Preparation method of molybdenum-titanium alloy target blank

Abstract

The invention provides a molybdenum-titanium alloy target blank preparation method, which comprises: (1) mixing molybdenum powder, titanium powder and carbon powder, and sequentially carrying out first ball milling and second ball milling to obtain mixed powder; and (2) the mixed powder obtained in the step (1) is subjected to cold isostatic pressing and vacuum sintering in sequence, and the molybdenum-titanium alloy target blank is obtained. The molybdenum-titanium alloy target blank which is low in oxygen, high in compactness and uniform in element distribution is prepared by adding a certain proportion of carbon powder, combining two times of high-energy ball milling and then sequentially performing cold isostatic pressing and vacuum sintering.

Description

Technical Field

[0001] The invention belongs to the technical field of target blank preparation, and relates to a method for preparing a molybdenum-titanium alloy target blank. Background Art

[0002] Thin films sputtered by molybdenum targets are widely used in the electronic information industry due to their good conductivity and extremely stable chemical properties. They are especially widely used in the display field and are usually used as diffusion barriers in wiring. However, pure molybdenum target films are slightly insufficient in adhesion. Adding a certain amount of titanium to the molybdenum target can effectively improve this defect, making its various properties such as adhesion more balanced.

[0003] Molybdenum-titanium alloys are mostly prepared by melt casting and powder metallurgy. Molybdenum-titanium alloys prepared by powder metallurgy have become the mainstream preparation method because of their small and uniform grain size and good uniformity of element distribution. The main process of preparing molybdenum-titanium alloys by powder metallurgy is: uniform powder mixing, pressing and sintering.

[0004] Sintering is usually divided into hot isostatic pressing, hot pressing and vacuum sintering. Due to its high pressure characteristics, hot isostatic pressing can sinter at a lower temperature to obtain alloys with higher density and finer grain size, but its equipment is expensive and the manufacturing cost is high. Hot pressing sintering can also obtain higher density alloys. CN111304607A discloses a method for manufacturing a molybdenum-titanium alloy target, which includes: mixing molybdenum powder and titanium powder under the protection of an inert gas; cold isostatic pressing the mixed powder; pressurizing and sintering the formed molybdenum-titanium mixed powder to obtain a molybdenum-titanium ingot, but its size is usually affected. Vacuum sintering equipment is simple and low in cost, and has been widely used, but when preparing alloys with large melting point differences, such as molybdenum and titanium with large melting point differences and molybdenum melting point as high as 2620°C, it is usually difficult to meet the requirements of high density and grain size when using vacuum sintering, and has certain defects.

[0005] In addition, due to the strong oxygen affinity of titanium, it is difficult to prepare low-oxygen titanium powder, resulting in a high oxygen content in the sintered molybdenum-titanium alloy. The performance of the sputtered film will also be restricted to a certain extent. Therefore, the oxygen content of the molybdenum-titanium target needs to be optimized.

[0006] In summary, providing a method for preparing a molybdenum-titanium alloy target blank with low oxygen, high density and uniform element distribution is an issue that needs to be urgently solved by those skilled in the art. Summary of the invention

[0007] The object of the present invention is to provide a method for preparing a molybdenum-titanium alloy target blank, by adding a certain proportion of carbon powder combined with two high-energy ball milling, followed by cold isostatic pressing and vacuum sintering in sequence, to obtain a molybdenum-titanium alloy target blank with low oxygen, high density and uniform element distribution.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] The present invention provides a method for preparing a molybdenum-titanium alloy target blank, the preparation method comprising the following steps:

[0010] (1) mixing molybdenum powder, titanium powder and carbon powder, and sequentially performing a first ball milling and a second ball milling to obtain a mixed powder;

[0011] (2) The mixed powder of step (1) is subjected to cold isostatic pressing and vacuum sintering in sequence to obtain the molybdenum-titanium alloy target blank.

