A method for precision blade repair using laser fuses based on synchronized coordination of workpiece swing and dynamic energy regulation

Abstract

A method for precision blade repair using laser fuses based on the synchronous coordination of workpiece swing and dynamic energy regulation belongs to the technical field of aircraft engine and gas turbine blade repair. It solves the problem that conventional laser repair of high-temperature alloy blades is prone to unfused and dented, and variable power laser repair of high-temperature alloy blades cannot be precisely controlled, resulting in ablation of the repair position and deformation of the substrate. Method: 1. Fixing the turbine blades; 2. Parameter setting; 3. Laser welding dynamic regulation and repair; 4. Machining. The present invention is used for precision blade repair using laser fuses based on the synchronous coordination of workpiece swing and dynamic energy regulation.

Description

Technical Field

[0001] The invention belongs to the technical field of repairing blades of aircraft engines and gas turbines. Background Art

[0002] Some turbine blades for aircraft engines and gas turbines are cast from high-temperature alloys. For example, rotor blades and guide vanes, which are high-temperature parts that operate at temperatures of 1000°C, have serrated crown structures that can improve turbine performance. Turbine blades are extremely susceptible to damage from long-term exposure to high temperatures, high-speed impact, and corrosion. This damage is primarily concentrated in the blade body and serrated crown, causing bending deformation, corrosion spots, pits, and cracks. The crown is particularly susceptible to wear and cracking. High-temperature alloys contain relatively high levels of elements such as Al and Ti, which form dense Al and Ti oxides on the surfaces of fatigue cracks. Mechanical cleaning methods are required to remove oxide films and inclusions from the defective surfaces. Replacing blades with new ones is expensive, so repairing damaged blades helps achieve long-term reuse of blades over multiple cycles, offering extremely high economic benefits.

[0003] Currently, manual argon arc welding (GTAW) is the most common method for blade repair, using CoCrW wire as the welding material. Manual GTAW has a large heat source area and a large heat-affected zone, making it prone to cracks and other defects during the blade repair process. Furthermore, GTAW is also limited by blade size when repairing turbine blades. Excessive heat input can cause deformation in the repaired area, reducing material reliability.

[0004] Laser additive manufacturing, as a repair technology, uses laser as a heat source to apply heat input to the base material and filler material (powder or wire) to melt and combine, and then cool and solidify rapidly to form a weld overlay. Currently, laser powder cladding can achieve precise repair of turbine blade serrated surface wear, sealing tooth wear or cracks. However, the difficulty of densification of laser powder deposition itself greatly restricts its application in blade damage repair. At the same time, the overall thickness of the damaged part of the blade is inconsistent. The use of conventional laser repair technology has the problem of inconsistent matching between the laser power and the thickness of the repaired part, which is prone to defects such as unfused or pits. Therefore, variable power is generally used for processing, but the blade repair forming is still difficult to control accurately, and problems such as ablation of the repair position of the repaired blade and deformation of the substrate often occur. Summary of the Invention

[0005] The present invention aims to solve the problems of unfused and dented parts that are prone to occur in the existing conventional laser repair of high-temperature alloy blades, and the problem that variable power laser repair of high-temperature alloy blades cannot be precisely controlled, resulting in ablation of the repair position and deformation of the substrate, and further provides a method for precise blade repair with laser fuse based on the synchronous coordination of workpiece swing and dynamic energy regulation.

[0006] A method for precision blade repair using laser fuses based on synchronous coordination of workpiece swing and dynamic energy regulation is carried out in the following steps:

[0007] 1. Fixing turbine blades:

[0008] Fix the turbine blade with damaged interlocking surface on the CNC machine tool with a fixture, and keep the interlocking surface at an angle of 20° to 30° with the horizontal plane of the CNC machine tool, and the short side of the interlocking surface is parallel to the X-axis;

[0009] 2. Parameter settings:

[0010] The turbine blade with a damaged interlocking surface is set to swing along the X-axis of the CNC machine tool at a swing speed of 400 mm / min to 1000 mm / min; the swing amplitude of the turbine blade with a damaged interlocking surface along the X-axis of the CNC machine tool is set to l, and the length of the short side of the interlocking surface is set to L, where L>l; the laser beam is set to move along the Y-axis of the CNC machine tool;

[0011] 3. Laser welding dynamic control repair:

[0012] Under the conditions of a swing speed of 400 mm / min to 1000 mm / min, a swing amplitude of 1, a laser beam moving speed of 0.06 m / min to 0.1 m / min, and a wire feeding speed of 0.6 m / min to 0.96 m / min, the interlocking surface is repaired by laser welding using welding wire under dynamic control to obtain a repaired blade.

