A method for preparing a molybdenum alloy target, a molybdenum alloy target and application thereof

Abstract

The present invention belongs to the technical field of powder metallurgy, and specifically provides a molybdenum alloy target material and a preparation method and application thereof. The preparation method of the molybdenum alloy target material comprises the following steps: preparing raw materials: weighing and mixing raw materials according to the mass ratio of each element of the target material, the target material comprises the following components in mass percentage, Ni: 10% to 30%, Ti: 5% to 25%, W: 1% to 20% and Re: 0.5% to 5%, the remainder being Mo and unavoidable impurities, and the mass percentage of Mo is ≥50%; cold isostatic pressing; hot isostatic pressing; hot rolling; annealing. The target material prepared by the method of the present application has good plastic toughness, good deformation ability, and fine and uniform grains. The thickness distribution of the thin film deposited by sputtering of the target material prepared by the present application is more uniform, and it can be attached to the main conductive layer of the laminated wiring film for electronic components by sputtering to form a metal covering layer, which is used for flat panel displays, thin-film solar energy and semiconductor devices, etc.

Description

Technical Field

[0001] The invention relates to the technical field of rare metals and powder metallurgy, and in particular to a molybdenum alloy target material and a preparation method and application thereof. Background Art

[0002] The technological upgrading of flat display devices such as liquid crystal displays and display panels requires lower resistance of wiring films. At the same time, the large screen, high definition, high-speed response of flat panel displays, as well as the large-scale flexible panels, also require lower film resistance levels.

[0003] Thin film transistors (TFTs) are driving elements of display panels, and use Al or Cu as the main wiring material. However, if Al or Cu is in direct contact with Si, thermal diffusion will occur during the preparation process due to thermal processing, which will deteriorate the performance of the thin film transistor. Mo and molybdenum alloys such as Mo-Nb and Mo-Ti have good corrosion resistance and heat resistance, and have good adhesion to the substrate. However, during the preparation process, after the laminated wiring film is formed on the substrate, it is sometimes placed in the atmosphere for a long time. When installing signal cables on the display panel, it is sometimes necessary to heat it in the atmosphere, and in the semiconductor film using oxides, in order to achieve improved performance and stabilization, it is necessary to heat it in an aerobic environment, so there is a strong demand for enhanced oxidation resistance. In addition, the resin film used in portable, lightweight, flexible display panels is moisture permeable compared to glass substrates, and the laminated wiring film is required to have higher moisture resistance. However, the moisture resistance and oxidation resistance of materials such as pure Mo and Mo-Ti are not sufficient, and sometimes oxidation will occur, causing a significant increase in the resistance value of Al or Cu.

[0004] Patent "CN2012102930608" discloses a molybdenum alloy target for laminated wiring film. In order to improve the moisture resistance and oxidation resistance of pure molybdenum coating, a certain amount of Ni and Ti are added to the molybdenum, which helps to stabilize the manufacturing of electronic components and improve reliability.

[0005] Patent "CN2014100909230" discloses a molybdenum alloy target for electronic components, which can improve oxidation resistance by adding Ni and moisture resistance by adding W;

[0006] Patent "CN2017114460697" discloses a molybdenum alloy target material composition containing elements such as Ni, Nb, and Ti, which can better improve the moisture resistance and oxidation resistance of pure molybdenum and maintain a low film resistance.

[0007] The above patent adds a certain amount of Ni, Ti or W elements to the molybdenum matrix to improve the moisture resistance and oxidation resistance of the molybdenum target sputtering film and maintain a low resistance value. However, the preparation of the target is mainly through hot isostatic pressing (HIP). As the length of the target increases, the HIP method is severely restricted by the size of the HIP equipment, and it is impossible to mass-produce high-performance molybdenum alloy targets. In addition, since the current molybdenum alloy is brittle after adding titanium and is prone to cracking when deformed greatly, it is impossible to prepare a series of target products of different lengths through deformation methods such as rolling and forging. Summary of the invention

[0008] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a molybdenum alloy target material and its preparation method and application. The molybdenum alloy target material provided by the present invention has a low plastic-brittle transition temperature, strong deformation ability, more uniform grains, and a more uniform film thickness when used as a target material to prepare a film layer, and a faster sputtering speed.

[0009] To achieve the above purpose, the technical solution adopted by the present invention is:

[0010] In a first aspect, the present invention provides a method for preparing a molybdenum alloy target, comprising the following steps:

[0011] (1) preparing raw materials: weighing raw materials according to the mass ratio of each element of the target material and mixing them to obtain a mixed powder; wherein, the target material includes the following components, in terms of mass percentage, Ni: 10% to 30% (for example, 15%, 20%, 25%), Ti: 5% to 25% (for example, 10%, 15%, 20%), W: 1% to 20% (for example, 5%, 12.5%, 15%, 17.5%) and Re: 0.5% to 5% (for example, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%), and the balance is Mo and unavoidable impurities, and the mass percentage of Mo is ≥50% (for example, 55%, 60%, 65%, 70%, 75%, 80%);

[0012] (2) Cold isostatic pressing: the mixed powder in step (1) is loaded into a mold and subjected to cold isostatic pressing to obtain a cold pressed green body;

[0013] (3) Hot isostatic pressing: The cold pressed green body is placed in a sheath and hot isostatically pressed to obtain a hot pressed green body with a sheath;

[0014] (4) Hot rolling: After removing the sheath of the hot pressed green body, the hot pressed green body is covered with a metal plate, and then hot rolled. After hot rolling, the molybdenum plate is removed to obtain a rolled product;

[0015] (5) Annealing: Annealing the rolled piece to obtain the molybdenum alloy target.

