阅读说明：本技术 大变径比异形钛合金薄壁件一体化成形模具及成形方法 (Integrated forming die and forming method for large-reducing-ratio special-shaped titanium alloy thin-wall part ) 是由 王斌 梁滨 刘太盈 李升� 王瑞 朱冬妹 周福见 郭成龙 于 2020-12-01 设计创作，主要内容包括：本发明涉及一种大变径比异形薄壁件一体化成形模具及成形方法,属于航空材料技术领域,解决了现有技术中对大变径比异性薄壁钛合金材料一次吹塑成形中难以控制壁厚均匀性的问题。本发明提供的一种大变径比异形钛合金薄壁件一体化成形模具,包括第一加热区、第二加热区、第三加热区和第四加热区；第一加热区为高温区,对应零件小变形区,设置温度为930℃至950℃；第二加热区为次高温区,对应零件中变形区,设置温度为910℃至930℃；第三加热区为低温区,对应零件大变形区,设置温度为890℃至910℃；第四加热区为次高温区,对应零件中变形区,设置温度为910℃至930℃。实现了在大变径比异性钛合金薄壁件一体化均匀成形。(The invention relates to an integrated forming die and a forming method for a large-reducing-ratio special-shaped thin-wall part, belongs to the technical field of aviation materials, and solves the problem that the uniformity of the wall thickness is difficult to control in one-time blow molding of a large-reducing-ratio special-shaped thin-wall titanium alloy material in the prior art. The invention provides an integrated forming die for a large-reducing-ratio special-shaped titanium alloy thin-wall part, which comprises a first heating area, a second heating area, a third heating area and a fourth heating area, wherein the first heating area is a cylindrical surface; the first heating area is a high-temperature area, corresponds to a small deformation area of the part and is set to be 930-950 ℃; the second heating area is a secondary high temperature area, corresponds to a deformation area in the part and is set to be 910-930 ℃; the third heating area is a low-temperature area, corresponds to a large deformation area of the part and is set to be 890-910 ℃; the fourth heating area is a secondary high-temperature area, and the temperature is set to be 910-930 ℃ corresponding to the deformation area in the part. The integrated uniform forming of the anisotropic titanium alloy thin-wall part with the large diameter-changing ratio is realized.)

1. The integrated forming die for the special-shaped titanium alloy thin-wall part with the large reducing ratio is characterized by comprising a first heating area, a second heating area, a third heating area and a fourth heating area;

the first heating area is a high-temperature area, corresponds to a small part deformation area, and is set to be 930-950 ℃;

the second heating area is a secondary high-temperature area, corresponds to a deformation area in the part and is set to be 910-930 ℃;

the third heating area is a low-temperature area, corresponds to a large deformation area of the part and is set to be 890-910 ℃;

the fourth heating area is a secondary high-temperature area, corresponds to a deformation area in the part, and is set to be 910-930 ℃.

2. The integrated forming die for the large-reducing-ratio special-shaped titanium alloy thin-wall part according to claim 1, wherein a first heating zone, a second heating zone, a third heating zone and a fourth heating zone are sequentially arranged, and a large-diameter end of a blank of the large-reducing-ratio special-shaped titanium alloy thin-wall part corresponds to the first heating zone; and the small-diameter end of the blank of the special-shaped titanium alloy thin-wall part with the large reducing ratio corresponds to the fourth heating area.

3. The integrated forming die for the large reducing ratio special-shaped titanium alloy thin-wall part according to claim 1, wherein the blank of the large reducing ratio special-shaped titanium alloy thin-wall part is conical.

4. The integral forming die for the large reducing ratio special-shaped titanium alloy thin-wall part according to claim 1, wherein the titanium alloy comprises one or more of TC4, TA15, Ti55, Ti60 and Ti2 AlNb.

5. The integrated forming die for the large reducing ratio special-shaped titanium alloy thin-wall part according to claim 1, wherein the wall thickness of the thin-wall part is not more than 3 mm.

