A method for laser bending forming of TC4 titanium alloy capable of field regulation

Abstract

A kind of TC4 titanium alloy laser bending forming method of energy field regulation, the present application belongs to laser processing technical field.The present application solves the problem of lower efficiency of existing titanium alloy plate laser bending forming.Method: one, pretreatment and installation positioning;Two, laser bending forming is carried out using swing laser or point ring laser.The present application is used for the TC4 titanium alloy laser bending forming of energy field regulation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of laser processing. BACKGROUND

[0002] After decades of development, laser processing technology has become a common processing technology in the industrial field. Among them, laser forming is a non-contact flexible laser processing method. Its principle is that when the laser beam irradiates on the workpiece surface according to the predetermined scanning path, due to the thermal expansion and contraction characteristics of the material, non-uniform thermal stress is generated inside the workpiece, so that the material is plastically deformed.

[0003] Compared with conventional forming technology, laser forming technology has the following advantages: (1) no mold forming, short production cycle, high flexibility; (2) laser bending forming belongs to thermal accumulation forming, which can be used for forming materials that are difficult to deform at room temperature or have high hardening index; (3) There is no external force in the laser forming process, so there is no workpiece springback phenomenon, and the forming precision is high; (4) The good directionality and coherence of the laser beam make the laser bending forming technology can be applied to the workpiece processing which is limited by structure, traditional tools cannot contact or approach.

[0004] The laser bending forming technology is currently mainly applied to single-layer homogeneous plate bending, double-layer and multi-layer composite plate bending, pipe bending and double-curvature part bending. Large plate bending is one of the important laser forming manufacturing processes. Laser bending forming technology locally heats the plate according to the predetermined path on the plate, so that the plate plastically deforms in the thickness direction due to stress gradient.

[0005] At present, the main laser mode used in laser bending forming technology is conventional single laser. Under the requirement of larger bending angle, the metal plate needs to be scanned by multiple lasers to achieve the required bending forming angle, which has low forming efficiency and limits the further improvement of processing efficiency. SUMMARY

[0006] The present application solves the problem of low efficiency of existing titanium alloy plate laser bending forming, and provides a TC4 titanium alloy laser bending forming method capable of field regulation.

[0007] A TC4 titanium alloy laser bending forming method capable of field regulation, which is performed according to the following steps:

[0008] I. Pretreatment and installation positioning:

[0009] The TC4 titanium alloy plate is pretreated, and then one end of the pretreated TC4 titanium alloy plate is clamped and fixed;

[0010] II. Laser bending forming:

[0011] Under the conditions of laser power of 800W-2400W, welding speed of 4m / min-8m / min and defocusing amount of 0mm-+40mm, the surface of TC4 titanium alloy plate is acted on by swing laser or point ring laser, and is scanned 10-25 times with a predetermined scanning path to obtain the bent and formed TC4 titanium alloy plate.

[0012] The present application has the following advantages:

[0013] 1. The method can realize laser bending and forming of TC4 titanium alloy plate with a maximum size of 200mm*200mm and a thickness of 0.5mm-2mm.

[0014] 2. Compared with the conventional single laser mode, the method can obtain a TC4 titanium alloy sheet with a larger bending angle under the same process parameters by regulating the laser energy field.

[0015] 3. Under the same bending and forming angle requirement, the method can achieve the required bending and forming angle with fewer processing times by using swing laser mode or point ring laser mode and the same process parameters.

[0016] 4. The swing laser mode or point ring laser mode is used to replace the conventional single laser for laser bending and forming of TC4 titanium alloy sheet, which is easy to realize and control, easy to accurately bend and form titanium alloy sheet, and easy to operate.

[0017] The present application is a method for energy field regulated TC4 titanium alloy laser bending and forming. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 Figure 1 is a schematic diagram of the energy field regulated TC4 titanium alloy swing laser bending and forming method of Example 3, 1 is a laser, 2 is a laser processing head, 3 is a clamp, 4 is a TC4 titanium alloy plate, and 5 is a laser swing path.

