Molybdenum-niobium alloy sintered blank and preparation method thereof, molybdenum-niobium alloy target material and application thereof

Abstract

The present application relates to the technical field of molybdenum-niobium alloy target materials, and specifically to a molybdenum-niobium alloy sintered blank and a preparation method thereof, a molybdenum-niobium alloy target material and an application thereof. The preparation method comprises the steps of: sintering a molybdenum-niobium alloy pressed blank to obtain a molybdenum-niobium alloy sintered blank; wherein the molybdenum-niobium alloy pressed blank comprises molybdenum powder and niobium hydride powder; the sintering treatment step comprises sintering in a hydrogen atmosphere after vacuum sintering; the temperature of the vacuum sintering is 1300°C to 1500°C; the temperature of the hydrogen atmosphere sintering is 2000°C to 2250°C. The internal structure of the molybdenum-niobium alloy sintered blank has no defects such as pores, cracks, delamination, inclusions, etc., the density is more than 99%, the oxygen content is less than 100ppm, the hydrogen content is less than 10ppm, the grains of the sintered blank are uniform, and the average grain size is less than 55μm.

Description

Technical Field

[0001] The present application relates to the technical field of molybdenum-niobium alloy target materials, and in particular to a molybdenum-niobium alloy sintered blank and a preparation method thereof, a molybdenum-niobium alloy target material and applications thereof. Background Art

[0002] High-purity molybdenum sputtering targets are widely used in flat panel displays, and molybdenum-niobium alloy sputtering targets formed by adding niobium to molybdenum can improve the clarity and resolution of liquid crystal displays. The main factor affecting clarity and resolution is the film quality of the molybdenum-niobium alloy sputtering target, and the main reason affecting the film quality of the target is the density, impurity content and internal structural uniformity of the molybdenum-niobium alloy sputtering target itself, which is closely related to the preparation method of the target.

[0003] At present, the method for preparing molybdenum-niobium alloy sputtering targets generally adopts the powder metallurgy method, and the sintering processes therein are more commonly used in the hot isostatic pressing, vacuum sintering and hydrogen atmosphere protection sintering. For example, one of the prior arts discloses a method for preparing a molybdenum-niobium alloy sputtering target, which comprises mixing molybdenum powder and niobium powder, cold isostatically pressing a blank, placing the blank in a medium frequency furnace for hydrogen sintering, wherein the sintering temperature zones are 0°C to 1000°C, 1000°C to 1500°C, 1500°C to 1700°C, and 1700°C to 1950°C, and each temperature zone is sintered for at least 5 hours to obtain a molybdenum-niobium alloy target plate; in the preparation method, niobium will react with hydrogen to form niobium hydride starting from 200°C, and when the temperature reaches 360°C, the rate of hydrogen absorption is the highest; sintering is carried out in a medium frequency sintering furnace in a hydrogen atmosphere, within a sintering range of 0°C to 1000°C, for at least 5 hours, during which niobium expands in volume due to absorption of hydrogen in the hydrogen atmosphere, which can easily cause microcracks in the blank and remain in the alloy blank after sintering, thereby affecting the processing performance and use performance of the molybdenum-niobium alloy. The second prior art discloses a method for preparing a low-oxygen molybdenum-niobium alloy sputtering target, which is to mix molybdenum powder, niobium metal powder and alkali metal halide, and then place it at a relatively low temperature of 350°C to 1200°C and in a hydrogen atmosphere for heat treatment and pressing; this method not only introduces new impurities due to the addition of alkali metal halide; but also the mixed molybdenum-niobium powder is still placed in a relatively low temperature and hydrogen atmosphere for heat treatment, so that the niobium powder still absorbs a large amount of hydrogen and expands in volume, causing microcracks in the billet and retaining them in the sintered alloy billet. Summary of the invention

[0004] To solve the above problems, the present application proposes a molybdenum-niobium alloy sintered blank and a preparation method thereof, a molybdenum-niobium alloy target and an application thereof. The internal structure of the molybdenum-niobium alloy sintered blank prepared by the preparation method has no defects such as pores, cracks, delamination, inclusions, etc., and the density is more than 99%, the oxygen content is less than 100 ppm, and the hydrogen content is less than 10 ppm. The grains of the sintered blank are uniform, and the average grain size is less than 55 μm.

[0005] This application is implemented through the following technical solutions:

[0006] One of the purposes of the present application is to provide a method for preparing a molybdenum-niobium alloy sintered blank, comprising the following steps:

[0007] The molybdenum-niobium alloy compact is sintered to obtain a molybdenum-niobium alloy sintered compact;

[0008] Wherein, the molybdenum-niobium alloy compact comprises molybdenum powder and niobium hydride powder;

[0009] The sintering treatment step includes vacuum sintering followed by hydrogen atmosphere sintering;

[0010] The vacuum sintering temperature is 1300°C to 1500°C;

[0011] The temperature of the hydrogen atmosphere sintering is 2000°C~2250°C.

[0012] In some possible implementations, the insulation time of the vacuum sintering is 3h~6h.

[0013] In some possible implementations, the insulation time of the vacuum sintering is 4h~6h.

[0014] In some possible implementations, the vacuum sintering temperature is 1300°C to 1400°C.