6. The integrated forming method of the special-shaped titanium alloy thin-wall part with the large reducing ratio is characterized in that the integrated forming die of the special-shaped titanium alloy thin-wall part with the large reducing ratio, which is disclosed by claims 1 to 5, is used for integrally forming a special-shaped component in an air pressure loading forming mode.

7. The integrated forming method of the large reducing ratio special-shaped titanium alloy thin-wall part according to claim 6, characterized by comprising the following steps of:

step a, heating a first heating area, a second heating area, a third heating area and a fourth heating area by a heating unit, and starting air pressure loading forming after each heating area reaches a set temperature field;

b, loading air pressure to 0.2-0.5MPa, and keeping the pressure;

c, increasing the air pressure, loading the air pressure to 1.0-2.0MPa, keeping the pressure, and waiting for the material in the high-temperature area to be completely attached to the die;

and d, uniformly heating all the heating areas, loading the air pressure to 1.0-2.0MPa, and keeping the pressure so that each part of the part is fully attached to the die.

8. The integrated forming method for the large reducing ratio special-shaped titanium alloy thin-wall part according to claim 7, wherein in the step b, the pressure is kept for 10-25 min;

keeping the pressure in the step c for 10-20 min;

and d, keeping the pressure for 10-20min in the step d.

9. The integrated forming method for the large reducing ratio special-shaped titanium alloy thin-wall part according to claim 7, wherein the pressure loading rate in the step b is 0.01-0.015 MPa/min;

and the pressure loading rate in the step c is 0.01-0.015 MPa/min.

10. The integrated forming method for the special-shaped titanium alloy thin-wall part with the large reducing ratio as claimed in claim 7, wherein in the step d, all heating regions are uniformly heated to 940-960 ℃.

Technical Field

The invention relates to the technical field of aviation materials, in particular to an integrated forming die and a forming method for a special-shaped titanium alloy thin-wall part with a large reducing ratio.

Background

Along with the improvement of the flying speed of the aircraft, the appearance of the main structure is more complex, the size is obviously increased, and the precision control requirement is stricter. The structural form of the aircraft is changed from a single revolving body to a complex profile, and from split small part assembly to integrated large-scale parts, the aircraft has the characteristics of large-scale integration, thin wall and light weight, complicated shape and the like, has high manufacturing difficulty, high precision requirement and long production period, and has become a bottleneck for restricting the rapid development of the aircraft.

The large-reducing-ratio part is a special curved surface part with the ratio of the maximum diameter to the minimum diameter of the part larger than 3, the large-reducing-ratio thin-wall integral titanium alloy part mainly comprises TC4, TA15, Ti55, Ti60 and Ti2AlNb, and the application of the large-reducing-ratio thin-wall integral titanium alloy part is more and more in demand along with the development of aerospace. The traditional hot forming and tailor-welding manufacturing method needs multiple forming, welding and high-temperature annealing to finish the process, so that the precision is difficult to improve, the tissue performance is repeatedly lost due to frequent high temperature, and the thickness of the oxygen-enriched layer on the surface is rapidly increased. For some parts with complex profile, small cross sections at two ends and large size of the middle cross section, the height difference between the two ends and the middle part is large, and the two ends of the skin are wrinkled only by hot-press forming. In order to avoid hot-press forming wrinkles, blank pressing stretching forming is needed, so that large hot forming equipment with an automatic blank pressing device is needed, and the prior art does not meet the requirement of titanium alloy hot stretching equipment. The existing process method adopts a forming mode of peripheral screw fixation, and due to the special shape of a part, screws need to be fastened for many times in the forming process, so that a skin needs to enter a furnace for many times to undergo thermal cycle, the forming time is long, the thickness of an oxygen-rich alpha layer on the surface after forming reaches more than 0.2mm, the thick oxide layer is difficult to remove in an acid washing or grinding mode, the oxygen-rich alpha layer is a typical brittle layer and seriously damages the mechanical property of the titanium alloy, and meanwhile, the oxygen-rich alpha layer is a welding crack source, and the serious consequence of the oxygen-rich alpha layer is that batch cracks are generated during the welding of subsequent reinforcing ribs, the product cannot be used.