[0019] Figure 2 Figure 1 is a schematic diagram of the energy field regulated TC4 titanium alloy swing laser bending and forming method of Example 3, 1 is a laser, 2 is a laser processing head, 3 is a clamp, 4 is a TC4 titanium alloy plate, and 5 is a laser swing path.

[0020] Figure 3 Figure 1 is a schematic diagram of the energy field regulated TC4 titanium alloy swing laser bending and forming method of Example 3, 1 is a laser, 2 is a laser processing head, 3 is a clamp, 4 is a TC4 titanium alloy plate, and 5 is a laser swing path.

[0021] Figure 4 The TC4 titanium alloy plate laser bending forming sample obtained in the TC4 titanium alloy laser bending forming method capable of field regulation under different point ring power ratios in the point ring laser mode, 1 is a conventional laser sample of a comparative experiment one, 2 is a point ring laser sample of a comparative experiment three, 3 is a point ring laser sample of an embodiment one, 4 is a point ring laser sample of an embodiment two, and 5 is a ring light laser sample of a comparative experiment two;

[0022] Figure 5 The TC4 titanium alloy plate laser bending forming sample obtained in the TC4 titanium alloy laser bending forming method capable of field regulation under different laser modes, 1 is a conventional laser sample of a comparative experiment one, 2 is a point ring laser sample of an embodiment one, and 3 is a swing laser sample of an embodiment three. DETAILED DESCRIPTION

[0023] The technical scheme of the present application is not limited to the following specific embodiments, and any combination of the specific embodiments is also included.

[0024] Specific embodiment one: the present embodiment is a TC4 titanium alloy laser bending forming method capable of field regulation, which is performed according to the following steps:

[0025] I. Pretreatment and installation positioning:

[0026] The TC4 titanium alloy plate is pretreated, and then one end of the pretreated TC4 titanium alloy plate is clamped and fixed.

[0027] II. Laser bending forming:

[0028] Under the conditions of a laser power of 800 W to 2400 W, a welding speed of 4 m / min to 8 m / min, and a defocusing amount of 0 mm to +40 mm, swing laser or point ring laser is used to act on the surface of the TC4 titanium alloy plate to perform scanning 10 to 25 times with a predetermined scanning path, so as to obtain the bent and formed TC4 titanium alloy plate.

[0029] The present embodiment has the following beneficial effects:

[0030] 1. The method of the present embodiment can realize laser bending forming of a TC4 titanium alloy plate with a maximum size of 200 mm x 200 mm and a thickness of 0.5 mm to 2 mm. The bent and formed plate does not have warping phenomenon, and the bending forming degree of the plate in the scanning direction is uniform.

[0031] 2. The method of this embodiment can obtain TC4 titanium alloy thin plate laser bending forming samples with larger bending angles under the same process parameters by adjusting the laser energy field; under the same process parameters, the bending angle of the bending forming samples obtained by the method can be increased by about 61.5%.

[0032] 3. Under the same bending angle requirement, the method of this embodiment requires fewer processing steps to achieve the required bending angle using the same process parameters through oscillating laser mode or dot ring laser mode; energy field control of TC4 titanium alloy laser bending forming effectively improves the processing efficiency of laser bending forming.

[0033] 4. Using oscillating laser mode or dot ring laser mode to replace conventional single laser for laser bending of TC4 titanium alloy thin plates makes the forming process easy to realize and control, facilitates precise bending of titanium alloy thin plates, and is simple and convenient to operate.

[0034] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the thickness of the TC4 titanium alloy plate mentioned in step one is 0.5mm to 2mm. Everything else is the same as in Specific Implementation Method One.

[0035] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that the pretreatment described in step one is carried out as follows: the surface to be processed is polished to remove the surface oxide film and oil stains, and then the surface to be processed is cleaned with acetone after polishing. Everything else is the same as in Specific Implementation Method One or Two.

[0036] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the angle between the laser and the surface of the TC4 titanium alloy plate in step two is 80° to 100°. Everything else is the same as in Specific Implementation Methods One to Three.

[0037] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that: in step two, a oscillating laser or a dot-ring laser is used, and the laser emitted by the laser is applied to the surface of the TC4 titanium alloy sheet through a laser processing head. Everything else is the same as in Specific Implementation Methods One to Four.