[0016] In the above-mentioned method for preparing the molybdenum alloy target, as a preferred embodiment, the target also includes 0.01%-15% (for example, 0.05%, 0.1%, 0.5%, 1%, 3%, 5%, 8%, 11%, 13%) of M in mass percentage, and the M is at least one of Cr, Zr, Ta, and Nb, and the M is used to replace part of Ti.

[0017] In the above-mentioned method for preparing the molybdenum alloy target, as a preferred embodiment, the target includes, by mass percentage, Ni: 15% to 25% (e.g., 18%, 21%, 23%), Ti: 10% to 20% (e.g., 12%, 14%, 16%, 18%), W: 1% to 10% (e.g., 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%), Re: 1% to 5% (e.g., 2%, 3%, 4%) and M: 0%-5% (e.g., 1%, 2%, 3%, 4%), the remainder being Mo and unavoidable impurities, and the mass percentage of Mo is ≥50% (e.g., 55%, 60%, 65%, 70%).

[0018] Ni can improve the oxidation resistance of the film layer formed by the target material of the present invention, and Ti can improve the moisture resistance of the film layer. The proper addition of the two can not only ensure the oxidation resistance and moisture resistance of the film layer, but also ensure the low resistance of the wiring film without affecting the etching speed of the etchant.

[0019] A small amount of Re element is added to the molybdenum alloy target material of the present invention. The addition of rhenium element in a specific proportion works together with other elements in a specific proportion in the molybdenum alloy to exert a "rhenium effect" in the molybdenum alloy, improve the room temperature plasticity of the molybdenum alloy, reduce the plastic-brittle transition temperature, refine the grains, etc. By adding the Re element to the molybdenum alloy target material, the deformation performance of the target material can be improved, and no cracks will be generated during large deformation processing. Since the target material has fine grains, the target material obtained by the preferred molybdenum alloy component ratio has a particularly small grain difference and uniform grains, and the film layer prepared by the target material of the present invention has a more uniform thickness and a faster sputtering speed. When the amount of Re element exceeds 5%, on the one hand, the cost increases, and on the other hand, the large amount of Re element added will form an alloy phase with other components, making the distribution of the organizational components in the target material uneven, affecting the subsequent coating effect. When the amount of Re element is less than 0.5%, it cannot effectively refine the grains and enhance the plasticity of the target material.

[0020] The M element in the present invention has moisture resistance and can be used to partially replace Ti, which also has moisture resistance. However, from the perspective of the interaction between various components in the target material, it is preferred that the M element can only partially replace Ti. On the other hand, the addition of the M element can improve the moisture resistance of the molybdenum alloy target material while further improving the oxidation resistance of the molybdenum alloy target material.

[0021] In the molybdenum alloy target material of the present invention, the W element not only has the effect of enhancing moisture resistance, but also can strengthen the "rhenium effect" and further refine the grains. The Re element will play a "rhenium effect" in molybdenum and tungsten, improve the room temperature plasticity of the material, reduce the ductile-brittle transition temperature, refine the grains, etc., and improve the deformation performance of the target material. In addition, the W element can improve the comprehensive performance of the film layer formed by the target material of the present application, such as heat resistance.

[0022] In the preparation method of the above-mentioned molybdenum alloy target, as a preferred embodiment, the raw material of the component Mo in the target is molybdenum powder with a purity of ≥3N5, and its Fisher particle size range is preferably 2.5μm to 4μm (for example, 2.8μm, 3μm, 3.5μm, 3.8μm); preferably, the raw material of the component Ni in the target is nickel powder with a purity of ≥3N, and its Fisher particle size range is preferably 2μm to 3μm (for example, 2.2μm, 2.4μm, 2.6μm, 2.8μm); preferably, the raw material of the component Ti in the target is titanium powder with a purity of ≥3N, and its Fisher particle size range is preferably 2μm to 4μm (for example, 2.3μm, 2.6μm, 3 μm, 3.3μm, 3.6μm); preferably, the raw material of the target component W is tungsten powder with a purity ≥3N5, and its Fisher particle size is preferably 2.0μm-3.0μm (for example, 2.2μm, 2.4μm, 2.6μm, 2.8μm); preferably, the raw material of the target component Re is rhenium powder or ammonium rhenate, the purity of the rhenium powder is ≥4N, and the Fisher particle size is preferably 2μm-4μm (for example, 2.3μm, 2.6μm, 3μm, 3.3μm, 3.6μm), the ammonium rhenate has a purity ≥4N, and the particle size is preferably 150-350 mesh (for example, 180 mesh, 220 mesh, 260 mesh, 300 mesh, 325 mesh).

[0023] Compared with using alloy powders such as molybdenum-titanium alloy powder and molybdenum-nickel alloy powder as raw materials, in the preferred embodiment of the present invention, molybdenum powder, nickel powder and titanium powder whose purity meets the relevant standards are used as raw materials for preparing the target material of the present invention, which can make the component distribution in the prepared target material more uniform and the coating effect better.

[0024] In the above-mentioned method for preparing the molybdenum alloy target, as a preferred embodiment, the rhenium element in the molybdenum alloy target is added in the form of tungsten-rhenium alloy powder; the tungsten-rhenium alloy powder is obtained by mixing the tungsten powder in the raw material with ammonium rhenate and then subjecting it to reduction treatment; preferably, the tungsten-rhenium mass ratio of the tungsten-rhenium alloy powder is 95:5-50:50 (for example, 18:1, 15:1, 12:1, 9:1, 6:1, 3:1, 2:1); preferably, the reduction treatment is carried out in a hydrogen atmosphere, the reduction treatment temperature is 500°C-900°C (for example, 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, 850°C), and the reduction treatment time is 2h-8h (for example, 3h, 4h, 5h, 6h, 7h).