[0015] In some possible implementations, the vacuum degree of the vacuum sintering is 10 -5 Pa~10 -3 Pa.

[0016] Preferably, in the vacuum sintering step, the vacuum sintering holding time is 4h~6h; the vacuum degree of the vacuum sintering is 10 -5 Pa~10 -3 Pa.

[0017] In some possible implementations, the holding time of the hydrogen atmosphere sintering is 4h~8h.

[0018] In some possible implementations, the holding time of the hydrogen atmosphere sintering is 6h~8h.

[0019] In some possible implementations, the temperature of the hydrogen atmosphere sintering is 2100° C. to 2250° C.

[0020] In some possible implementations, the hydrogen flow rate of the hydrogen atmosphere sintering is 4m 3 / h~8m 3 / h.

[0021] Preferably, the holding time for sintering in the hydrogen atmosphere is 6h~8h.

[0022] In some possible implementations, the density of the molybdenum-niobium alloy compact is 9.90 g / cm 3 ~9.99g / cm 3 .

[0023] The second objective of the present application is to provide a molybdenum-niobium alloy sintered blank prepared by the method for preparing the molybdenum-niobium alloy sintered blank provided in the present application.

[0024] The third object of the present application is to provide a molybdenum-niobium alloy target, including a molybdenum-niobium alloy target obtained by machining the molybdenum-niobium alloy sintered blank provided by the present application.

[0025] In some possible implementations, the average grain size of the molybdenum-niobium alloy target is 45 μm to 54 μm.

[0026] In some possible implementations, the hydrogen content of the molybdenum-niobium alloy target is less than 10 ppm.

[0027] The third purpose of the present application is to provide an application of the molybdenum-niobium alloy target provided in the present application in the field of electronics, optics, flat panel display or photovoltaics.

[0028] The molybdenum-niobium alloy sintered blank and its preparation method, and the molybdenum-niobium alloy target provided by the present invention have at least the following beneficial technical effects:

[0029] (1) The preparation method of the molybdenum-niobium alloy sintered blank provided in the present application uses a molybdenum-niobium alloy pressed blank containing molybdenum powder and hydrogenated niobium powder, and adopts a two-step sintering method of vacuum low-temperature sintering and hydrogen atmosphere high-temperature sintering. Compared with the prior art, the preparation method described in the present application has a short production process; the internal structure of the prepared molybdenum-niobium alloy sintered blank has no defects such as pores, cracks, delamination, inclusions, etc., the density is more than 99%, the oxygen content is less than 100ppm (preferably 87ppm~95ppm), the hydrogen content is less than 10ppm (preferably 6ppm~8ppm), the grains of the sintered blank are uniform, and the average grain size is less than 55μm (preferably 45μm~54μm).

[0030] (2) The molybdenum-niobium alloy sintered blank provided in the present application is prepared by the method for preparing the molybdenum-niobium alloy sintered blank provided in the present application. Compared with the prior art, the molybdenum-niobium alloy sintered blank has an average grain size of less than 55 μm, an oxygen content of less than 100 ppm, and a hydrogen content of less than 10 ppm; the internal structure of the molybdenum-niobium alloy sintered blank is free of defects such as pores, cracks, delamination, and inclusions. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present drawings or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present drawings. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0032] Figure 1 A schematic diagram of the metallographic structure of a molybdenum-niobium alloy sintered blank prepared by the method for preparing a molybdenum-niobium alloy sintered blank in Example 1 of the present application;

[0033] Figure 2 A schematic diagram of the metallographic structure of a molybdenum-niobium alloy sintered blank prepared by a method for preparing a molybdenum-niobium alloy sintered blank in Example 2 of the present application;

[0034] Figure 3 A schematic diagram of the metallographic structure of a molybdenum-niobium alloy sintered blank prepared by a method for preparing a molybdenum-niobium alloy sintered blank in Example 3 of the present application;

[0035] Figure 4 Schematic diagram of XRD of the molybdenum-niobium alloy sintered billets of Example 1 and Comparative Example 1 of the present application.

[0036] The purpose, features and advantages of this figure will be further explained in conjunction with the embodiments with reference to the accompanying drawings. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0038] Obviously, the following descriptions are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios without creative work. In addition, it can also be understood that although the efforts made in this development process may be complicated and lengthy, for ordinary technicians in the field related to the content disclosed in this application, some changes in design, manufacturing or production based on the technical content disclosed in this application are just conventional technical means, and should not be understood as insufficient content disclosed in this application.

[0039] However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of substantially the same structures may be omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the following description is provided for those skilled in the art to fully understand the present application and is not intended to limit the subject matter described in the claims.

[0040] If not otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution, and all technical features and optional technical features of the present application can be combined with each other to form a new technical solution.

[0041] At present, the method for preparing molybdenum-niobium alloy target material generally involves sintering the molybdenum-niobium alloy compact in a hydrogen atmosphere to remove oxygen from the molybdenum-niobium alloy compact and reduce the oxygen content in the alloy. Although niobium can effectively remove oxygen when it absorbs hydrogen, the niobium powder will also expand in volume due to the absorption of hydrogen, causing microcracks in the blank and remaining in the alloy blank after sintering.

