Disclosure of Invention
The invention provides a current-assisted SPF/DB integrated forming process, which realizes integrated forming of a plate by adopting a current-assisted SPF/DB integrated forming die, wherein a vertical electrode is used as a part of the die, so that the vertical electrode can be in direct contact with a diffusion connection area of the plate, and the current is more concentrated when the plate is subjected to diffusion connection.
The invention also provides a hollow sandwich structural member.
The current-assisted SPF/DB integrated forming process adopts the following technical scheme: the utility model provides a current-assisted SPF DB integration forming technology, its integration through adopting current-assisted SPF DB integration forming die to realize panel takes shape, the mould includes insulating mould main part, be equipped with cavity and pilot hole in the insulating mould main part, the pilot hole runs through the cavity sets up, pilot hole department is equipped with perpendicular electrode, perpendicular electrode assembly in behind the pilot hole will the cavity is separated into 1 at least die cavity that is used for the panel shaping, be close to on the perpendicular electrode the terminal surface of the one end of the open end of cavity is used for laminating, carries out electric heating to the diffusion bonding region of treating of panel.
As a further preferable technical solution, a part of the vertical electrode forming the boundary of the cavity is an insulating surface, and the insulating surface is made by coating an insulating material on the surface of the vertical electrode; the insulating die main body is made of ceramics.
As a further preferred technical scheme, one surface of the vertical electrode, which is used for being attached to the plate and electrically heating the to-be-diffused connection region of the plate, is a heating surface, and the number of the insulating surfaces is 2, and the insulating surfaces are respectively arranged on two sides of the heating surface.
As a further preferred aspect, the insulating surface is provided symmetrically with respect to the heating surface.
As a further preferable technical solution, the vertical electrode is installed at one end of the insulating mold body, which is far away from the opening end of the cavity, protruding from the assembling hole; the insulating die main body is further provided with a temperature measuring hole, and the temperature measuring hole is communicated with the concave cavity.
As a further preferable technical scheme, a transparent material is further arranged between the temperature measuring hole and the concave cavity.
As a further preferable technical solution, the vertical electrode is adapted to the size of the assembly hole, and the vertical electrode is attached to the insulating mold main body after being assembled in the assembly hole; the transparent material is transparent ceramic.
In a more preferable embodiment, when the sheet material is integrally formed, the sheet material is placed between the two molds, and the open ends of the two molds are opposed to each other.
As a further preferable technical solution, the molds arranged opposite to the open end are respectively a first mold and a second mold, the vertical electrode in the first mold is a first vertical electrode, and the vertical electrode in the second mold is a second vertical electrode; the first vertical electrode is connected with the positive electrode/negative electrode of a power supply, the second vertical electrode is connected with the negative electrode/positive electrode of the power supply, and the direction of current between the first vertical electrode and the second vertical electrode is from the first vertical electrode to the second vertical electrode or from the second vertical electrode to the first vertical electrode.
In a further preferred embodiment, the surface of the plate material is further provided with a horizontal electrode for horizontally heating the entire plate material, and the horizontal electrode is disposed at a position other than the surface of the plate material and the insulating main body.
As a further preferable technical solution, the horizontal electrode includes a first horizontal electrode and a second horizontal electrode, the first horizontal electrode and the second horizontal electrode are disposed along an extending direction of the plate, the first horizontal electrode is connected to a positive electrode/a negative electrode of a power supply, the second horizontal electrode is connected to a negative electrode/a positive electrode of the power supply, and a direction of current flowing between the first horizontal electrode and the second horizontal electrode is from the first horizontal electrode to the second horizontal electrode or from the second horizontal electrode to the first horizontal electrode.
As a further preferred technical solution, the apparatus used in the integrated forming process further includes a loading pressure cylinder, and the loading pressure cylinder acts on one end of the mold or the mold assembly away from the plate to maintain the mold fixed.
As a further preferable technical solution, the loading pressure cylinder acts on the vertical electrode, and an insulating medium is provided between the loading pressure cylinder and the vertical electrode.
As a further preferable technical scheme, the forming device further comprises a power supply, an infrared thermometer, any one or combination of a plurality of a first switch for controlling the on/off of the vertical electrode, a second switch for controlling the on/off of the horizontal electrode and a lead, wherein the infrared thermometer is arranged at the temperature measuring hole.