[0025] In the above hydrogen reduction process, the gas flow rate is determined according to the size of the reduction furnace, and the pressure can be slightly positive. Ammonium rhenate is selected as the rhenium source to make the prepared tungsten-rhenium powder more uniform; rhenium powder can also be directly used as the source for direct mixing, but the powder uniformity is not as good as the reduction process using ammonium rhenate mixed with tungsten powder.

[0026] In the above-mentioned method for preparing the molybdenum alloy target, as a preferred embodiment, in step (1), the mixing method is ball milling, and the ball-to-material ratio of the ball milling is (0.5-2):1 (for example, 0.8:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1); preferably, the ball milling time is 10h-16h (for example, 11h, 12h, 13h, 14h, 15h); preferably, the ball milling is carried out in an inert gas; preferably, the inert gas is argon; preferably, the rotation speed of the ball mill is 50-300r / min (for example, 100r / min, 150r / min, 200r / min, 250r / min).

[0027] In the above-mentioned method for preparing the molybdenum alloy target, as a preferred embodiment, in step (2), the pressure of the cold isostatic pressing is 150-220 MPa (for example, 160 MPa, 170 MPa, 180 MPa, 190 MPa, 200 MPa, 210 MPa); preferably, the holding time of the cold isostatic pressing is 8-15 min (for example, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min).

[0028] The cold isostatic pressing process of the present invention can make the relative density of the cold pressed blank be 50% to 75%; preferably, the mold is a plate-shaped mold made of stainless steel.

[0029] In the above-mentioned method for preparing the molybdenum alloy target, as a preferred embodiment, in step (3), the holding temperature of the hot isostatic pressing is 900°C to 980°C (for example, 910°C, 920°C, 930°C, 940°C, 950°C, 960°C, 970°C); preferably, the pressure of the hot isostatic pressing is 100MPa to 170MPa (for example, 110MPa, 120MPa, 130MPa, 140MPa, 150MPa, 160MPa); preferably, the holding time of the hot isostatic pressing is 2h to 5h (for example, 2h, 3h, 4h).

[0030] The density of the hot pressed green body obtained after the hot isostatic pressing process of the present invention can reach 100%.

[0031] In the above-mentioned method for preparing the molybdenum alloy target, as a preferred embodiment, in step (3), the cold-pressed green body is first shaped, and then the cold-pressed green body is placed in a bag for vacuum evacuation and sealing; preferably, the vacuum is evacuated to a vacuum degree of 10 -1 Pa.

[0032] In the above-mentioned method for preparing the molybdenum alloy target, as a preferred embodiment, in step (3), the thickness of the hot-pressed green body is 40 mm to 60 mm (for example, 42.5 mm, 45 mm, 47.5 mm, 50 mm, 52.5 mm, 55 mm, 57.5 mm).

[0033] In the above-mentioned method for preparing the molybdenum alloy target, as a preferred embodiment, in step (3), the starting temperature of the hot rolling process is 1000℃~1350℃ (for example, 1150℃, 1200℃, 1250℃, 1300℃), and the final rolling temperature is 900-1100℃ (for example, 950℃, 1000℃, 1050℃).

[0034] The preferred solution of the present invention can improve the strength and plasticity of the material by appropriately cooling the rolling temperature of each pass during the rolling process, that is, controlling the starting rolling temperature of each pass to be lower than the starting rolling temperature of the adjacent previous pass by more than 0°C and less than or equal to 50°C. If the starting rolling temperature of each pass is cooled too much based on the starting rolling temperature of the adjacent previous pass, it will lead to increased grain resistance, increase the risk of cracking of the rolled billet, and reduce the yield rate of hot rolling.

[0035] In the above-mentioned method for preparing the molybdenum alloy target, as a preferred embodiment, in step (3), in the hot rolling process, the single rolling deformation is 15% to 25% (for example, 17.5%, 20%, 22.5%), and the total deformation of the hot rolling process is 40% to 80% (for example, 45%, 50%, 55%, 60%, 65%, 70%, 75%); preferably, in the hot rolling process, heating and heat preservation are performed before each rolling, and the heat preservation temperature is 1000°C to 1300°C (for example, 1050°C, 1100°C, 1150°C). , 1200℃, 1250℃), the insulation time is 30 minutes to 120 minutes (for example, 40min, 50min, 60min, 70min, 80min, 90min, 100min, 110min); preferably, the heating and insulation temperature before each rolling pass is reduced by more than 0℃ and less than or equal to 50℃ (for example, 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃) based on the heating and insulation temperature before the previous rolling pass; preferably, the hot rolling is carried out in air or argon atmosphere.

[0036] In the above-mentioned method for preparing the molybdenum alloy target, as a preferred embodiment, in step (4), the thickness of the metal plate is 0.5-1 mm (for example, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm); preferably, the rolled piece also includes rough processing after removing the metal plate; preferably, the thickness of the rolled piece is 6 mm to 24 mm (for example, 8 mm, 10 mm, 12.5 mm, 15 mm, 17.5 mm, 20 mm, 22 mm); preferably, the metal plate is a molybdenum plate, a stainless steel plate or a nickel plate, preferably a molybdenum plate.

[0037] In the present invention, the preferred metal plate material is molybdenum plate, the matrix of the molybdenum plate is molybdenum element, which can reduce the pollution of other component elements and affect the composition. Other metal plates such as stainless steel plate or nickel plate can also be used.

[0038] In the above-mentioned method for preparing the molybdenum alloy target, as a preferred embodiment, in step (5), the annealing treatment is carried out in an argon atmosphere; preferably, the temperature of the annealing treatment is 950°C to 1250°C (for example, 960°C, 1000°C, 1050°C, 1100°C, 1150°C, 1200°C), and the holding time of the annealing treatment is 60 minutes to 120 minutes (for example, 70min, 80min, 90min, 100min, 110min).

