Aluminum zinc oxide target material and preparation method thereof

Abstract

The invention belongs to the technical field of new materials, and discloses a preparation method of an aluminum zinc oxide target material, which comprises the following steps: mixing molten aluminum and zinc mixed metal liquid with inert gas to prepare spray, and mixing the spray with oxygen to carry out oxidation reaction to prepare aluminum zinc oxide powder; and the aluminum zinc oxide target material is prepared from the aluminum zinc oxide powder. According to the method, the aluminum zinc oxide powder is prepared by adopting a molten metal liquid spray oxidation method, related production equipment can be used for a long time only through one-time investment, additional expensive reagents are not needed, the production cost is low, and the process is simple.

Description

Technical Field

[0001] The present invention relates to the field of new materials, and in particular to an aluminum zinc oxide target material and a preparation method thereof. Background Art

[0002] As an important optoelectronic information material, transparent conductive oxides have been widely used in the manufacture of light-emitting devices, thin-film solar cells, surface acoustic wave devices, sensors, flat-panel liquid crystal displays, infrared reflectors and other fields. At present, the most widely used is indium tin oxide (ITO), but In is a scarce resource, expensive and toxic, so there is an urgent need to find a material to replace ITO. Aluminum zinc oxide transparent conductive film has excellent infrared reflection characteristics in the infrared region, and metal aluminum zinc is widely available and inexpensive. Its stability in H plasma is better than that of ITO. It has broad application prospects in the fields of thin-film solar cells, flat-panel displays, infrared reflective window films and thermal reflectors. At present, my country advocates energy conservation and emission reduction. Aluminum zinc oxide coated glass can reduce a large part of energy loss when used in architectural glass due to its excellent infrared reflection performance, thereby achieving the purpose of energy saving. Therefore, it is of great significance to carry out research on transparent, highly conductive, near-infrared reflective aluminum zinc oxide films;

[0003] TW201925094A discloses a silver-doped aluminum zinc oxide composite target material and a preparation method thereof, wherein a precursor is prepared by a precipitation method, and then sintered to obtain an aluminum zinc oxide nano-target material.

[0004] CN118561591A discloses a zinc tin oxide target material and a preparation method thereof, which also adopts a precipitation method to prepare a precursor, and then sintering and molding to obtain the zinc tin oxide target material.

[0005] The problem with the above-mentioned process using the precipitation method is that the process is relatively complicated, requiring a precipitant as well as operations such as precipitation and washing, and the process is relatively complicated and the production cost is relatively high.

[0006] The technical problem solved in this case is how to further reduce the difficulty of preparing aluminum zinc oxide targets while ensuring their ultra-low resistivity. Summary of the invention

[0007] The purpose of the present invention is to provide a method for preparing an aluminum zinc oxide target material. The method adopts a molten metal liquid spray oxidation method to prepare aluminum zinc oxide powder. The related production equipment only requires a one-time investment and can be used for a long time without the need for additional expensive reagents. The production cost is low and the process is simple.

[0008] At the same time, the present invention also provides an aluminum zinc oxide target prepared based on the method.

[0009] To achieve the above objectives, this application discloses:

[0010] A method for preparing an aluminum zinc oxide target material comprises mixing molten aluminum and zinc mixed metal liquid with an inert gas to prepare a spray, and mixing the spray with oxygen to carry out an oxidation reaction to prepare aluminum zinc oxide powder; and using the aluminum zinc oxide powder to prepare the aluminum zinc oxide target material.

[0011] In the prior art, the use of spray oxidation to prepare oxides is generally applicable to light metals such as potassium and sodium. For example, the invention with publication number CN107879361A and the invention name of a method for preparing potassium superoxide powder by spray oxidation of potassium metal uses spray oxidation to prepare potassium superoxide. The method achieves mixing of molten metal and air through inner and outer nested nozzles.

[0012] In the research of the present invention, it was found that the following problems exist when spraying a melt with zinc as the main material to prepare oxides: 1. The nozzle is blocked, and the pre-mixing with the oxygen-containing gas causes some metals to oxidize prematurely, especially the precipitate generated after the reaction of aluminum and oxygen tends to float on the molten metal and accumulate at the nozzle position, accelerating the blockage; 2. Compared with potassium, the density of zinc is more than 8 times that of potassium, and it is difficult to form a relatively uniform spray with a high-density metal liquid; and uniform spraying is a prerequisite for achieving sufficient oxidation.