[0012] In the present invention, the atomic ratio of molybdenum to titanium in the molybdenum-titanium alloy target blank is 1:1.

[0013] The preparation method of the molybdenum-titanium alloy target blank provided by the present invention obtains MoTi alloy powder with uniform element distribution and high specific surface energy by adding a certain proportion of carbon powder and combining with two high-energy ball millings, and has higher density at the same vacuum sintering temperature, and then sequentially performs cold isostatic pressing and vacuum sintering. During vacuum sintering, oxygen combines with carbon to volatilize, so as to prepare a low-oxygen, high-density and uniformly distributed molybdenum-titanium alloy target blank.

[0014] As a preferred technical solution of the present invention, the average particle size of the molybdenum powder in step (1) is 2-6 μm, for example, it can be 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm or 5.5 μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] Preferably, the oxygen content of the molybdenum powder in step (1) is 300-2000ppm, for example, it can be 400ppm, 500ppm, 600ppm, 700ppm, 800ppm, 900ppm, 1000ppm, 1200ppm, 1500ppm, 1600ppm or 1800ppm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] In the present invention, the oxygen content is the mass content of oxygen.

[0017] Preferably, the average particle size of the titanium powder in step (1) is 30-50 μm, for example, it can be 32 μm, 34 μm, 35 μm, 38 μm, 40 μm, 42 μm, 44 μm, 45 μm or 48 μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] Preferably, the oxygen content of the titanium powder in step (1) is ≥3000ppm, for example, it can be 3100ppm, 3200ppm, 3300ppm, 3400ppm, 3500ppm, 3600ppm, 3800ppm, 4000ppm or 4200ppm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] As a preferred technical solution of the present invention, the average particle size of the carbon powder in step (1) is 1-4 μm, for example, it can be 1 μm, 1.2 μm, 1.5 μm, 1.8 μm, 2 μm, 2.2 μm, 2.5 μm, 2.8 μm, 3 μm, 3.2 μm, 3.5 μm or 3.8 μm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0020] It is worth noting that, in the present invention, a trace amount of carbon powder is added, and the carbon combines with oxygen in the alloy powder during vacuum sintering and then volatilizes, thereby reducing the oxygen content in the alloy.

[0021] In the present invention, the oxygen content in the carbon powder in step (1) is less than 0.5% of the mass of the carbon powder, and relative to the amount of carbon powder added, and relative to the oxygen content of molybdenum powder and titanium powder, the oxygen content in the carbon powder can be ignored.

[0022] As a preferred technical solution of the present invention, the mass content of molybdenum powder in the mixed powder obtained in step (1) is 66.7-95wt%, for example, it can be 68wt%, 70wt%, 72wt%, 75wt%, 78wt%, 80wt%, 82wt%, 85wt%, 88wt%, 90wt%, 92wt% or 94wt%, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0023] Preferably, the mass content of titanium powder in the mixed powder obtained in step (1) is 5-33.3wt%, for example, it can be 8wt%, 10wt%, 12wt%, 15wt%, 18wt%, 20wt%, 22wt%, 25wt%, 28wt%, 30wt%, 32wt% or 33wt%, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0024] Preferably, the amount of carbon powder added in step (1) is 55-70% of the oxygen content in the obtained mixed powder, for example, it can be 56%, 58%, 60%, 62%, 65%, 66% or 68%, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0025] As a preferred technical solution of the present invention, the medium for the first ball milling in step (1) includes molybdenum balls.

[0026] Preferably, the ball-to-material ratio of the first ball milling in step (1) is 1:(4-7), for example, it can be 1:4.5, 1:5, 1:5.5, 1:6 or 1:6.5, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0027] Preferably, the rotation speed of the first ball mill in step (1) is 300-400 r / min, for example, it can be 310 r / min, 320 r / min, 330 r / min, 340 r / min, 350 r / min, 360 r / min, 370 r / min, 380 r / min or 390 r / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0028] Preferably, the time for the first ball milling in step (1) is 6-8 h, for example, 6.2 h, 6.5 h, 6.8 h, 7 h, 7.2 h, 7.5 h or 7.8 h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0029] Preferably, the first ball milling in step (1) is carried out in a protective atmosphere.