[0039] In the present invention, the annealing temperature is controlled within this range, which can eliminate the anisotropy of the target material after extrusion and obtain a molybdenum alloy target material with uniform structure and fine grains. When the annealing temperature is lower than 950°C, the target material structure is not completely crystallized, and there is a state of grain deformation in some areas. When the annealing temperature is higher than 1250°C, the grains grow abnormally, mixed crystals appear, and the structure is unevenly distributed, which affects the effect of target sputtering coating.

[0040] In the above-mentioned method for preparing the molybdenum alloy target, as a preferred embodiment, the grain size of the molybdenum alloy target prepared in step (5) is ≤100μm; preferably 60μm to 95μm (for example, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm).

[0041] In the above-mentioned method for preparing the molybdenum alloy target, as a preferred embodiment, the grain size of the molybdenum alloy target prepared in step (5) is level 4 to 5; preferably, in the same molybdenum alloy target prepared in step (5), the grain size difference is less than or equal to 1, preferably 0.

[0042] In the above-mentioned method for preparing the molybdenum alloy target, as a preferred embodiment, the molybdenum alloy target prepared in step (5) is a plate-type target.

[0043] In a second aspect, the present invention provides a molybdenum alloy target prepared by the above preparation method.

[0044] In a third aspect, the present invention also provides an application of the above-mentioned molybdenum alloy target material, wherein the molybdenum alloy target material is attached to the main conductive layer of a laminated wiring film for electronic components by sputtering to form a metal covering layer; preferably, the electronic component is a display, a semiconductor device or a thin-film solar cell.

[0045] Compared with the prior art, the beneficial effects of this application are:

[0046] 1) After adding rhenium element, the plastic toughness of the target material is increased, and the deformation processing ability of the target material is improved.

[0047] 2) The molybdenum alloy target can be refined by hot rolling and annealing in the subsequent preparation process, and a uniform fine-grained target with a grain size of ≤100μm and a grain size of 4 to 5 can be obtained.

[0048] 3) This application effectively improves the target material performance and processing capability by adding a small amount of rhenium in combination with other components.

[0049] 4) The molybdenum alloy target prepared by the present application has fine grains, and the sputtering rate is faster than that of the target with coarse grains; and the grain size difference is small (uniform distribution), and the thickness distribution of the film deposited by the target sputtering is more uniform. The quality of the film obtained by sputtering the molybdenum alloy target prepared by the present application can be greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is the metallographic structure diagram of the molybdenum alloy target prepared by the method of Example 1 of the present invention. DETAILED DESCRIPTION

[0051] The present invention is further described in detail below in conjunction with specific embodiments, and the examples provided are only for illustrating the present invention, rather than for limiting the scope of the present invention. The examples provided below can be used as a basis for further improvement or application by those of ordinary skill in the art, and do not constitute specific limitations of the present invention in any way.

[0052] The experimental methods in the following examples are conventional methods unless otherwise specified and can be carried out according to the techniques or conditions described in the literature in the art or according to the product instructions. The materials used in the following examples can all be obtained from conventional commercial channels.

[0053] The present invention improves the room temperature plasticity of molybdenum alloy, reduces the ductile-brittle transition temperature, refines grains, etc. by using the "rhenium effect" of Re element in molybdenum and tungsten. By adding Re element and W element to the molybdenum alloy target material, the deformation performance of the target material can also be improved, that is, a large-sized plate-shaped target material can be prepared by deformation methods such as rolling, and a target material with uniform fine grains can be obtained by annealing.

[0054] The present application is described in detail below through specific embodiments.

[0055] Unless otherwise specified, the powder particle sizes in the following examples are all Fisher particle sizes, and the ratios are by mass ratios.

[0056] The grain size grade test in the embodiments of the present application is based on the standard "GB / T6394 Method for Determination of Average Grain Size of Metals".

[0057] The yield rate indicated in the following examples is the number of qualified rolled pieces obtained after hot rolling / the number of hot-rolled billets subjected to hot rolling*100%.

[0058] Embodiment 1: A molybdenum alloy target and a preparation method thereof, comprising the following steps:

[0059] Step 1, pure Mo powder with a purity of 3N5 and a particle size of 3.2 μm, Ni powder with a purity of 3N and a particle size of 3.0 μm, Ti powder with a purity of 3N and a particle size of 2.8 μm, tungsten powder with a purity of 3N5 and a particle size of 3.0 μm, and rhenium powder with a purity of 4N and a particle size of 3.2 μm, according to the mass ratio of each element in the target material, Mo:Ni:Ti:W:Re=60:20:18:1:1, prepare 140 kg of raw materials;

[0060] Step 2, the powder obtained in step 1 is placed in a ball mill with a ball-to-material ratio of 2:1, the air is evacuated to negative pressure, argon is filled to one atmosphere, and ball milling is performed for 10 hours at a ball mill speed of 200 r / min;

[0061] Step 3, placing the mixed powder obtained in step 2 into a stainless steel mold, performing cold isostatic pressing, with a pressing pressure of 150 MPa and a holding time of 10 minutes, to obtain a cold pressed green body;

[0062] Step 4, shaping the cold pressed blank so that the blank has regular and complete geometric dimensions;

[0063] Step 5: Place the shaped compact into the bag and evacuate the air to 10 -1 Pa, keep pumping for 4h, sealed;

[0064] Step 6, subjecting the package in step 5 to HIP at a temperature of 930° C., a pressure of 130 MPa, and a holding time of 3 h to obtain a hot pressed green body;

[0065] Step 7, remove the jacket of the hot pressed green body in step 6 by machining to ensure that the large surface of the sheet is flat and has no protrusions, and the thickness of the hot pressed green body is 52 mm;