[0038] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that the oscillation amplitude of the oscillating laser described in step two is 1mm to 2.0mm, and the oscillation frequency is 110Hz to 200Hz. Everything else is the same as in Specific Implementation Methods One to Five.

[0039] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that the oscillation mode of the oscillating laser described in step two is a circular oscillation mode. Everything else is the same as in Specific Implementation Methods One to Six.

[0040] Specific embodiment eight: the difference between this embodiment and one of the specific embodiments one to seven is that in step two, when using point-ring laser, the laser power is the sum of the point light power and the ring light power, and the ring light power accounts for 30% to 90% of the laser power. The others are the same as specific embodiments one to seven.

[0041] Specific embodiment nine: the difference between this embodiment and one of the specific embodiments one to eight is that in step two, the point-ring laser is output directly through a coaxial single optical fiber, an in-laser fiber coupler, an in-laser integrated optical shutter, or a two-in-one optical fiber. The others are the same as specific embodiments one to eight.

[0042] Specific embodiment ten: the difference between this embodiment and one of the specific embodiments one to nine is that the two-in-one optical fiber is composed of an internal core and an external ring core, the internal core diameter is 100 μm, the external ring core outer diameter is 400 μm, and the external ring core width is 100 μm. The others are the same as specific embodiments one to nine.

[0043] The beneficial effects of the present application are verified by the following examples:

[0044] Example one, combined Figures 2-3 :

[0045] A TC4 titanium alloy laser bending forming method capable of field regulation, which is carried out according to the following steps:

[0046] I. Pretreatment and positioning:

[0047] The TC4 titanium alloy plate is pretreated, and then one end of the pretreated TC4 titanium alloy plate is clamped and fixed;

[0048] II. Laser bending forming:

[0049] Under the conditions of a laser power of 1600 W, a welding speed of 6 m / min, and a defocusing amount of +20 mm, a point-ring laser is used, the laser emitted by the laser is acted on the surface of the TC4 titanium alloy plate through a laser processing head, and scanning is performed 10 times with a predetermined scanning path, the interval of single scanning is 10 s, and the bent and formed TC4 titanium alloy plate is obtained.

[0050] The thickness of the TC4 titanium alloy plate in step one is 1 mm, and the size is 200 mm x 200 mm.

[0051] The pretreatment in step one is specifically carried out according to the following steps: the surface to be processed is polished to remove the surface oxidation film and oil stains, and then the surface to be processed is cleaned with acetone after polishing.

[0052] The included angle between the laser and the surface of the TC4 titanium alloy plate in step two is 90°.

[0053] The laser in step two is a TruDisk solid-state laser of IPG company. The laser processing head is a YW52 laser processing head.

[0054] The laser power in step two is the sum of the spot light power and the ring light power, and the ratio of the spot light power to the ring light power is 1:1, the spot light power is 800W, and the ring light power is 800W.

[0055] The spot ring laser in step two is output through a two-in-one optical fiber; the two-in-one optical fiber is a Brightline optical fiber of TRUMPF company, which is composed of an internal core and an external ring core, the diameter of the internal core is 100μm, the external ring core has an outer diameter of 400μm, and the width of the external ring core is 100μm.

[0056] Embodiment two: different from embodiment one is that the laser power in step two is the sum of the spot light power and the ring light power, and the ratio of the spot light power to the ring light power is 1:3, the spot light power is 400W, and the ring light power is 1200W. The others are the same as embodiment one.

[0057] Comparative experiment one: different from embodiment one is that in step two, under the conditions that the laser power is 1600W, the welding speed is 6m / min, and the defocusing amount is +20mm, a conventional single laser is used, and the laser emitted by the laser is used on the surface of the TC4 titanium alloy plate through the laser processing head. The others are the same as embodiment one.

[0058] Comparative experiment two: different from embodiment one is that in step two, under the conditions that the laser power is 1600W, the welding speed is 6m / min, and the defocusing amount is +20mm, a ring light laser is used, and the laser emitted by the laser is used on the surface of the TC4 titanium alloy plate through the laser processing head. The others are the same as embodiment one.

