Titanium alloy rotary target extrusion process

Abstract

A titanium alloy rotary target material extrusion process needs to use an extruder and an extrusion die; two taper extrusion surfaces with different inner diameters are arranged in a die cavity of the extrusion die, and spiral grooves with opposite rotation directions are arranged on the taper extrusion surfaces; an insertion slot and an insertion plate are arranged on the extrusion die. The extrusion process comprises the following steps: S1: inserting the insertion plate into the insertion slot, then heating a titanium alloy ingot to 800-950 DEG C and placing it into an extrusion cylinder; S2: starting a piercing cylinder to perform reverse extrusion on the titanium alloy ingot; S3: removing the insertion plate, starting a main working cylinder to perform forward extrusion on the titanium alloy ingot, and obtaining a titanium alloy rotary target material. The total extrusion ratio of the titanium alloy ingot is improved by three extrusions, the length-diameter ratio of the titanium alloy ingot and the extrusion cylinder is shortened, and the manufacturing difficulty and cost are reduced. In addition, the extruded titanium alloy material is contracted in a spiral shape by one reverse extrusion and forward extrusion with opposite rotation directions twice, the pores are eliminated, and the density is improved.

Description

Technical Field

[0001] This invention relates to the field of target preparation technology, and in particular to a titanium alloy rotary target extrusion process. Background Technology

[0002] Sputtering targets are the raw materials for thin film deposition, and sputtering is one of the main technologies for preparing thin film materials. The solid being bombarded is the raw material for thin film deposition by sputtering, and is called the sputtering target. With the continuous advancement of VLSI technology and solar cell technology, titanium alloy rotating targets have been widely used.

[0003] In the fabrication process of titanium alloy rotating targets, an extrusion die is used to extrude titanium alloy ingots into perforated rotating targets. Due to the properties of titanium, titanium alloy ingots are difficult to extrude, and the extrusion ratio is typically only 3-8. This necessitates the use of extrusion cylinders and dies with low extrusion ratios. The problem with this approach is that, to ensure the extruded length of the rotating target, both the titanium alloy ingot and the extrusion cylinder need to have a large length-to-diameter ratio, and the extrusion press also requires a large stroke. This increases the manufacturing difficulty and cost of the titanium alloy ingot and extrusion cylinder.

[0004] Furthermore, titanium alloy ingots contain numerous pores, and a low extrusion ratio is not conducive to eliminating these pores, resulting in low density of existing titanium alloy rotary targets. Density is a crucial indicator of target preparation quality. Therefore, a new extrusion process is needed to improve the density of titanium alloy rotary targets while maintaining the overall extrusion ratio. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this invention discloses a titanium alloy rotating target extrusion process, the purpose of which is:

[0006] 1. By using multiple extrusions to increase the total extrusion ratio, the length-to-diameter ratio of titanium alloy ingots and extrusion cylinders is shortened, thereby reducing the manufacturing difficulty and cost of titanium alloy ingots and extrusion cylinders.

[0007] 2. The density of the titanium alloy target material is improved by one reverse extrusion and two forward extrusions with opposite rotation directions.

[0008] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0009] A titanium alloy rotary target extrusion process is disclosed, using an extruder and an extrusion die. The extruder comprises a piercing cylinder, a piercing needle, a main working cylinder, an extrusion shaft, and an extrusion cylinder. The extrusion die is installed at the discharge end of the extrusion cylinder and has a die cavity. Two conical extrusion surfaces with different inner diameters are coaxially arranged at the feed end of the die cavity. Spiral grooves are evenly distributed along the circumference of the conical extrusion surfaces, and the width of the spiral grooves gradually decreases from the feed end to the discharge end. The spiral grooves on the larger inner diameter conical extrusion surface have opposite spiral directions to those on the smaller inner diameter conical extrusion surface. A slot is provided on the extrusion die, and a detachable insert plate is installed in the slot. The insert plate is used to close the discharge end of the die cavity.

[0010] The extrusion process includes the following steps:

[0011] S1: Insert the insert plate into the slot, then heat the titanium alloy ingot to 800-950℃ and put it into the extrusion cylinder;

[0012] S2: Start the piercing cylinder to reverse the pressure of the titanium alloy ingot;

[0013] S3: Remove the insert plate, start the main working cylinder, and make the extrusion shaft perform forward extrusion on the titanium alloy ingot to obtain the titanium alloy rotating target.