[0030] In the present invention, the protective atmosphere includes argon; and the first ball milling is performed under a slight positive pressure.

[0031] As a preferred technical solution of the present invention, the medium for the second ball milling in step (1) includes molybdenum balls.

[0032] Preferably, the ball-to-material ratio of the second ball mill in step (1) is 1:(4-7), for example, it can be 1:4.5, 1:5, 1:5.5, 1:6 or 1:6.5, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] Preferably, the rotation speed of the second ball mill in step (1) is 450-550 r / min, for example, it can be 460 r / min, 470 r / min, 480 r / min, 490 r / min, 500 r / min, 510 r / min, 520 r / min, 530 r / min or 540 r / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0034] In the present invention, by controlling the rotation speed parameter range of the first ball mill and the second ball mill, high-energy ball milling is used to not only ensure a more uniform distribution of elements, but also improve the specific surface energy and activation energy of the alloy powder, and the density of the alloy is higher at the same vacuum sintering temperature, while shortening the ball milling time.

[0035] Preferably, the time for the second ball milling in step (1) is 8-10 h, for example, 8.2 h, 8.5 h, 8.8 h, 9 h, 9.2 h, 9.5 h or 9.8 h, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0036] Preferably, the second ball milling in step (1) is carried out in a protective atmosphere.

[0037] In the present invention, the second ball milling is performed under a slight positive pressure.

[0038] As a preferred technical solution of the present invention, the pressure of the cold isostatic pressing in step (2) is 200-300 MPa, for example, it can be 210 MPa, 220 MPa, 230 MPa, 240 MPa, 250 MPa, 260 MPa, 270 MPa, 280 MPa or 290 MPa, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0039] Preferably, the holding time of the cold isostatic pressing in step (2) is 5-40 min, for example, it can be 10 min, 15 min, 20 min, 25 min, 30 min or 35 min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0040] In the present invention, the cold isostatic pressing process also includes mold installation, and then a compaction tool is used to perform mold installation and compaction to ensure that the thickness in each direction is within the same horizontal range; the cold isostatic pressing process also includes demolding to obtain a molybdenum-titanium alloy green body.

[0041] As a preferred technical solution of the present invention, the vacuum degree of the vacuum sintering in step (2) is less than 10 -3 Pa, for example, can be 9×10 -4 Pa, 7×10 -4 Pa, 5×10 -4 Pa, 3×10 -4 Pa or 10 -4 Pa, etc., but not limited to the listed values, other values ​​not listed within the numerical range are also applicable.

[0042] Preferably, the vacuum sintering in step (2) includes a first heating, a second heating and furnace cooling performed sequentially.

[0043] Preferably, the end point of the first heating is 700-1000°C, for example, it can be 720°C, 750°C, 780°C, 800°C, 820°C, 850°C, 870°C, 900°C, 920°C, 950°C or 980°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0044] Preferably, the first heating holding time is 1-3h, for example, it can be 1.2h, 1.5h, 1.8h, 2h, 2.2h, 2.5h or 2.8h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0045] In the present invention, by controlling the process parameters of the first heating, it is beneficial to volatilize the volatile substances in the molybdenum-titanium alloy green body and reduce the impurity content in the target blank after vacuum sintering.

[0046] Preferably, the end point of the second heating is 1400-1600°C, for example, it can be 1420°C, 1450°C, 1480°C, 1500°C, 1520°C, 1550°C or 1580°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0047] Preferably, the second heating holding time is 2-6h, for example, it can be 2.5h, 3h, 3.5h, 4h, 4.5h, 5h or 5.5h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0048] In the present invention, by controlling the process parameters of the second heating, it is beneficial to improve the densification degree of the molybdenum-titanium alloy target blank and volatilize the carbon and oxygen to reduce the oxygen content.