[0042] In order to reduce the oxygen in the molybdenum-niobium alloy target, improve its density and make the internal structure of the molybdenum-niobium alloy target free of defects such as pores, cracks, delamination, inclusions, etc., the embodiment of the present application proposes a molybdenum-niobium alloy sintered blank and its preparation method, molybdenum-niobium alloy target and application. The preparation method of the molybdenum-niobium alloy sintered blank uses hydrogenated niobium powder and molybdenum powder as raw materials, and undergoes two sintering steps of vacuum low-temperature sintering and hydrogen atmosphere high-temperature sintering. The internal structure of the prepared molybdenum-niobium alloy sintered blank has no defects such as pores, cracks, delamination, inclusions, etc., and the density is more than 99%, the oxygen content is less than 100ppm, and the hydrogen content is less than 10ppm. The grains of the sintered blank are uniform, and the average grain size is less than 55μm.

[0043] The following is a detailed description of a molybdenum-niobium alloy sintered blank and a preparation method thereof, a molybdenum-niobium alloy target material and applications in the embodiments of the present application.

[0044] A method for preparing a sintered molybdenum-niobium alloy

[0045] The first aspect of the embodiment of the present application provides a method for preparing a molybdenum-niobium alloy sintered blank, comprising the following steps:

[0046] The molybdenum-niobium alloy compact is sintered to obtain a molybdenum-niobium alloy sintered compact;

[0047] The molybdenum-niobium alloy compact includes molybdenum powder and niobium hydride powder;

[0048] The sintering treatment step includes vacuum sintering followed by hydrogen atmosphere sintering;

[0049] The temperature of vacuum sintering is 1300℃~1500℃;

[0050] The sintering temperature in hydrogen atmosphere is 2000℃~2250℃.

[0051] The preparation method of the molybdenum-niobium alloy sintered blank provided in the embodiment of the present application selects a molybdenum-niobium alloy compact containing molybdenum powder and niobium hydride powder, and adopts two sintering steps of vacuum low-temperature sintering and hydrogen atmosphere high-temperature sintering. During the vacuum low-temperature sintering, hydrogen in the niobium hydride is released, and impurities such as oxygen inside the molybdenum-niobium alloy compact and attached to the surface of the powder are removed, thereby improving the density of the molybdenum-niobium alloy compact and reducing the content of hydrogen and oxygen in the molybdenum-niobium alloy compact; the reducing gas hydrogen in the hydrogen atmosphere high-temperature sintering can effectively reduce the metal oxides in the molybdenum-niobium alloy compact to a metallic state, and further remove oxygen in the molybdenum-niobium alloy compact. More importantly, since the density of the molybdenum-niobium alloy compact (especially the density of its surface) is improved after vacuum low-temperature sintering, when sintered in a hydrogen atmosphere at a temperature of 2000°C to 2250°C, the amount of hydrogen in the hydrogen atmosphere absorbed by the niobium in the molybdenum-niobium alloy compact reaches a negligible level. The method for preparing the molybdenum-niobium alloy sintered blank has a short production process; the internal structure of the prepared molybdenum-niobium alloy sintered blank has no defects such as pores, cracks, delamination, inclusions, etc., the density is more than 99%, the oxygen content is less than 100 ppm, the hydrogen content is less than 10 ppm, the grains of the molybdenum-niobium alloy sintered blank are uniform, and the average grain size is less than 55 μm.

[0052] In the embodiment, the vacuum sintering temperature is 1300° C. to 1500° C., and can be a typical but non-limiting temperature such as 1300° C., 1400° C., 1500° C., or a range between any two temperatures.

[0053] In the embodiment, the temperature of the hydrogen atmosphere sintering is 2000° C. to 2250° C., which may be a typical but non-limiting temperature such as 2000° C., 2100° C., 2200° C., 2250° C., or a range between any two temperatures.

[0054] In the embodiment, the density of the molybdenum-niobium alloy sintered blank prepared by the method for preparing the molybdenum-niobium alloy sintered blank provided in the embodiment of the present application is above 99%, preferably 99.3% to 99.7%, and can be a typical but non-limiting density such as 99.3%, 99.5%, 99.7%, or a range between any two densities.

[0055] In the embodiment, the oxygen content of the molybdenum-niobium alloy sintered billet prepared by the method for preparing the molybdenum-niobium alloy sintered billet provided in the embodiment of the present application is less than 100 ppm, preferably 87 ppm to 95 ppm, and can be a typical but non-limiting oxygen content such as 87 ppm, 89 ppm, 95 ppm, or a range between any two oxygen contents.

[0056] In the embodiment, the hydrogen content of the molybdenum-niobium alloy sintered billet prepared by the method for preparing the molybdenum-niobium alloy sintered billet provided in the embodiment of the present application is less than 10 ppm, preferably 6 ppm to 8 ppm, and can be a typical but non-limiting hydrogen content such as 6 ppm, 7 ppm, 8 ppm, or a range between any two hydrogen contents.

[0057] In the embodiment, the average grain size of the molybdenum-niobium alloy sintered billet prepared by the method for preparing the molybdenum-niobium alloy sintered billet provided in the embodiment of the present application is less than 55 μm, preferably 45 μm to 54 μm, and can be a typical but non-restrictive average grain size such as 45 μm, 50 μm, 54 μm, or a range between any two average grain sizes.