[0066] Step 8, the hot pressed green body obtained in step 7 is coated with a 0.5 mm molybdenum plate, placed in a muffle furnace, heated to a blanking temperature of 1350° C. in an air atmosphere, the holding time is 90 minutes, the single-pass deformation rate is 15-25%, and the green body needs to be returned to the furnace for heating and insulation before each rolling pass. The heating and insulation temperature before each rolling pass is reduced by 50° C. on the basis of the heating and insulation temperature before the previous rolling pass. The heating and insulation time before each rolling pass is 90 minutes, the rolling passes are 4 times, the final rolling temperature is 1100° C., and the size of the rolled piece is 20 mm×240 mm×2900 mm (thickness×width×length);

[0067] Step 9, removing the molybdenum plate from the rolled piece obtained in step 8, and machining to obtain a rolled piece with a size of 18 mm×230 mm×2750 mm (thickness×width×length);

[0068] Step 10, annealing the rolled piece in step 9 in an Ar atmosphere at a temperature of 1200°C for 60 minutes to obtain a uniform fine-grained plate with a grain size of 70 μm to 95 μm. Figure 1 , the grain size grade is 4.

[0069] The plate-shaped target material obtained in this embodiment has no cracks and the yield rate is 100%.

[0070] Embodiment 2: A molybdenum alloy target and a preparation method thereof, comprising the following steps:

[0071] Step 1, pure Mo powder with a purity of 3N5 and a particle size of 3.8 μm, Ni powder with a purity of 3N and a particle size of 2.4 μm, Ti powder with a purity of 3N and a particle size of 3.0 μm, tungsten powder with a purity of 3N5 and a particle size of 2.5 μm, ammonium rhenate with a purity of 4N and a particle size of 3.5 μm, according to the mass ratio of each element in the target material Mo:Ni:Ti:W:Re=68:15:10:5:2, 140 kg of raw materials are prepared, wherein rhenium is added as follows: firstly, the tungsten powder in the raw material is mixed with ammonium rhenate, and the mixture is reduced at 750°C for 4 hours in a hydrogen atmosphere to obtain a tungsten-rhenium alloy powder, and the reduced tungsten-rhenium alloy powder is added to the remaining raw material powder;

[0072] Step 2, the powder obtained in step 1 was placed in a ball mill with a ball-to-material ratio of 1:2, the air was evacuated to negative pressure, argon was filled to one atmosphere, and ball milling was performed for 16 hours at a ball mill speed of 200 r / min;

[0073] Step 3, placing the mixed powder obtained in step 2 into a stainless steel mold, performing cold isostatic pressing, with a pressing pressure of 200 MPa and a holding time of 8 minutes, to obtain a cold pressed green body;

[0074] Step 4, shaping the cold pressed blank so that the blank has regular and complete geometric dimensions;

[0075] Step 5: Place the shaped compact into the bag and evacuate the air to 10 -1 Pa, keep pumping for 4h, sealed;

[0076] Step 6, subjecting the package in step 5 to HIP at a temperature of 950° C., a pressure of 150 MPa, and a holding time of 4 hours to obtain a hot pressed green body;

[0077] Step 7, remove the jacket of the hot pressed green body in step 6 by machining, ensure that the large surface of the sheet is flat and has no protrusions, and the thickness of the hot pressed green body is 50 mm;

[0078] Step 8, the hot pressed green body obtained in step 7 is coated with a 1 mm molybdenum plate, placed in a muffle furnace, heated to a blanking temperature of 1350° C. in an air atmosphere, the holding time is 90 minutes, the single-pass deformation rate is 15-25%, and the green body needs to be returned to the furnace for heating and insulation before each rolling pass. The heating and insulation temperature before each rolling pass is reduced by 50° C. on the basis of the heating and insulation temperature before the previous rolling pass. The heating and insulation time before each rolling pass is 90 minutes, the rolling passes are 5 times, the final rolling temperature is 1050° C., and the size of the rolled piece is 18 mm×240 mm×2900 mm (thickness×width×length);

[0079] Step 9, removing the molybdenum plate from the rolled piece obtained in step 8, and machining to obtain a rolled piece with a size of 16 mm×230 mm×2750 mm (thickness×width×length);

[0080] Step 10, annealing the rolled piece in step 9 in an Ar atmosphere at a temperature of 1150° C. for 90 minutes to obtain a uniform fine-grained plate with a grain size of 65 μm to 90 μm and a grain size grade of 4.

[0081] The plate-shaped target material obtained in this embodiment has no cracks and the yield rate is 100%.

[0082] Embodiment 3: A molybdenum alloy target and a preparation method thereof, comprising the following steps:

[0083] Step 1, pure Mo powder with a purity of 3N5 and a particle size of 3.2 μm, Ni powder with a purity of 3N and a particle size of 3.5 μm, Ti powder with a purity of 3N and a particle size of 3.5 μm, tungsten powder with a purity of 3N5 and a particle size of 3.2 μm, ammonium rhenate with a purity of 4N and a particle size of 3.5 μm, according to the mass ratio of each element in the target material Mo:Ni:Ti:W:Re=60:15:10:10:5, 70 kg of raw materials are prepared, wherein rhenium is added as follows: firstly, the tungsten powder in the raw material is mixed with ammonium rhenate, and reduced at 800°C for 3h in a hydrogen atmosphere to obtain a tungsten-rhenium alloy powder, and the reduced tungsten-rhenium alloy powder is added to the remaining raw material powder;

[0084] Step 2, the powder obtained in step 1 is placed in a ball mill with a ball-to-material ratio of 1:1, the air is evacuated to negative pressure, argon is filled to one atmosphere, and ball milling is performed for 13 hours at a ball mill speed of 200 r / min;

[0085] Step 3, placing the mixed powder obtained in step 2 into a stainless steel mold, performing cold isostatic pressing, with a pressing pressure of 150 MPa and a holding time of 15 minutes, to obtain a cold pressed green body;

