Mn-Cu alloy, which has obvious advantages in improving the sputtering rate at the target application end. In addition, the small and uniform grain size will also make the film thickness more uniform during thin film deposition, greatly improve the film quality, and be more beneficial to improving the overall sulfurization and oxidation performance.

[0061] 2. Resistivity

[0062] The silver alloy targets prepared in Examples 1-9 and Comparative Examples 1-3 that passed the binding test were placed on a flat marble platform, and a four-probe resistivity meter was used to perform resistivity testing. Each position was tested 3 times, and the average of the 3 times was taken as the final measurement result. The results are as follows: Figure 3 shown.

[0063] Figure 3 D1-D3 in the table correspond to the silver alloy targets prepared in comparative examples 1-3, and S1-S9 correspond to the silver alloy targets prepared in examples 1-9. Figure 3 It can be seen that in each comparative example and example, the resistivity changes with the Ag content and shows a positive correlation. This is mainly because Ag has a very low resistivity compared to Cu, Al, Mn, and their alloys. In the present invention, the Ag content accounts for more than 99 wt%, so the overall resistivity of the target material is determined by the Ag content.

[0064] 3. Hardness

[0065] The hardness of the silver alloy targets prepared in Examples 1-9 and Comparative Examples 1-3 was tested using an MH-3 microhardness tester. Each position was measured 5 times, and the average value was taken as the final measurement result. The results are shown in FIG. Figure 4 shown.

[0066] Figure 4 D1-D3 correspond to the silver alloy targets prepared in Comparative Examples 1-3, respectively, and S1-S9 correspond to the silver alloy targets prepared in Examples 1-9, respectively. Figure 4 It can be seen that the hardness of Examples 1-9 is higher than that of Comparative Examples 1-3. The main reason for this is the different target grain sizes. According to the Hall-Petch hardness test, the grain size is inversely proportional to the hardness. Therefore, under normal circumstances, the smaller the grain size, the greater the hardness, which is also beneficial for later processing.

[0067] 4. Anti-sulfurization and anti-oxidation properties

[0068] A coating test was performed on a cleaned glass substrate (glass plate size 100 mm × 300 mm) with a gas pressure of 0.5 Pa, an Ar gas environment, and a sputtering power of 200 W. The results are shown in Table 3.

[0069] Anti-sulfurization performance test: Under the conditions of temperature 85°C and humidity 85%, the coated silver alloy film is placed in a closed chamber with H2S. The condition of the silver alloy film is observed, and the time when it starts to turn black and the final state of the film are recorded.

[0070] Oxidation resistance test: Place the coated silver alloy film in a sealed chamber with O2 at a temperature of 85°C and a humidity of 85%. Observe the silver alloy film and record the time when it starts to turn black and the final state of the film.

[0071] Table 3:

[0072]

[0073]

[0074] As shown in Table 3, the silver alloy targets prepared in Examples 1-9, due to the addition of Ce, Al-Cu alloy, and Mn-Cu alloy to Ag, exhibited superior improvements in both sulfidation and oxidation resistance compared to the silver alloy targets prepared in Comparative Examples 1-3, which only incorporated In. This is primarily due to the fact that Ce, Al-Cu alloy, and Mn-Cu alloy synergistically increase the electrode potential of Ag and react with S and O prior to Ag, resulting in better resistance to sulfidation and oxidation.

[0075] Comparing Comparative Examples 1-3 with Examples 2 and 7, it can be seen that when the amount of Al-Cu alloy and Mn-Cu alloy is maintained at 0.05, increasing the Ce content on the basis of removing In significantly improves the sulfidation and oxidation resistance. The sulfidation and oxidation resistance are improved from 7.5 hours and 7.2 hours in Comparative Example 3 to 8.1 hours and 7.2 hours in Comparative Example 1, and 10.2 hours and 9.5 hours in Comparative Example 7, respectively. This demonstrates that the addition of Ce has a more excellent effect on the sulfidation and oxidation resistance of Ag, and can be used as a potential beneficial element for optimizing performance.

[0076] By comparing comparative examples 1-4 with comparative examples 6-9, it can be seen that when Ce, Al-Cu alloy and Mn-Cu alloy are added together, the anti-sulfurization and oxidation effects of Ag increase with the increase of Ce content, and when the Ce content is 0.55wt%, the anti-oxidation and sulfurization effects reach the best, which are 11.2 hours and 10.6 hours respectively.

[0077] For those skilled in the art to which the present invention belongs, a number of simple deductions or substitutions can be made without departing from the concept of the present invention, without having to resort to creative work. Therefore, based on the disclosure of the present invention, simple improvements made by those skilled in the art to the present invention should be within the scope of protection of the present invention. The above embodiments are preferred embodiments of the present invention, and all processes similar to the present invention and equivalent changes made should fall within the scope of protection of the present invention.

Claims

1. A silver alloy target, characterized in that: The invention is composed of the following raw materials in weight percentage: Ag 99.25-99.93%, Ce 0.05-0.55%, aluminum-copper alloy 0.01-0.05%, manganese-copper alloy 0.01-0.15%; The mass ratio of aluminum to copper in the aluminum-copper alloy is (1-3):1, and the mass ratio of manganese to copper in the manganese-copper alloy is (2.5-5):

1.

2. The silver alloy target according to claim 1, wherein The invention is composed of the following raw materials in the following weight percentages: Ag 99.25-99.56%, Ce 0.35-0.55%, aluminum-copper alloy 0.02-0.05%, and manganese-copper alloy 0.01-0.15%.

3. The silver alloy target according to claim 1, characterized in that The purity of Ag and Ce is not less than 99.99%.

4. A method for preparing a silver alloy target according to any one of claims 1 to 3, characterized in that: The following steps are involved: Ag, Ce, aluminum-copper alloy and manganese-copper alloy are mixed and smelted; the smelted alloy solution is then cast into an ingot; and the silver alloy target is obtained through forging, rolling, processing and binding.

5. The method for preparing a silver alloy target according to claim 4, wherein: The smelting temperature condition is: smelting at 1250-1350° C. for 4-6 hours.

6. The method for preparing a silver alloy target according to claim 4, wherein: The forging step also includes a step of performing a forging heat treatment on the ingot before and after the forging, and the temperature condition of the forging heat treatment is: performing a heat treatment at 700-750° C. for 45-50 minutes.

7. The method for preparing a silver alloy target according to claim 4, wherein: The method also includes a step of performing rolling heat treatment on the forged billet before and after the rolling, wherein the temperature condition of the rolling heat treatment is: performing heat treatment at 500-550° C. for 1-2 hours.

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