[0059] Comparative experiment three: different from embodiment one is that the laser power in step two is the sum of the spot light power and the ring light power, and the ratio of the spot light power to the ring light power is 3:1, the spot light power is 1200W, and the ring light power is 400W. The others are the same as embodiment one.

[0060] In the above embodiments, embodiments one to two and comparative experiment three are spot ring lasers, and no laser swing is performed, comparative experiment one is a conventional single laser, and no laser swing is performed, and comparative experiment two is a ring light laser, and no laser swing is performed.

[0061] The bending angle of the bent and formed TC4 titanium alloy plate can be obtained by measuring the plate coordinates through the laser sensor and through the inverse trigonometric function conversion.

[0062] Figure 4The images show laser bending test specimens of TC4 titanium alloy plates obtained under the point-ring laser mode with different point-ring power ratios in the energy field-controlled laser bending forming method for TC4 titanium alloy. 1 is the conventional laser specimen of Comparative Experiment 1, 2 is the point-ring laser specimen of Comparative Experiment 3, 3 is the point-ring laser specimen of Example 1, 4 is the point-ring laser specimen of Example 2, and 5 is the ring laser specimen of Comparative Experiment 2.

[0063] Comparative Experiment 1: TC4 titanium alloy sheet bent and shaped as follows Figure 4 As shown in Figure 1, calculations showed that a sample with a bending angle of 10.6° was obtained under conventional single-laser conditions with these parameters. The deformation was relatively limited, which was not conducive to improving the production efficiency of laser bending forming.

[0064] Example 1: TC4 titanium alloy sheet formed by bending. Figure 4 As shown in Figure 3, calculations showed that a sample with a bending angle of 13.75° was obtained under the point ring laser condition with these parameters, and the deformation was increased by about 30%. In the point ring laser mode with a 50% ring light ratio, the bending degree of the titanium alloy sheet was improved.

[0065] Example 2: TC4 titanium alloy sheet formed by bending. Figure 4 As shown in Figure 4, calculations show that under these parameters, a sample with a bending angle of 13.55° was obtained under the point ring laser condition, while still maintaining a deformation increase of nearly 30%.

[0066] Comparative Experiment 2: TC4 titanium alloy sheet formed by bending, such as Figure 4 As shown in Figure 5, calculations show that a sample with a bending angle of 12.10° was obtained under pure aurora conditions with these parameters, and the increase in deformation was reduced.

[0067] Comparative Experiment 3: TC4 titanium alloy sheet formed by bending, such as Figure 4 As shown in Figure 2, calculations showed that a sample with a bending angle of 11.1° was obtained under the point ring laser condition with these parameters, and the deformation was not significantly improved. Under the point ring laser mode with a 25% ring light ratio, the bending degree of the titanium alloy sheet did not change significantly.

[0068] In summary, under appropriate point-ring power ratios, the laser energy field modulation brought about by the point-ring laser mode can effectively improve the bending deformation of titanium alloy thin plates, which is beneficial to improving the efficiency of laser bending forming.

[0069] Example 3, combined with Figure 1 :

[0070] A laser bending forming method for TC4 titanium alloy with energy field control is performed according to the following steps:

[0071] I. Pre-treatment and installation positioning:

[0072] The TC4 titanium alloy plate is pretreated, and one end of the pretreated TC4 titanium alloy plate is clamped and fixed;

[0073] II. Laser bending forming:

[0074] Under the conditions of a laser power of 1600 W, a welding speed of 6 m / min, and a defocusing amount of +20 mm, the laser emitted by the laser is applied to the surface of the TC4 titanium alloy plate through the laser processing head, and the laser is scanned 10 times along the predetermined scanning path in a circular swing mode, with a single scanning interval of 10 s, to obtain the bent and formed TC4 titanium alloy plate.

[0075] The TC4 titanium alloy plate in step one has a thickness of 1 mm and a size of 200 mm*200 mm.

[0076] The pretreatment in step one is specifically performed as follows: the surface to be processed is polished to remove the surface oxidation film and oil stains, and the surface to be processed is cleaned with acetone after polishing.

[0077] The angle between the laser and the surface of the TC4 titanium alloy plate in step two is 90°.