Therefore, the air pressure loading forming, namely the superplastic forming, is a new technical trend without the screw fixing form. However, the traditional air pressure loading generally completes pressurization and pressure maintaining through a stepped loading curve, the loading mode is relatively simple, and the reason that the deformation uniformity is improved by effectively utilizing the temperature field change and the air pressure loading change cannot be effectively utilized.

Disclosure of Invention

In view of the above analysis, the invention aims to provide an integrated forming method for a large-reducing-ratio special-shaped thin-wall part, which is used for solving the problem that the uniformity of the wall thickness is difficult to control in the one-time blow molding of a large-reducing-ratio special-shaped thin-wall titanium alloy material in the prior art.

On one hand, the invention provides an integrated forming die for a large-reducing-ratio special-shaped titanium alloy thin-wall part, which comprises a first heating zone, a second heating zone, a third heating zone and a fourth heating zone;

the first heating area is a high-temperature area, corresponds to a small part deformation area, and is set to be 930-950 ℃;

the second heating area is a secondary high-temperature area, corresponds to a deformation area in the part and is set to be 910-930 ℃;

the third heating area is a low-temperature area, corresponds to a large deformation area of the part and is set to be 890-910 ℃;

the fourth heating area is a secondary high-temperature area, corresponds to a deformation area in the part, and is set to be 910-930 ℃.

Further, the first heating zone, the second heating zone, the third heating zone and the fourth heating zone are sequentially arranged, and the large-diameter end of the blank of the special-shaped titanium alloy thin-wall part with the large reducing ratio corresponds to the first heating zone; and the small-diameter end of the blank of the special-shaped titanium alloy thin-wall part with the large reducing ratio corresponds to the fourth heating area.

Further, the blank of the special-shaped titanium alloy thin-wall part with the large reducing ratio is conical.

Further, the titanium alloy includes one or more of TC4, TA15, Ti55, Ti60, and Ti2 AlNb.

Further, the wall thickness of the thin-wall part is not more than 3 mm.

On the other hand, the invention provides an integrated forming method of a large-reducing-ratio special-shaped titanium alloy thin-wall part, which is characterized in that the integrated forming die of the large-reducing-ratio special-shaped titanium alloy thin-wall part is used for integrally forming a special-shaped component in an air pressure loading forming mode.

Further, comprising:

step a, heating each heating area by a heating unit, and starting air pressure loading and forming after each heating area reaches a set temperature field;

b, loading air pressure to 0.2-0.5MPa, and keeping the pressure;

c, increasing air pressure, loading the air pressure to 1.0-2.0MPa, keeping the pressure, and waiting for the material in the deformation area to be completely attached to the mold;

and d, uniformly heating all the heating areas, loading the air pressure to 1.0-2.0MPa, and keeping the pressure so that each part of the part is fully attached to the die.

Further, keeping the pressure in the step b for 10-25 min;

keeping the pressure in the step c for 10-20 min;

and d, keeping the pressure for 10-20min in the step d.

Further, the pressure loading rate in the step b is 0.01-0.015 MPa/min;

and the pressure loading rate in the step c is 0.01-0.015 MPa/min.

Further, in the step d, all the heating zones are uniformly heated to 940-960 ℃.

Compared with the prior art, the invention can realize at least one of the following beneficial effects:

(1) the traditional air pressure loading generally completes pressurization and pressure maintaining through a stepped loading curve, the loading mode is relatively simple, and the deformation sequence of different areas of a complex structure is controlled through dynamic combination of temperature field change and air pressure loading change.

(2) According to the invention, the mould is partitioned, different partitions are heated at different temperatures at different stages, different loading air pressures are adopted at different stages, a dynamic loading mode matched with the dynamic loading mode is formed aiming at the shape characteristics of the thin-wall component with the large reducing ratio and the circular cross section, the stress-strain distribution, the strain rate change characteristic and the influence of the deformation characteristic on the integral thickness distribution of the component under the loading condition are fully considered, and the uniform superplastic forming of the special-shaped thin-wall component with the large reducing ratio is effectively realized by the temperature/follow-up distribution air pressure loading deformation uniformity control technology.