[0058] [Molybdenum-niobium alloy compact]

[0059] In some embodiments, the molybdenum powder has a Fisher particle size of 2.0 μm to 5.0 μm. In exemplary embodiments, the molybdenum powder may be a typical but non-limiting particle size such as 2.0 μm, 3.0 μm, 4.0 μm, 5.0 μm, or a range between any two particle sizes.

[0060] In some embodiments, the purity of the molybdenum powder is 99.97% or more. In this case, the impurity content of the molybdenum powder is lower and the inhomogeneous structure inside the alloy is less.

[0061] In some specific embodiments, the molybdenum powder has a Fisher particle size of 2.0 μm to 4.0 μm. In this case, the molybdenum powder is easier to mix evenly with the niobium powder, promoting uniform distribution of alloy elements. This helps to reduce alloy segregation and phase separation, and improve the uniformity and stability of the target material.

[0062] In some embodiments, the niobium hydride powder has a Fisher particle size of 1.0 μm to 3.0 μm. In an exemplary embodiment, it can be a typical but non-limiting particle size such as 1.0 μm, 2.0 μm, 3.0 μm, or a range between any two particle sizes. In some embodiments, the purity of the niobium hydride powder is 99.97% or more. In this case, the niobium hydride powder has a very high specific surface area, which can promote the diffusion rate of alloy elements during the sintering process and help form a uniform alloy phase.

[0063] In some specific embodiments, the Fisher particle size of the niobium hydride powder is 1.0 μm to 2.0 μm. In this case, the powder is more evenly distributed during mixing, avoiding the accumulation or agglomeration of large particles, thereby ensuring the uniform distribution of niobium elements in the alloy target and improving the composition consistency of the alloy.

[0064] In some embodiments, the preparation of the molybdenum-niobium alloy compact comprises the following steps:

[0065] S1. Molybdenum powder and niobium hydride powder are mixed and ball-milled to obtain molybdenum-niobium alloy powder.

[0066] S2. The molybdenum-niobium alloy powder is subjected to cold isostatic pressing to obtain a molybdenum-niobium alloy compact.

[0067] In some embodiments, in the above step S1, the mass ratio of molybdenum powder to niobium hydride is (9-19):1. In the exemplary embodiment, it can be a typical but non-limiting mass ratio such as 9:1, 10:1, 12:1, 15:1, 19:1, or a range between any two mass ratios. In this case, the uniformity and adhesion of the target sputtering film layer are better. It should be noted that the mass ratios of molybdenum powder and niobium hydride, such as 9:1 and 19:1, are all commonly used mass ratios in the art (niobium hydride content 5%, 10%). In the embodiment of the present application, the mass ratio does not affect the effect of the preparation method of the molybdenum-niobium alloy sintered blank in the embodiment of the present application.

[0068] In some embodiments, in the above step S1, the time of the mixed ball milling is 20 hours to 30 hours. In the exemplary embodiment, it can be a typical but non-limiting time such as 20 hours, 22 hours, 25 hours, 30 hours, or a range between any two times. In this case, the molybdenum and niobium hydride in the molybdenum-niobium alloy powder obtained by the mixed ball milling are uniformly mixed, and the average particle size of the molybdenum-niobium alloy powder obtained after the ball milling is 1 μm to 2 μm.

[0069] In some embodiments, in the above step S1, the mixing and ball milling time is 20h to 25h. In this case, the specific surface area of ​​the powder increases, which helps to promote the mutual bonding between particles in the subsequent sintering process, reduce the sintering temperature, and improve the density of the target material.

[0070] In some embodiments, in the above step S1, in the mixed ball milling, the material of the grinding ball is pure molybdenum, and the particle size is 0.4 mm to 1.0 mm. In the exemplary embodiment, the particle size can be 0.4 mm, 0.6 mm, 0.8 mm, 1.0 mm, etc., which are typical but non-limiting particle sizes, or a range between any two particle sizes. In this case, pure molybdenum ball milling avoids other impurities from being introduced into the mixed powder.

[0071] In some embodiments, in the above step S1, the average particle size Dv50 of the molybdenum-niobium alloy powder obtained by ball milling is 1.2-1.5 μm. Within this particle size range, the activity of the powder particles is high, making it easier to densify during the sintering process, reducing porosity and forming a high-density molybdenum-niobium alloy target.

[0072] In some embodiments, in the cold isostatic pressing step, the pressing pressure applied is 160MPa-180MPa, and the holding time is 5min-10min; after holding, the pressure is reduced to normal pressure at a rate of 20MPa / min-40MPa / min to obtain a molybdenum-niobium alloy compact. In this case, the cold isostatic pressing can eliminate some pores and defects between powder particles and improve the density and strength of the molybdenum-niobium alloy compact.

[0073] In the embodiment, the pressing pressure applied is 160 MPa-180 MPa, which can be a typical but non-limiting pressure such as 160 MPa, 170 MPa, 180 MPa, or a range between any two pressures.

[0074] In the embodiment, the holding time of applying the pressing pressure is 5 min to 10 min, which can be a typical but non-limiting holding time such as 5 min, 8 min, 10 min, or a range between any two holding times.