[0013] After research, the present invention mixes inert gas into the melt before forming spray and reacting with oxygen, so as to disperse bubbles in the molten metal and reduce the density of the molten metal, so that the molten metal can contact with oxygen in the form of tiny droplets when forming spray, thereby improving the oxidation effect and preventing oxide blockage from forming at the nozzle position.

[0014] In the above preparation method, the weight ratio of aluminum to zinc in the molten metal is 0.5-2:98-99.5.

[0015] The weight ratio of aluminum to zinc is the ratio required by the target material of the present invention. In actual production, the ratio of aluminum to zinc can be flexibly adjusted according to the component requirements of the target material.

[0016] As a further extension of the present invention, the oxidation of other heavier metal elements can also adopt the technical solution of the present invention. The amount of inert gas added to the spray melt can be flexibly adjusted according to the density of the metal element so that the final spray density reaches the desired target, forming a more dispersed, small droplet spray.

[0017] In the above preparation method, the melting temperature of the molten metal is 900-1100°C.

[0018] In the present invention, the melting point of zinc is 419°C, and the melting point of aluminum is 660°C. The present invention controls the melting temperature of the molten metal to be 300 to 500°C higher than the melting point of aluminum, which can ensure that the temperature of the molten metal is high enough. On the one hand, it can balance the temperature reduction caused by the heat absorption of the inert gas; on the other hand, it can allow the spray to exist in a molten state in the oxidation chamber for a longer time, avoid too fast solidification, and improve the oxidation effect.

[0019] In the above preparation method, the volume ratio of the molten metal to the inert gas is 1:1-2.

[0020] In the present invention, the volume of inert gas refers to the volume under standard conditions (standard atmospheric pressure, 298K temperature); when the temperature rises to 1100°C, its volume will increase by 4 times, which can reduce the density of the mixture formed by molten metal and inert gas to 10-20% of the density of the molten metal, thereby improving the atomization effect of the spray.

[0021] In some embodiments of the present invention, the volume ratio of the molten metal to the inert gas is 1:1, 1:1.5, or 1:2;

[0022] In the above preparation method, the spraying speed of the mixture formed by the molten metal and the inert gas is 18-22 ml / min; the flow rate of oxygen is 40 L / min-50 L / min.

[0023] In the above preparation method, the oxidation reaction is carried out in an oxidation chamber, and the oxygen is injected into the oxidation chamber.

[0024] In the above-mentioned preparation method, the method for preparing the aluminum zinc oxide target material using aluminum zinc oxide powder is:

[0025] The aluminum zinc oxide powder is molded, cold isostatically pressed and sintered to obtain an aluminum zinc oxide target, wherein the sintering temperature is 1280°C to 1350°C.

[0026] At the same time, the present invention also discloses an aluminum zinc oxide target material, which is prepared by any of the above methods.

[0027] This application has at least the following beneficial effects:

[0028] The present invention adopts the method of spray oxidation of molten metal liquid to prepare aluminum zinc oxide powder. The relevant production equipment only needs one-time investment and can be used for a long time without additional expensive reagents. The production cost is low and the process is simple.

[0029] The process of the present invention has the following process points:

[0030] 1. During the melting stage, nitrogen is used to mix with the molten metal to prevent the molten metal from oxidizing prematurely and clogging the spray pipe;

[0031] 2. During the oxidation stage, the ratio of molten metal to inert gas needs to be controlled so that the molten metal is spread out in the form of a spray to facilitate the full oxidation reaction. DETAILED DESCRIPTION

[0032] The present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. In the description of the present invention, it should be noted that, if no specific conditions are specified in the embodiments, the conditions are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0033] Example 1

[0034] (1) adding 0.26 kg of aluminum ingot and 39.74 kg of zinc ingot into a nitrogen melting chamber and heating to 900° C. to melt the aluminum ingot and the zinc ingot and then fully mix them;

[0035] (2) mixing the uniformly mixed molten aluminum-zinc liquid with high-pressure nitrogen to form a gas-liquid mixture, and allowing the gas-liquid mixture to flow from the melting chamber into the oxidation chamber at 850° C. at a rate of 20 ml / min; the volume ratio of the molten aluminum-zinc liquid to the high-pressure nitrogen is prepared according to the volume ratio of the molten aluminum-zinc liquid to the nitrogen at 1 standard atmospheric pressure and 298K; the volume ratio of the molten aluminum-zinc liquid to the nitrogen at 1 standard atmospheric pressure and 298K is 1:1.5; the pressure of the high-pressure nitrogen is 3 standard atmospheres;