[0013] The laser welding dynamic control repair is specifically carried out according to the following steps:

[0014] ① Taking the concave R zone where the interlocking surface and the non-working surface transition are located as the starting point, the laser beam stays in the concave R zone where the interlocking surface and the non-working surface transition are located for 0.5s to 1.0s under the conditions that the laser beam output power is 600W to 800W and the focal length of the laser beam on the interlocking surface is +2mm to +3mm;

[0015] ② Under the conditions that the laser beam output power is 550W to 650W and the focal length of the laser beam on the interlocking surface is +2mm to +3mm, the laser beam moves on the interlocking surface until it reaches a position 1.5mm to 2mm from the end of the interlocking surface;

[0016] ③ Under the conditions that the laser beam output power is 550W to 650W and the focal length of the laser beam on the interlocking surface is +2mm to +3mm, the laser beam stays at a distance of 1.5mm to 2mm from the end of the interlocking surface for 0.4s to 0.6s;

[0017] ④ Reduce the laser power. Under the conditions that the laser beam output power is 500W to 600W and the focal length of the laser beam on the interlocking surface is +2mm to +3mm, move the laser beam on the interlocking surface until it reaches the end of the interlocking surface.

[0018] ⑤ Under the conditions that the laser beam output power is 500W to 600W and the focal length of the laser beam on the interlocking surface is +2mm to +3mm, the laser beam stays at the end of the interlocking surface for 0.4s to 0.6s;

[0019] ⑥ Under the condition that the laser beam output power is 500W~600W, lift the laser head along the Z axis until the focal length of the laser beam on the interlocking surface is +3mm~+4mm, and then under the condition that the laser beam output power is 500W~600W and the focal length of the laser beam on the interlocking surface is +3mm~+4mm, the laser beam stays at the end of the interlocking surface for 0.4s~0.6s;

[0020] ⑦ Under the condition that the laser beam output power is 500W to 600W, lift the laser head along the Z axis for the second time, then turn off the CNC machine tool and the laser, and take out the repaired blade;

[0021] 4. Machining:

[0022] The interlocking surfaces of the repaired blades are mechanically processed to restore their original appearance, thus completing a method for precision blade repair using laser fuses based on the synchronous coordination of workpiece swing and dynamic energy regulation.

[0023] The beneficial effects of the present invention are:

[0024] The preparation method for laser fuse blade repair based on the synchronous coordination of workpiece swing and dynamic energy regulation is to fix the blade on a specific fixture, and then use a CNC machine tool to swing the turbine blade with damaged interlocking surface along the X-axis direction to increase the scanning area during the laser fuse repair process. The dynamic adjustment refers to the dynamic change of the laser beam output power in different surface areas of the blade repair position during the laser fuse process. At the same time, the laser beam is paused at different repair positions to compensate for the unstable fusion problem caused by variable power during the fuse process. For laser fuse repair of interlocking surface wear, the laser head needs to be lifted at the end of the repair position so that the repair position reaches a certain thickness to form a covering weld layer.

[0025] The main advantages of using this method to repair turbine blades are as follows:

[0026] 1. Using CNC machine tools to swing turbine blades with damaged interlocking surfaces can increase the scanning area during laser welding, reduce the number of welds, avoid problems such as poor fusion that are prone to occur with multiple welding paths, and precisely repair damaged blade parts. At the same time, the swing amplitude can be changed according to the different blade models and sizes, which can repair different damaged parts on the blade and has greater adaptability.