[0075] In the embodiment, the depressurization rate is 20 MPa / min to 40 MPa / min, and can be typical but non-limiting depressurization rates such as 20 MPa / min, 30 MPa / min, 40 MPa / min, or a range between any two depressurization rates.

[0076] In some embodiments, the holding time is 5 min to 8 min.

[0077] In some embodiments, in the cold isostatic pressing step, the mold filled with the molybdenum-niobium alloy powder is pressed in a cold isostatic press.

[0078] In some specific embodiments, in the cold isostatic pressing step, the molybdenum-niobium alloy powder is placed in a rubber package for cold isostatic pressing.

[0079] In some embodiments, the density of the molybdenum-niobium alloy compact is 9.90 g / cm 3 ~9.99g / cm 3 In the example, it can be 9.90g / cm 3 , 9.91g / cm 3 , 9.92g / cm 3 , 9.93g / cm 3 , 9.94g / cm 3 , 9.95g / cm 3 , 9.96g / cm 3 , 9.97g / cm 3 , 9.98g / cm 3 , 9.99g / cm 3Typical but non-limiting densities or the range between any two densities. In this density range, the sputtering speed of molybdenum-niobium alloy is uniform and there is no abnormal discharge. The uniformity and precision of the sputtered film are higher.

[0080] [Two-step sintering]

[0081] In some embodiments, in the vacuum sintering step, the vacuum sintering holding time is 3 hours to 6 hours. In an exemplary embodiment, it can be a typical but non-limiting holding time of 3 hours, 4 hours, 5 hours, 6 hours, or a range between any two holding times. In this case, the molybdenum-niobium alloy after vacuum sintering has good density and uniform grains.

[0082] In some specific embodiments, in the vacuum sintering step, the vacuum sintering holding time is 4h~6h. In the exemplary example, it can be a typical but non-limiting holding time such as 4h, 5h, 6h, or a range between any two holding times. In this case, some low melting point impurities in the molybdenum-niobium alloy have been reduced to the minimum, and there is no significant change in the impurity content when the time is further extended.

[0083] In some embodiments, during the vacuum sintering step, the vacuum degree of the vacuum sintering is 10 -3 Pa or more. In some embodiments, in the vacuum sintering step, the vacuum sintering temperature is 1300°C to 1400°C. In the exemplary embodiment, it can be a typical but non-restrictive temperature such as 1300°C, 1350°C, 1400°C, or a range between any two temperatures. In this case, niobium powder is easy to absorb hydrogen at low temperatures. Therefore, vacuum low-temperature sintering can avoid niobium powder from absorbing hydrogen, and at the same time, the hydrogen in niobium hydride can be used to remove impurities such as oxygen adsorbed inside and on the surface of the molybdenum-niobium alloy compact, thereby improving the density of the molybdenum-niobium alloy compact and reducing the content of hydrogen and oxygen in the molybdenum-niobium alloy compact.

[0084] In some specific embodiments, the vacuum degree of vacuum sintering is 10 -5 Pa~10 -3 Pa.

[0085] In some embodiments, the holding time of hydrogen atmosphere sintering is 4 hours to 8 hours. In the exemplary embodiment, it can be a typical but non-limiting holding time such as 4 hours, 6 hours, 8 hours, or a range between any two holding times. In this case, the molybdenum-niobium alloy sintered blank obtained by sintering has good density and uniform grains.

[0086] In some specific embodiments, the holding time of hydrogen atmosphere sintering is 6h~8h. In the exemplary embodiment, it can be a typical but non-limiting holding time such as 6h, 7h, 8h or a range between any two holding times. In this case, the density of the molybdenum-niobium alloy sintered blank obtained by sintering is higher than 9.93g / cm 3 .

[0087] In some embodiments, during the hydrogen atmosphere sintering step, the hydrogen flow rate is 4m 3 / h~8m 3 / h, in the example, it can be 4m 3 / h、6m 3 / h、8m 3 / h or any range between two hydrogen flow rates. In this case, hydrogen can promote the gas discharge inside the material, accelerate the sintering process, and improve the density of the molybdenum-niobium alloy sintered billet.

[0088] In some embodiments, the temperature of hydrogen atmosphere sintering is 2100° C. to 2250° C., and in exemplary embodiments, it can be a typical but non-limiting temperature such as 2100° C., 2200° C., 2250° C., or a range between any two temperatures. In this case, the niobium element diffuses more fully, and the alloy components are more evenly distributed on a microscopic scale.

[0089] In some embodiments, a method for preparing a molybdenum-niobium alloy sintered blank is provided, comprising the following steps:

[0090] S01. Select molybdenum powder with a Fisher particle size of 2.0 μm to 5.0 μm and niobium hydride powder with a Fisher particle size of 1.0 μm to 3.0 μm.

[0091] S02. Molybdenum powder and niobium hydride powder are mixed and ball-milled in a mass ratio of (9-19):1 for 20h-30h to obtain molybdenum-niobium alloy powder.

[0092] S03. The molybdenum-niobium alloy powder is cold isostatically pressed at a pressing pressure of 160 MPa to 180 MPa and a holding time of 5 min to 10 min to prepare a molybdenum-niobium alloy blank.