In the invention, the technical schemes can be combined with each other to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.

FIG. 1a is a schematic front view of a titanium alloy part with a large diameter-changing ratio;

FIG. 1b is a schematic sectional view of a titanium alloy part A-A with a large reducing ratio;

FIG. 1c is a schematic cross-sectional view of a titanium alloy part B-B with a large reducing ratio;

FIG. 2 is a schematic view of a conical billet;

FIG. 3 is a schematic view of a two-end welding seal plate;

FIG. 4 is a schematic view of a welded air inlet tube;

FIG. 5 is a schematic view of a temperature zone distribution;

fig. 6 is a schematic view of material flow during forming.

Reference numerals:

1-a first seal welding plate; 2-a second seal welding plate; 3, an air inlet pipe; 4-a first heating zone; 5-a second heating zone; 6-a third heating zone; 7-fourth heating zone.

Detailed Description

The large reducing ratio part is a special curved surface part with the ratio of the maximum diameter to the minimum diameter of the part larger than 3. The superplastic forming component with the large reducing ratio is mainly formed by air pressure loading, the deformation characteristic of the component is directly determined by an air pressure loading mode, at present, the traditional air pressure loading generally completes pressurization and pressure maintaining through a stepped loading curve, the loading mode is relatively simple, and the temperature field change and the air pressure loading change cannot be effectively utilized to improve the deformation uniformity. The study on the temperature/follow-up distributed air pressure loading technology mainly realizes the control of the deformation sequence of different areas of a complex structure through the dynamic combination of the temperature field change and the air pressure loading change.

The invention provides an integrated forming die for a large-reducing-ratio special-shaped thin-wall part, which comprises a first heating area 4, a second heating area 5, a third heating area 6 and a fourth heating area 7;

the first heating area 4 is a high-temperature area, corresponds to a small deformation area of the part and is set to be 920-950 ℃;

the second heating area 5 is a secondary high temperature area, corresponds to a deformation area in the part and is set to be 900-930 ℃;

the third heating area 6 is a low-temperature area, corresponds to a large deformation area of the part and is set to be 880-910 ℃;

the fourth heating zone 7 is a secondary high temperature zone corresponding to the deformation zone in the part and is set at 900-930 ℃.

The heating function of each heating zone in the die can be realized by three modes of pipeline heating, electric heating and optical heating. The pipe heating is provided with a plurality of heating pipes in the heating area, and heating fluid passes through the heating pipes. The electric heating mode adopts an electric heating wire, and heating is realized through the thermal resistance of the electric heating wire after electrification. The optical heating is to heat the blank by light waves suitable for heating to realize the air pressure loading forming, and in consideration of the characteristics of various light waves, infrared light or microwaves are adopted to realize the heating function of the heating area in one possible embodiment. In order to realize uniform heating, the arrangement of the heating pipe for heating the pipeline, the heating wire for realizing the electric heating mode and the light generator in the light heating mode should be uniformly arranged, so that the influence on the forming process caused by nonuniform heating is prevented.

On the same cross section, the diameter of the blank before the air pressure loading forming is d₀And if the diameter of the formed thin-wall part is d, the deformation rate delta is as follows:

the small deformation area is delta less than 10%, the medium deformation area is delta more than or equal to 10% and less than 20%, and the large deformation area is delta more than or equal to 20%.

Because the titanium alloy has the special thermal property of high temperature resistance, the anisotropic piece with large variation ratio can not realize effective deformation in the existing integrated forming die in the air pressure loading forming process, the deformation effect is not good, and the wall thickness of the titanium alloy thin-wall piece after integrated forming is uneven. The invention adopts zone heating, the heating temperature of different zones is continuously changed along with the heating in the forming process, and the loading air pressure is continuously changed, so that the integrated forming die which is changed along with the temperature is obtained.

