Laser hybrid additive remanufacturing process

Abstract

The application relates to the field of additive remanufacturing technology, and particularly discloses a laser composite additive remanufacturing process method, which melts alloy powder through a laser cladding nozzle and sprays the alloy powder on a surface to be repaired to form a cladding layer, and then repairs volume damage in the form of corrosion holes, cracks and fractures on the part to be repaired, and laser shock strengthening is performed on the cladding layer by using a laser impact device to improve the fatigue life strength of the cladding layer. The device does not need to input a large amount of heat, thereby reducing the influence on the mechanical properties of the original part to be repaired, and laser shock strengthening is performed on the cladding layer by using the laser impact device, so that the phenomenon that the repair layer is coarse and the residual stress distribution of the cladding layer is uneven is avoided.

Description

Technical Field

[0001] This invention relates to the field of additive remanufacturing technology, and more particularly to laser composite additive remanufacturing process methods. Background Technology

[0002] The centrifugal force generated by the high-speed or ultra-high-speed operation of an aircraft engine, combined with the impact of strong airflow, creates axial tensile, non-directional torsional, and non-periodic, non-amplitude vibration loads on the aircraft engine and its internal blades. Simultaneously, the blade edges at the air intake end and the tips of the front fan blades are prone to volumetric damage such as pitting, cracks, and fractures due to the combined effects of centrifugal force, aerodynamic excitation force, and the impact of rigid foreign objects carried by strong airflow.

[0003] In existing technologies, micro-arc welding, high-speed arc spraying, and flame spraying are commonly used to remanufacture damaged parts. However, excessive heat input leads to a decline in the mechanical properties of the remanufactured interface, resulting in a coarse and distorted remanufactured coating structure and an uneven distribution of residual stress in the coating.

[0004] Therefore, there is an urgent need for laser composite additive remanufacturing processes to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a laser composite additive remanufacturing process to solve the problems in related technologies that commonly use micro-arc welding, high-speed arc spraying, and flame spraying to remanufacture damaged parts. These methods result in excessive heat input, leading to a decline in the mechanical properties of the remanufactured interface, coarse and distorted remanufactured coating structure, and uneven distribution of residual stress in the coating.

[0006] On one hand, the present invention provides a laser composite additive remanufacturing process method, which includes the following steps:

[0007] S10: Clean the surface of the part to be repaired and grind it flat;

[0008] S20: Prepare alloy powder for use in laser cladding nozzles, wherein the proportion of each element in the alloy powder is the same as the proportion of each element in the material used for the part to be repaired;

[0009] S30: Make the jetting direction of the laser cladding nozzle perpendicular to the surface to be repaired, move along the planned path of the surface to be repaired, and lay the cladding layer on the surface to be repaired;

[0010] The impact beam of the laser shocker and the cladding beam of the laser cladding nozzle move synchronously. The impact beam of the laser shocker performs synchronous laser shock enhancement on the part above and below the interface between the cladding layer and the part to be repaired, so as to form a repair layer on the surface to be repaired.

[0011] S40: Determine whether the repair layer is flush with the surface of the part to be repaired. If yes, proceed to S50; otherwise, proceed to S30.

[0012] S50: Determine whether the repair layer of the part to be repaired is qualified.

[0013] As a preferred technical solution for laser composite additive remanufacturing process, S60 is executed before S40;

[0014] S60: Stop the laser cladding nozzle and the laser impactor, and clean and remove contaminants from the repair layer on the surface to be repaired.

[0015] As a preferred technical solution for laser composite additive remanufacturing process, S70 is executed first after S60 is completed and before S40 is executed.

[0016] S70: The laser shock beam of the laser shocker strengthens the repair layer on two sides perpendicular to the surface to be repaired by laser shock. The laser shock process parameters are a power density of no more than 3 gW / cm³. 2 The frequency should not exceed 2Hz, the pulse width should not exceed 10ns, the spot diameter should be 2.5-3mm, and the spot overlap rate should not exceed 30%.

[0017] As a preferred technical solution for the laser composite additive remanufacturing process, S70 further includes: simultaneously forming a water constraint layer on the surface of the repair layer, wherein the thickness of the water constraint layer is 2-3 mm.

[0018] As a preferred technical solution for laser composite additive remanufacturing processes, S50 specifically includes:

[0019] S51: Use penetrant testing to test the surface of the repair layer. If it passes, proceed to S52; otherwise, proceed to S10.

[0020] S52: Use X-ray flaw detection to test the repair layer and the surface to be repaired. If it passes, proceed to S53; if it fails, proceed to S10.

[0021] S53: Repair complete.

[0022] As a preferred technical solution for the laser composite additive remanufacturing process, S30 further includes: the cladding spot of the laser cladding nozzle precedes the impact spot of the laser impactor by 1-2 mm on the planned path.

