Operation method and system for producing metal or alloy target material based on directional solidification

Abstract

The invention belongs to the technical field of metal target production, and particularly relates to an operation method and system for producing a metal or alloy target based on directional solidification, and the operation method comprises the following steps: S1, preparing raw materials; s2, filling the raw materials; s3, heating and melting the raw materials; s4, the molten raw material solution is transferred into a directional solidification crystallizer; s5, controlling the temperature gradient of the upper part and the lower part of the directional solidification crystallizer. According to the invention, a metal directional solidification technology is utilized, solidification is carried out according to required crystal orientation, and the directional structure metal or alloy target material with the crystal grain direction parallel to the rotating shaft direction of the target material is produced. According to the method, the crystal grains are axially arranged along the target material in the crystallization process, and transverse crystal boundaries are reduced, so that the film forming performance and the coating efficiency of the target material can be effectively improved, batch production of the whole target material can be realized, the utilization rate of the target material is improved by more than 35%, and the production cost of the target material is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal and alloy target material production, and in particular relates to an operation method and system for producing metal or alloy target materials based on directional solidification. Background Art

[0002] Conventional metal target materials are polycrystalline materials composed of countless small grains (generally in the micrometer range). At room temperature, the finer the grains, the higher the strength and the better the uniformity of the metal. However, at the atomic microscopic level or under magnetron film forming conditions, the grain boundary becomes the weak link in the metal, which will affect the sputtering process, film quality and film consistency.

[0003] Traditional metal targets are generally produced through powder metallurgy molding processes or metal ingots through metal rolling and heat treatment processes. All targets are polycrystalline materials formed by countless small grains. Taking MCrAlY alloy target as an example, the existing technology obtains the alloy through induction melting and casting, performs mechanical processing, cuts it into specified sizes, and then forges or extrude the alloy ingot multiple times to make it into a billet or billet segment. Then, the billet is annealed, rolled, heat treated and machined to obtain an alloy target body with a specific texture and size, and then processed or bonded with a copper back target to obtain a finished MCrAlY alloy target. The focus of this method is on multiple forging and rolling to obtain sufficient deformation to obtain a target product with a specific texture. There are problems such as complex process, high production cost, low target utilization, and poor consistency of target thickness and axial structure. Summary of the invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the present invention provides an operation method and system for producing metal or alloy targets based on directional solidification, which can establish a temperature gradient in the required direction above and below the crystallizer, so that the molten alloy solidifies in the opposite direction of the heat flow according to the required crystallization orientation, and produces the required alloy target. The present invention introduces seed crystals to arrange the grains in the required direction during the crystallization process, reduce grain boundaries, effectively improve the film-forming performance and coating efficiency of the target, realize the mass production of the overall target, increase the target utilization rate by more than 35%, and reduce the production cost of the target.

[0005] The specific technical solution adopted by the present invention is:

[0006] An operating method for producing a metal or alloy target material based on directional solidification comprises the following steps:

[0007] S1. Raw material preparation, wherein the raw material comprises at least one of a single metal or an alloy;

[0008] S2. Adding the raw materials into a vacuum or atmosphere-protected molten pool or crucible;

[0009] S3. heating and melting the raw materials;

[0010] S4. The molten raw material melt is transferred to a directional solidification crystallizer;

[0011] S5. Control the temperature gradient of the upper and lower parts of the directional solidification crystallizer to achieve sequential solidification from bottom to top to form a solidified billet;

[0012] S6. The solidified blank after directional solidification is subjected to heat treatment under vacuum or atmosphere protection to eliminate the blank stress and form the required directional grain structure;

[0013] S7. machining the heat-treated blank to produce a target blank having the required size and structure for target production;

[0014] S8. Target blank inspection;

[0015] S9. The target material blank is prepared into a target material product according to the design requirements.

[0016] In the step S1, the single metal includes any one of tantalum, cobalt, titanium, copper, aluminum, nickel, and silicon, and the raw material is in the shape of an ingot, a rod, or granules.

[0017] In the step S3, the heating method is electron beam heating, plasma heating, induction heating or resistance heating.