Specifically, a first heating zone 4, a second heating zone 5, a third heating zone 6 and a fourth heating zone 7 can be sequentially arranged, and the large-diameter end of the blank of the special-shaped titanium alloy thin-wall part with the large reducing ratio corresponds to the first heating zone; and the small-diameter end of the blank of the special-shaped titanium alloy thin-wall part with the large reducing ratio corresponds to the fourth heating area.

Specifically, the blank of the special-shaped titanium alloy thin-wall part with the large reducing ratio is conical.

Specifically, the titanium alloy includes one or more of TC4, TA15, Ti55, Ti60, and Ti2 AlNb.

Specifically, the wall thickness of the thin-wall part is not more than 3 mm.

The invention provides an integrated forming method of a large-reducing-ratio special-shaped thin-wall part, which comprises the following steps:

design of blank

The blank is designed into a cone shape in the embodiment, the maximum diameter of the cross section of the cone-shaped blank is 0.7-0.8 times of the maximum diameter of the cross section of the target special-shaped component, the maximum diameter of the cross section of the cone-shaped blank is 0.9-0.9 times of the maximum diameter of the cross section of the target special-shaped component, and the length of the blank is 1.1-1.2 times of the length of the target special-shaped component.

Step two, forming process design

Through experimental research, the forming temperature fields of Ti55 and Ti60 are in the range of 880-940 ℃, and the forming temperature field of TA15 titanium alloy is in the range of 880-920 ℃; the forming temperature field of TC4 is between 880 and 960 ℃, and the forming temperature field of Ti2AlNb is between 900 and 960 ℃; finite element software can be adopted for simulation, the temperature field distribution during forming is simulated, and the forming temperature field and the loading air pressure change at different stages are determined.

Step three, preparing conical blank

Step 3a, calculating a developed material according to a blank result of simulation optimization;

step 3b, laser cutting and blanking;

step 3c. preparing a conical billet, illustratively using the rolling + thermoforming of patent ZL 201218006301.7;

step 3d, pickling the conical tube blank;

welding seal welding plate

And 4a, preparing a first sealing and welding plate 1 and a second sealing and welding plate 2 of titanium alloy at two ends by blanking, wherein a titanium alloy plate made of the same material as the tube blank is adopted, and the thickness of the titanium alloy sealing and welding plate is the thickness of the target special-shaped component.

Step 4b, pickling the first sealing and welding plate 1 and the second sealing and welding plate 2 according to a titanium alloy pickling process;

step 4c, welding a first titanium alloy sealing plate 1 and a second titanium alloy sealing plate 2 at two ends of the conical barrel blank, and performing sealing welding by adopting a vacuum argon arc welding mode or an argon arc welding mode with good protection measures;

step 4d, welding the air inlet pipe 3, wherein the air inlet pipe can adopt a TA15 or TA18 titanium alloy pipe, and the diameter of the titanium alloy pipeThe length is 5-15 mm;

step 4e, checking air tightness, namely checking the air tightness of the welding seam by adopting pressing, keeping the pressure for 4-6min at 0.01-0.03MPa, and simultaneously detecting the leakage by combining soapy water;

step 4f, coating an anti-oxidation coating on the outer surface of the part after sealing and welding and naturally drying;

step five, assembling

Step 5a, putting the blank into a die;

step 5b, checking the air tightness again;

step six, setting process parameters

Step 6a, setting heating temperatures of heating zones in the die:

the first heating area 4 is a high-temperature area, and corresponds to a small deformation area of a part, and the temperature is set as follows: 920 to 940 ℃;

the second zone of heating 5 is inferior high temperature region, corresponds deformation zone in the part, sets up the temperature: 910 to 960 ℃;

the third heating area 6 is a low-temperature area, corresponds to a large deformation area of the part, and is set with the following temperature: 880 to 900 ℃;

the fourth zone of heating 7 is inferior high temperature region, corresponds deformation zone in the part, sets up the temperature: 910 to 960 ℃;