[0049] As a preferred technical solution of the present invention, the oxygen content of the molybdenum-titanium alloy target blank in step (2) is less than 800 ppm, for example, it can be 700 ppm, 600 ppm, 500 ppm, 400 ppm, 300 ppm, 200 ppm or 100 ppm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, preferably less than 300 ppm.

[0050] Preferably, the density of the molybdenum-titanium alloy target blank in step (2) is ≥98%.

[0051] As a preferred technical solution of the present invention, the preparation method comprises the following steps:

[0052] (1) mixing molybdenum powder with an average particle size of 2-6 μm and an oxygen content of 300-2000 ppm, titanium powder with an average particle size of 30-50 μm and an oxygen content of ≥3000 ppm, and carbon powder with an average particle size of 1-4 μm, and then performing a first ball milling for 6-8 h in a protective atmosphere at a ball-to-material ratio of 1:(4-7) and a rotation speed of 300-400 r / min, and then performing a second ball milling for 8-10 h in a protective atmosphere at a ball-to-material ratio of 1:(4-7) and a rotation speed of 450-550 r / min to obtain a mixed powder;

[0053] The mass content of molybdenum powder in the obtained mixed powder is 66.7-95wt%; the mass content of titanium powder in the obtained mixed powder is 5-33.3wt%; the amount of carbon powder added is 55-70% of the oxygen content in the obtained mixed powder;

[0054] (2) The mixed powder of step (1) is subjected to cold isostatic pressing at a pressure of 200-300 MPa and maintained at the pressure for 5-40 min, and then the mixture is placed in a vacuum of less than 10 -3 Vacuum sintering is performed under 2000 ppm Pa to obtain a molybdenum-titanium alloy target blank with an oxygen content of less than 800 ppm and a density of ≥ 98%;

[0055] The vacuum sintering includes a first heating, a second heating and furnace cooling performed sequentially;

[0056] The first heating end point is 700-1000° C. and the holding time is 1-3 hours;

[0057] The end point of the second heating is 1400-1600° C. and the insulation time is 2-6 hours.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] The preparation method of the molybdenum-titanium alloy target blank provided by the present invention obtains MoTi alloy powder with uniform element distribution and high specific surface energy by adding a certain proportion of carbon powder and combining with two high-energy ball millings, and has higher density at the same vacuum sintering temperature, and then sequentially performs cold isostatic pressing and vacuum sintering. During vacuum sintering, oxygen combines with carbon to volatilize, thereby reducing the oxygen content in the molybdenum-titanium alloy. At the same time, with reasonable process parameters, a low-oxygen, high-density and uniformly distributed molybdenum-titanium alloy target blank can be obtained. DETAILED DESCRIPTION

[0060] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0061] In the following embodiments and comparative examples, the atomic ratio of molybdenum to titanium in the molybdenum-titanium alloy target blank is 1:1; the oxygen content refers to the mass content of the oxygen element; and the amount of carbon powder added is determined based on the oxygen content in the obtained mixed powder.

[0062] Example 1

[0063] This embodiment provides a method for preparing a molybdenum-titanium alloy target blank, and the preparation method comprises the following steps:

[0064] (1) Molybdenum powder with a purity of 3N, an average particle size of 4 μm, and an oxygen content of 600 ppm, titanium powder with a purity of 3N, an average particle size of 40 μm, and an oxygen content of 3000 ppm, and carbon powder with an average particle size of 2 μm are mixed, and then the mixture is first ball-milled for 7 h in a slightly positive pressure argon gas, with a ball-to-material ratio of 1:5, a ball-milling medium of molybdenum balls, and a rotation speed of 350 r / min, and then second ball-milled for 9 h in a slightly positive pressure argon gas, with a ball-to-material ratio of 1:5, a ball-milling medium of molybdenum balls, and a rotation speed of 500 r / min, to obtain a mixed powder;