[0018] The system is a step heating device for controlling the temperature gradient of the upper and lower parts of the directional solidification crystallizer in step S5. The step heating device has a hollow hourglass-shaped structure. The upper and lower ends of the step heating device are both trumpet-shaped structures. The directional solidification crystallizer is barrel-shaped and is mounted in the hollow cavity of the step heating device. The step heating device includes a support frame with an hourglass-shaped structure, and an annular sleeve wrapped around the outside of the support frame like a swimming ring. A driving roller group is also provided on the outside of the annular sleeve. The driving roller group is supported on the concave section of the hourglass-shaped structure of the support frame, and drives the annular sleeve to roll back and forth along the inner and outer sides of the support frame with the help of the rotation of the driving roller group. The annular sleeve is covered with multiple turns of induction coils. The step heating device also includes a graphite sleeve arranged on the inner side of the induction coil. The graphite sleeve also has a trumpet-shaped structure and generates induction heat by energizing the induction coil.

[0019] The driving roller group comprises an upper roller group and a lower roller group, and the upper roller group and the lower roller group are respectively supported on the concave sections on the upper and lower sides of the supporting frame, and the supporting frame is fixed by means of the upper and lower supports of the upper roller group and the lower roller group, and the upper roller group and the lower roller group are in an annular structure surrounding the supporting frame, and the upper roller group and the lower roller group respectively comprise a plurality of rollers connected in series, and the rollers are supported by means of brackets, and adjacent rollers are connected in series by means of universal joints, and the upper roller group and the lower roller group are respectively provided with driving gears, and at least one roller in the upper roller group and the lower roller group is provided with teeth on both sides that mesh with the driving gear for transmission, and the driving gear is connected to a driving motor.

[0020] The annular sleeve is a swimming ring-like structure made of elastic material. The supporting frame is wrapped around the inside of the annular sleeve. The outside of the annular sleeve is fixedly wound with an induction coil arranged at intervals. The wheel surface of the roller is provided with a groove matching the diameter of the induction coil. The annular sleeve is engaged with the groove of the roller by means of the induction coil to form a transmission fit.

[0021] The support frame is a cage-like structure including vertical ribs and transverse rings, and the transverse rings are arranged in multiple groups along the direction of the vertical ribs of the support frame.

[0022] The beneficial effects of the present invention are:

[0023] The present invention utilizes metal directional solidification technology to pour molten metal or alloy solution into a directional solidification crystallizer of a certain shape, and establishes a temperature gradient in a specific direction above and below the directional solidification crystallizer, so that the molten alloy solidifies in the opposite direction of the heat flow according to the required crystal orientation, and produces a directional organization metal or alloy target material with the crystal grain direction parallel to the target material rotation axis direction. The present invention can effectively improve the film-forming performance and coating efficiency of the target material by arranging the grains along the axial direction of the target material during the crystallization process and reducing the lateral grain boundaries, and can realize the mass production of the overall target material, improve the target material utilization rate by more than 35%, and reduce the target material production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the process flow of the present invention;

[0025] Figure 2 is a schematic diagram of a directional solidification crystallizer;

[0026] Figure 3 is a schematic diagram of a step heating device;

[0027] Figure 4 is a schematic diagram of a step heating device viewed from above;

[0028] Figure 5 A schematic diagram of the supporting skeleton;

[0029] In the accompanying drawings, 1. directional solidification crystallizer, 101. hollow cavity, 102. graphite sleeve, 2. support frame, 201. vertical ribs, 202. horizontal rings, 3. annular sleeves, 301. induction coils, 4. driving roller group, 41. upper roller group, 42. lower roller group, 43. bracket, 401. roller, 4011. teeth, 4012. grooves, 402. universal joints, 5. driving gears. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:

[0031] Specific implementation examples Figure 1 As shown, the present invention is an operation method for producing metal or alloy target materials based on directional solidification, comprising the following steps:

[0032] S1. Raw material preparation, wherein the raw material comprises at least one of a single metal or an alloy;

[0033] S2. Adding the raw materials into a vacuum or atmosphere-protected molten pool or crucible;

[0034] S3. heating and melting the raw materials;

[0035] S4. The molten raw material melt is transferred to a directional solidification crystallizer 1;

[0036] S5. Control the temperature gradient of the upper and lower parts of the directional solidification crystallizer 1 to achieve sequential solidification from bottom to top to form a solidified billet;

[0037] S6. The solidified blank after directional solidification is subjected to heat treatment under vacuum or atmosphere protection to eliminate the blank stress and form the required directional grain structure;

[0038] S7. machining the heat-treated blank to produce a target blank having the required size and structure for target production;

[0039] S8. Target blank inspection;

[0040] S9. The target material blank is prepared into a target material product according to the design requirements.

