Conical wave-conical flat double-roller rotary forging forming method for magnesium-aluminum composite disc

Abstract

The invention discloses a cone wave-cone flat double-roller rotary forging forming method for a magnesium-aluminum composite disc, which comprises the following steps: placing a magnesium-aluminum composite disc blank in a lower die of forming equipment; the conical flat roller and the conical wave roller revolve around the central axis of the main shaft, the lower die drives the magnesium-aluminum composite disc blank to be fed upwards, and axial rolling and forming of the magnesium-aluminum composite disc blank are achieved; and after the magnesium-aluminum composite disc blank reaches the target deformation amount, the lower die stops feeding, the conical flat roller and the conical wave roller continue to revolve, the upper surface of the magnesium-aluminum composite disc blank is rolled into a plane, and the magnesium-aluminum composite disc is obtained. According to the novel cone wave-cone flat double-roller rotary forging forming method, on one hand, the compression time of the bonding interface of the magnesium-aluminum composite disc can be prolonged, elements on the bonding interface can be promoted to be fully diffused, and strong metallurgical bonding is formed; and on the other hand, the bonding interface can form a three-dimensional structure interface under the rolling of the cone wave-cone flat double rollers, and the mechanical property of the magnesium-aluminum composite disc is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of forming and manufacturing of bimetallic composite discs, and particularly to a conical wave - conical flat double - roller rotary forging forming method for magnesium - aluminum composite discs. Background Art

[0002] Magnesium - aluminum composite discs combine the advantages of high specific strength, high specific stiffness, and good damping performance of magnesium alloys, as well as good corrosion resistance and easy formability of aluminum alloys, and have great application prospects in the fields of aerospace, weapons and equipment, etc. At present, magnesium - aluminum composite discs are first prepared into magnesium - aluminum composite plates by rolling, and then processed by cutting. Cutting will damage the metal streamline and reduce the mechanical properties of magnesium - aluminum composite discs. In addition, during the rolling process of forming magnesium - aluminum composite plates, under the action of rolling pressure, the contact time at the interface of the magnesium - aluminum composite disc is short, and element diffusion is insufficient, resulting in low bonding strength at the interface. The corrugated roll rolling technology can make the interface of the rolled magnesium - aluminum composite plate become a three - dimensional structure and improve the bonding interface performance of the magnesium - aluminum composite plate. However, during the corrugated roll rolling process, secondary heating of the magnesium - aluminum composite disc blank will cause an increase in the grain size at the bonding interface and the formation of a too - thick brittle intermetallic compound. The brittle compound will break and embed into the bonding interface of the magnesium - aluminum composite plate during the second - pass rolling process, becoming a crack propagation source and reducing the bonding performance of the magnesium - aluminum composite plate interface.

[0003] At present, the existing forming technologies cannot meet the conditions of long - term pressure on the bonding interface of magnesium - aluminum composite discs and a three - dimensional structure of the bonding interface after forming, resulting in poor mechanical properties of the composite disc interface and a risk of interlayer failure. Summary of the Invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a conical wave - conical flat double - roller rotary forging forming method for magnesium - aluminum composite discs, including:

[0005] Placing the magnesium - aluminum composite disc blank in the lower die of the forming equipment;

[0006] The conical flat roll and the conical wave roll revolve around the central axis of the main shaft, and the lower die drives the magnesium - aluminum composite disc blank to feed upward to achieve axial rolling and forming of the magnesium - aluminum composite disc blank;

[0007] When the magnesium - aluminum composite disc blank reaches the target deformation amount, the lower die stops feeding, and the conical flat roll and the conical wave roll continue to revolve to roll the upper surface of the magnesium - aluminum composite disc blank into a plane to obtain the magnesium - aluminum composite disc.

[0008] Further, during the forming process, the magnesium - aluminum composite disc blank needs to meet the static stability condition to maintain stable rolling.

[0009]

[0010] Among them, D0 is the initial radius of the magnesium-aluminum composite disk blank, v is the feeding speed of the lower die, n is the revolution speed of the conical flat roller and the conical wave roller, μ1 is the friction coefficient between the conical flat roller and the conical wave roller and the upper surface of the composite disk blank, and μ2 is the friction coefficient between the lower die and the lower surface of the magnesium-aluminum composite disk blank.

[0011] Furthermore, the waveform parameters of the conical wave roller are

[0012] y = Asin(wt);

[0013] Among them, the amplitude A is between 2 - 5 mm; the frequency w is between 0.2 - 0.6 rad.