step 6b, adjusting a gas pipeline and setting a loading gas pressure parameter;

step seven, air pressure loading forming

Step 7a, heating each heating area of the die, and starting air pressure loading and forming after each heating area of the die reaches a set temperature field;

step 7b, loading air pressure to 0.2-0.5MPa at a loading rate of 0.01-0.015MPa/min, and maintaining the pressure for 10-25min to enable the material to deform slightly, wherein the first heating area 4 and the fourth heating area 7 of the material have large material softening deformation due to high temperature, the second heating area 5 and the third heating area 6 have large material deformation difficulty due to low temperature, and the second heating area 5 and the third heating area 6 can drag the materials of the first heating area 4 and the fourth heating area 7 to the middle;

and 7c, increasing the air pressure, loading the air pressure to 1.0-2.0MPa at a loading rate of 0.01-0.015MPa/min, and maintaining the pressure for 10-20 min. Waiting for the material of the easily-deformable area to be completely attached to the mold;

step 7d, uniformly heating the first heating area 4, the second heating area 5, the third heating area 6 and the fourth heating area 7 to 890-;

and 7e, starting to cool, wherein in the cooling process, in order to maintain the shape of the part, the air pressure is kept at 0.01-0.05 MPa.

Step eight, discharging and taking out

Cooling after the forming is finished, unloading the internal air pressure of the part when the part is cooled to 400-650 ℃, and taking out the part;

step nine, cutting off the technical edge

And (5) mechanically processing to remove the process edge of the part, and then treating the surface of the part.

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.

Example one

The invention discloses a method for integrally forming a special-shaped thin-wall part with a large reducing ratio.

In the embodiment, the selected material is Ti60 high-temperature titanium alloy, the axial size (length) of the part is 560mm, the maximum diameter is 480mm, the minimum diameter is 150mm, the diameter change ratio is 3.2, and the thickness of the selected material plate is 2mm, as shown in figures 1a, 1b and 1 c.

Design of blank

The blank is optimally designed by adopting a finite element method to maximize the shape of the blank, and the blank is designed to be tapered (the longitudinal section is trapezoidal), wherein the maximum diameter of the tapered blank is 420mm, the minimum diameter is 140mm, and the length is 650mm, as shown in fig. 2.

Step two, forming process design

And (3) determining the deformation size of each area in the forming process by adopting finite element software through a simulation forming process so as to determine the distribution of the heating area and determine the change of loading air pressure at different stages. According to simulation, the Ti60 forming temperature field is in the range of 880-940 ℃;

step three, preparing conical blank

Step 3a, calculating a developed material according to a blank result of simulation optimization;

step 3b, laser cutting and blanking;

step 3c, preparing a conical blank, specifically, preparing the conical blank by using the rolling and hot forming of patent ZL 201218006301.7;

step 3d, pickling the conical tube blank;

welding seal welding plate

Step 4a, preparing a first titanium alloy seal welding plate 1 and a second titanium alloy seal welding plate 2 by blanking, wherein the diameter of the first seal welding plate 1 is 420mm, the thickness of the first seal welding plate is 2mm, a titanium alloy plate made of the same material as the tube blank is adopted, the diameter of the second titanium alloy seal welding plate 2 is 140mm, the thickness of the second titanium alloy seal welding plate is 2mm, and a titanium alloy plate made of the same material as the tube blank is also adopted, as shown in figure 3;

step 4b, pickling the first sealing and welding plate 1 and the second sealing and welding plate 2 according to a titanium alloy pickling process;

step 4c, welding a first titanium alloy sealing plate 1 and a second titanium alloy sealing plate 2 at two ends of the conical barrel blank, and performing sealing welding by adopting a vacuum argon arc welding mode or an argon arc welding mode with good protection measures;

and 4d, as shown in fig. 4, welding an air inlet pipe 3 at the end of the first seal welding plate 1, wherein the air inlet pipe can be a TA15 titanium alloy pipe with the diameterThe length of the titanium alloy tube is 8 mm;