[0036] (3) The gas-liquid mixture flowing into the oxidation chamber is dispersed in a jet-like manner, and oxygen is introduced into the oxidation chamber at a rate of 40 L / min;

[0037] (4) collecting the oxidized oxide powder and cooling it to room temperature to obtain aluminum zinc oxide powder with a powder particle size D90 of 0.259 μm;

[0038] (5) The aluminum zinc oxide powder obtained in step (4) is subjected to hydraulic molding, cold isostatic pressing, and sintering at 1280° C. to obtain an aluminum zinc oxide target having a relative density of 99.1% and a resistivity of 1.76 mΩ.cm.

[0039] Example 2

[0040] (1) adding 0.53 kg of aluminum ingot and 39.47 kg of zinc ingot into a nitrogen melting chamber and heating to 1000° C. to melt the aluminum ingot and the zinc ingot and then fully mix them;

[0041] (2) mixing the uniformly mixed molten aluminum-zinc liquid with high-pressure nitrogen to form a gas-liquid mixture, and allowing the gas-liquid mixture to flow from the melting chamber into the oxidation chamber at 900° C. at a rate of 20 ml / min; the volume ratio of the molten aluminum-zinc liquid to the nitrogen at 1 standard atmosphere and 298K is 1:1; the pressure of the high-pressure nitrogen is 5 standard atmospheres;

[0042] (3) The gas-liquid mixture flowing into the oxidation chamber is dispersed in a jet-like manner, and oxygen is introduced into the oxidation chamber at a rate of 45 L / min;

[0043] (4) collecting the oxidized oxide powder and cooling it to room temperature to obtain aluminum zinc oxide powder with a powder particle size D90 of 0.245 μm;

[0044] (5) The aluminum zinc oxide powder obtained in step (4) is subjected to hydraulic molding, cold isostatic pressing, and sintering at 1320° C. to obtain an aluminum zinc oxide target having a relative density of 99.3% and a resistivity of 0.57 mΩ.cm.

[0045] Example 3

[0046] (1) adding 0.80 kg of aluminum ingot and 39.20 kg of zinc ingot into a nitrogen melting chamber and heating to 1100° C. to melt the aluminum ingot and the zinc ingot and then fully mix them;

[0047] (2) mixing the uniformly mixed molten aluminum-zinc liquid with high-pressure nitrogen to form a gas-liquid mixture, and allowing the gas-liquid mixture to flow from the melting chamber into the oxidation chamber at 950° C. at a rate of 20 ml / min; the volume ratio of the molten aluminum-zinc liquid to the nitrogen at 1 standard atmosphere and 298K is 1:2; the pressure of the high-pressure nitrogen is 4 standard atmospheres;

[0048] (3) The gas-liquid mixture flowing into the oxidation chamber is dispersed in a jet-like manner, and oxygen is introduced into the oxidation chamber at a rate of 50 L / min;

[0049] (4) collecting the oxidized oxide powder and cooling it to room temperature to obtain aluminum zinc oxide powder with a powder particle size D90 of 0.288 μm;

[0050] (5) The aluminum zinc oxide powder obtained in step (4) is subjected to hydraulic molding, cold isostatic pressing, and sintering at 1350° C. to obtain an aluminum zinc oxide target having a relative density of 99.1% and a resistivity of 1.92 mΩ.cm.

[0051] Example 4

[0052] The method is substantially the same as Example 3, except that in step (1), the heating and melting temperature is 800°C.

[0053] Comparative Example 1

[0054] (1) adding 0.26 kg of aluminum ingot and 39.74 kg of zinc ingot into an oxygen melting chamber and heating to 900° C. to melt the aluminum ingot and the zinc ingot and then fully mix them;

[0055] (2) After the uniformly mixed molten aluminum-zinc liquid is mixed with high-pressure oxygen, it is allowed to flow from the melting chamber into an oxidation chamber at 850° C. at a rate of 20 ml / min; the amount of oxygen used is the same as the amount of nitrogen used in Example 1;

[0056] (3) The gas-liquid mixture flowing into the oxidation chamber is dispersed in a jet-like manner, and oxygen is introduced into the oxidation chamber at a rate of 40 L / min;

[0057] (4) collecting the oxidized oxide powder and cooling it to room temperature to obtain aluminum zinc oxide powder with a powder particle size D90 of 383.4 μm;

[0058] (5) The aluminum zinc oxide powder obtained in step (4) is subjected to hydraulic molding, cold isostatic pressing, and sintering at 1280° C. to obtain an aluminum zinc oxide target having a relative density of 97.2% and a resistivity of 4.25 mΩ.cm;

[0059] During the production process, nozzles are often clogged and the machine needs to be shut down for cleaning.