[0065] The mass content of molybdenum powder in the obtained mixed powder is 66.7wt%; the mass content of titanium powder in the obtained mixed powder is 33.3wt%; the added amount of the carbon powder is 840ppm;

[0066] (2) The mixed powder of step (1) is placed in a cold isostatic pressing mold, and then compacted using a compaction tool, cold isostatically pressed at a pressure of 250 MPa and maintained at the pressure for 20 min. After demolding, the mixture is placed in a vacuum of 10 -4 Vacuum sintering is performed under Pa, and finally machining is performed to obtain a molybdenum-titanium alloy target blank;

[0067] The vacuum sintering includes a first heating, a second heating and furnace cooling performed sequentially;

[0068] The first heating end point is 850° C. and the holding time is 2 h;

[0069] The end point of the second heating is 1400° C. and the holding time is 4 hours.

[0070] Example 2

[0071] This embodiment provides a method for preparing a molybdenum-titanium alloy target blank, and the preparation method comprises the following steps:

[0072] (1) Molybdenum powder with a purity of 3N, an average particle size of 2 μm, and an oxygen content of 600 ppm, titanium powder with a purity of 3N, an average particle size of 32 μm, and an oxygen content of 3300 ppm, and carbon powder with an average particle size of 1 μm are mixed, and then the mixture is first ball-milled for 8 h in a slightly positive pressure argon gas at a ball-to-material ratio of 1:5, a ball-milling medium of molybdenum balls, and a rotation speed of 300 r / min, and then second ball-milled for 10 h in a slightly positive pressure argon gas at a ball-to-material ratio of 1:5, a ball-milling medium of molybdenum balls, and a rotation speed of 450 r / min to obtain a mixed powder;

[0073] The mass content of molybdenum powder in the obtained mixed powder is 66.7wt%; the mass content of titanium powder in the obtained mixed powder is 33.3wt%; the added amount of the carbon powder is 900ppm;

[0074] (2) The mixed powder of step (1) is placed in a cold isostatic pressing mold, and then compacted using a compaction tool, cold isostatically pressed at a pressure of 200 MPa and maintained at the pressure for 35 min. After demolding, the mixed powder is placed in a vacuum of 3×10 -4 Vacuum sintering is performed under Pa, and finally machining is performed to obtain a molybdenum-titanium alloy target blank;

[0075] The vacuum sintering includes a first heating, a second heating and furnace cooling performed sequentially;

[0076] The first heating end point is 700°C and the holding time is 2.5h;

[0077] The end point of the second heating is 1500° C. and the holding time is 5 hours.

[0078] Example 3

[0079] This embodiment provides a method for preparing a molybdenum-titanium alloy target blank, and the preparation method comprises the following steps:

[0080] (1) Molybdenum powder with a purity of 3N, an average particle size of 6 μm, and an oxygen content of 1800 ppm, titanium powder with a purity of 3N, an average particle size of 45 μm, and an oxygen content of 3900 ppm, and carbon powder with an average particle size of 1 μm are mixed, and then the mixture is first ball-milled for 6 h in a slightly positive pressure argon gas, with a ball-to-material ratio of 1:5, a ball-milling medium of molybdenum balls, and a rotation speed of 400 r / min, and then second ball-milled for 8 h in a slightly positive pressure argon gas, with a ball-to-material ratio of 1:5, a ball-milling medium of molybdenum balls, and a rotation speed of 550 r / min, to obtain a mixed powder;

[0081] The mass content of molybdenum powder in the obtained mixed powder is 66.7wt%; the mass content of titanium powder in the obtained mixed powder is 33.3wt%; the added amount of the carbon powder is 1500ppm;