step 4e, checking air tightness, namely checking the air tightness of the welding seam by adopting pressing, keeping the pressure for 5min at 0.02MPa, and simultaneously detecting leakage by combining soapy water;

step 4f, coating an anti-oxidation coating on the outer surface of the part after sealing and welding and naturally drying;

step five, assembling

Step 5a, putting the blank into a die;

step 5b, checking the air tightness again;

step six, setting process parameters

Step 6a, setting the heating temperature of each electric heating zone in the die, as shown in fig. 5:

the first heating area 4 is a high-temperature area, and corresponds to a small deformation area of a part, and the temperature is set as follows: 920 to 940 ℃;

the second zone of heating 5 is inferior high temperature region, corresponds deformation zone in the part, sets up the temperature: 900 to 920 ℃;

the third heating area 6 is a low-temperature area, corresponds to a large deformation area of the part, and is set with the following temperature: 880 to 900 ℃;

the fourth zone of heating 7 is inferior high temperature region, corresponds deformation zone in the part, sets up the temperature: 900-920 ℃;

step 6b, adjusting a gas pipeline and setting a loading gas pressure parameter;

step seven, air pressure loading forming

Step 7a, heating each heating area of the die, and starting air pressure loading and forming after each heating area of the die reaches a set temperature field;

step 7b, loading air pressure to 0.3MPa at a loading rate of 0.01MPa/min, maintaining the pressure for 15min, so that the material is slightly deformed, at the moment, the materials in the first heating area 4 and the fourth heating area 7 are softened and deformed greatly due to high temperature, the materials in the second heating area 5 and the third heating area 6 are deformed difficultly due to low temperature, and the materials in the first heating area 4 and the fourth heating area 7 are dragged towards the middle by the second heating area 5 and the third heating area 6, as shown in FIG. 6;

and 7c, increasing the air pressure, loading the air pressure to 1.0MPa at the loading rate of 0.01MPa/min, and maintaining the pressure for 15 min. Waiting for the materials of the first heating area 4 and the fourth heating area 7 to be completely attached to the die;

step 7d, uniformly heating the first heating area 4, the second heating area 5, the third heating area 6 and the fourth heating area 7 to 940 ℃, loading the air pressure to 1.5MPa, and maintaining the pressure for 15min to ensure that each part of the part is fully attached to the die;

and 7e, starting to cool, wherein in the cooling process, in order to maintain the shape of the part, the air pressure is kept at 0.02 MPa.

Step eight, discharging and taking out

Cooling after the forming is finished, unloading the air pressure in the part when the part is cooled to 600 ℃, and discharging and taking out the part;

step nine, cutting off the technical edge

And (5) mechanically processing to remove the process edge of the part, and then treating the surface of the part.

After forming, the wall thickness of each part is measured, and the wall thickness of each part of the two parts is between 1.8mm and 2.2mm, so that the requirements of the wall thickness and the uniformity are met.

Example two

The invention discloses a method for integrally forming a special-shaped thin-wall part with a large reducing ratio.

In the embodiment, the selected material is TA15 high-temperature titanium alloy, the axial size (length) of the part is 600mm, the maximum diameter is 500mm, the minimum diameter is 150mm, the diameter change ratio is 3.33, and the thickness of the selected material plate is 2 mm.

Design of blank

The blank is designed into a cone shape in the embodiment, the maximum diameter of the cone-shaped blank is 450mm, the minimum diameter is 145mm, and the length is 700 mm.