[0086] Step 4, shaping the cold pressed blank so that the blank has regular and complete geometric dimensions;

[0087] Step 5: Place the shaped compact into the bag and evacuate the air to 10 -1 Pa, keep pumping for 5h, sealed;

[0088] Step 6, subjecting the package in step 5 to HIP at a temperature of 980° C., a pressure of 140 MPa, and a holding time of 4 hours to obtain a hot pressed green body;

[0089] Step 7, remove the jacket of the hot pressed green body in step 6 by machining to ensure that the large surface of the sheet is flat and has no protrusions, and the thickness of the hot pressed green body is 45 mm;

[0090] Step 8, the hot pressed green body obtained in step 7 is coated with a 1 mm molybdenum plate, placed in a muffle furnace, heated to a blanking temperature of 1350° C. in an air atmosphere, the holding time is 90 minutes, the single pass deformation rate is 15-25%, and the green body needs to be returned to the furnace for heating and insulation before each rolling pass. The heating and insulation temperature before each rolling pass is reduced by 50° C. on the basis of the heating and insulation temperature before the previous rolling pass. The heating and insulation time before each rolling pass is 90 minutes, the rolling passes are 4 times, the final rolling temperature is 1100° C., and the size of the rolled piece is 20 mm×240 mm×1500 mm (thickness×width×length);

[0091] Step 9, removing the molybdenum plate from the rolled piece obtained in step 8, and machining to obtain a rolled piece with a size of 18 mm×230 mm×1350 mm (thickness×width×length);

[0092] Step 10, annealing the rolled piece in step 9 in an Ar atmosphere at an annealing temperature of 1200° C. for 90 minutes to obtain a uniform fine-grained plate with a grain size of 65 to 90 μm and a grain size grade of 4.

[0093] The plate-shaped target material obtained in this embodiment has no cracks and the yield rate is 100%.

[0094] Embodiment 4: A molybdenum alloy target and a preparation method thereof, comprising the following steps:

[0095] Step 1, pure Mo powder with a purity of 3N5 and a particle size of 3.8 μm, Ni powder with a purity of 3N and a particle size of 3.5 μm, Ti powder with a purity of 3N and a particle size of 3.2 μm, tungsten powder with a purity of 3N5 and a particle size of 2.5 μm, and rhenium powder with a purity of 4N and a particle size of 2.8 μm, according to the mass ratio of each element in the target material, Mo:Ni:Ti:W:Re=65:15:10:5:5, prepare 70 kg of raw materials;

[0096] Step 2, the powder obtained in step 1 is placed in a ball mill with a ball-to-material ratio of 1:1, the air is evacuated to negative pressure, argon is filled to one atmosphere, and ball milling is performed for 12 hours at a ball mill speed of 200 r / min;

[0097] Step 3, placing the mixed powder obtained in step 2 into a stainless steel mold, performing cold isostatic pressing, with a pressing pressure of 200 MPa and a holding time of 10 minutes, to obtain a cold pressed green body;

[0098] Step 4, shaping the cold pressed blank so that the blank has regular and complete geometric dimensions;

[0099] Step 5: Place the shaped compact into the bag and evacuate the air to 10 -1 Pa, keep pumping for 4h, sealed;

[0100] Step 6, subjecting the package in step 5 to HIP at a temperature of 940° C., a pressure of 170 MPa, and a holding time of 3 h to obtain a hot pressed green body;

[0101] Step 7, remove the jacket of the hot pressed green body in step 6 by machining, ensure that the large surface of the sheet is flat and has no protrusions, and the thickness of the hot pressed green body is 50 mm;

[0102] Step 8, the hot pressed green body obtained in step 7 is coated with a 0.5 mm molybdenum plate, placed in a muffle furnace, heated to a blanking temperature of 1350° C. in an air atmosphere, the holding time is 90 minutes, the single-pass deformation rate is 15-25%, and the green body needs to be returned to the furnace for heating and insulation before each rolling pass. The heating and insulation temperature before each rolling pass is reduced by 50° C. on the basis of the heating and insulation temperature before the previous rolling pass. The heating and insulation time before each rolling pass is 90 minutes, the rolling passes are 5 times, the final rolling temperature is 1050° C., and the size of the rolled piece is 22 mm×240 mm×1500 mm (thickness×width×length);

[0103] Step 9, removing the molybdenum plate from the rolled piece obtained in step 8, and machining to obtain a rolled piece with a size of 20 mm×230 mm×1350 mm;

[0104] Step 10, annealing the rolled piece in step 9 in an Ar atmosphere at a temperature of 1250° C. for 60 minutes to obtain a uniform fine-grained plate with a grain size of 60 μm to 85 μm and a grain size grade of 5.

[0105] The plate-shaped target material obtained in this embodiment has no cracks and the yield rate is 100%.

[0106] Embodiment 5: A molybdenum alloy target and a preparation method thereof, comprising the following steps:

[0107] Step 1, pure Mo powder with a purity of 3N5 and a particle size of 3.2μm, Ni powder with a purity of 3N and a particle size of 3.0μm, Ti powder with a purity of 3N and a particle size of 2.8μm, tungsten powder with a purity of 3N5 and a particle size of 3.0μm, rhenium powder with a purity of 4N and a particle size of 3.2μm, and the raw material of Cr is chromium powder, and according to the mass ratio of each element in the target material, Mo:Ni:Ti:W:Re:Cr=60:20:16:1:1:2, 140Kg of raw materials are prepared;

[0108] Step 2, the powder obtained in step 1 is placed in a ball mill with a ball-to-material ratio of 2:1, the air is evacuated to negative pressure, argon is filled to one atmosphere, and ball milling is performed for 10 hours at a ball mill speed of 200 r / min;