[0027] 2. Dynamic energy adjustment: By controlling the output of the laser beam power and changing the defocus, the overall morphology of the surfacing layer at the repair location is reshaped, solving problems such as lack of fusion, depression, ablation at the repair location, and substrate deformation. At the same time, gradient power can repair blades of various models, helping to obtain a well-formed surfacing layer and improving the repair quality and pass rate of the blade repair location.

[0028] 3. Compared with oscillating laser wire feeding, the oscillation of the workpiece enables the laser beam to always act evenly on the base material and the wire, ensuring consistent energy distribution between the base material and the wire. However, oscillating laser fuse repair uses the oscillation of the galvanometer to achieve the oscillation of the beam, which makes the beam energy distribution inconsistent, easily causing fuse instability during the repair process.

[0029] 4. Compared with traditional argon arc welding and laser powder feeding repair, the laser fuse repair has a close bond between the surfacing layer and the base material, no defects at the interface, a more uniform structure, no cracks, pores and other defects inside the surfacing layer, and a thickness of 3mm, leaving a certain margin for subsequent machining.

[0030] The present invention is used for a method for precisely repairing blades by laser fuse based on synchronous coordination of workpiece swing and energy dynamic regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic structural diagram of a turbine blade with damaged interlocking surfaces as described in step 1 of the present invention, wherein 1 is the tenon, 2 is the blade body, 3 is the serration crown, and 4 is the sealing tooth;

[0032] Figure 2 This is a partial enlarged top view of a turbine blade serration crown with damaged interlocking surface as described in step 1 of the present invention, 5 is the interlocking surface; 6 is the concave R area where the interlocking surface and the non-working surface transition;

[0033] Figure 3 This is a partial enlarged view of the damaged interlocking surface of a turbine blade serration crown with damaged interlocking surface as described in step 1 of the present invention, where 4 is the sealing tooth, 7 is the damaged interlocking surface, and 8 is the end of the interlocking surface;

[0034] Figure 4 Schematic diagram of the power and path of laser fuse precision blade repair based on synchronized coordination of workpiece swing and dynamic energy control in Example 1. t0-t1 is the laser beam dwell time in step 1 of step 3, t1-t2 is the laser beam travel and dwell time in steps 2 and 3 of steps 3, and t2-t3 is the laser beam travel and dwell time in steps 4 to 7 of steps 3.

[0035] Figure 5Schematic diagram of laser fuse repair of a swinging workpiece on a CNC machine tool for laser fuse precision repair of a blade based on synchronous coordination of workpiece swing and dynamic energy regulation in Example 1, 9 is a CNC machine tool, 10 is an interlocking surface, and 11 is a laser beam;

[0036] Figure 6 This is the surface and cross-sectional morphology of the surfacing layer at the repair position after the laser fuse precision repair of the blade based on the synchronous coordination of workpiece swing and energy dynamic regulation in Example 1. DETAILED DESCRIPTION

[0037] Specific implementation method 1, combined with Figures 1 to 3 Specific analysis: This embodiment provides a method for laser fuse precision repair of blades based on the synchronous coordination of workpiece swing and energy dynamic regulation, which is carried out in the following steps:

[0038] 1. Fixing turbine blades:

[0039] Fix the turbine blade with damaged interlocking surface on the CNC machine tool with a fixture, and keep the interlocking surface at an angle of 20° to 30° with the horizontal plane of the CNC machine tool, and the short side of the interlocking surface is parallel to the X-axis;

[0040] 2. Parameter settings:

[0041] The turbine blade with a damaged interlocking surface is set to swing along the X-axis of the CNC machine tool at a swing speed of 400 mm / min to 1000 mm / min; the swing amplitude of the turbine blade with a damaged interlocking surface along the X-axis of the CNC machine tool is set to l, and the length of the short side of the interlocking surface is set to L, where L>l; the laser beam is set to move along the Y-axis of the CNC machine tool;

[0042] 3. Laser welding dynamic control repair:

[0043] Under the conditions of a swing speed of 400 mm / min to 1000 mm / min, a swing amplitude of 1, a laser beam moving speed of 0.06 m / min to 0.1 m / min, and a wire feeding speed of 0.6 m / min to 0.96 m / min, the interlocking surface is repaired by laser welding using welding wire under dynamic control to obtain a repaired blade.