[0041] The directional solidification referred to in the present invention is also called directional crystallization, which refers to a process for directional growth of crystals of metals or alloys in the melt. Directional solidification technology is a process for establishing a temperature gradient in a specific direction during the solidification process of the metal, so that the molten metal or alloy solidifies in the opposite direction of the heat flow according to the required crystal orientation. The temperature gradient refers to the phenomenon that the temperature of the upper and lower parts of the molten pool of the metal solution increases or decreases in a step-by-step manner according to a certain cooling rate or gradient in a specific thermal field area.

[0042] The present invention utilizes metal directional solidification technology to pour molten metal or alloy solution into a cold wall crystallizer of a certain shape, and establishes a temperature gradient in a specific direction above and below the crystallizer, so that the molten alloy solidifies in the opposite direction of the heat flow according to the required crystal orientation, and produces a metal or alloy target material with a directional organization in which the crystal grain direction is parallel to the target material rotation axis direction. The present invention can effectively improve the film-forming performance and coating efficiency of the target material by arranging the grains along the axial direction of the target material during the crystallization process and reducing the lateral grain boundaries, so as to realize the mass production of the overall target material, improve the target material utilization rate by more than 35%, and reduce the target material production cost.

[0043] In the specific operation position, the directional solidification crystallizer 1 is slowly extracted from the lower side of the temperature field, so that the heat of the directional solidification crystallizer 1 is slowly diffused in the form of radiant heat, and the water-cooled seat at the bottom is used to cool down to produce condensation nuclei, or in the process of directional solidification of high-purity metals or alloys, seed crystals are introduced and pre-placed into the directional solidification crystallizer 1 as condensation nuclei, which can produce high-purity metal or alloy targets composed of a whole large single crystal. The single crystal target produced by this patent has higher purity, and the crystal orientation can be artificially selected and controlled to ensure the consistency of the target thickness and axial tissue orientation. When the metal target produced by this patent is subjected to vacuum sputtering film formation, the sputtering rate is stable, the film is uniform and consistent, and the film resistivity is low, and it can be defect-free in theory. At the same time, this method is highly operable and can produce high-thickness integrated targets in one step, which has broad application prospects.

[0044] Furthermore, in step S1, the single metal includes any one of nickel, cobalt, titanium, copper, aluminum, silicon, molybdenum, tantalum, and zirconium, and the raw material is in the shape of an ingot, a rod, or granules. The alloy includes any one of a nickel-based, cobalt-based, molybdenum-based, silicon-based, and titanium-based alloy, and the raw material is in the shape of an ingot, a rod, or granules.

[0045] The above raw materials can be prepared by electron beam melting, electrolysis, zone melting purification, compound deposition, chemical synthesis and other purification processes or other metallurgical purification methods.

[0046] In the step S3, the heating method is electron beam heating, plasma heating, induction heating or resistance heating.

[0047] According to the size of the directional target material for directional solidification, the feeding method can be a one-time feeding, or multiple continuous or intermittent feeding.

[0048] like Figure 2 As shown, in the directional solidification crystallizer 1, from top to bottom, there are a liquid phase, a solid-liquid coexistence phase, and a solid phase at the bottom, and the directional solidification crystallizer 1 is a ceramic mold. The directional solidification crystallizer 1 adopts a cold wall structure, and the outer wall of the directional solidification crystallizer 1 is radiated by heat to achieve uniform cooling. Figure 2The middle annular sleeve 3 and the induction coil 301 are not shown.

[0049] Further, such as Figure 3 and Figure 4 As shown, the system is a step heating device for controlling the temperature gradient of the upper and lower parts of the directional solidification crystallizer 1 in step S5. The step heating device is a hollow hourglass-shaped structure, and the upper and lower ends of the step heating device are both trumpet-shaped structures. The directional solidification crystallizer 1 is barrel-shaped and sleeved in the hollow cavity 101 of the step heating device. The step heating device includes a support frame 2 with an hourglass-shaped structure, and an annular sleeve 3 wrapped around the outside of the support frame 2 like a swimming ring. A driving roller group 4 is also arranged on the outside of the annular sleeve 3. The driving roller group 4 is supported on the concave section of the hourglass-shaped structure of the support frame 2, and the annular sleeve 3 is driven to roll back and forth along the inner and outer sides of the support frame 2 by the rotation of the driving roller group 4. The annular sleeve 3 is laid with multiple turns of induction coil 301. The step heating device also includes a graphite sleeve 102 arranged on the inner side of the induction coil 301, and the graphite sleeve 102 is also trumpet-shaped and generates induction heat by energizing the induction coil 301.