As a further preferred technical solution, the forming process comprises the steps of: (1) coating a solder resist on a non-diffusion connection area of two adjacent layers of plates; (2) placing the plate obtained by the treatment in the step (1) among 2 moulds, enabling the opening end of a cavity to face the plate and enabling the vertical electrode to be in contact with a to-be-diffused connection area of the plate; (3) a loading pressure cylinder applies pressure to the die to maintain the fixation of the whole die; (4) electrifying the vertical electrode, and heating the area of the plate, which is in contact with the vertical electrode, so as to realize diffusion connection of the plate; (5) after the diffusion connection is finished, the vertical electrode is powered off; (6) electrifying the horizontal electrode to horizontally and integrally heat the plate;
(6) and after the temperature of the plates reaches a set temperature, introducing gas between the two layers of plates to enable the plates to be attached to the cavity, thus obtaining the formed member.
As a further preferable technical solution, the plate material is a titanium alloy, and the titanium alloy includes, but is not limited to, a titanium-aluminum-niobium alloy and/or a titanium-aluminum alloy; the solder resist is an insulating solder resist.
As a further preferable technical scheme, the plate is a titanium-aluminum-niobium alloy plate and a titanium-aluminum alloy plate which are attached to each other, and the superplastic forming temperature of the titanium-aluminum-niobium alloy plate and the titanium-aluminum alloy plate is 970-1000 ℃.
The hollow sandwich structure member adopts the following technical scheme: a hollow sandwich structural member processed by the integrated forming process as described in any one of the preceding claims.
The invention has the beneficial effects that: the current-assisted SPF/DB integrated forming process realizes the integrated forming of the plate by adopting a current-assisted SPF/DB integrated forming die, a vertical electrode in the die can be directly contacted with a to-be-diffused connection area of the plate, only the contact area is heated, the temperature of the contact area is improved, the deformation resistance of the contact area is reduced, the healing elimination of an interface hole is accelerated by utilizing a current crack healing effect, the diffusion of interface elements is promoted, and the low-voltage and short-time rapid diffusion connection of a composite interface can be realized.
The current-assisted SPF/DB integrated forming die can realize heating of only the to-be-diffused connection area of the plate, effectively improve the forming performance of the material by utilizing the electro-plastic effect, greatly shorten the heating time and reduce the performance reduction caused by coarsening of the structure.
The vertical electrode in the current-assisted SPF/DB integrated forming die can divide the cavity into cavities (the vertical electrode is used as the boundary of the cavities) for superplastic forming of the plates, the die does not need to be replaced or adjusted after diffusion connection, the integrated forming of the plates can be realized, the forming efficiency can be effectively improved, and the cost can be reduced.
When the current-assisted SPF/DB integrated forming die is used for diffusion connection of plates, only the diffusion connection area is heated, and the total current is greatly reduced under the condition of unchanged current density.
The current-assisted SPF/DB integrated forming process adopts the horizontal electrode to heat the plate, so that compared with vertical heating, the current sectional area is greatly reduced, the material heating self-resistance is improved, the heating speed is high, and the total current is reduced; in addition, the horizontal electrodes directly heat the non-diffusion connection areas of the plate by current instead of heat conduction, so that the temperature is more uniform.
When the current-assisted SPF/DB integrated forming process is adopted to process the plate, the plate does not need to be processed under the protective atmosphere of a heat-preservation sealing box, the die can be exposed in the air, and the plate is cooled along with the die after being formed, so that the production efficiency is improved, and the cost is reduced.
The current-assisted SPF/DB integrated forming process realizes the rapid heating of the Ti2AlNb-TiAl alloy by using current joule heat, and can realize the heating to the deformation temperature (about 1000 ℃) of the Ti2 AlNb-based alloy and the TiAl alloy within a few minutes compared with the traditional furnace temperature heating for 2-4 hours.
The current Joule heat and the electric crack healing are utilized to accelerate the diffusion connection of the Ti2 AlNb-TiAl-based alloy, the deformation performance of the material is improved by utilizing the Joule heat and the electric plasticity, the high-temperature exposure time is further shortened by utilizing the integrated forming design, and the shape control performance of the high-efficiency composite hollow component is realized.
