Bidirectional extrusion device based on self-rotation of metal blank

Abstract

According to the bidirectional extrusion device based on self rotation of the metal blank, the blank with difficult-to-deform powder such as high-temperature alloy or titanium alloy with a magnetic wrapping material is extruded into an input cylinder through a pressing head, and under the weightlessness and vacuum environment of the input cylinder, in cooperation with a magnetic field generator, by means of the Gannikov effect, the powder with the difficult-to-deform powder is extruded into the input cylinder; the green body can rotate along the axis at different speeds and turn around in situ; after a metal blank enters the input cylinder, due to the rotation along the axis and the in-situ turning action, the blank can easily move back and forth to the extrusion die cores on the two sides, multi-pass extrusion under the non-repeated heating condition is achieved, due to the fact that the loss of a temperature field is small, the extrusion amount of each pass can be flexibly adjusted, the probability of macroscopic defects and residual stress are reduced, and the production efficiency is improved. The yield is improved; the action of the metal blank in the input cylinder is completely determined by the extrusion speed of the magnetic field generator and the pressing head, influence factors are few, and operation and control are easy.

Description

Technical Field

[0001] The invention relates to a bidirectional extrusion device based on the self-rotation of metal blanks, belonging to the technical field of hot processing. Background Art

[0002] Welding wire is an important raw material for welding process. At present, some imported high-temperature alloy welding wires are usually obtained by cold processing of ingots, but the welding wires obtained in this way usually have poor structure, resulting in poor welding performance. This year, welding wires are prepared by powder metallurgy, and the process route is hot isostatic pressing + extrusion. However, due to problems with the domestic powder metallurgy powder making process, there is a certain amount of hollow powder in the powder, which will release internal gas during the hot isostatic pressing process. Due to the closed nature of the hot isostatic pressing package, these gases cannot be released, thereby reducing the density of the billet. This low-density billet cannot be deformed into place at one time during a single-pass extrusion process, and the extruded billet is often large at both ends and small in the middle, reducing the yield rate. Summary of the invention

[0003] The present invention is designed to address the deficiencies in the above-mentioned prior art and provides a bidirectional extrusion device based on self-rotation of metal billets, with the aim of solving the problems of uneven fur size specifications and low yield rate in the powder metallurgy forming process of high-temperature alloy welding wire.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] The bidirectional extrusion device based on the self-rotation of metal blanks proposed in the technical solution of the present invention includes a horizontally placed input cylinder 4, which can rotate along the central axis. A magnetic field generator 9 is arranged on the circumferential surface of the inner wall of the input cylinder 4, and a channel 10 connected to the inner cavity is processed at the axial position of the two ends of the input cylinder 4. A left pressure head 7 is arranged in the channel 10 at the left end of the input cylinder 4, and a right pressure head 5 is arranged in the channel 10 at the right end of the input cylinder 4. An extrusion die core 8 is arranged in the channel 10 at the left and right ends of the input cylinder 4. After the metal blank 6 with a stainless steel sheath is extruded through the channels 10 at the left and right ends of the input cylinder 4 into the vacuum inner cavity of the input cylinder 4, under the action of the magnetic field generator 9, the end face of the metal blank 6 can be turned in the direction of the central axis of the input cylinder 4. At the same time, the metal blank 6 can move along the central axis in a weightless state into the opposite channel 10 for the next extrusion process.

[0006] During implementation, the input cylinder 4 is installed on the base 1 through the guide column 2, and can be driven by the pulley 3 installed on the top of the guide column 2 to realize rotation along the central axis.

[0007] In practice, the steps of using the device to perform self-rotating bidirectional extrusion to open the metal blank are as follows:

[0008] Step 1: Preparation of metal blank 6

[0009] According to the diameter of the hole 10 at the right end of the input tube 4, a metal blank 6 is prepared. The outer side of the metal blank 6 is provided with a stainless steel sheath, and the inner side is a hard-to-deform powder such as a high-temperature alloy or a titanium alloy.

[0010] Step 2: Prepare the input tube 4

[0011] Before the metal blank 6 enters the input tube 4, the inner cavity of the input tube 6 is kept clean and in a vacuum state, the extrusion ratio of the extrusion die core 8 is adjusted to the process requirements, and the left pressure head 7 and the right pressure head 5 are ready for extrusion;

[0012] Step 3: First extrusion

[0013] The metal blank 6 is heated and kept warm in a resistance furnace. The heating temperature and the holding time are determined according to the plastic deformation window of the metal material. The heated metal blank 6 is placed in the channel 10 at the right end of the input cylinder 4. The right pressure head 5 is started to squeeze the metal blank 6 into the inner cavity of the input cylinder 4. At the same time, the input cylinder 4 is started to rotate around the central axis. When the metal blank 6 completely enters the inner cavity of the input cylinder 4, the magnetic field generator 9 is started. Thereafter, under the combined action of the vacuum environment of the inner cavity of the input cylinder 4 and the magnetic field, the end face of the metal blank 6 is turned in the direction of the central axis of the input cylinder 4 by relying on the Janibekov effect, and the metal blank 6 moves along the central axis in a weightless state into the channel 10 at the left end of the input cylinder 4. Since the extrusion die core 8 in the channel 10 at the left end of the input cylinder 4 has an extrusion ratio set in advance, the metal blank 6 can easily enter without plastic deformation. The input cylinder 4 stops rotating and the magnetic field generator 9 is turned off.