[0050] Since the layout of the induction coil 301 requires a certain electrical spacing, the induced heat field generated on the graphite sleeve 102 is not uniform. Therefore, the driving roller group 4 is set to rotate back and forth, so that each position of the graphite sleeve 102 can capture the induced electric field and generate induced heat, thereby improving the uniformity of the temperature gradient. In addition, the hourglass-shaped support frame 2 and the hourglass-shaped graphite sleeve 102 are set so that the directional solidification crystallizer is far away from the heat source when entering and leaving, thereby avoiding sudden temperature changes and improving the uniformity of crystallization.

[0051] like Figure 3 As shown, when the step heating device is working, the directional solidification crystallizer 1 is placed in the cavity of the support frame 2 of the step heating device, and the support frame 2 is squeezed and fixed by the support of the driving roller group 4, so as to avoid the position change of the support frame 2 when the driving roller group 4 rotates. When the driving roller group 4 rotates, the annular sleeve 3 reciprocates and slides around the inner and outer sides of the support frame 2, so that the outer wall of the directional solidification crystallizer 1 is located on the annular surface of the same horizontal plane, and the temperature conditions tend to be consistent, thereby forming a relatively consistent temperature gradient on each busbar around the directional solidification crystallizer 1, and better ensuring the directional solidification effect.

[0052] Further, such as Figure 3 and Figure 4As shown, the driving roller group 4 includes an upper roller group 41 and a lower roller group 42, and the upper roller group 41 and the lower roller group 42 are respectively supported on the concave sections on the upper and lower sides of the support frame 2, and the support frame 2 is fixed by means of the upper and lower supports of the upper roller group 41 and the lower roller group 42, and the upper roller group 41 and the lower roller group 42 are in an annular structure surrounding the support frame 2, and the upper roller group 41 and the lower roller group 42 respectively include a plurality of rollers 401 connected in series, and the rollers 401 are supported by a bracket 43, and adjacent rollers 401 are connected in series by means of a universal joint 402, and the upper roller group 41 and the lower roller group 42 are respectively provided with a driving gear 5, and at least one roller 401 in the upper roller group 41 and the lower roller group 42 is provided with teeth 4011 on both sides that mesh with the driving gear 5 for transmission, and the driving gear 5 is connected to a driving motor.

[0053] The upper roller group 41 and the lower roller group 42 of the driving roller group 4 are respectively rotated by means of the driving gear 5 driven by the driving motor, and the roller 401 is arranged around the annular sleeve 3. The ends of the rollers 401 close to the annular sleeve 3 are arranged adjacent to each other with a spacing of no more than 3 mm. The wire of the induction coil 301 adopts a spiral or zigzag shape to meet the deformation when the driving roller group 4 drives the annular sleeve 3 to rotate, and the contact surface between the roller 401 and the induction coil 301 is an arc surface, thereby ensuring that the force is uniform when the roller 401 squeezes the induction coil 301 to avoid crushing.

[0054] The annular sleeve 3 is a swimming ring-like structure made of elastic material. The support frame 2 is wrapped inside the annular sleeve 3. The annular sleeve 3 is fixed with induction coils 301 arranged at intervals. The wheel surface of the roller 401 is provided with a groove 4012 matching the diameter of the induction coil 301. The annular sleeve 3 is engaged with the groove 4012 of the roller 401 by means of the induction coil 301 to form a transmission match. The surface of the roller 401 is provided with a raised ridge, and the groove 4012 is formed by the ridge and the arc-shaped plane on the surface of the roller 401. The induction coil 301 is covered with an insulating sheath, and the ridge is inserted into the gap of the insulating sheath between adjacent induction coils 301.

[0055] Furthermore, the support frame 2 is a cage-like structure including vertical ribs 201 and horizontal circles 202, and the horizontal circles 202 are arranged in multiple groups along the vertical ribs 201 of the support frame 2. The vertical ribs 201 and the horizontal circles 202 form a cage-like structure, thereby improving the structural strength of the support frame 2.