[0082] (2) The mixed powder of step (1) is placed in a cold isostatic pressing mold, and then compacted using a compaction tool, cold isostatically pressed at a pressure of 300 MPa and maintained at the pressure for 10 min. After demolding, the mixed powder is placed in a vacuum of 5×10 -4 Vacuum sintering is performed under Pa, and finally machining is performed to obtain a molybdenum-titanium alloy target blank;

[0083] The vacuum sintering includes a first heating, a second heating and furnace cooling performed sequentially;

[0084] The first heating end point is 1000° C. and the holding time is 1.5 h;

[0085] The end point of the second heating is 1600° C. and the holding time is 2 h.

[0086] Example 4

[0087] This embodiment provides a method for preparing a molybdenum-titanium alloy target blank. Except that the amount of carbon powder added in step (1) is adjusted to 400 ppm, other conditions are the same as those in Example 1.

[0088] Example 5

[0089] This embodiment provides a method for preparing a molybdenum-titanium alloy target blank. Except that the amount of carbon powder added in step (1) is adjusted to 2000 ppm, other conditions are the same as those in Example 1.

[0090] Example 6

[0091] This embodiment provides a method for preparing a molybdenum-titanium alloy target blank. Except that the rotation speeds of the first ball mill and the second ball mill in step (1) are both adjusted to 200 r / min, other conditions are the same as those in Example 1.

[0092] Example 7

[0093] This embodiment provides a method for preparing a molybdenum-titanium alloy target blank. Except that the rotation speed of the second ball mill in step (1) is adjusted to 350 r / min, other conditions are the same as those in Example 1.

[0094] Example 8

[0095] This embodiment provides a method for preparing a molybdenum-titanium alloy target blank. Except that the end point of the first heating in step (2) is adjusted to 500° C., other conditions are the same as those in Embodiment 1.

[0096] Example 9

[0097] This embodiment provides a method for preparing a molybdenum-titanium alloy target blank. Except that the end point of the second heating in step (2) is adjusted to 1200° C., other conditions are the same as those in Embodiment 1.

[0098] Example 10

[0099] This embodiment provides a method for preparing a molybdenum-titanium alloy target blank. Except that the end point of the second heating in step (2) is adjusted to 1800° C., other conditions are the same as those in Embodiment 1.

[0100] Embodiment 11

[0101] This embodiment provides a method for preparing a molybdenum-titanium alloy target blank. Except that the first temperature rise is not performed in step (2) of vacuum sintering, other conditions are the same as those in Example 1.

[0102] Example 12

[0103] This embodiment provides a method for preparing a molybdenum-titanium alloy target blank. Except that the vacuum sintering in step (2) is not subjected to the second heating, other conditions are the same as those in Embodiment 1.

[0104] Comparative Example 1

[0105] This comparative example provides a method for preparing a molybdenum-titanium alloy target blank. Except that no carbon powder is added, other conditions are the same as those in Example 1.

[0106] Comparative Example 2

[0107] This comparative example provides a method for preparing a molybdenum-titanium alloy target blank. Except that the second ball milling is not performed, other conditions are the same as those in Example 1.

[0108] Performance Testing

[0109] The actual density of the molybdenum-titanium alloy target blanks obtained in the above embodiments and comparative examples was measured according to GB / T3850-2015 "Density Measurement Method for Dense Sintered Metal Materials and Cemented Carbides", and the theoretical density was calculated according to the theoretical formula. According to the calculation formula: density = actual density / theoretical density × 100%, the results are shown in Table 1.

[0110] The oxygen content in the molybdenum-titanium alloy target blanks obtained in the above examples and comparative examples was measured using a LECO oxygen, nitrogen and hydrogen analyzer. The results are shown in Table 1.