[0014] Further improvements to the technical solution resulted in a larger taper of the large inner diameter conical extrusion surface compared to the small inner diameter conical extrusion surface.

[0015] To further improve the technical solution, a cylindrical transition surface is provided between the large inner diameter conical extrusion surface and the small inner diameter conical extrusion surface.

[0016] Further improvements to the technical solution include the coaxial arrangement of a large conical surface and a small conical surface at the tip of the piercing needle. During forward extrusion, the large conical surface of the piercing needle mates with the large inner diameter conical extrusion surface to form a primary extrusion zone; the small conical surface of the piercing needle mates with the small inner diameter conical extrusion surface to form a secondary extrusion zone.

[0017] The technical solution was further improved by installing a heating device inside the piercing needle.

[0018] Further improvements to the technical solution include S2, where the reverse extrusion ratio is 3-5, the extrusion speed is 80-120 mm / s, and a glass lubricant is used.

[0019] Further improvements to the technical solution: In S3, the extrusion ratio of forward extrusion is 4-8, the extrusion speed is 50-80 mm / s, and glass lubricant is used.

[0020] By adopting the above technical solution, compared with the prior art, the present invention has the following beneficial effects:

[0021] This invention improves the total extrusion ratio of titanium alloy ingots through three extrusion processes, shortens the length-to-diameter ratio of titanium alloy ingots and extrusion cylinders, and reduces the manufacturing difficulty and cost of titanium alloy ingots and extrusion cylinders.

[0022] Furthermore, the present invention causes the extruded titanium alloy rotating target to shrink in a spiral shape by one reverse extrusion and two forward extrusions with opposite directions, thereby eliminating pores and improving the density of the titanium alloy rotating target. Attached Figure Description

[0023] Figure 1 The diagram shows the installation structure of this extrusion die on the extruder.

[0024] Figure 2 The diagram shown is a structural schematic of this extrusion die.

[0025] Figure 3 The diagram shown is a partially enlarged structural schematic of the perforating needle.

[0026] Figure 4 The diagram shown is a structural schematic of this extrusion die during reverse extrusion.

[0027] Figure 5 The diagram shown is a structural schematic of this extrusion die during forward extrusion.

[0028] In the picture:

[0029] 10. Extrusion die;

[0030] 11. Large inner diameter conical extrusion surface; 12. Transition surface; 13. Small inner diameter conical extrusion surface; 14. Spiral groove; 15. Mold cavity; 16. Slot; 17. Insert plate;

[0031] 20. Extrusion cylinder;

[0032] 30. Extrusion shaft;

[0033] 40. Perforating needle;

[0034] 41. Large conical surface; 42. Small conical surface;

[0035] 50. Titanium alloy ingots. Detailed Implementation

[0036] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. It should be noted that in the description of the present invention, terms such as "front," "rear," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, it should not be construed as a limitation of the present invention. It should also be noted that in the description of the present invention, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances. Example 1:

[0037] A titanium alloy rotating target extrusion process requires the use of an extruder and an extrusion die.

[0038] like Figure 1 As shown, the extruder includes a piercing cylinder (not shown), a piercing needle 40, a main working cylinder (not shown), an extrusion shaft 30, and an extrusion cylinder 20. The piercing needle 40 is driven by the piercing cylinder, and the extrusion shaft 30 is driven by the main working cylinder. The outer diameter of the extrusion shaft 30 is equal to the inner diameter of the extrusion cylinder 20. The extrusion shaft 30 is a hollow shaft, and the piercing needle 40 is located inside the extrusion shaft 30 and can slide back and forth within the extrusion shaft 30 under the drive of the piercing cylinder.

[0039] Reference Figure 2 The extrusion die 10 has a cavity 15. Two conical extrusion surfaces with different inner diameters are coaxially arranged at the feed end of the cavity 15. The larger inner diameter conical extrusion surface 11 is located at the outer end of the smaller inner diameter conical extrusion surface 13. A cylindrical transition surface 12 is provided between the larger inner diameter conical extrusion surface 11 and the smaller inner diameter conical extrusion surface 13. In this embodiment, the taper of the larger inner diameter conical extrusion surface 11 is greater than the taper of the smaller inner diameter conical extrusion surface 13.