[0044] The laser welding dynamic control repair is specifically carried out according to the following steps:

[0045] ① Taking the concave R zone where the interlocking surface and the non-working surface transition are located as the starting point, the laser beam stays in the concave R zone where the interlocking surface and the non-working surface transition are located for 0.5s to 1.0s under the conditions that the laser beam output power is 600W to 800W and the focal length of the laser beam on the interlocking surface is +2mm to +3mm;

[0046] ② Under the conditions that the laser beam output power is 550W to 650W and the focal length of the laser beam on the interlocking surface is +2mm to +3mm, the laser beam moves on the interlocking surface until it reaches a position 1.5mm to 2mm from the end of the interlocking surface;

[0047] ③ Under the conditions that the laser beam output power is 550W to 650W and the focal length of the laser beam on the interlocking surface is +2mm to +3mm, the laser beam stays at a distance of 1.5mm to 2mm from the end of the interlocking surface for 0.4s to 0.6s;

[0048] ④ Reduce the laser power. Under the conditions that the laser beam output power is 500W to 600W and the focal length of the laser beam on the interlocking surface is +2mm to +3mm, move the laser beam on the interlocking surface until it reaches the end of the interlocking surface.

[0049] ⑤ Under the conditions that the laser beam output power is 500W to 600W and the focal length of the laser beam on the interlocking surface is +2mm to +3mm, the laser beam stays at the end of the interlocking surface for 0.4s to 0.6s;

[0050] ⑥ Under the condition that the laser beam output power is 500W~600W, lift the laser head along the Z axis until the focal length of the laser beam on the interlocking surface is +3mm~+4mm, and then under the condition that the laser beam output power is 500W~600W and the focal length of the laser beam on the interlocking surface is +3mm~+4mm, the laser beam stays at the end of the interlocking surface for 0.4s~0.6s;

[0051] ⑦ Under the condition that the laser beam output power is 500W to 600W, lift the laser head along the Z axis for the second time, then turn off the CNC machine tool and the laser, and take out the repaired blade;

[0052] 4. Machining:

[0053] The interlocking surfaces of the repaired blades are mechanically processed to restore their original appearance, thus completing a method for precision blade repair using laser fuses based on the synchronous coordination of workpiece swing and dynamic energy regulation.

[0054] In step one of this specific implementation method, the damaged area of ​​the serrated crown of the high-temperature alloy turbine blade is firstly inspected for damage to determine the types of wear and crack defects, the blades with worn interlocking surfaces are picked out, and the blades with damaged interlocking surfaces are polished and cleaned with minimal grinding loss to the substrate. During repair, regardless of the size of the damaged area of ​​the interlocking surface, the entire interlocking surface is mechanically cleaned and then repaired.

[0055] In steps 3 ⑥ and ⑦ of this specific embodiment, the laser head is lifted along the Z axis to repair the end of the damaged surface, ensure a certain processing allowance at the end, and also to prevent excessive heat input at the end from causing ablation problems.

[0056] The beneficial effects of this specific embodiment are:

[0057] The preparation method for laser fuse blade repair based on the synchronous coordination of workpiece swing and dynamic energy regulation is to fix the blade on a specific fixture, and then use a CNC machine tool to swing the turbine blade with damaged interlocking surface along the X-axis direction to increase the scanning area during the laser fuse repair process. The dynamic adjustment refers to the dynamic change of the laser beam output power in different surface areas of the blade repair position during the laser fuse process. At the same time, the laser beam is paused at different repair positions to compensate for the unstable fusion problem caused by variable power during the fuse process. For laser fuse repair of interlocking surface wear, the laser head needs to be lifted at the end of the repair position so that the repair position reaches a certain thickness to form a covering weld layer.

[0058] The main advantages of using this method to repair turbine blades are as follows:

[0059] 1. Using CNC machine tools to swing turbine blades with damaged interlocking surfaces can increase the scanning area during laser welding, reduce the number of welds, avoid problems such as poor fusion that are prone to occur with multiple welding paths, and precisely repair damaged blade parts. At the same time, the swing amplitude can be changed according to the different blade models and sizes, which can repair different damaged parts on the blade and has greater adaptability.