[0111] Table 1

[0112] Density(%) Oxygen content (ppm) Example 1 98.42 282 Example 2 98.59 276 Example 3 98.66 263 Example 4 98.32 823 Example 5 98.39 279 Example 6 95.37 301 Example 7 96.21 289 Example 8 98.10 650 Example 9 95.20 770 Example 10 98.43 289 Embodiment 11 97.78 870 Example 12 95.24 915 Comparative Example 1 96.85 1120 Comparative Example 2 94.21 326

[0113] From Table 1, we can see that:

[0114] (1) The preparation method of the molybdenum-titanium alloy target blank provided in Examples 1-3 of the present invention can prepare a molybdenum-titanium alloy target blank with low oxygen, high density and uniform element distribution by adding a certain proportion of carbon powder combined with two high-energy ball millings, followed by cold isostatic pressing and vacuum sintering in sequence;

[0115] (2) It can be seen from the comparison between Example 1 and Examples 4-5 that when the amount of carbon powder added is small, the oxygen in the molybdenum powder and the titanium powder cannot be fully removed, resulting in a high oxygen content in the obtained molybdenum-titanium alloy target blank; when the amount of carbon powder added is large, the carbon content in the obtained molybdenum-titanium alloy target blank is high, which affects the sputtering performance;

[0116] (3) From the comparison between Example 1 and Examples 6-7, it can be seen that when the first ball milling and / or the second ball milling is low-energy ball milling, it is not conducive to uniform mixing of the raw materials within the same ball milling time, which reduces the specific surface energy of the molybdenum-titanium alloy powder and leads to a decrease in the density of the obtained molybdenum-titanium alloy target blank;

[0117] (4) It can be seen from the comparison between Example 1 and Examples 8 and 11 that when the end temperature of the first heating is low or the first heating is not performed, it is not conducive to the volatilization of volatile substances in the molybdenum-titanium green body, resulting in a higher impurity content in the obtained molybdenum-titanium alloy target blank;

[0118] (5) By comparing Example 1 with Examples 9-10 and 12, it can be seen that when the end temperature of the second heating is low or the second heating is not performed, the density of the molybdenum-titanium alloy target blank decreases, and it is not conducive to the full combination and volatilization of carbon and oxygen, resulting in a higher oxygen content in the obtained molybdenum-titanium alloy target blank; when the end temperature of the second heating is high, although the density and oxygen content of the obtained target blank do not change significantly, the composition segregation of the obtained molybdenum-titanium alloy target blank is more serious, and the molybdenum-titanium alloy target blank still has the risk of cracking during the processing;

[0119] (6) By comparing Example 1 with Comparative Example 1, it can be seen that when no carbon powder is added, the oxygen in the molybdenum powder and the titanium powder cannot be completely removed, resulting in a higher oxygen content and a lower density of the obtained molybdenum-titanium alloy target blank;

[0120] (7) From the comparison between Example 1 and Comparative Example 2, it can be seen that when the second ball milling is not performed, it is not conducive to the uniform mixing of the raw materials, which reduces the specific surface energy of the molybdenum-titanium alloy powder, resulting in a decrease in the density of the obtained molybdenum-titanium alloy target blank and a slight increase in the oxygen content.

[0121] The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed structural features, that is, it does not mean that the present invention must rely on the above-mentioned detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a molybdenum-titanium alloy target blank, characterized in that: The preparation method comprises the following steps: (1) mixing molybdenum powder, titanium powder and carbon powder, and sequentially performing a first ball milling and a second ball milling to obtain a mixed powder; (2) The mixed powder of step (1) is subjected to cold isostatic pressing and vacuum sintering in sequence to obtain the molybdenum-titanium alloy target blank.

2. The preparation method according to claim 1, characterized in that: The average particle size of the molybdenum powder in step (1) is 2-6 μm; Preferably, the oxygen content of the molybdenum powder in step (1) is 300-2000 ppm.

3. The preparation method according to claim 1 or 2, characterized in that: The average particle size of the titanium powder in step (1) is 30-50 μm; Preferably, the oxygen content of the titanium powder in step (1) is ≥3000 ppm; Preferably, the average particle size of the carbon powder in step (1) is 1-4 μm.