The invention innovatively provides current-assisted Ti2An integrated forming technology of an AlNb-TiAl alloy composite hollow structure, which is capable of realizing Ti2A new method for low-pressure, fast diffusion connection and fast superplastic forming of AlNb-TiAl-based alloy.
Ti prepared by adopting the current-assisted SPF/DB integrated forming process2The AlNb-TiAl alloy composite hollow structure can effectively solve the problem of reduced structure performance caused by excessive plastic deformation and long-term high temperature in the prior art, and realizes Ti2The shape control performance of the AlNb-TiAl alloy composite hollow structure has wide application prospect in the field of aerospace.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or the orientations or positional relationships that the products of the present invention are conventionally placed in use, and are only used for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In the present invention, a first feature is "on" or "under" a second feature unless explicitly stated or limited otherwise "
It may include the first and second features being in direct contact, or it may include the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.
Example 1
As shown in fig. 1-9, a current-assisted SPF/DB integrated forming mold comprises an insulating mold body 1, wherein a cavity 3 and a mounting hole 2 are arranged on the insulating mold body 1, the mounting hole 2 is arranged through the cavity 3, a vertical electrode 4 is mounted at the mounting hole 2, the cavity 3 is divided into at least 1 cavity 5 for forming a plate 6 after the vertical electrode 4 is mounted in the mounting hole 2 (as shown in fig. 9, after the vertical electrode 4 is inserted into the mounting hole 2, an inclined surface 41 ("inclined surface" does not limit the shape of the outer peripheral surface of the part of the bottom of the vertical electrode 4 located in the cavity range and attached to the plate in the present invention, and is replaced by "inclined surface" only for convenience of description, and in the practical application process, various shapes/structures such as a vertical plane perpendicular to the plate or an irregular curved surface or plane can be adopted, not specifically defined), and the other end is located at the end surface of the open end of the cavity 3, the inclined surface 41 and the cavity 3 form a cavity 5 which is open at only one end and can be used for sheet forming, and the end surface (the bottom surface 42 of the vertical electrode in the figure) of the vertical electrode 4 close to the open end of the cavity 3 is used for jointing with the sheet 6 and electrically heating the area to be diffusion-connected of the sheet.
The working principle of adopting the current-assisted SPF/DB integrated forming die to carry out integrated forming processing on the plates is as follows: when the method is used, a forming die (as shown in fig. 9) is placed on the surface of a plate 6 to be processed, a solder resist 7 (preferably an insulating solder resist is selected to avoid connection of a non-diffusion connection area caused by current loop or local discharge formed in the non-diffusion connection area between two plates) is coated on the non-diffusion connection area of the two layers of plate 6 to be processed in advance, the bottom surface 42 of the vertical electrode 4 is attached to the area to be diffusion connected of the plate, the vertical electrode 4 is electrified, and the bottom surface 42 of the vertical electrode is subjected to current auxiliary field activated diffusion connection under the action of current. After the diffusion connection of the plate 6 is finished, the die does not need to be replaced, the whole body of the plate 6 is heated, after the superplastic forming temperature of the plate 6 is reached, gas is introduced between the two layers of plates, the plates can be expanded to enter the cavity 5 and be attached to the cavity 5, and then the integrated forming processing of the plate 6 is completed.
The die is suitable for diffusion bonding/superplastic forming of materials such as titanium alloy and the like (such as titanium alloy and the like, wherein the titanium alloy comprises but is not limited to titanium aluminum alloy, titanium aluminum niobium alloy and the like) which can be rapidly heated under the action of electric current joule heat. During diffusion bonding, the mold only heats the region to be diffusion bonded of the plate 6, can increase the temperature of the region to be diffusion bonded (the region where the bottom surface 42 of the vertical electrode contacts the plate), reduce the deformation resistance of the region to be diffusion bonded of the plate, accelerate the healing of the interface hole by using the effect of 'current crack healing', promote the diffusion of interface elements, and realize the low-pressure and short-time rapid diffusion bonding of the diffusion bonding region interface (the diffusion bonding region of two layers of plates, the two layers of plates can be independently selected from the same or different specific materials) between the plates. Because this integration forming die is when carrying out diffusion bonding to panel, only to treating the diffusion bonding region heating of panel, for the whole technical scheme who heats in order to realize the diffusion bonding of treating the diffusion bonding region of panel to panel, under the unchangeable condition of current density, can reduce total current in very big degree.