[0060] 2. Dynamic energy adjustment: By controlling the output of the laser beam power and changing the defocus, the overall morphology of the surfacing layer at the repair location is reshaped, solving problems such as lack of fusion, depression, ablation at the repair location, and substrate deformation. At the same time, gradient power can repair blades of various models, helping to obtain a well-formed surfacing layer and improving the repair quality and pass rate of the blade repair location.

[0061] 3. Compared with oscillating laser wire feeding, the oscillation of the workpiece enables the laser beam to always act evenly on the base material and the wire, ensuring consistent energy distribution between the base material and the wire. However, oscillating laser fuse repair uses the oscillation of the galvanometer to achieve the oscillation of the beam, which makes the beam energy distribution inconsistent, easily causing fuse instability during the repair process.

[0062] 4. Compared with traditional argon arc welding and laser powder feeding repair, the laser fuse repair has a close bond between the surfacing layer and the base material, no defects at the interface, a more uniform structure, no cracks, pores and other defects inside the surfacing layer, and a thickness of 3mm, leaving a certain margin for subsequent machining.

[0063] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the material of the turbine blade with damaged interlocking surface in step 1 is DZ125 alloy. Other aspects are the same as specific embodiment 1.

[0064] Specific Embodiment 3: This embodiment differs from either Specific Embodiment 1 or 2 in that the turbine blade with damaged interlocking surfaces described in step 1 is a pre-treated turbine blade. The pre-treatment is specifically performed in the following steps: polishing and cleaning the turbine blade under an argon atmosphere to remove the damaged surface oxide film, then wiping the interlocking surfaces and surrounding areas with anhydrous ethanol and acetone, followed by drying to reveal a metallic luster. Other aspects are the same as Specific Embodiment 1 or 2.

[0065] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that: in step 2, L1=0.4mm-0.6mm. Other aspects are the same as specific embodiments 1 to 3.

[0066] Specific embodiment 5: This embodiment differs from specific embodiments 1 to 4 in that in step 2, the laser head is set at an angle of 5° to 10° with the interlocking surface. Other aspects are the same as specific embodiments 1, 2 to 4.

[0067] Specific embodiment 6: This embodiment differs from specific embodiments 1 to 5 in that the welding wire in step 3 is CoCrW welding wire. Other aspects are the same as specific embodiments 1 to 5.

[0068] Specific embodiment 7: This embodiment differs from specific embodiments 1 to 6 in that the diameter of the welding wire in step 3 is 1.0 mm to 1.2 mm. Other aspects are the same as specific embodiments 1 to 6.

[0069] Specific Embodiment 8: This embodiment differs from Specific Embodiments 1 to 7 in that the welding wire described in step 3 is pretreated. The pretreatment is performed by polishing the wire with 400-grit sandpaper, wiping it with anhydrous ethanol, and drying it. Other aspects are the same as Specific Embodiments 1 to 7.

[0070] Specific Embodiment 9: This embodiment differs from any one of Specific Embodiments 1 to 8 in that, in step 3, under the following conditions, the interlocking surface-damaged turbine blade is subjected to dynamic laser welding repair using a welding wire under the following conditions: a swing speed of 400 mm / min to 1000 mm / min, an amplitude of 1, a laser beam movement speed of 0.06 m / min to 0.1 m / min, a wire feed speed of 0.6 m / min to 0.96 m / min, and an argon shielding gas flow rate of 15 L / min to 20 L / min, to obtain a repaired blade. The remainder of this embodiment is the same as Specific Embodiments 1 to 8.

[0071] Specific Embodiment 10: This embodiment differs from Specific Embodiments 1 to 9 in that, in step 3 (7), under the condition that the laser beam output power is 500W to 600W, the laser head is raised along the Z axis a second time until the laser beam focal length on the interlocking surface is +4mm to +5mm. Then, the CNC machine tool and the laser are turned off, and the repaired blade is removed. Other steps are the same as Specific Embodiments 1 to 9.