4. The preparation method according to any one of claims 1 to 3, characterized in that The mass content of molybdenum powder in the mixed powder obtained in step (1) is 66.7-95wt%; Preferably, the mass content of titanium powder in the mixed powder obtained in step (1) is 5-33.3wt%; Preferably, the amount of carbon powder added in step (1) is 55-70% of the oxygen content in the obtained mixed powder.

5. The preparation method according to any one of claims 1 to 4, characterized in that: Step (1) The first ball milling medium includes molybdenum balls; Preferably, the ratio of balls to materials in the first ball milling in step (1) is 1:(4-7); Preferably, the rotation speed of the first ball mill in step (1) is 300-400 r / min; Preferably, the first ball milling time in step (1) is 6-8 hours; Preferably, the first ball milling in step (1) is carried out in a protective atmosphere.

6. The preparation method according to any one of claims 1 to 5, characterized in that: Step (1) The medium of the second ball milling comprises molybdenum balls; Preferably, the ratio of balls to materials in the second ball milling in step (1) is 1:(4-7); Preferably, the rotation speed of the second ball mill in step (1) is 450-550 r / min; Preferably, the second ball milling time in step (1) is 8-10 hours; Preferably, the second ball milling in step (1) is carried out in a protective atmosphere.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The cold isostatic pressing pressure in step (2) is 200-300 MPa; Preferably, the holding time of the cold isostatic pressing in step (2) is 5-40 minutes.

8. The preparation method according to any one of claims 1 to 7, characterized in that: The vacuum degree of the vacuum sintering in step (2) is less than 10 -3 Pa; Preferably, the vacuum sintering in step (2) comprises a first heating, a second heating and furnace cooling in sequence; Preferably, the end point of the first heating is 700-1000°C; Preferably, the first heating holding time is 1-3h; Preferably, the end point of the second heating is 1400-1600°C; Preferably, the second heating holding time is 2-6 hours.

9. The preparation method according to any one of claims 1 to 8, characterized in that: The oxygen content of the molybdenum-titanium alloy target blank in step (2) is less than 800 ppm, preferably less than 300 ppm; Preferably, the density of the molybdenum-titanium alloy target blank in step (2) is ≥98%.

10. The preparation method according to any one of claims 1 to 9, characterized in that: The preparation method comprises the following steps: (1) mixing molybdenum powder with an average particle size of 2-6 μm and an oxygen content of 300-2000 ppm, titanium powder with an average particle size of 30-50 μm and an oxygen content of ≥3000 ppm, and carbon powder with an average particle size of 1-4 μm, and then performing a first ball milling for 6-8 h in a protective atmosphere at a ball-to-material ratio of 1:(4-7) and a rotation speed of 300-400 r / min, and then performing a second ball milling for 8-10 h in a protective atmosphere at a ball-to-material ratio of 1:(4-7) and a rotation speed of 450-550 r / min to obtain a mixed powder; The mass content of molybdenum powder in the obtained mixed powder is 66.7-95wt%; the mass content of titanium powder in the obtained mixed powder is 5-33.3wt%; the amount of carbon powder added is 55-70% of the oxygen content in the obtained mixed powder; (2) The mixed powder of step (1) is subjected to cold isostatic pressing at a pressure of 200-300 MPa and maintained at the pressure for 5-40 min, and then the mixture is placed in a vacuum of less than 10 -3 Vacuum sintering is performed under 2000 ppm Pa to obtain a molybdenum-titanium alloy target blank with an oxygen content of less than 800 ppm and a density of ≥ 98%; The vacuum sintering includes a first heating, a second heating and furnace cooling performed sequentially; The first heating end point is 700-1000° C. and the holding time is 1-3 hours; The end point of the second heating is 1400-1600° C. and the insulation time is 2-6 hours.