[0109] Step 3, placing the mixed powder obtained in step 2 into a stainless steel mold, performing cold isostatic pressing, with a pressing pressure of 150 MPa and a holding time of 10 minutes, to obtain a cold pressed green body;

[0110] Step 4, shaping the cold pressed blank so that the blank has regular and complete geometric dimensions;

[0111] Step 5: Place the shaped compact into the bag and evacuate the air to 10 -1 Pa, keep pumping for 4h, sealed;

[0112] Step 6, subjecting the package in step 5 to HIP at a temperature of 930° C., a pressure of 130 MPa, and a holding time of 3 h to obtain a hot pressed green body;

[0113] Step 7, remove the jacket of the hot pressed green body in step 6 by machining to ensure that the large surface of the sheet is flat and has no protrusions, and the thickness of the hot pressed green body is 52 mm;

[0114] Step 8, the hot pressed green body obtained in step 7 is coated with a 0.5 mm molybdenum plate, placed in a muffle furnace, heated to a blanking temperature of 1350° C. in an air atmosphere, the holding time is 90 minutes, the single-pass deformation rate is 15-25%, and the green body needs to be returned to the furnace for heating and insulation before each rolling pass. The heating and insulation temperature before each rolling pass is reduced by 50° C. on the basis of the heating and insulation temperature before the previous rolling pass. The heating and insulation time before each rolling pass is 90 minutes, the rolling passes are 4 times, the final rolling temperature is 1150° C., and the size of the rolled piece is 24 mm×240 mm×2900 mm (thickness×width×length);

[0115] Step 9, removing the molybdenum plate from the rolled piece obtained in step 8, and machining to obtain a rolled piece with a size of 22 mm×230 mm×2750 mm (thickness×width×length);

[0116] Step 10, annealing the rolled piece in step 9 in an Ar atmosphere at an annealing temperature of 1200° C. for 60 minutes to obtain a uniform fine-grained plate with a grain size of 60 μm to 90 μm and a grain size grade of 4 to 5.

[0117] The plate-shaped target material obtained in this embodiment has no cracks and the yield rate is 100%.

[0118] Comparative Example 1

[0119] In this comparative example, 140 kg of raw materials were prepared according to the mass ratio of the elements in the target material, Mo:Ni:Ti:W:Re=55:20:18:1:6, and the rest was the same as in Example 1.

[0120] The molybdenum alloy target prepared in Example 1 has a much higher cost, and the rhenium content is too high, which increases the difficulty of deformation, and cracks appear on the surface of the blank during the deformation process. At the same time, when the Re content is high, Re can form an alloy phase with other components, affecting the subsequent coating effect.

[0121] In this comparative example, a uniform fine-grained plate with a grain size of 70 to 100 μm and a grain size grade of 4 is obtained.

[0122] The plate-shaped target material obtained in this comparative example had cracks, and the yield rate was 55%.

[0123] Comparative Example 2

[0124] The same as Example 1, the only difference is that the annealing temperature of this comparative example is 1350°C.

[0125] The annealing temperature of this comparative example is too high, resulting in abnormal growth of some grains. The obtained plate-shaped target material has a large grain size, mixed crystals, and locally large grains. The grain size is 75μm to 130μm, and the grain size is level 3 to 4.

[0126] The plate-shaped target material obtained in this comparative example had cracks, and the yield rate was 90%.

[0127] Comparative Example 3

[0128] The same as Example 1, the only difference is that the deformation amount of a single pass in the rolling process of this comparative example is 30%.

[0129] During the rolling process of this comparative example, edge cracks occurred in the first pass and cracks occurred in the second pass, and the sheet could not be prepared.

[0130] Comparative Example 4

[0131] The same as Example 1, the only difference is that in the rolling process of this comparative example, the heating and insulation temperature of each pass is reduced by 80°C based on the previous heating and insulation temperature.

[0132] The grain size of the plate-shaped target material obtained in this comparative example is 60 μm to 120 μm, and the grain size in the same plate is level 3 to 5.

[0133] The plate-shaped target material obtained in this comparative example had cracks, and the yield rate was 60%.

[0134] In this comparative example, the temperature of each heating and insulation pass during hot rolling is reduced too much based on the previous heating and insulation temperature, which leads to increased grain resistance, increased risk of cracking of the rolled billet, and reduced hot rolling yield.

[0135] The present invention has been described in detail above. It will be apparent to those skilled in the art that the present invention may be implemented in a wide range under equivalent parameters, proportions and conditions without departing from the spirit and scope of the present invention and without unnecessary experimentation. Although the present invention provides specific embodiments, it should be understood that further improvements may be made to the present invention. In short, according to the principles of the present invention, this application is intended to include any changes, uses or improvements to the present invention, including changes made by conventional techniques known in the art that are outside the scope of the disclosure in this application. Some of the basic features may be applied within the scope of the following claims.

Claims

1. A method for preparing a molybdenum alloy target, comprising the following steps: (1) preparing raw materials: weighing raw materials according to the mass ratio of each element of the target material and mixing them to obtain a mixed powder; wherein: The target material comprises the following components in mass percentage: Ni: 10% to 30%, Ti: 5% to 25%, W: 1% to 20% and Re: 0.5% to 5%, the remainder being Mo and unavoidable impurities, and the mass percentage of Mo is ≥50%; (2) Cold isostatic pressing: the mixed powder in step (1) is loaded into a mold and subjected to cold isostatic pressing to obtain a cold pressed green body; (3) Hot isostatic pressing: The cold pressed green body is placed in a sheath and hot isostatically pressed to obtain a hot pressed green body with a sheath; (4) hot rolling: after removing the sheath of the hot pressed billet, the hot pressed billet is covered with a metal plate, and then hot rolled, and the metal plate is removed after hot rolling to obtain a rolled product; wherein the heating and insulation temperature before each rolling pass is reduced by more than 0°C and less than or equal to 50°C based on the heating and insulation temperature before the previous rolling pass; the blanking temperature of the hot rolling process is 1000°C to 1350°C, and the final rolling temperature is 900-1100°C; the deformation of a single rolling pass is 15% to 25%, and the total deformation of the hot rolling process is 40% to 80%; (5) Annealing: Annealing the rolled piece to obtain the molybdenum alloy target.