[0014] Step 4: Second extrusion

[0015] The heated metal blank 6 is placed into the channel 10 at the left end of the input tube 4 for extrusion, and the operation of step 3 is repeated to allow the metal blank 6 to enter the channel 10 at the right end of the input tube 4;

[0016] Step 5: Post-processing

[0017] After the extrusion of the metal blank 6 is completed, the metal blank 6 is withdrawn from the input tube 4, cleaned, and the surface is machined.

[0018] During implementation, in step 2, the vacuum degree of the inner cavity of the input tube 6 is 1×10 -3 ~1×10 -4 MPa.

[0019] The characteristics and beneficial effects of the technical solution of the present invention are as follows:

[0020] First, the technical solution of the present invention is mainly aimed at high-temperature alloys and titanium alloys and other difficult-to-deform powder metallurgy materials that cannot meet the strict requirements of blank specifications, organizational properties and yield rate through conventional single-pass extrusion. Through the implementation of the solution of the present invention, the blank can achieve the technical requirements of high dimensional accuracy, high straightness and high yield rate;

[0021] Second, in the technical solution of the present invention, a hard-to-deform powder metallurgy material blank such as a high-temperature alloy and a titanium alloy with a magnetic sheath material is squeezed into the input tube through a pressing head. In the weightless and vacuum environment of the input tube, the blank can achieve self-rotation along the axis at different speeds and turn around in place by means of a magnetic field generator and the Janibekov effect;

[0022] Third, in the technical solution of the present invention, after the metal billet enters the input cylinder, due to the self-rotation along the axis and the in-situ U-turn, the billet can easily go back and forth between the extrusion die cores on both sides, realizing multi-pass extrusion under non-repeated heating conditions. Due to the small temperature field loss, the extrusion amount of each pass can be flexibly adjusted, reducing the probability of macro defects and residual stress, and improving the yield rate;

[0023] Fourth, starting from the second extrusion, the metal billet can rotate along the axis with controllable speed with the help of the magnetic field generator. In this process, the forming streamline of the metal billet is changed, the structural rigidity of the billet is increased, and the overall stress level of the billet is balanced after the plastic deformation is completed, which reduces the probability of deformation during cold working and improves the yield rate of parts.

[0024] Fifth, the movement of the metal blank in the input cylinder is completely determined by the extrusion speed of the magnetic field generator and the pressure head, with few influencing factors and simple control. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The schematic diagram of the structure of the bidirectional extrusion device in the technical solution of the present invention is DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments:

[0027] See attached Figure 1As shown, the bidirectional extrusion device based on the self-rotation of metal blanks comprises a transversely placed input cylinder 4, which is mounted on a base 1 through a guide column 2 and can be driven by a pulley 3 mounted on the top of the guide column 2 to realize rotation along the central axis, a magnetic field generator 9 is arranged on the circumferential surface of the inner wall of the input cylinder 4, a hole 10 connected to the inner cavity is processed at the axial position of both ends of the input cylinder 4, a left pressure head 7 is arranged in the hole 10 at the left end of the input cylinder 4, and a magnetic field generator 9 is arranged in the hole 10 at the right end of the input cylinder 4. A right pressure head 5 is provided, and extrusion cores 8 are provided in the channels 10 at the left and right ends of the input cylinder 4. After the metal blank 6 with the stainless steel sheath is extruded through the channels 10 at the left and right ends of the input cylinder 4 into the vacuum inner cavity of the input cylinder 4, under the action of the magnetic field generator 9, the end face of the metal blank 6 can be turned in the direction of the central axis of the input cylinder 4. At the same time, the metal blank 6 can move along the central axis in a weightless state into the opposite channel 10 for the next extrusion process.

[0028] The steps of using the device to perform self-rotating bidirectional extrusion and blanking on a metal blank are as follows:

[0029] Step 1: Preparation of metal blank 6

[0030] According to the diameter of the hole 10 at the right end of the input cylinder 4, a metal blank 6 is prepared, the outer side of the metal blank 6 is provided with a stainless steel sheath, and the inner side is a hard-to-deform powder such as a high-temperature alloy or a titanium alloy;

[0031] Step 2: Prepare the input tube 4

[0032] Before the metal blank 6 enters the input tube 4, the inner cavity of the input tube 6 is kept clean and in a vacuum state, with a vacuum degree of 1×10 -3 ~1×10 -4 MPa, adjust the extrusion ratio of the extrusion die core 8 to the process requirements, and prepare the left pressure head 7 and the right pressure head 5 for extrusion;