[0060] Comparative Example 2

[0061] (1) adding 0.53 kg of aluminum ingot and 39.47 kg of zinc ingot into a nitrogen melting chamber and heating to 1000° C. to melt the aluminum ingot and the zinc ingot and then fully mix them;

[0062] (2) After the uniformly mixed molten aluminum-zinc liquid is mixed with high-pressure nitrogen, it is allowed to flow from the melting chamber into the oxidation chamber at 900° C. at a rate of 20 ml / min; the amount of nitrogen used is the same as that of the nitrogen used in Example 2;

[0063] (3) The gas-liquid mixture flowing into the oxidation chamber is dispersed in a jet-like manner, and oxygen is introduced into the oxidation chamber at a rate of 10 L / min;

[0064] (4) The oxidized oxide powder is collected and cooled to room temperature to obtain a mixed powder of aluminum zinc oxide and aluminum zinc alloy, which does not meet the requirements.

[0065] Performance Testing

[0066] The test items include relative density and resistivity;

[0067] The test method for relative density is: relative density = density (drainage method) / true density (immersion method)

[0068] The resistivity test method is: four-probe method

[0069] The test results are shown in Table 1 below;

[0070] Table 1 Test results

[0071] Case Relative density (%) Resistivity (mΩ.cm) Example 1 99.1 1.76 Example 2 99.3 0.57 Example 3 99.1 1.92 Example 4 98.2 8.48 Comparative Example 1 97.2 4.25 Comparative Example 2 / /

[0072] Result analysis:

[0073] 1. It can be seen from Examples 1 to 3 that by reasonably controlling the use of nitrogen and adopting the spray oxidation method, the relative density can be effectively increased and the resistivity can be reduced.

[0074] 2. It can be seen from Examples 3 and 4 that the temperature of the melt is relatively important. When the melt temperature is low, it cools down faster when mixed with nitrogen, and cannot exist in a liquid state for a long time for oxidation after spraying, and will solidify quickly; at the same time, the temperature reduction may also cause the oxide layer to float on the surface of the droplets, reducing the degree of reaction between oxygen and metal liquid;

[0075] 3. It can be seen from Example 1 and Comparative Example 1 that the use of inert gas can avoid nozzle clogging on the one hand, and can effectively control the particle size of the oxide powder on the other hand. The possible reasons for the increase in the particle size of the oxide powder are: oxygen is consumed in advance to form oxides, and the spray fineness is not enough, resulting in an increase in the particle size.

[0076] 4. It can be seen from Example 2 and Comparative Example 2 that sufficient oxygen supply is the key to preparing qualified products.

[0077] 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 present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A method for preparing an aluminum zinc oxide target, characterized in that: The molten aluminum and zinc mixed metal liquid is mixed with an inert gas to prepare a spray, and the spray is mixed with oxygen to undergo an oxidation reaction to prepare aluminum zinc oxide powder; and the aluminum zinc oxide target is prepared using the aluminum zinc oxide powder.

2. The preparation method according to claim 1, characterized in that: The weight ratio of aluminum to zinc in the molten metal is 0.5-2:98-99.

5.

3. The preparation method according to claim 2, characterized in that: The melting temperature of the molten metal is 900-1100°C.

4. The preparation method according to claim 1, characterized in that: The volume ratio of the molten metal to the inert gas is 1:1-2.

5. The preparation method according to claim 1, characterized in that: The spraying speed of the mixture formed by the molten metal and the inert gas is 18-22 ml / min; the flow rate of oxygen is 40 L / min-50 L / min.

6. The preparation method according to claim 5, characterized in that: The oxidation reaction is carried out in an oxidation chamber, and the oxygen is injected into the oxidation chamber.

7. The preparation method according to claim 1, characterized in that: The method for preparing the aluminum zinc oxide target material by using aluminum zinc oxide powder is as follows: The aluminum zinc oxide powder is molded, cold isostatically pressed and sintered to obtain an aluminum zinc oxide target, wherein the sintering temperature is 1280°C to 1350°C.

8. An aluminum zinc oxide target, characterized in that: The method is prepared by any one of claims 1 to 7.