[0078] The laser in step two is a TruDisk solid-state laser of IPG Company. The laser processing head is a YW52 laser processing head.

[0079] The swing laser in step two is a conventional single laser, and the swing amplitude is 1 mm and the swing frequency is 150 Hz.

[0080] Comparative Experiment Four: The swing amplitude of the swing laser in step two in this comparative experiment is 0.5 mm and the swing frequency is 100 Hz, which is different from Example Three. The others are the same as Example Three.

[0081] Comparative Experiment Five: The swing laser in step two in this comparative experiment is a conventional single laser, which is different from Example Three. The laser emitted by the laser is applied to the surface of the TC4 titanium alloy plate through the laser processing head under the conditions of a laser power of 1600 W, a welding speed of 6 m / min, and a defocusing amount of +20 mm, and is scanned 15 times along the predetermined scanning path. The others are the same as Example Three.

[0082] In the above examples, Example Three and Comparative Experiment Four are swing laser modes under a conventional single laser, and Comparative Experiment Five is a conventional single laser without laser swing.

[0083] The TC4 titanium alloy sheet of Example Three was calculated to have a bending angle of 16.75° under the parameters of the swinging laser condition, and the bending deformation was increased by nearly 61.5% compared with the single laser condition under the same process parameters (Comparative Experiment One);

[0084] The TC4 titanium alloy sheet of Comparative Experiment Four was calculated to have a bending angle of 11.37° under the parameters of the swinging laser condition, and the bending deformation was not significantly improved compared with the single laser condition under the same process parameters (Comparative Experiment One);

[0085] The TC4 titanium alloy sheet of Comparative Experiment Five was calculated to have a bending angle of 15.45° under the parameters of the conventional single laser condition. Compared with Example Three, the TC4 titanium alloy sheet bending forming sample obtained under the single laser condition for 15 times under the same laser parameters still did not reach the TC4 titanium alloy sheet bending forming sample obtained under the swinging laser condition for 10 times. Under the swinging laser mode, the same bending angle of the forming sample can be obtained with fewer scanning times through the energy field distribution regulation. The laser bending forming method of energy field regulation is an effective means to improve the processing efficiency of laser bending forming.

[0086] Figure 5 For the TC4 titanium alloy laser bending forming samples obtained under different laser modes in the TC4 titanium alloy laser bending forming method of energy field regulation, 1 is the conventional laser sample of Comparative Experiment One, 2 is the point ring laser sample of Example One, and 3 is the swinging laser sample of Example Three. Under the same laser parameters, the laser energy field regulation method effectively increases the bending deformation of the sheet; under the swinging laser mode, a titanium alloy sheet bending forming sample with a larger bending angle is obtained through the energy field distribution regulation.

Claims

1. A method for laser bend forming of a field-controllable TC4 titanium alloy, characterized in that It is carried out according to the following steps: I. Pretreatment and installation positioning: The TC4 titanium alloy plate is pretreated, and then one end of the pretreated TC4 titanium alloy plate is clamped and fixed; II. Laser bending forming: Under the conditions of laser power of 800W-1600W, welding speed of 4m / min-8m / min and defocusing amount of 0mm-+40mm, the surface of the TC4 titanium alloy plate is acted on by the swing laser to scan 10-25 times with a predetermined scanning path, to obtain the bent and formed TC4 titanium alloy plate; The thickness of the TC4 titanium alloy plate is 0.5mm-2mm; The included angle between the laser and the surface of the TC4 titanium alloy plate is 80°-100°; The swing amplitude of the swing laser is 1mm-2.0mm, and the swing frequency is 110Hz-150Hz; the swing mode of the swing laser is a circular swing mode.

2. The method of claim 1, wherein the laser bending forming method of TC4 titanium alloy with energy field regulation is characterized in that The pretreatment in step I is specifically carried out according to the following steps: the surface to be processed is polished to remove the surface oxide film and oil stains, and then the surface to be processed is cleaned with acetone after polishing.

3. The energy field regulated TC4 titanium alloy laser bend forming method according to claim 1, characterized in that In step II, the swing laser is used, and the laser emitted by the laser is acted on the surface of the TC4 titanium alloy plate through the laser processing head.

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