[0093] S04. Place the molybdenum-niobium alloy billet in a vacuum environment, heat it from room temperature to 1300°C~1500°C at a heating rate of 3°C / min~6°C / min, and then keep it at 1300°C~1500°C for 3h~6h.

[0094] S05. After vacuum sintering, at a hydrogen flow rate of 4m 3 / h~8m 3 / h in a hydrogen atmosphere, the temperature is increased from 1300℃~1500℃ to 2000℃~2250℃ at a heating rate of 2℃ / min~4℃ / min, and kept at 2000℃~2250℃ for 4h~8h to obtain a molybdenum-niobium alloy sintered billet.

[0095] In some specific embodiments, a method for preparing a molybdenum-niobium alloy sintered blank is provided, comprising the following steps:

[0096] X01. Select molybdenum powder with a Fisher particle size of 2.0μm~4.0μm and niobium hydride powder with a Fisher particle size of 1.0μm~2.0μm.

[0097] X02. Mix molybdenum powder and niobium hydride powder in a mass ratio of (9~19):1 and ball mill for 20h~25h to obtain molybdenum-niobium alloy powder.

[0098] X03. The molybdenum-niobium alloy powder is cold isostatically pressed at a pressing pressure of 160MPa~180MPa and a holding time of 5min~8min to produce a molybdenum-niobium alloy blank.

[0099] X04. Place the molybdenum-niobium alloy billet in a vacuum environment, heat it from room temperature to 1300°C~1400°C at a heating rate of 3°C / min~6°C / min, and then keep it at 1300°C~1400°C for 4h~6h.

[0100] X05. After vacuum sintering, at a hydrogen flow rate of 4m 3 / h~8m 3 / h in a hydrogen atmosphere, the temperature is increased from 1300℃~1400℃ to 2100℃~2250℃ at a heating rate of 2℃ / min~4℃ / min, and kept at 2100℃~2250℃ for 6h~8h to obtain a molybdenum-niobium alloy sintered billet.

[0101]

Molybdenum-niobium alloy sintered billet

[0102] A second aspect of the embodiments of the present application provides a molybdenum-niobium alloy sintered blank prepared by the method for preparing the molybdenum-niobium alloy sintered blank provided in the present application.

[0103] The molybdenum-niobium alloy sintered blank provided in the present application is prepared by the method for preparing the molybdenum-niobium alloy sintered blank provided in the present application. The molybdenum-niobium alloy sintered blank has an average grain size of less than 55 μm, an oxygen content of less than 100 ppm, and a hydrogen content of less than 10 ppm; the internal structure of the molybdenum-niobium alloy sintered blank is free from defects such as pores, cracks, delamination, and inclusions.

[0104]

Molybdenum-niobium alloy target

[0105] A third aspect of the embodiments of the present application provides a molybdenum-niobium alloy target, including a molybdenum-niobium alloy sintered blank prepared by the method for preparing a molybdenum-niobium alloy sintered blank provided in the embodiments of the present application or a molybdenum-niobium alloy target obtained by machining the molybdenum-niobium alloy sintered blank provided in the embodiments of the present application.

[0106] Machining refers to the further mechanical processing of the molybdenum-niobium alloy sintered billet, which is aimed at processing the molybdenum-niobium alloy sintered billet into parts or products that meet specific size, shape and precision requirements.

[0107] In some embodiments, the average grain size of the molybdenum-niobium alloy target is 45 μm to 54 μm. In an exemplary embodiment, the average grain size may be 45 μm, 50 μm, 54 μm, or any range between two average grain sizes. In this case, the molybdenum-niobium alloy target has high strength, hardness, and good electrical conductivity.

[0108] In some embodiments, the oxygen content in the molybdenum-niobium alloy target is 87ppm-95ppm. In the exemplary embodiment, the oxygen content may be 87ppm, 89ppm, 95ppm, or any range between two oxygen contents. In this case, the molybdenum-niobium alloy target with low oxygen content can not only increase the sputtering rate, thereby improving the production efficiency, but also improve the conductive properties of the film.

[0109] In some embodiments, the density of the molybdenum-niobium alloy target is 99.3% to 99.7%. In the exemplary embodiment, it can be a typical but non-limiting density such as 99.3%, 99.6%, 99.7%, or a range between any two densities. In this case, during the sputtering process, the high-density molybdenum-niobium alloy target has a compact internal structure, which reduces the particle splashing caused by defects such as pores and cracks, improves the uniformity and flatness of the coating, and reduces film surface defects.

[0110] In some embodiments, the hydrogen content of the molybdenum-niobium alloy target is less than 10ppm. In some specific embodiments, the hydrogen content of the molybdenum-niobium alloy target is 6ppm-8ppm. In the exemplary embodiment, it can be a typical but non-limiting hydrogen content such as 6ppm, 7ppm, 8ppm, or a range between any two hydrogen contents. In this case, the low hydrogen content can improve the density, mechanical strength, hardness and wear resistance of the molybdenum-niobium alloy target, thereby improving the coating quality and extending the service life of the molybdenum-niobium alloy target.