[0014] Furthermore, the revolution speed of the conical flat roller and the conical wave roller is 75 - 125 r / min;

[0015] The lower generatrix of the conical flat roller and the conical wave roller is parallel to the horizontal plane.

[0016] Furthermore, the upward feeding speed of the lower die is 0.5 - 2.0 mm / s.

[0017] Furthermore, the deformation rate of the magnesium-aluminum composite disk blank is controlled within 30% - 70%.

[0018] Furthermore, the preparation method of the magnesium-aluminum composite disk blank includes

[0019] After the surfaces of the magnesium alloy and the aluminum alloy are polished and drilled in sequence, they are riveted together.

[0020] It should be noted that for better processing and forming, the difficult-to-deform magnesium alloy is placed above, and the easy-to-deform aluminum alloy material is placed below, so that the difficult-to-deform magnesium alloy is placed above and in partial contact with the conical flat roller and the conical wave roller, and the easy-to-deform aluminum alloy material is placed below and in overall contact with the lower die. The materials of the magnesium alloy and the aluminum alloy do not need to be strictly limited. Exemplarily, the aluminum alloy material is Al5052, Al6061 and other materials with good corrosion resistance and forming performance, and the magnesium alloy is AZ31B, AZ61B and other materials with high specific strength and good damping performance.

[0021] Furthermore, the diameter of the drilled hole is between 6 - 30 mm, and the height of the pin is 2 - 4 mm higher than the total thickness of the magnesium alloy and the aluminum alloy, playing a fixing role in the radial and axial directions.

[0022] Furthermore, the layer thickness ratio k of the magnesium alloy and the aluminum alloy is 0.3 - 3. This thickness ratio is calculated based on the principle of equal volume.

[0023] Furthermore, after riveting, it is kept warm at 250 - 400 °C for 10 - 20 min.

[0024] The present invention also provides a magnesium-aluminum composite disk prepared by the above method.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention proposes a new method of conical wave-conical flat double-roll rotary forging forming. On the one hand, it can increase the pressure time of the bonding interface of the magnesium-aluminum composite disk, promote the full diffusion of elements at the bonding interface, and form a strong metallurgical bond. On the other hand, under the rolling of the conical wave-conical flat double-roll, the bonding interface can form a three-dimensional structure interface, improving the mechanical properties of the magnesium-aluminum composite disk. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 Shows a schematic structural diagram of a magnesium-aluminum composite disk blank in the embodiment;

[0029] Figure 2 Shows a schematic structural diagram of a conical wave roll in the embodiment;

[0030] Figure 3 Shows a schematic flow diagram of the conical wave-conical flat double-roll rotary forging forming method of the magnesium-aluminum composite disk in the embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] In the scope disclosed in the present invention, the endpoints and any values of the range are not limited to the exact range or value. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and a single point value, and between single point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in the present invention.

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the specific embodiments of the present invention and the drawings of the specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0033] Embodiment

[0034] A conical wave-conical flat double-roll rotary forging forming method of a magnesium-aluminum composite disk includes the following steps

[0035] S1. Preparation of magnesium-aluminum composite disk blank: The surfaces of the magnesium alloy AZ31B and aluminum alloy Al5052 disk blanks are polished clean with a flap wheel and a wire brush. The AZ31B and Al5052 disk blanks are drilled around their perimeters using a drilling machine, and then riveted together with aluminum alloy Al5052 pins to obtain the magnesium-aluminum composite disk blank as shown in Figure 1 . The layer thickness ratio k between the AZ31B disk blank and the Al5052 disk blank is 0.5. A total of four holes are drilled, each with a diameter of 20 mm. The height of the pins is 3 mm higher than the total thickness of the magnesium alloy and the aluminum alloy, which plays a role in fixing in the radial and axial directions.

[0036] S2. Positioning of the magnesium-aluminum composite disk blank: The prepared magnesium-aluminum composite disk blank is placed in a vacuum heating furnace and heated to the forging temperature of 300 °C and held for 15 min, and then transferred to the bottom step of the lower die of the forming equipment. Among them, the aluminum alloy Al5052 side faces downward and is in overall contact with the lower die. The forming equipment uses a flat cone roller and a wave cone roller for rolling forming. The lower generatrix of the flat cone roller and the wave cone roller is parallel to the horizontal plane. Among them, as shown in Figure 2 , the waveform parameters of the wave cone roller are

[0037] y = Asin(wt);

[0038] where the amplitude A is 3 mm; the frequency w is 0.5 rad.