[0040] Spiral grooves 14 are evenly distributed along the circumference of the conical extrusion surface. The width of the spiral grooves 14 gradually decreases from the feed end to the discharge end. Moreover, the spiral grooves 14 on the large inner diameter conical extrusion surface 11 are arranged in the opposite direction to the spiral grooves 14 on the small inner diameter conical extrusion surface 13.

[0041] A slot 16 is provided on the extrusion die 10, and a plate 17 is detachably provided in the slot 16. The plate 17 is used to close the discharge end of the die cavity 15.

[0042] Reference Figure 3 A large conical surface 41 and a small conical surface 42 are coaxially arranged at the head end of the piercing needle 40, with the small conical surface 42 located at the head end of the large conical surface 41. A heating device (not shown in the figure) is installed inside the piercing needle to heat the interior of the titanium alloy ingot 50. Titanium alloy billets have low thermal conductivity, resulting in a large temperature difference between the surface and inner layers during extrusion, which can reach 200-250 degrees Celsius. The heating device installed inside the piercing needle 40 heats the interior of the titanium alloy ingot 50, eliminating this temperature difference.

[0043] To address the problems in the background art, this extrusion process includes the following steps:

[0044] S1: Reference Figure 1 Insert the insert plate into the slot, and then heat the titanium alloy ingot to 950°C and put it into the extrusion cylinder.

[0045] S2: Start the piercing cylinder to reverse the pressure of the titanium alloy ingot.

[0046] Specifically, the piercing cylinder is activated, causing the piercing needle 40 to be inserted into the titanium alloy ingot 50, thus extruding the titanium alloy ingot 50. In this embodiment, the extrusion ratio is 5, the extrusion speed is 120 mm / s, and glass lubricant is used.

[0047] Because the discharge end of the mold cavity 15 is closed by the insert plate 17, the flow direction of the titanium alloy is opposite to the movement direction of the piercing needle 40, so this extrusion is a reverse extrusion. After the reverse extrusion, the titanium alloy ingot 50 is pierced into a tubular shape, and its cross-sectional area is reduced for the first time.

[0048] S3: Remove the insert plate, start the main working cylinder, and make the extrusion shaft perform forward extrusion on the titanium alloy ingot to obtain the titanium alloy rotating target.

[0049] Specifically, the main working cylinder is activated, causing the extrusion shaft 30 to enter the extrusion cylinder 20 and extrude the tubular titanium alloy. Since the flow direction of the titanium alloy is the same as the movement direction of the extrusion shaft 30, this extrusion is a forward extrusion. In this embodiment, the extrusion ratio is 8, the extrusion speed is 80 mm / s, and glass lubricant is used.

[0050] During extrusion, the large conical surface 41 of the piercing needle 40 mates with the large inner diameter conical extrusion surface 11 to form the primary extrusion zone; the small conical surface 42 of the piercing needle 40 mates with the small inner diameter conical extrusion surface 13 to form the secondary extrusion zone. After passing through the primary extrusion zone, the cross-sectional area of ​​the titanium alloy is reduced for the second time. After passing through the secondary extrusion zone, the cross-sectional area of ​​the titanium alloy is reduced for the third time. After three extrusion processes, a titanium alloy rotating target of the required size is obtained.

[0051] Within the primary extrusion zone, the titanium alloy flows spirally along the spiral grooves 14 due to the multiple forward-rotating spiral grooves 14 on the large-diameter conical extrusion surface 11. Since the width of the spiral grooves 14 gradually decreases from the feed end to the discharge end, the titanium alloy exiting the primary extrusion zone experiences significant extrusion pressure, which is beneficial for improving the density of the titanium alloy rotating target. After passing through the primary extrusion zone, the cross-sectional area of ​​the titanium alloy is reduced a second time.

[0052] Similarly, within the secondary extrusion zone, the titanium alloy flows spirally along the spiral grooves 14 on the small-diameter conical extrusion surface 13, and is then subjected to another extrusion as it exits the secondary extrusion zone. However, the flow direction of the titanium alloy in the secondary extrusion zone is exactly opposite to its flow direction in the primary extrusion zone. This is like wringing a towel; rotating one end forward and the other backward causes the towel to spiral and shrink, squeezing out the water. Likewise, rotating the titanium alloy ingot 50 in both directions eliminates porosity within the ingot and increases the density of the titanium alloy rotating target.