Claims

1. A method for producing a metal or alloy target material based on directional solidification, characterized in that: The following steps are included: S1. Raw material preparation, wherein the raw material comprises at least one of a single metal or an alloy; S2. Adding the raw materials into a vacuum or atmosphere-protected molten pool or crucible; S3. heating and melting the raw materials; S4. The molten raw material melt is transferred to a directional solidification crystallizer (1); S5. Controlling the temperature gradient of the upper and lower parts of the directional solidification crystallizer (1) to achieve sequential solidification from bottom to top to form a solidified billet; S6. The solidified blank after directional solidification is subjected to heat treatment under vacuum or atmosphere protection to eliminate the blank stress and form the required directional grain structure; S7. machining the heat-treated blank to produce a target blank having the required size and structure for target production; S8. Target blank inspection; S9. The target material blank is prepared into a target material product according to the design requirements.

2. The method for producing metal or alloy targets based on directional solidification according to claim 1, characterized in that: In the step S1, the single metal includes any one of nickel, cobalt, titanium, copper, aluminum, silicon, molybdenum, tantalum, and zirconium, and the raw material is in the shape of an ingot, a rod, or granules. The alloy includes any one of a nickel-based, cobalt-based, molybdenum-based, silicon-based, and titanium-based alloy, and the raw material is in the shape of an ingot, a rod, or granules.

3. The method for producing metal or alloy targets based on directional solidification according to claim 1, characterized in that: In the step S3, the heating method is electron beam heating, plasma heating, induction heating or resistance heating.

4. A system for implementing the method of claim 1, characterized in that: The system is a step heating device for controlling the temperature gradient of the upper and lower parts of the directional solidification crystallizer (1) in step S5, the step heating device is a hollow hourglass-shaped structure, the upper end and the lower end of the step heating device are both trumpet-shaped structures, the directional solidification crystallizer (1) is barrel-shaped and is sleeved in the hollow cavity (101) of the step heating device, the step heating device comprises a support frame (2) with an hourglass-shaped structure, an annular sleeve (3) wrapped around the outside of the support frame (2) like a swimming ring, and the outside of the annular sleeve (3) is A driving roller group (4) is also provided. The driving roller group (4) is supported on the concave section of the hourglass-shaped structure of the supporting frame (2). The driving roller group (4) drives the annular sleeve (3) to roll back and forth along the inner and outer sides of the supporting frame (2) by means of the rotation of the driving roller group (4). The annular sleeve (3) is provided with a plurality of turns of induction coil (301). The step heating device further comprises a graphite sleeve (102) arranged on the inner side of the induction coil (301). The graphite sleeve (102) also has a bell-shaped structure and generates induction heat by means of the induction coil (301) being energized.

5. The system according to claim 4, characterized in that: The driving roller group (4) comprises an upper roller group (41) and a lower roller group (42), wherein the upper roller group (41) and the lower roller group (42) are respectively supported on the inner concave sections on the upper and lower sides of the supporting frame (2), and the supporting frame (2) is fixed by means of the upper and lower supports of the upper roller group (41) and the lower roller group (42), and the upper roller group (41) and the lower roller group (42) are in an annular structure surrounding the supporting frame (2), and the upper roller group (41) and the lower roller group (42) respectively comprise a plurality of rollers connected in series. Rollers (401), the rollers (401) are supported by a bracket (43), adjacent rollers (401) are connected in series by means of a universal joint (402), the upper roller group (41) and the lower roller group (42) are respectively provided with a driving gear (5), at least one roller (401) in the upper roller group (41) and the lower roller group (42) is provided with teeth (4011) on both sides that mesh with the driving gear (5), and the driving gear (5) is connected to a driving motor.

6. The system according to claim 5, characterized in that: The annular sleeve (3) is a swimming ring-like structure made of elastic material. The support frame (2) is wrapped around the inside of the annular sleeve (3). The outside of the annular sleeve (3) is fixedly wound with an induction coil (301) arranged at intervals. The wheel surface of the roller (401) is provided with a groove (4012) matching the diameter of the induction coil (301). The annular sleeve (3) is connected with the groove (4012) of the roller (401) by means of the induction coil (301) to form a transmission fit.

7. The system according to claim 5, characterized in that: The support frame (2) is a cage-like structure comprising vertical ribs (201) and transverse circles (202), and a plurality of transverse circles (202) are arranged along the direction of the vertical ribs (201) of the support frame (2).

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