In addition, when the mold is actually used, a person skilled in the art may select the specific number and size of the assembly holes and/or the vertical electrodes included in the mold according to needs (the number of the assembly holes and/or the vertical electrodes shown in the drawings is 2, and the person skilled in the art knows that the number of the assembly holes and/or the vertical electrodes may be set to 1 or more according to actual needs, etc.); the specific shape of the assembly hole and/or the vertical electrode can be selected by a person skilled in the art according to the needs, and the requirement that the vertical electrode can form a cavity for plate forming with the cavity after being assembled in the assembly hole is met; when the die is actually used, the number of the dies can be selected according to actual needs, and the positions of the dies are combined and distributed; for example, if necessary, dies may be provided on both upper and lower ends of the plate material 6, or as shown in fig. 9, the dies of the present invention may be provided only on the upper side of the plate material, and electrodes of corresponding shapes may be provided only on the region to be diffusion-bonded (the region corresponding to the bottom surface 42 of the vertical electrode in fig. 9) on the lower side of the plate material, so as to electrically heat the region to be diffusion-bonded of the plate material.
Example 2
In example 1, the portion of the vertical electrode 4 that forms the boundary of the cavity 3 (the inclined surface 41 of the bottom of the vertical electrode) is an insulating surface, and the insulating surface is formed by coating an insulating material (such as insulating varnish, which is a high-temperature-resistant insulating material that is easily applied, has a small thickness, and has easily controlled uniformity) on the surface of the inclined surface 41 of the bottom of the vertical electrode. By coating the insulating material on the inclined surface 41 at the bottom of the vertical electrode forming the cavity 3, the current when the vertical electrode is electrified can be effectively concentrated in the area covered by the bottom surface 42 of the vertical electrode, so that the current is concentrated in the area to be diffusion-connected of the plate material, and the diffusion connection process of the area to be diffusion-connected is accelerated. The insulating mold body 1 may be made of ceramic or the like.
Example 3
On the basis of embodiment 2, the surface of the vertical electrode 4 for adhering to the plate material 6 and electrically heating the region to be diffusion-bonded of the plate material 6 is a heating surface (bottom surface 42 of the vertical electrode in the figure), and 2 insulating surfaces are provided and are respectively provided on both sides of the heating surface. Through set up insulating surface (the inclined plane 41 of vertical electrode bottom) respectively in the both sides of the bottom surface 42 of vertical electrode for vertical electrode 4 assembles behind pilot hole 2, and the inclined plane 41 of both sides all can cooperate with cavity 3, as the border that is used for fashioned die cavity 5 of panel, and then applicable in the processing that needs to form a plurality of hollow structure's panel, provides the efficiency of panel processing.
Example 4
On the basis of any of embodiments 1 to 3, the insulating surface is disposed symmetrically with respect to the heating surface. If the inclined surface 41 of the bottom of the vertical electrode is symmetrical with respect to the heating surface (the bottom surface 42 of the vertical electrode), the cavity 3 can be divided into at least 2 cavities 5 which are symmetrical on one side after the vertical electrode 4 is assembled in the assembly hole. If the entire cavity 3 is of a bilaterally symmetrical structure, the same cavity 5 can be obtained when the inclined surfaces 41 on both sides of the bottom surface 42 of the vertical electrode are symmetrical, and the plate can be conveniently processed into a product with a plurality of identical hollow structures. It should be noted that the present invention does not necessarily limit the cavity 3 to a cavity having a symmetrical structure and/or the inclined surfaces on both sides of the inclined surface 41 of the vertical electrode to have a symmetrical structure, and when a product having a plurality of hollow structures of different shapes needs to be simultaneously processed on the same plate, it is known to those skilled in the art that the specific shape of the cavity 5 can be changed by changing the shape of the cavity and/or the inclined surface 41.
Example 5
As shown in fig. 10, in any of embodiments 1 to 4, the vertical electrode 4 is mounted in the mounting hole 2 and protrudes from the end of the insulating mold body 1 away from the open end of the cavity 3. The arrangement is convenient for adopting the loading pressure cylinder to act on the vertical electrode 4 when the die disclosed by the invention is used for processing the plate, so that the displacement between the plate and the vertical electrode 4 and the insulating die body 1 can be avoided, and the normal diffusion connection and superplastic forming of the plate can be further ensured.