2. The method for preparing a molybdenum alloy target according to claim 1, wherein: In terms of mass percentage, the target material further includes 0.01%-15% of M, wherein M is at least one of Cr, Zr, Ta, and Nb, and the M is used to replace part of Ti.

3. The method for preparing a molybdenum alloy target according to claim 1, characterized in that: In terms of mass percentage, the target material comprises Ni: 15% to 25%, Ti: 10% to 20%, W: 1% to 10%, Re: 1% to 5% and M: 0% to 5%, and the remainder is Mo and unavoidable impurities, and the mass percentage of Mo is ≥50%.

4. The method for preparing a molybdenum alloy target according to claim 1, characterized in that: The raw material of the component Mo in the target material is molybdenum powder with a purity of ≥3N5, and its Fisher particle size range is 2.5μm to 4μm; the raw material of the component Ni in the target material is nickel powder with a purity of ≥3N, and its Fisher particle size range is 2μm to 3μm; the raw material of the component Ti in the target material is titanium powder with a purity of ≥3N, and its Fisher particle size range is 2μm to 4μm; the raw material of the component W in the target material is tungsten powder with a purity of ≥3N5, and its Fisher particle size is 2.0μm to 3.0μm; the raw material of the component Re in the target material is rhenium powder or ammonium rhenate, the purity of the rhenium powder is ≥4N, and the Fisher particle size is 2μm to 4μm, the purity of the ammonium rhenate is ≥4N, and the particle size is 150 to 350 meshes.

5. The method for preparing a molybdenum alloy target according to claim 1, characterized in that: The rhenium element in the molybdenum alloy target is added in the form of tungsten-rhenium alloy powder; the tungsten-rhenium alloy powder is obtained by mixing tungsten powder in the raw material with ammonium rhenate and then subjecting it to reduction treatment.

6. The method for preparing a molybdenum alloy target according to claim 5, characterized in that: The mass ratio of tungsten to rhenium in the tungsten-rhenium alloy powder is 95:5 to 50:

50.

7. The method for preparing a molybdenum alloy target according to claim 5, characterized in that: The reduction treatment is carried out in a hydrogen atmosphere, the temperature of the reduction treatment is 500° C. to 900° C., and the time of the reduction treatment is 2 h to 8 h.

8. The method for preparing a molybdenum alloy target according to claim 1, characterized in that: In step (1), the mixing method is ball milling, and the ball-to-material ratio of the ball milling is (0.5-2):

1.

9. The method for preparing a molybdenum alloy target according to claim 8, characterized in that: The ball milling time is 10 hours to 16 hours; the ball milling is carried out in an inert gas; and the rotation speed of the ball mill is 50 to 300 r / min.

10. The method for preparing a molybdenum alloy target according to claim 1, characterized in that: In step (2), the pressure of the cold isostatic pressing is 150 to 220 MPa; and the holding time of the cold isostatic pressing is 8 to 15 minutes.

11. The method for preparing a molybdenum alloy target according to claim 1, characterized in that: In step (3), the holding temperature of the hot isostatic pressing is 900° C. to 980° C.; the pressure of the hot isostatic pressing is 100 MPa to 170 MPa; and the holding time of the hot isostatic pressing is 2 h to 5 h.

12. The method for preparing a molybdenum alloy target according to claim 1, characterized in that: In step (3), the cold-pressed green body is first shaped, and then placed into a package for vacuum evacuation and sealing; the green body thickness of the hot-pressed green body is 40 mm to 60 mm.

13. The method for preparing a molybdenum alloy target according to claim 1, characterized in that: In the hot rolling process, heating and heat preservation are performed before each rolling process, the heat preservation temperature is 1000° C. to 1300° C., and the heat preservation time is 30 minutes to 120 minutes.

14. The method for preparing a molybdenum alloy target according to claim 1, characterized in that: The hot rolling process is performed in air or argon atmosphere.

15. The method for preparing a molybdenum alloy target according to claim 1, characterized in that: In step (4), the thickness of the metal plate is 0.5 to 1 mm.

16. The method for preparing a molybdenum alloy target according to claim 1, characterized in that: The rolled piece also includes rough processing after the metal plate is removed; the thickness of the rolled piece is 6mm to 24mm; the metal plate is a molybdenum plate, a stainless steel plate or a nickel plate.

17. The method for preparing a molybdenum alloy target according to claim 1, characterized in that: In step (5), the annealing treatment is carried out in an argon atmosphere; the temperature of the annealing treatment is 950° C. to 1250° C., and the holding time of the annealing treatment is 60 minutes to 120 minutes.

18. The method for preparing a molybdenum alloy target according to claim 1, characterized in that: The grain size of the molybdenum alloy target prepared in step (5) is ≤100 μm; the grain size of the molybdenum alloy target prepared in step (5) is grade 4 to 5; in the same molybdenum alloy target prepared in step (5), the grain size difference is less than or equal to 1; the molybdenum alloy target prepared in step (5) is a plate-type target.

19. A molybdenum alloy target prepared by the preparation method according to any one of claims 1 to 18.

20. Use of the molybdenum alloy target material according to claim 19, wherein the molybdenum alloy target material is attached to a main conductive layer of a laminated wiring film for electronic components by sputtering to form a metal coating layer.

21. The use according to claim 20, characterized in that The electronic component is a display, a semiconductor device or a thin-film solar cell.

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