[0053] As described above, this invention increases the total extrusion ratio of the titanium alloy ingot 50 through three extrusion processes, shortens the length-to-diameter ratio of the titanium alloy ingot 50 and the extrusion cylinder 20, and reduces the manufacturing difficulty and cost of the titanium alloy ingot 50 and the extrusion cylinder 20. Furthermore, through one reverse extrusion and two forward extrusions with opposite rotation directions, the extruded titanium alloy rotating target material shrinks in a spiral shape, eliminating porosity and increasing the density of the titanium alloy rotating target material. Example 2:

[0054] Unlike Example 1, this extrusion process includes the following steps:

[0055] S1: Insert the insert plate into the slot, then heat the titanium alloy ingot to 900°C and place it into the extrusion cylinder.

[0056] S2: Start the piercing cylinder to reverse the piercing needle and extrude the titanium alloy ingot. The extrusion ratio is 4, the extrusion speed is 100mm / s, and glass lubricant is used.

[0057] S3: Remove the insert plate, start the main working cylinder, and make the extrusion shaft perform forward extrusion on the titanium alloy ingot to obtain a titanium alloy rotating target. The extrusion ratio is 6, the extrusion speed is 70mm / s, and glass lubricant is used. Example 3:

[0058] Unlike Example 1, this extrusion process includes the following steps:

[0059] S1: Insert the insert plate into the slot, then heat the titanium alloy ingot to 800°C and place it into the extrusion cylinder.

[0060] S2: Start the piercing cylinder to reverse the piercing needle and extrude the titanium alloy ingot. The extrusion ratio is 3, the extrusion speed is 80 mm / s, and glass lubricant is used.

[0061] S3: Remove the insert plate, start the main working cylinder, and make the extrusion shaft perform forward extrusion on the titanium alloy ingot to obtain a titanium alloy rotating target. The extrusion ratio is 4, the extrusion speed is 50mm / s, and glass lubricant is used.

[0062] The parts not detailed herein are prior art. Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A titanium alloy rotary target extrusion process, characterized in that: An extruder and an extrusion die are used; the extruder has a piercing cylinder, a piercing needle, a main working cylinder, an extrusion shaft, and an extrusion cylinder; the extrusion die is installed at the discharge end of the extrusion cylinder, and a die cavity is provided inside the extrusion die; two conical extrusion surfaces with different inner diameters are coaxially provided at the feed end of the die cavity, and spiral grooves are evenly distributed along the circumference of the conical extrusion surfaces. The width of the spiral grooves gradually decreases from the feed end to the discharge end, and the spiral grooves on the larger inner diameter conical extrusion surface are arranged in opposite directions to the spiral grooves on the smaller inner diameter conical extrusion surface; a slot is provided on the extrusion die, and an insert plate is detachably installed in the slot. The insert plate is used to close the discharge end of the die cavity; The extrusion process includes the following steps: S1: Insert the insert plate into the slot, then heat the titanium alloy ingot to 800-950℃ and put it into the extrusion cylinder; S2: Start the piercing cylinder to reverse the pressure of the titanium alloy ingot; S3: Remove the insert plate, start the main working cylinder, and make the extrusion shaft perform forward extrusion on the titanium alloy ingot to obtain the titanium alloy rotating target.

2. The titanium alloy rotary target extrusion process as described in claim 1, characterized in that: The taper of a large inner diameter conical extrusion surface is greater than that of a small inner diameter conical extrusion surface.

3. The titanium alloy rotary target extrusion process as described in claim 1, characterized in that: A cylindrical transition surface is provided between the large inner diameter conical extrusion surface and the small inner diameter conical extrusion surface.

4. The titanium alloy rotating target extrusion process as described in claim 1, characterized in that: in The head end of the piercing needle is coaxially provided with a large conical surface and a small conical surface. During forward extrusion, the large conical surface of the piercing needle cooperates with the large inner diameter conical extrusion surface to form a primary extrusion zone; the small conical surface of the piercing needle cooperates with the small inner diameter conical extrusion surface to form a secondary extrusion zone.

5. The titanium alloy rotary target extrusion process as described in claim 1, characterized in that: A heating device is installed inside the piercing needle.

6. The titanium alloy rotary target extrusion process as described in claim 1, characterized in that: In S2, the reverse extrusion ratio is 3-5, the extrusion speed is 80-120 mm / s, and glass lubricant is used.

7. The titanium alloy rotary target extrusion process as described in claim 1, characterized in that: In S3, the forward extrusion ratio is 4-8, the extrusion speed is 50-80 mm / s, and glass lubricant is used.

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