[0072] The following examples are used to verify the beneficial effects of the present invention:

[0073] Example 1, combined with Figure 4 and Figure 5 Specific instructions:

[0074] A method for precision blade repair using laser fuses based on synchronous coordination of workpiece swing and dynamic energy regulation is carried out in the following steps:

[0075] 1. Fixing turbine blades:

[0076] The turbine blade with damaged interlocking surface is fixed on the CNC machine tool by a fixture, with the interlocking surface and the horizontal plane of the CNC machine tool maintained at an angle of 25 degrees, and the short side of the interlocking surface is parallel to the X-axis;

[0077] 2. Parameter settings:

[0078] The turbine blade with a damaged interlocking surface is set to swing along the X-axis of the CNC machine tool at a swing speed of 600 mm / min. The swing amplitude of the turbine blade with a damaged interlocking surface along the X-axis of the CNC machine tool is set to l, and the short side lengths of the interlocking surface are set to L = 4.5 mm, l = 4 mm, and Ll = 0.5 mm. The laser beam is set to move along the Y-axis of the CNC machine tool.

[0079] 3. Laser welding dynamic control repair:

[0080] Under the conditions of a swing speed of 600 mm / min, a swing amplitude of 4 mm, a laser beam moving speed of 0.06 m / min, a wire feeding speed of 0.72 m / min, and an argon shielding gas flow rate of 18 L / min, the interlocking surfaces were repaired by laser welding using a welding wire under dynamic control to obtain a repaired blade.

[0081] The laser welding dynamic control repair is specifically carried out according to the following steps:

[0082] ① Taking the concave R area where the interlocking surface and the non-working surface transition are located as the starting point, the laser beam stays in the concave R area where the interlocking surface and the non-working surface transition are located for 0.5s under the conditions of a laser beam output power of 650W and a focal length of the laser beam on the interlocking surface of +2mm;

[0083] ② Under the conditions of a laser beam output power of 600W and a focal length of the laser beam on the interlocking surface of +2mm, the laser beam moves on the interlocking surface until it reaches a point 2mm from the end of the interlocking surface;

[0084] ③ Under the conditions of laser beam output power of 600W and focal length of laser beam on the interlocking surface of +2mm, the laser beam stays at 2mm from the end of the interlocking surface for 0.5s;

[0085] ④ Reduce the laser power. Under the conditions of the laser beam output power of 500W and the focal length of the laser beam on the interlocking surface of +2mm, the laser beam moves on the interlocking surface until it reaches the end of the interlocking surface.

[0086] ⑤ Under the conditions of laser beam output power of 500W and focal length of laser beam on the interlocking surface of +2mm, the laser beam stays at the end of the interlocking surface for 0.5s;

[0087] ⑥ Under the condition that the laser beam output power is 500W, lift the laser head along the Z axis until the focal length of the laser beam on the interlocking surface is +3mm. Then, under the condition that the laser beam output power is 500W and the focal length of the laser beam on the interlocking surface is +3mm, the laser beam stays at the end of the interlocking surface for 0.5s;

[0088] ⑦ Under the condition of laser beam output power of 500W, lift the laser head along the Z axis for the second time until the focal length of the laser beam on the interlocking surface is +4mm, then turn off the CNC machine tool and laser, and remove the repaired blade;

[0089] 4. Machining:

[0090] The interlocking surfaces of the repaired blades are mechanically processed to restore their original appearance, thus completing a method for precision blade repair using laser fuses based on the synchronous coordination of workpiece swing and dynamic energy regulation.

[0091] The material of the turbine blade with interlocking surface damage described in step 1 is DZ125 alloy, which is a directionally solidified high-temperature alloy. Due to the high-pressure and high-temperature service environment, the turbine blades and nozzles are corroded, oxidized, and suffer from thermal fatigue and mechanical fatigue. Since it contains a large amount of elements such as Al and Ti, dense oxides such as Al and Ti will be formed on the surface of the fatigue cracks. Mechanical cleaning methods are required to remove the oxide film and inclusions on the defective surface.