Step two, forming process design

Finite element software is adopted, the simulation forming is temperature field distribution, and the loading air pressure changes at different stages. According to simulation, the forming temperature field range of TA15 titanium alloy is 880-920 ℃;

step three, preparing conical blank

Step 3a, calculating a developed material according to a blank result of simulation optimization;

step 3b, laser cutting and blanking;

step 3c, preparing a conical blank by using the rolling and hot forming of patent ZL 201218006301.7;

step 3d, pickling the conical tube blank;

welding seal welding plate

And 4a, preparing a first titanium alloy seal welding plate 1 and a second titanium alloy seal welding plate 2 by blanking, wherein the diameter of the first seal welding plate 1 is 450mm, the thickness of the first seal welding plate is 2mm, a titanium alloy plate made of the same material as the tube blank is adopted, the diameter of the second titanium alloy seal welding plate 2 is 145mm, the thickness of the second titanium alloy seal welding plate is 2mm, and a titanium alloy plate made of the same material as the tube blank is also adopted.

Step 4b, pickling the first sealing and welding plate 1 and the second sealing and welding plate 2 according to a titanium alloy pickling process;

step 4c, welding a first titanium alloy sealing plate 1 and a second titanium alloy sealing plate 2 at two ends of the conical barrel blank, and performing sealing welding by adopting a vacuum argon arc welding mode or an argon arc welding mode with good protection measures;

step 4d, welding an air inlet pipe 3 at the end of the first seal welding plate 1, wherein the air inlet pipe can be a TA18 titanium alloy pipe, and the diameter of the titanium alloy pipeThe length is 10 mm;

step 4e, checking air tightness, namely checking the air tightness of the welding seam by adopting pressing, keeping the pressure for 5min at 0.015MPa, and simultaneously detecting leakage by combining soapy water;

step 4f, coating an anti-oxidation coating on the outer surface of the part after sealing and welding and naturally drying;

step five, assembling

Step 5a, putting the blank into a die;

step 5b, checking the air tightness again;

step six, setting process parameters

Step 6a, setting the heating temperature of each light heating area in the die:

the first heating area 4 is a high-temperature area, and corresponds to a small deformation area of a part, and the temperature is set as follows: 930-950 ℃;

the second zone of heating 5 is inferior high temperature region, corresponds deformation zone in the part, sets up the temperature: 910 to 930 ℃;

the third heating area 6 is a low-temperature area, corresponds to a large deformation area of the part, and is set with the following temperature: 890 to 910 ℃;

the fourth zone of heating 7 is inferior high temperature region, corresponds deformation zone in the part, sets up the temperature: 910 to 930 ℃;

step 6b, adjusting a gas pipeline and setting a loading gas pressure parameter;

step seven, air pressure loading forming

Step 7a, heating each heating area of the die, and starting air pressure loading and forming after each heating area of the die reaches a set temperature field;

step 7b, loading air pressure to 0.2MPa at a loading rate of 0.012MPa/min, maintaining the pressure for 15min, so that the material is slightly deformed, at the moment, the materials in the first heating area 4 and the fourth heating area 7 are softened and deformed greatly due to high temperature, the materials in the second heating area 5 and the third heating area 6 are deformed difficultly due to low temperature, and the materials in the first heating area 4 and the fourth heating area 7 are dragged towards the middle by the second heating area 5 and the third heating area 6;

and 7c, increasing the air pressure, loading the air pressure to 1.5MPa at the loading rate of 0.012MPa/min, and maintaining the pressure for 15 min. Waiting for the materials of the first heating area 4 and the fourth heating area 7 to be completely attached to the die;

step 7d, uniformly heating the first heating area 4, the second heating area 5, the third heating area 6 and the fourth heating area 7 to 950 ℃, loading the air pressure to 1.6MPa, and maintaining the pressure for 15min to ensure that each part of the part is fully attached to the die;

and 7e, starting to cool, wherein in the cooling process, in order to maintain the shape of the part, the air pressure is kept at 0.02 MPa.

Step eight, discharging and taking out

Cooling after the forming is finished, unloading the air pressure in the part when the part is cooled to 650 ℃, discharging the part out of the furnace and taking out the part;

step nine, cutting off the technical edge

And (5) mechanically processing to remove the process edge of the part, and then treating the surface of the part.

After forming, the wall thickness of each part is measured, and the wall thickness of each part of the two parts is between 1.8mm and 2.2mm, so that the requirements of the wall thickness and the uniformity are met.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.