[0111] In some embodiments, the size of the molybdenum-niobium alloy target is (5 mm to 30 mm) (200mm~500mm) 3300mm.

[0112]

application

[0113] A fourth aspect of the embodiments of the present application proposes an application of the molybdenum-niobium alloy target provided by the embodiments of the present application in the fields of electronics, optics, flat panel displays or photovoltaics.

[0114] The following is further described in conjunction with specific embodiments.

[0115] Example 1

[0116] Example 1 provides a method for preparing a molybdenum-niobium alloy sintered blank, the steps of which are as follows:

[0117] (1) Select molybdenum powder with a Fisher particle size of 3.6 μm and a purity of more than 99.97% and niobium hydride powder with a Fisher particle size of 1.6 μm and a purity of more than 99.97%.

[0118] (2) Under a nitrogen protective atmosphere, molybdenum powder and niobium hydride powder were mixed and ball-milled in a mass ratio of 19:1 for 20 h to obtain molybdenum-niobium alloy powder.

[0119] (3) The molybdenum-niobium alloy powder was loaded into a rubber bag by vibration loading and cold isostatic pressing was carried out at a pressing pressure of 180 MPa. The pressure was maintained for 5 min, and then the pressure was reduced to 1 atmosphere at a rate of 30 MPa / min to obtain a molybdenum-niobium alloy blank.

[0120] (4) Vacuum sintering: at 10 -3 In a Pa vacuum environment, the Mo-Nb alloy billet was heated from room temperature (25°C) to 1300°C at a heating rate of 3°C / min and then kept at 1300°C for 4h.

[0121] (5) Sintering in hydrogen atmosphere: When the hydrogen flow rate is 6m 3 / h in a hydrogen atmosphere, the temperature was increased from 1300°C to 2250°C at a heating rate of 2°C / min, and kept at 2250°C for 6h to obtain a molybdenum-niobium alloy sintered billet.

[0122] Example 2

[0123] Example 2 provides a method for preparing a molybdenum-niobium alloy sintered blank, the steps of which are as follows:

[0124] (1) Select molybdenum powder with a Fisher particle size of 3.0 μm and a purity of more than 99.97%, and niobium hydride powder with a Fisher particle size of 1.0 μm and a purity of more than 99.97%.

[0125] (2) Under a nitrogen protective atmosphere, molybdenum powder and niobium hydride powder were mixed and ball-milled in a mass ratio of 9:1 for 22 h to obtain molybdenum-niobium alloy powder.

[0126] (3) The molybdenum-niobium alloy powder was loaded into a rubber bag by vibration loading and cold isostatic pressing was carried out at a pressing pressure of 160 MPa. The pressure was maintained for 8 minutes, and then the pressure was reduced to 1 atmosphere at a rate of 20 MPa / min to obtain a molybdenum-niobium alloy compact.

[0127] (4) Vacuum sintering: at 10 -3 In a Pa vacuum environment, the Mo-Nb alloy billet was heated from room temperature (25°C) to 1400°C at a heating rate of 4°C / min and then kept at 1400°C for 5h.

[0128] (5) Sintering in hydrogen atmosphere: When the hydrogen flow rate is 8m3 / h in a hydrogen atmosphere, the temperature was increased from 1400°C to 2150°C at a heating rate of 4°C / min, and kept at 2150°C for 8h to obtain a molybdenum-niobium alloy sintered billet.

[0129] Example 3

[0130] Example 3 provides a method for preparing a molybdenum-niobium alloy sintered blank, the steps of which are as follows:

[0131] (1) Select molybdenum powder with a Fisher particle size of 4.0 μm and a purity of more than 99.97% and niobium hydride powder with a Fisher particle size of 2.0 μm and a purity of more than 99.97%.

[0132] (2) Under a nitrogen protective atmosphere, molybdenum powder and niobium hydride powder were mixed and ball-milled in a mass ratio of 9:1 for 25 h to obtain molybdenum-niobium alloy powder.

[0133] (3) The molybdenum-niobium alloy powder was loaded into a rubber bag by vibration loading and cold isostatic pressing was carried out at a pressing pressure of 180 MPa. The pressure was maintained for 6 min, and then the pressure was reduced to 1 atmosphere at a rate of 40 MPa / min to obtain a molybdenum-niobium alloy compact.

[0134] (4) Vacuum sintering: at 10 -3 In a Pa vacuum environment, the molybdenum-niobium alloy billet was heated from room temperature (25°C) to 1350°C at a heating rate of 6°C / min and then kept at 1350°C for 5h.

[0135] (5) Sintering in hydrogen atmosphere: When the hydrogen flow rate is 6m 3 / h in a hydrogen atmosphere, the temperature was increased from 1350°C to 2200°C at a heating rate of 3°C / min, and kept at 2200°C for 6h to obtain a molybdenum-niobium alloy sintered billet.

[0136] Comparative Example 1

[0137] Comparative Example 1 proposes a method for preparing a molybdenum-niobium alloy sintered blank, and the steps are basically the same as those of Example 1, except that in the two-step sintering step, hydrogen atmosphere sintering is performed first, and then vacuum sintering is performed.