[0092] The turbine blade with damaged interlocking surface described in step one is a pretreated turbine blade; the pretreatment is specifically carried out according to the following steps: in an argon environment, the turbine blade is polished and cleaned to remove the oxide film on the damaged surface, and then the damaged surface and the surrounding area are wiped with anhydrous ethanol and acetone in turn, and finally dried to reveal the metallic luster.

[0093] In step 2, the laser head is set at an angle of 10° to the interlocking surface.

[0094] The welding wire described in step 3 is a CoCrW welding wire, which is composed of 29.64% by mass of C, 1.15% by mass of C, 4.12% by mass of W, and the balance of Co.

[0095] The diameter of the welding wire described in step 3 is 1.0 mm.

[0096] The welding wire described in step three is a pretreated welding wire; the pretreatment is specifically carried out according to the following steps: polish it smooth with 400-grit sandpaper, then wipe it with anhydrous ethanol and dry it.

[0097] Table 1 Parameters of laser fuse precision blade repair based on synchronous coordination of workpiece swing and energy dynamic control in Example 1

[0098]

[0099] Figure 6 This is Example 1, which shows the surface and cross-sectional morphology of the weld layer at the repair position after the blade is precisely repaired by laser fuse based on the synchronous coordination of workpiece swing and energy dynamic regulation. As can be seen from the figure, the surface of the blade wear-resistant layer repaired by laser fuse based on the synchronous coordination of workpiece swing assistance and energy dynamic regulation is smooth, and the thickness of the weld layer reaches 3mm. The melting of the metal at the repair position can be accurately controlled by energy regulation to ensure that there is no burning on the left and right sides of the interlocking surface and the end of the repair position, no substrate deformation problem, and the interlocking surface and the non-working surface transition concave R zone are continuously fused without unfused and concave problems. The repaired wear-resistant layer has no defects such as cracks and pores, and the bonding strength between the weld layer and the base material is high. After milling, the surface of the weld layer is flat and smooth, and the transition to the base material is continuous and uniform, which meets the current usage standards. The process has good stability and can adapt to the repair of damaged parts of blades of various models with a high pass rate.

Claims

1. A method for precision blade repair using laser fuses based on the synchronous coordination of workpiece swing and energy dynamic control, characterized in that It is carried out in the following steps:

1. Fixing turbine blades: Fix the turbine blade with damaged interlocking surface on the CNC machine tool with a fixture, and keep the interlocking surface at an angle of 20° to 30° with the horizontal plane of the CNC machine tool, and the short side of the interlocking surface is parallel to the X-axis; 2. Parameter settings: The turbine blade with a damaged interlocking surface is set to swing along the X-axis of the CNC machine tool at a swing speed of 400 mm / min to 1000 mm / min; the swing amplitude of the turbine blade with a damaged interlocking surface along the X-axis of the CNC machine tool is set to l, and the length of the short side of the interlocking surface is set to L, where L>l; the laser beam is set to move along the Y-axis of the CNC machine tool; 3. Laser welding dynamic control repair: Under the conditions of a swing speed of 400 mm / min to 1000 mm / min, a swing amplitude of 1, a laser beam moving speed of 0.06 m / min to 0.1 m / min, and a wire feeding speed of 0.6 m / min to 0.96 m / min, the interlocking surface is repaired by laser welding using welding wire under dynamic control to obtain a repaired blade. The laser welding dynamic control repair is specifically carried out according to the following steps: ① Taking the concave R zone where the interlocking surface and the non-working surface transition are located as the starting point, the laser beam stays in the concave R zone where the interlocking surface and the non-working surface transition are located for 0.5s to 1.0s under the conditions that the laser beam output power is 600W to 800W and the focal length of the laser beam on the interlocking surface is +2mm to +3mm; ② Under the conditions that the laser beam output power is 550W to 650W and the focal length of the laser beam on the interlocking surface is +2mm to +3mm, the laser beam moves on the interlocking surface until it reaches a position 1.5mm to 2mm from the end of the interlocking surface; ③ Under the conditions that the laser beam output power is 550W to 650W and the focal length of the laser beam on the interlocking surface is +2mm to +3mm, the laser beam stays at a distance of 1.5mm to 2mm from the end of the interlocking surface for 0.4s to 0.6s; ④ Reduce the laser power. Under the conditions that the laser beam output power is 500W to 600W and the focal length of the laser beam on the interlocking surface is +2mm to +3mm, move the laser beam on the interlocking surface until it reaches the end of the interlocking surface. ⑤ Under the conditions that the laser beam output power is 500W to 600W and the focal length of the laser beam on the interlocking surface is +2mm to +3mm, the laser beam stays at the end of the interlocking surface for 0.4s to 0.6s; ⑥ Under the condition that the laser beam output power is 500W~600W, lift the laser head along the Z axis until the focal length of the laser beam on the interlocking surface is +3mm~+4mm, and then under the condition that the laser beam output power is 500W~600W and the focal length of the laser beam on the interlocking surface is +3mm~+4mm, the laser beam stays at the end of the interlocking surface for 0.4s~0.6s; ⑦ Under the condition that the laser beam output power is 500W to 600W, lift the laser head along the Z axis for the second time, then turn off the CNC machine tool and the laser, and take out the repaired blade; 4. Machining: The interlocking surfaces of the repaired blades are mechanically processed to restore their original appearance, thus completing a method for precision blade repair using laser fuses based on the synchronous coordination of workpiece swing and dynamic energy regulation.

