CN-122007560-A - Rolling welding/high-pressure air expansion composite forming method for high-temperature titanium alloy skin with hollow reinforcing ribs

CN122007560ACN 122007560 ACN122007560 ACN 122007560ACN-122007560-A

Abstract

The invention discloses a roll welding/high-pressure air expansion composite forming method for a high-temperature titanium alloy skin with hollow reinforcing ribs, and relates to the technical field of plastic processing. The high-temperature titanium alloy is subjected to high-pressure gas expansion forming at a low temperature (lower than 850 ℃), and the material performance loss is reduced by combining a novel low-temperature high-pressure gas expansion composite forming process through roll welding connection. The high-temperature titanium alloy skin comprises skin and reinforcing ribs, wherein the reinforcing ribs are communicated in a crisscross mode and are arranged on the inner side of the skin, the skin is arranged on the outer side of the skin, and the high-temperature titanium alloy skin is formed according to the following steps of S1, roll welding connection of skin reinforcing rib plates, and S2, low-temperature high-pressure inflation forming of the skin reinforcing rib plates. The low-temperature high-pressure air-expansion forming is adopted, the condition that the performance of a formed part is obviously reduced due to high forming temperature is effectively improved, the performance loss is reduced, the wrinkle defect on the surface of the part is effectively reduced, the surface quality of the part is good, and the subsequent surface treatment is easy.

Inventors

LIU TAIYING
LIANG BIN
WU YONG
CHEN MINGHE
DONG JIANJIAN

Assignees

南京航空航天大学

Dates

Publication Date: 20260512
Application Date: 20260209

Claims (5)

1. The roll welding/high-pressure air expansion composite forming method for the high-temperature titanium alloy skin with the hollow reinforcing ribs is characterized in that the high-temperature titanium alloy skin comprises a skin and reinforcing ribs, wherein the reinforcing ribs are communicated in a crisscross manner and are arranged on the inner side of the skin, the skin is arranged on the outer side, and the forming is carried out according to the following steps: Step S1, roll welding and connecting skin reinforcing rib plates; S1.1, designing the sizes of the skin and the reinforcing rib plate, reserving a preset allowance at the periphery of the area where the reinforcing rib is positioned, performing laser cutting on the skin and the reinforcing rib plate, and polishing burrs; s1.2, designing a roll welding template according to the position of the formed reinforcing rib; s1.3, polishing the welding surfaces of the skin and the reinforcing rib plate, and cleaning the surfaces of the plates by pickling; s1.4, drawing a roll welding position line on the plate according to a roll welding template, assembling a skin and a reinforcing rib plate, roll welding the peripheral area of the reinforcing rib on the two layers of plates and the peripheral edge area of the plate, firstly roll welding the roll welding position line of the middle part, and then roll welding four sides; s2, performing low-temperature high-pressure inflation forming on the skin reinforcing rib plate; s2.1, carrying out numerical simulation on the reinforcing rib plate to determine low-temperature high-pressure air-expansion forming technological parameters; s2.2, manually argon arc welding a vent pipe on the part welded in the step S1.4, then installing the part on a die, positioning the part by using a positioning pin, and installing the die in a high-temperature forming equipment platform; Step S2.3, installing an externally connected ventilation pipeline, heating according to the technological parameters determined in the step S2.1, and performing low-temperature internal high-pressure forming after reaching the temperature; And S2.4, cooling to a preset temperature and taking out the part.
2. The roll-welding/high-pressure air-expanding composite forming method for the high-temperature titanium alloy skin with the hollow reinforcing ribs according to claim 1, wherein in the step S1.4, the roll-welding width is 5mm, and the roll-welding distance is 1mm from the edge of the reinforcing ribs.
3. The roll welding/high-pressure air-expanding composite forming method for the high-temperature titanium alloy skin with the hollow reinforcing ribs according to claim 2, wherein when the skin and the reinforcing rib plate are made of different titanium alloy materials; The skin and the reinforcing rib plate designed in the step S1.1 are respectively extended with transition tongue plates at the positions of the air inlets, so that the positions of the reserved air inlets are formed after assembly; in step S1.4, in addition to the seam welding at the seam welding position line and four sides, two additional seam welding steps are required to be performed at the reserved air inlet position, and an air inlet channel is formed between the two seam welding positions.
4. The method for forming the high-temperature titanium alloy skin by low-temperature high-pressure gas expansion according to claim 3, wherein the vent pipe welded in the step S2.2 is made of TA18 with the specification of phi 6 multiplied by 1, and stainless steel pipes are sleeved outside the vent pipe for increasing the bearing capacity; when the skin and the reinforcing rib plate are made of different titanium alloy materials, the ventilation pipe is sleeved on the transition tongue plate of the skin and the reinforcing rib plate and welded with the transition tongue plate.
5. The roll welding/high-pressure air-expanding composite forming method for the high-temperature titanium alloy skin with the hollow reinforcing ribs according to claim 1, wherein the step S2.3 is specifically: The skin is arranged in a mould, the mould is arranged on a platform of the equipment, the platform is pressed down to be close to the mould, the equipment is started to heat, the interior of a component is continuously vacuumized in the heating process, the temperature reaches 600 ℃, the platform is pressed down to enable the mould to compress the component, the pressure of 0.01MPa is introduced into the interior of the mould, the temperature is continuously increased to 850 ℃, the internal high-pressure superplastic forming is started, at the moment, a vent pipe is connected with a high-pressure air source to perform forming according to a set air pressure loading curve, the maximum pressure is increased to 19MPa, and the pressure is maintained for 90min.