Example 6
In any of embodiments 1 to 5, the vertical electrode 4 is adapted to the size of the mounting hole 2, and the vertical electrode 4 is attached to the insulating mold body 1 after being mounted in the mounting hole 2, thereby reducing the movement of the vertical electrode 4 in the mounting hole 2 during the plate processing and contributing to maintaining the sealing of the entire plate processing system.
Example 7
On the basis of any one of embodiments 1 to 6, as shown in fig. 11, the insulating mold body 1 is further provided with a temperature measuring hole 8, the temperature measuring hole 8 is communicated with the cavity 3, and a transparent material 10 is further provided between the temperature measuring hole 8 and the cavity 3 (for ensuring normal infrared temperature measurement, temperature measurement is mainly performed by using the light transmittance of the transparent material). When the plate is processed, because the plate is completely placed in the die, the contact type galvanic couple driven by electric heating cannot be used, and the temperature can be measured by utilizing the light transmittance of the transparent material. The transparent material 10 may be transparent and high temperature resistant material such as transparent ceramic and glass.
Example 8
In any of examples 1 to 7, when a sheet material is integrally formed, the sheet material is placed between two molds with the open ends of the two molds facing each other. As shown in fig. 12 to 14, when the sheets are processed, the vertical electrode 4 of the mold placed above the sheet 6 heats the region to be diffusion-bonded of the sheet 6 on the upper layer, the vertical electrode of the mold placed below the sheet heats the region to be diffusion-bonded of the sheet 6 on the lower layer, and after the temperature of diffusion bonding is reached, the regions to be diffusion-bonded of the sheets on the upper and lower layers are diffusion-bonded. And then heating the upper plate and the lower plate 6 to a superplastic forming temperature, introducing gas between the two plates 6, allowing the solder resist-coated area of the upper plate 6 to enter the cavity 5 of the upper die to be attached to the cavity 5 of the upper die, and allowing the solder resist-coated area of the lower plate 6 to enter the cavity 5 of the lower die to be attached to the cavity 5 of the lower die, so as to obtain a product with two layers of hollow structures.
Example 9
On the basis of any one of embodiments 1 to 8, the molds with the opposite open ends are respectively a first mold and a second mold, the vertical electrode in the first mold is a first vertical electrode, and the vertical electrode in the second mold is a second vertical electrode; the first vertical electrode is connected with the positive electrode/negative electrode of a power supply, the second vertical electrode is connected with the negative electrode/positive electrode of the power supply, and the direction of current between the first vertical electrode and the second vertical electrode is from the first vertical electrode to the second vertical electrode or from the second vertical electrode to the first vertical electrode. As shown in fig. 15, if the die above the plate 6 in fig. 15 is a first die, and the die below the plate 16 is a second die, the first vertical electrode above the plate is connected to the negative electrode of the power supply through the lead 13, and the second vertical electrode below the plate is connected to the positive electrode of the power supply through the lead 13 (or the first vertical electrode above the plate is connected to the positive electrode of the power supply through the lead 13, and the second vertical electrode below the plate is connected to the negative electrode of the power supply through the lead 13), the on/off of the vertical electrodes is controlled by using the synchronous switch 14 (or other available switches known in the art may be used, without specific limitation). When the power supply is switched on, a current perpendicular to the plate 6 is formed between the first vertical electrode and the second vertical electrode which are symmetrically arranged up and down, the area of the plate to be diffused and connected is heated vertically, the current is controlled, the temperature of the area (the bottom surface 42 of the vertical electrode) where the vertical electrode is in contact with the plate is stable, and the current auxiliary field activated diffusion connection of the upper plate and the lower plate is carried out. And after the diffusion connection is finished, closing the synchronous switch 14 to cut off the power.