[0138] Comparative Example 2

[0139] Comparative Example 2 proposes a method for preparing a molybdenum-niobium alloy sintered blank, the steps of which are basically the same as those of Example 1, except that the sintering temperature in the hydrogen atmosphere in step (5) is 1800°C.

[0140] Comparative Example 3

[0141] Comparative Example 3 proposes a method for preparing a molybdenum-niobium alloy sintered blank, the steps of which are basically the same as those of Example 1, except that the sintering temperature in the hydrogen atmosphere in step (5) is 2400°C.

[0142] Comparative Example 4

[0143] Comparative Example 4 proposes a method for preparing a molybdenum-niobium alloy sintered blank, the steps of which are basically the same as those of Example 1, except that the vacuum degree in step (4) is 10 -2 Pa.

[0144] In order to verify the advancement of a molybdenum-niobium alloy sintered blank and a preparation method thereof provided in the examples of the present application, taking Examples 1 to 3 and Comparative Example 1 as examples, a metallographic microscope was used to collect metallographic organization diagrams of the molybdenum-niobium alloy sintered blanks prepared in Examples 1 to 3. Figures 1 to 3 As shown; Taking Example 1 and Comparative Example 1 as examples, XRD was used to detect the components in the molybdenum-niobium alloy sintered blank, as shown Figure 4 The density, oxygen content, hydrogen content and average particle size of the molybdenum-niobium alloy sintered blanks prepared in the examples and comparative examples were tested, and the results are shown in Table 1 below.

[0145]

[0146] From Table 1 above and the instructions attached Figures 1 to 4 At least the following conclusions can be drawn:

[0147] (1) Based on Table 1 above and the instructions Figures 1 to 3 It can be seen that the method for preparing the molybdenum-niobium alloy sintered blank provided in the embodiment of the present application first performs vacuum sintering, which can significantly reduce the oxygen content and hydrogen content of the molybdenum-niobium alloy target; and then performs hydrogen atmosphere sintering, which can significantly improve the density of the molybdenum-niobium alloy target and refine the grains.

[0148] (2) Based on Table 1 above and the instructions Figure 4 It can be seen that, using molybdenum powder and niobium hydride powder as raw materials, vacuum sintering is first performed to improve the density of the molybdenum-niobium alloy compact and reduce the hydrogen in the molybdenum-niobium alloy compact; and then sintering in a hydrogen atmosphere is performed. Due to the density of the material surface, hydrogen can no longer enter the interior of the material, thereby significantly reducing the hydrogen content in the sintered compact.

[0149] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for preparing a molybdenum-niobium alloy sintered blank, characterized in that: The steps include: The molybdenum-niobium alloy compact is sintered to obtain a molybdenum-niobium alloy sintered compact; Wherein, the molybdenum-niobium alloy compact comprises molybdenum powder and hydride niobium powder; The sintering treatment step includes vacuum sintering followed by hydrogen atmosphere sintering; The vacuum sintering temperature is 1300°C to 1500°C; The temperature of the hydrogen atmosphere sintering is 2000°C~2250°C.

2. The method for preparing a molybdenum-niobium alloy sintered blank according to claim 1, characterized in that: In the vacuum sintering step, the following conditions (1) to (3) are met: (1) The holding time of the vacuum sintering is 3h~6h; (2) The vacuum sintering temperature is 1300°C to 1400°C; (3) The vacuum degree of the vacuum sintering is 10 -3 Pa or above.

3. The method for preparing a molybdenum-niobium alloy sintered blank according to claim 2, characterized in that: In the vacuum sintering step, the following conditions 1) to 2) are met: 1) The holding time of the vacuum sintering is 4h~6h; 2) The vacuum degree of the vacuum sintering is 10 -5 Pa~10 -3 Pa.

4. The method for preparing a molybdenum-niobium alloy sintered blank according to any one of claims 1 to 3, characterized in that: In the hydrogen atmosphere sintering step, the following conditions (a) to (c) are met: (a) The holding time of the hydrogen atmosphere sintering is 4h~8h; (b) The temperature of the hydrogen atmosphere sintering is 2100° C. to 2250° C.; (c) The hydrogen flow rate of the hydrogen atmosphere sintering is 4m 3 / h~8m 3 / h.

5. The method for preparing a molybdenum-niobium alloy sintered blank according to claim 4, characterized in that: The holding time of the hydrogen atmosphere sintering is 6h~8h.

6. The method for preparing a molybdenum-niobium alloy sintered blank according to any one of claims 1 to 3 or claim 5, characterized in that: The density of the molybdenum-niobium alloy compact is 9.90 g / cm 3 ~9.99g / cm 3 .

7. A molybdenum-niobium alloy sintered blank prepared by the method for preparing a molybdenum-niobium alloy sintered blank according to any one of claims 1 to 6.

8. A molybdenum-niobium alloy target, comprising the molybdenum-niobium alloy target obtained by machining the molybdenum-niobium alloy sintered blank as claimed in claim 7.

9. The molybdenum-niobium alloy target according to claim 8, characterized in that: The average grain size of the molybdenum-niobium alloy target is 45 μm-54 μm, and the hydrogen content is less than 10 ppm.

10. Use of the molybdenum-niobium alloy target material according to claim 8 or 9 in the field of electronics, optics, flat panel display or photovoltaics.

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