Description

Rolling welding/high-pressure air expansion composite forming method for high-temperature titanium alloy skin with hollow reinforcing ribs Technical Field The invention relates to the technical field of plastic processing, in particular to a roll welding/high-pressure air expansion composite forming method for a high-temperature titanium alloy skin with hollow reinforcing ribs. Background The novel aircraft structural material is gradually changed from aluminum alloy, titanium alloy to high-temperature titanium alloy (Ti 60/Ti 65) and other light high-temperature resistant materials, the novel aircraft fuselage wing and other skin structures are formed by adopting thin plates, so that the manufacturing period is further shortened, the reliability is improved, and the prior art proposes to adopt two layers of integral skin panels with reinforcing ribs as the production materials of the novel aircraft. The traditional processing method of the integral skin panel with the reinforcing ribs is mostly completed by adopting a superplastic forming/diffusion connecting process, but the traditional diffusion connecting process has complex pretreatment, poor precision of diffusion connecting areas and possibly causes defects such as grooves on the surface. On the other hand, the superplastic forming/diffusion connection of the high-temperature titanium alloy sheet is generally carried out at a high temperature (920-950 ℃), the working procedure is long, the high-temperature forming time is 7-9 hours, the heating and cooling time is usually 2-3 days, the surface oxidation is increased due to the long time in a high-temperature environment, meanwhile, titanium alloy grains are coarsened, the hydrogen absorption risk is increased, the forming size and precision are affected, and the performance is damaged. Particularly, the high-temperature titanium alloy has higher oxidation sensitivity, and has larger influence on plasticity and welding performance after long-time high Wen Liucheng, so that the application of the high-temperature titanium alloy in aerospace is restricted for a long time. Therefore, how to optimize the processing of the high-temperature titanium alloy sheet from the processing means, so that the high-temperature titanium alloy sheet can be stably formed into a preset structural form, and various defects caused by the traditional process can be avoided, and the high-temperature titanium alloy sheet is a technical problem to be solved by the person skilled in the art. Disclosure of Invention Aiming at the problems, the invention provides a roll welding/high-pressure air expansion composite forming method for a high-temperature titanium alloy skin with hollow reinforcing ribs, which enables the high-temperature titanium alloy to be subjected to high-pressure air expansion forming at a low temperature (lower than 850 ℃), and reduces material performance loss by combining a new low-temperature high-pressure air expansion composite forming process with roll welding connection, thereby being beneficial to material performance maintenance and solving the problems that the existing processing process cannot form a double-layer skin connection area and performance loss. The high-temperature titanium alloy skin comprises a skin and reinforcing ribs, wherein the reinforcing ribs are communicated in a crisscross manner and are arranged on the inner side of the skin, and the skin is positioned on the outer side: Step S1, roll welding and connecting skin reinforcing rib plates; S1.1, designing the sizes of the skin and the reinforcing rib plate, reserving a preset allowance at the periphery of the area where the reinforcing rib is positioned, performing laser cutting on the skin and the reinforcing rib plate, and polishing burrs; s1.2, designing a roll welding template according to the position of the formed reinforcing rib; s1.3, polishing the welding surfaces of the skin and the reinforcing rib plate, and cleaning the surfaces of the plates by pickling; s1.4, drawing a roll welding position line on the plate according to a roll welding template, assembling a skin and a reinforcing rib plate, roll welding the peripheral area of the reinforcing rib on the two layers of plates and the peripheral edge area of the plate, firstly roll welding the roll welding position line of the middle part, and then roll welding four sides; s2, performing low-temperature high-pressure inflation forming on the skin reinforcing rib plate; s2.1, carrying out numerical simulation on the reinforcing rib plate to determine low-temperature high-pressure air-expansion forming technological parameters; s2.2, manually argon arc welding a vent pipe on the part welded in the step S1.4, then installing the part on a die, positioning the part by using a positioning pin, and installing the die in a high-temperature forming equipment platform; Step S2.3, installing an externally connected ventilation pipeline, heating according to the technological par