Example 10
On the basis of any one of embodiments 1 to 9, the surface of the plate 6 is also provided with a horizontal electrode 11 for horizontally heating the whole plate 6; the horizontal electrode 11 is provided on the surface of the plate material 6 at a position other than the insulating mold body 1. As shown in fig. 15, horizontal electrodes 11 are disposed on the upper plate and the lower plate in fig. 15, so that the upper plate and/or the lower plate can be electrically heated by the horizontal electrodes 11. When the temperature of the upper and lower layers of plates is stabilized at the forming temperature of the upper and lower layers of plates, gas is introduced between the two plates, and in the process of introducing the gas, the vertical electrode 4 is kept not to move up and down, so that the upper plate and the cavity of the die positioned above the plates are attached to the die, the lower plate and the cavity of the die positioned below the plates are attached to the die, and the superplastic forming process of a hollow structure is realized.
By arranging the horizontal electrode 11 and heating the plate by using the horizontal electrode 11, the deformation performance of the material can be improved by using joule heat and electro-plasticity, and the integrated forming process can realize the integrated forming of the plate, further shorten the high-temperature exposure time and realize the shape control of the high-efficiency composite hollow member.
The superplastic forming adopts horizontal electrode electrifying heating, compared with vertical heating, the current sectional area is greatly reduced, the material heating self-resistance is improved, the heating speed is high, and the total current is reduced; the integrated forming process directly heats the non-diffusion connection area of the plate by current instead of heating the plate by heat conduction, so that the temperature of the plate is more uniform.
Example 11
In any one of embodiments 1 to 10, the horizontal electrodes include a first horizontal electrode and a second horizontal electrode, the first horizontal electrode and the second horizontal electrode are arranged along the extending direction of the plate, the first horizontal electrode is connected to a positive electrode/negative electrode of a power supply, the second horizontal electrode is connected to a negative electrode/positive electrode of the power supply, and the direction of the current flowing between the first horizontal electrode and the second horizontal electrode is from the first horizontal electrode to the second horizontal electrode or from the second pad electrode to the first horizontal electrode.
As shown in fig. 15, the horizontal electrodes disposed on the left and right sides of the insulating mold body 1 on the upper plate are respectively used as a first horizontal electrode and a second horizontal electrode, the first horizontal electrode is electrically connected to the negative electrode of the power supply, and the second horizontal electrode is electrically connected to the positive electrode of the power supply (or the first horizontal electrode is electrically connected to the positive electrode of the power supply, and the second horizontal electrode is electrically connected to the negative electrode of the power supply), and after the power supply is turned on, current flows in the left-right direction of the upper plate, so that the upper plate is horizontally and integrally heated; similarly, set up horizontal electrode on lower floor's panel, also can realize the heating to lower floor's panel, when treating the temperature of upper and lower two-layer panel and reach the temperature of taking shape, let in gas between two panels, at the in-process that lets in gas, keep perpendicular electrode 4 not to take place to reciprocate for the panel of top accomplishes the subsides mould with the die cavity of the mould that is located panel top, the subsides mould is accomplished with the die cavity of the mould that is located panel below to the panel of below, realize the superplastic forming process of panel, obtain the hollow structure component.
Example 12
On the basis of any one of embodiments 1 to 11, the apparatus used in the integrated forming process of the present invention further comprises a loading cylinder 12, wherein the loading cylinder 12 acts on the end of the mold or mold assembly remote from the sheet material to maintain the mold/vertical electrode 4 fixed.
Example 13
In addition to the embodiment 12, the loading pressure cylinder 12 acts on the vertical electrode 4, and the insulating medium 15 is arranged between the loading pressure cylinder 12 and the vertical electrode 4. As shown in fig. 15, the loading cylinder 12 directly acts on the vertical electrode 4, so as to effectively prevent the vertical electrode 4 from being displaced during the heating process of the plate material, which may affect the diffusion bonding and/or superplastic forming of the plate material.
Example 14
On the basis of any one of embodiments 1 to 13, the device used in the integrated forming process of the present invention further includes any one or a combination of several of a power supply, an infrared thermometer 9, a first switch for controlling the on/off of the vertical electrode 4, a second switch for controlling the on/off of the horizontal electrode 11, and a wire 13, wherein the infrared thermometer 9 is disposed at the temperature measuring hole 8 (as shown in fig. 12 and 15).