[0039] S3. Rolling forming: While the flat cone roller and the wave cone roller revolve around the central axis of the main shaft at a speed of 100 r / min, the lower die drives the magnesium-aluminum composite disk blank to feed upward at a speed of 1.2 mm / s. When the flat cone roller and the wave cone roller come into contact with the magnesium-aluminum composite disk blank, the flat cone roller and the wave cone roller rotate around their own axes under the friction of the magnesium-aluminum composite disk blank, realizing axial rolling of the composite disk blank. During the forming process, the bonding interface and the upper surface of the magnesium-aluminum composite disk blank rolled by the wave cone roller become three-dimensional structures.

[0040] During the forming process, for the magnesium-aluminum composite disk blank to maintain stable rolling, it is necessary to meet the static stability condition

[0041]

[0042] where D0 is the initial radius of the magnesium-aluminum composite disk blank, v is the feed speed of the lower die, n is the revolution speed of the flat cone roller and the wave cone roller, μ1 is the friction coefficient between the flat cone roller and the wave cone roller and the upper surface of the composite disk blank, and μ2 is the friction coefficient between the lower die and the lower surface of the magnesium-aluminum composite disk blank.

[0043] S4. Surface finishing: After the magnesium-aluminum composite disk blank reaches a target deformation of 60%, the lower die stops feeding, and the taper flat roll and taper wave roll continue to revolve around the main shaft to roll the upper surface of the magnesium-aluminum composite disk blank into a flat surface. At this time, the bonding interface is still a three-dimensional structure, and a magnesium-aluminum composite disk is obtained.

[0044] Figure 3 The above steps are summarized, and a structural schematic diagram of the magnesium-aluminum composite disk is given.

[0045] Comparative Example 1

[0046] That is, the traditional rolling method, and the specific steps are as follows.

[0047] S1. Preparation of magnesium-aluminum composite slab: Mechanically polish the surfaces of magnesium alloy AZ31B and aluminum alloy 6061, stack the magnesium-aluminum plates, with an interlayer thickness ratio of 0.5, and spot-weld the four sides to prevent dislocation.

[0048] S2. Positioning of magnesium-aluminum composite slab: Place the prepared magnesium-aluminum composite slab in a vacuum heating furnace, heat it to the forging temperature of 300 °C, and keep it warm for 15 minutes, and then transfer it to the forming equipment.

[0049] S3. Rolling forming: Under the action of external force, feed the composite slab into the rolling mill. Then, the rolling mill contacts the surface of the composite slab, and the frictional force between the two rolls the composite slab into the rolling mill. Relying on the pressure applied by the rolling mill, the composite slab is rolled into shape. At this time, a stable rolling stage is formed by relying on the frictional force between the rolling mill and the surface of the composite slab. Finally, take out the plate after rolling is completed.

[0050] S4. Machining: Machine the rolled composite plate to obtain a magnesium-aluminum composite disk with the same appearance structure as that of Example 1 but with a two-dimensional bonding interface.

[0051] Comparative Example 2

[0052] The difference compared with Example 1 is that two taper flat rolls are used to realize the axial rolling and forming of the magnesium-aluminum composite disk blank, and a magnesium-aluminum composite disk with the same appearance structure as that of Example 1 but with a two-dimensional bonding interface is obtained.

[0053] In order to ensure the high-quality bonding of the bonding interface of the magnesium-aluminum composite disk, based on the solid-state metallurgical bonding theory and bonding strength theory of dissimilar metals, the forming process adopted is as follows: It is required that the pressure received by the bonding interface of the magnesium-aluminum composite disk is large, which can break the oxide scale and hardened layer of the bonding interface, and is conducive to exposing the fresh metal of the bonding interface; it is required that the pressure application time of the bonding interface of the magnesium-aluminum composite disk is long, which is conducive to the diffusion of elements at the bonding interface and the formation of strong metallurgical bonding; it is required that the bonding interface of the magnesium-aluminum composite disk is a three-dimensional structure after forming, so as to inhibit the interlayer failure of the magnesium-aluminum composite disk.

[0054] In summary, the main advantages of the present invention are as follows:

[0055] First, during the forming process of the magnesium-aluminum composite disk-cone wave-cone flat double-roll rotary forging, under the action of non-uniform local strong stress of the cone wave-cone flat double-rolls, the oxide film is prone to rupture, which can promote the contact of fresh metals with each other and is beneficial to improving the bonding strength of the interface.

[0056] Second, during the forming process of the magnesium-aluminum composite disk-cone wave-cone flat double-roll rotary forging, under the long-term periodic rolling of the cone wave-cone flat double-rolls, the elements at the bonding interface can fully diffuse to form a strong metallurgical bond.