[0033] Step 3: First extrusion

[0034] The metal blank 6 is heated and kept warm in a resistance furnace. The heating temperature and the holding time are determined according to the plastic deformation window of the metal material. The heated metal blank 6 is placed in the channel 10 at the right end of the input cylinder 4. The right pressure head 5 is started to squeeze the metal blank 6 into the inner cavity of the input cylinder 4. At the same time, the input cylinder 4 is started to rotate around the central axis. When the metal blank 6 completely enters the inner cavity of the input cylinder 4, the magnetic field generator 9 is started. Thereafter, under the combined effect of the vacuum environment of the inner cavity of the input cylinder 4 and the magnetic field, the end face of the metal blank 6 is turned in the direction of the central axis of the input cylinder 4 by relying on the Janibekov effect. The metal blank 6 moves along the central axis in a weightless state into the channel 10 at the left end of the input cylinder 4 without plastic deformation. The input cylinder 4 stops rotating and the magnetic field generator 9 is turned off.

[0035] Step 4: Second extrusion

[0036] The heated metal blank 6 is placed into the channel 10 at the left end of the input tube 4 for extrusion, and the operation of step 3 is repeated to allow the metal blank 6 to enter the channel 10 at the right end of the input tube 4;

[0037] Step 5: Post-processing

[0038] After the extrusion of the metal blank 6 is completed, the metal blank 6 is withdrawn from the input tube 4, cleaned, and the surface is machined.

Claims

1. A bidirectional extrusion device based on self-rotation of metal billets, characterized in that: The device comprises a horizontally placed input cylinder (4), the input cylinder (4) being capable of rotating along a central axis, a magnetic field generator (9) being arranged on the circumferential surface of the inner wall of the input cylinder (4), holes (10) communicating with the inner cavity being processed at the axial positions of the two ends of the input cylinder (4), a left pressure head (7) being arranged in the hole (10) at the left end of the input cylinder (4), a right pressure head (5) being arranged in the hole (10) at the right end of the input cylinder (4), and holes (10) at the left and right ends of the input cylinder (4). An extrusion die core (8) is arranged in each of the two input cylinders (10). After the metal blank (6) with a stainless steel sheath is extruded through the channels (10) at the left and right ends of the input cylinder (4) into the vacuum inner cavity of the input cylinder (4), the end surface of the metal blank (6) can be turned in the direction of the central axis of the input cylinder (4) under the action of the magnetic field generator (9). At the same time, the metal blank (6) can move along the central axis in a weightless state into the opposite channel (10) to perform the next extrusion process.

2. The bidirectional extrusion device based on self-rotation of metal billet according to claim 1 is characterized in that: The input cylinder (4) is installed on the base (1) via a guide column (2), and can be driven by a pulley (3) installed on the top of the guide column (2) to rotate along the central axis.

3. The bidirectional extrusion device based on self-rotation of metal blank according to claim 1 is characterized in that: The steps of using the device to perform self-rotating bidirectional extrusion and blanking on a metal blank are as follows: Step 1: Preparation of metal blank (6) A metal blank (6) is prepared according to the diameter of the hole (10) at the right end of the input cylinder (4), wherein the metal blank (6) is provided with a stainless steel sheath on the outside and contains a high-temperature alloy or titanium alloy or other difficult-to-deform powder on the inside; Step 2: Input tube (4) preparation Before the metal blank (6) enters the input cylinder (4), the inner cavity of the input cylinder (6) is kept clean and in a vacuum state, the extrusion ratio of the extrusion die core (8) is adjusted to the process requirements, and the left pressure head (7) and the right pressure head (5) are ready for extrusion; Step 3: First extrusion The metal blank (6) is heated and kept warm in a resistance furnace, wherein the heating temperature and the holding time are determined according to the plastic deformation window of the metal material. The heated metal blank (6) is placed in the hole (10) at the right end of the input cylinder (4), and the right pressure head (5) is started to squeeze the metal blank (6) into the inner cavity of the input cylinder (4). At the same time, the input cylinder (4) is started to rotate around the central axis. When the metal blank (6) completely enters the inner cavity of the input cylinder (4), the magnetic field generator (9) is started. Thereafter, under the combined action of the vacuum environment of the inner cavity of the input cylinder (4) and the magnetic field, the end face of the metal blank (6) is turned in the direction of the central axis of the input cylinder (4) by relying on the Janibekov effect, and the metal blank (6) moves along the central axis in a weightless state into the hole (10) at the left end of the input cylinder (4) without undergoing plastic deformation. The input cylinder (4) stops rotating and the magnetic field generator (9) is turned off. Step 4: Second extrusion The heated metal blank (6) is placed in the hole (10) at the left end of the input tube (4) for extrusion, and the operation of step 3 is repeated to allow the metal blank (6) to enter the hole (10) at the right end of the input tube (4); Step 5: Post-processing After the extrusion of the metal blank (6) is completed, the metal blank (6) is withdrawn from the input cylinder (4), cleaned, and the surface is machined.

4. The bidirectional extrusion device based on self-rotation of metal billet according to claim 3 is characterized in that: In step 2, the vacuum degree of the inner cavity of the input tube (6) is 1×10 -3 ~1×10 -4 MPa.

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