Example 15
Based on any one of embodiments 1 to 14, the integrated current-assisted SPF/DB forming process of the present invention comprises the following steps: (1) coating a solder resist on a non-diffusion connection area of two adjacent layers of plates; (2) placing the plate 6 obtained by the treatment in the step (1) between 2 moulds, enabling the opening end of the cavity 5 to face the plate and enabling the vertical electrode 4 to be in contact with a to-be-diffused connection area of the plate; (3) the loading pressure cylinder 12 applies pressure to the die (the vertical electrode 4) to maintain the fixation of the whole die (the vertical electrode 4); (4) electrifying the vertical electrode 4, heating the area of the plate 6 contacted with the vertical electrode 4, and realizing the diffusion connection of the plate; (5) after the diffusion connection is completed, the vertical electrode 4 is powered off; (6) electrifying the horizontal electrode 11 to horizontally and integrally heat the plate 6; (6) after the temperature of the sheet material 6 reaches the set temperature, gas is introduced between the two sheet materials to attach the sheet material 6 to the cavity 5, and a formed member is obtained (see fig. 15).
Example 16
In any one of embodiments 1-15, the material of the plate is titanium alloy, and the titanium alloy includes, but is not limited to, titanium-aluminum-niobium alloy and/or titanium-aluminum alloy.
Example 17
In example 16, the plate material includes a titanium aluminum niobium alloy plate material and a titanium aluminum alloy plate material bonded to each other, and the superplastic forming temperature of the titanium aluminum niobium alloy plate material and the titanium aluminum alloy plate material is 970-1000 ℃.
The process can realize the integrated forming of the titanium-aluminum-niobium alloy plate and the titanium-aluminum alloy composite hollow structure and realize the Ti2The AlNb-TiAl-based alloy is subjected to low-pressure, rapid diffusion connection and rapid superplastic forming. The integrated forming process mainly comprises two stages: the first stage is an electro-active diffusion connection stage of the Ti2 AlNb-based alloy plate and the TiAl-based alloy plate, and the second stage is a superplastic forming stage of the Ti2 AlNb-based alloy plate and the TiAl-based alloy plate.
The specific process comprises the following steps: firstly, opening the two lower synchronous switches and closing the two upper synchronous switches, applying a certain pressure to the vertical electrode 4 through the loading pressure cylinder 12, vertically heating the Ti2 AlNb-based alloy plate and the TiAl-based alloy plate at the contact part of the vertical electrode 4, controlling the current, stabilizing the temperature of the contact plate area, and performing current auxiliary field activated diffusion connection of the two materials. After the connection is completed, the lower synchronous switch is closed, the upper synchronous switch is opened, the pressure of the loading pressure cylinder 12 is kept, the plate is horizontally and integrally heated, the current is controlled, when the temperature reaches and stabilizes at 970 + 1000 ℃ of the Ti2AlNb and TiAl thermoforming temperature, gas is introduced between the two plates, and in the process of introducing the gas, the vertical electrode 4 is ensured not to move up and down, so that the plate, the ceramic mold and the cavity 5 are attached to each other, and the superplastic forming process of the composite hollow structure is realized.
Example 18
The hollow sandwich structure member is prepared by adopting the current-assisted SPF/DB integrated forming process, can effectively avoid the problems of excessive plastic deformation and reduced structure performance caused by long-term high temperature in the diffusion connection/superplastic forming process, and realizes the shape control and the controllability of the hollow sandwich structure member.
With Ti2Taking an AlNb-TiAl-based alloy composite hollow structure as an example: the service temperature of the TiAl alloy can reach 700-900 ℃, and Ti can reach2The AlNb alloy has the use temperature of 650 ℃ and has wide application prospect in the field of aerospace. TiAl alloys for parts with higher operating temperatures, Ti2The AlNb alloy is used for parts with lower service temperature, and can exert respective performance advantages of the two materials.
In the aerospace field, the hollow sandwich structure can realize great weight reduction, and belongs to a typical lightweight structure. Therefore, the titanium-aluminum intermetallic compound is combined with the multilayer hollow sandwich structure, so that the advantages of light weight, high temperature resistance and light structure of the material can be fully exerted, double weight reduction is realized, and the titanium-aluminum intermetallic compound has great application potential in the fields of aerospace skins, thermal protection systems and the like with temperature gradients and complex thermal environments. Ti produced by the process of the present invention2The AlNb-TiAl-based alloy composite hollow structure can be applied to the field of aerospace, and solves the problem of structural property reduction caused by local excessive plastic deformation and long-term high temperature.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.