2. The method for precision blade repair by laser fuse based on synchronous coordination of workpiece swing and energy dynamic control according to claim 1 is characterized in that The material of the turbine blade with damaged interlocking surface described in step 1 is DZ125 alloy.

3. The method for laser fuse precision blade repair based on synchronous coordination of workpiece swing and energy dynamic control according to claim 1 is characterized in that The turbine blade with damaged interlocking surface described in step one is a pretreated turbine blade; the pretreatment is specifically carried out according to the following steps: in an argon environment, the turbine blade is polished and cleaned to remove the damaged surface oxide film, and then the interlocking surface and surrounding positions are wiped with anhydrous ethanol and acetone in turn, and finally dried to reveal the metallic luster.

4. The method for precision blade repair by laser fuse based on synchronous coordination of workpiece swing and energy dynamic control according to claim 1 is characterized in that In step 2, Ll = 0.4 mm to 0.6 mm.

5. The method for precision blade repair by laser fuse based on synchronous coordination of workpiece swing and energy dynamic control according to claim 1 is characterized in that In step 2, the laser head is set at an angle of 5° to 10° to the interlocking surface.

6. The method for precision blade repair by laser fuse based on synchronous coordination of workpiece swing and energy dynamic control according to claim 1 is characterized in that The welding wire described in step 3 is CoCrW welding wire.

7. The method for precision blade repair by laser fuse based on synchronous coordination of workpiece swing and energy dynamic control according to claim 1 is characterized in that The diameter of the welding wire described in step 3 is 1.0 mm to 1.2 mm.

8. The method for precision blade repair by laser fuse based on synchronous coordination of workpiece swing and energy dynamic control according to claim 1 is characterized in that The welding wire described in step three is a pretreated welding wire; the pretreatment is specifically carried out according to the following steps: polish it smooth with 400-grit sandpaper, then wipe it with anhydrous ethanol and dry it.

9. The method for precision blade repair by laser fuse based on synchronous coordination of workpiece swing and energy dynamic control according to claim 1 is characterized in that In step three, under the conditions that the swing speed of the turbine blade with damaged interlocking surface is 400mm / min~1000mm / min, the swing amplitude of the turbine blade with damaged interlocking surface is l, the laser beam moving speed is 0.06m / min~0.1m / min, the wire feeding speed is 0.6m / min~0.96m / min and the argon shielding gas flow rate is 15L / min~20L / min, the interlocking surface is dynamically controlled and repaired by laser welding using welding wire to obtain a repaired blade.

10. The method for precision blade repair by laser fuse based on synchronous coordination of workpiece swing and energy dynamic control according to claim 1 is characterized in that Step 3 ⑦: Under the condition of laser beam output power of 500W to 600W, lift the laser head along the Z axis for the second time until the focal length of the laser beam on the interlocking surface is +4mm to +5mm, then turn off the CNC machine tool and laser, and remove the repaired blade.

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