[0057] Third, during the forming process of the magnesium-aluminum composite disk-cone wave-cone flat double-roll rotary forging, under the rolling of the cone wave-cone flat double-rolls, a three-dimensional structure interface can be formed, improving the mechanical properties of the magnesium-aluminum composite disk.

[0058] Fourth, during the forming process of the magnesium-aluminum composite disk-cone wave-cone flat double-roll rotary forging, the difficult-to-deform magnesium alloy is placed on the upper side in local contact with the cone wave roll, and the relatively easy-to-deform aluminum alloy is placed on the lower side in overall contact with the lower die, which can promote the coordinated deformation of the magnesium-aluminum composite disk.

[0059] Fifth, in the finishing stage of the magnesium-aluminum composite disk-cone wave-cone flat double-roll rotary forging, the cone wave-cone flat double-rolls continuously roll the magnesium-aluminum composite disk, and the surface of the magnesium-aluminum composite disk can be rolled into a flat surface.

[0060] Sixth, without secondary heating, a composite disk with a three-dimensional structure at the bonding interface and a flat surface structure can be formed. It can avoid the growth of bonding grains and the formation of too thick intermetallic compounds in the magnesium-aluminum composite disk during the secondary heating process.

[0061] The methods and devices not described in detail in the present invention are all prior arts and will not be elaborated herein.

[0062] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A cone wave-cone flat double roller swing rolling forming method for a magnesium-aluminum composite disk, characterized in that: include, Placing the magnesium-aluminum composite disc blank in the lower mold of the forming equipment; The conical flat roller and the conical corrugated roller revolve around the central axis of the main shaft, and the lower die drives the magnesium-aluminum composite disc billet to feed upward, thereby realizing the axial rolling and forming of the magnesium-aluminum composite disc billet; When the magnesium-aluminum composite disc blank reaches the target deformation amount, the lower die stops feeding, and the conical flat roller and the conical corrugated roller continue to revolve, rolling the upper surface of the magnesium-aluminum composite disc blank into a flat surface to obtain a magnesium-aluminum composite disc.

2. The cone-wave-cone-flat double-roller swing-rolling forming method of the magnesium-aluminum composite disk according to claim 1 is characterized in that: During the forming process, the magnesium-aluminum composite disc blank needs to meet the static stability conditions to maintain stable rolling. Among them, D0 is the initial radius of the magnesium-aluminum composite disc blank, v is the feed speed of the lower mold, n is the revolution speed of the conical flat roller and the conical wave roller, μ1 is the friction coefficient between the conical flat roller and the conical wave roller and the upper surface of the composite disc blank, and μ2 is the friction coefficient between the lower mold and the lower surface of the magnesium-aluminum composite disc blank.

3. The cone-wave-cone-flat double-roller swing-rolling forming method of the magnesium-aluminum composite disk according to claim 1, characterized in that: The waveform parameters of the cone wave roller are: y = Asin(wt); Among them, the amplitude A is between 2-5mm; the frequency w is between 0.2-0.6rad.

4. The cone-wave-cone-flat double-roller swing-rolling forming method of the magnesium-aluminum composite disk according to claim 1, characterized in that: The revolution speed of the conical flat roller and the conical corrugated roller is 75-125 r / min; The lower generatrix of the conical flat roller and the conical corrugated roller is parallel to the horizontal plane.

5. The cone-wave-cone-flat double-roller swing-rolling forming method of the magnesium-aluminum composite disk according to claim 1, characterized in that: The upward feeding speed of the lower mold is 0.5-2.0 mm / s.

6. The cone-wave-cone-flat double-roller swing-rolling forming method of the magnesium-aluminum composite disk according to claim 1, characterized in that: The deformation rate of the magnesium-aluminum composite disk blank is controlled within a range of 30%-70%.

7. The cone-wave-cone-flat double-roller swing-rolling forming method of a magnesium-aluminum composite disk according to any one of claims 1 to 6, characterized in that: The method for preparing the magnesium-aluminum composite disk blank comprises: The surfaces of the magnesium alloy and aluminum alloy are polished and drilled in turn and then riveted together.

8. The cone-wave-cone-flat double-roller swing-rolling forming method of the magnesium-aluminum composite disk according to claim 7, characterized in that: The interlayer thickness ratio k of the magnesium alloy and the aluminum alloy is 0.3-3.

9. The cone-wave-cone-flat double-roller swing-rolling forming method of the magnesium-aluminum composite disk according to claim 1, characterized in that: After riveting, keep warm at 250-400℃ for 10-20min.

10. A magnesium-aluminum composite disk, characterized in that: The method is prepared by any one of claims 1 to 9.

Images