[0023] As a preferred technical solution for the laser composite additive remanufacturing process, S30 further includes: the impact spot of the laser impactor is 0.8 to 1.5 mm above the interface between the cladding layer and the part to be repaired, and 0.7 to 1.5 mm below the interface between the cladding layer and the part to be repaired.

[0024] As a preferred technical solution for the laser composite additive remanufacturing process, S20 further includes: the alloy powder is spherical, and the particle size of the alloy powder is 50-150μm.

[0025] As a preferred technical solution for the laser composite additive remanufacturing process, S20 further includes: the alloy powder is mixed by ultrasonic vibration, the ultrasonic vibration time is 30-60 min, and the frequency is 18-20 kHz.

[0026] As a preferred technical solution for the laser composite additive remanufacturing process, S20 further includes: placing the alloy powder into a vacuum drying oven, evacuating it to below 0.2 MPa, then heating it to 100℃-150℃, holding it at that temperature for 1h-2h, and then cooling it to room temperature with the vacuum drying oven.

[0027] The beneficial effects of this invention are as follows:

[0028] This invention provides a laser composite additive remanufacturing process, comprising: S10: cleaning and smoothing the surface of the part to be repaired; S20: preparing alloy powder for use in a laser cladding nozzle, wherein the proportions of each element in the alloy powder are the same as those in the material used for the part to be repaired; S30: moving the laser cladding nozzle perpendicular to the surface to be repaired along a planned path on the surface to be repaired, and laying a cladding layer on the surface to be repaired; the impact spot of the laser shocker and the cladding spot of the laser cladding nozzle move synchronously, and the impact beam of the laser shocker performs synchronous laser shock strengthening on the portion above and below the interface between the cladding layer and the part to be repaired, so as to form a repair layer on the surface to be repaired; S40: determining whether the repair layer is flush with the surface of the part to be repaired; if yes, proceed to S50; otherwise, proceed to S30; S50: determining whether the repair layer of the part to be repaired is qualified. The device melts alloy powder using a laser cladding nozzle and sprays it onto the surface to be repaired, forming a cladding layer. This layer repairs volumetric damage such as pitting, cracks, and fractures on the part being repaired. Simultaneously, a laser shock blaster strengthens the cladding layer, improving its fatigue life and strength. This device requires minimal heat input, thus reducing the impact on the mechanical properties of the original part being repaired. The laser shock blasting strengthens the cladding layer, preventing structural distortion, coarseness, and uneven residual stress distribution within the cladding layer. Attached Figure Description

[0029] Figure 1 This is a flowchart of the laser composite additive remanufacturing process method in an embodiment of the present invention;

[0030] Figure 2 This is an equipment layout diagram of the laser composite additive remanufacturing process method in an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of step S7 of the laser composite additive remanufacturing process in an embodiment of the present invention.

[0032] In the picture:

[0033] 1. Part to be repaired; 11. Surface to be repaired;

[0034] 2. Laser cladding nozzle; 21. Repair layer;

[0035] 3. Laser shocker; 31. Shock beam; 4. Water-constrained layer emitter. Detailed Implementation

[0036] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions. Furthermore, "above," "on top of," and "over" the first feature in relation to the second feature includes the first feature directly above and diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature includes the first feature directly below and diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0039] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0040] like Figures 1-3 As shown, this embodiment provides a laser composite additive remanufacturing process method, which includes:

[0041] S10: Clean the surface 11 to be repaired of the part 1 to be repaired and grind the surface 11 to be repaired smooth.

[0042] In this step, taking a titanium alloy blade as an example, the corrosion on the surface 11 of the titanium alloy blade to be repaired is removed. A grinding wheel or angle grinder is used to remove the rust and burrs caused by corrosion or particle erosion, and the surface 11 to be repaired is ground smooth.

[0043] S20: Prepare alloy powder for use in laser cladding nozzle 2. The proportion of each element in the alloy powder is the same as the proportion of each element in the material used for the part to be repaired 1.

[0044] In this step, the component to be repaired is a titanium alloy blade. The main elements and mass percentages of the alloy powder are as follows: 5.50-6.80% Al, 3.40-4.50% V, 0.25-0.30% Fe, 0.05-0.10% C, with the balance being Ti.

[0045] Preferably, the main elements and their mass percentages are as follows: 6.50% Al, 3.85% V, 0.28% Fe, 0.08% C, with the balance being Ti.

[0046] Preferably, the alloy powder has a particle size of 50-150 μm and is spherical. This configuration facilitates rapid melting of the alloy powder. This value was obtained through extensive testing.

[0047] In addition, depending on the specific working conditions of the titanium alloy blades and their requirements for corrosion resistance and wear resistance, it may be selected whether to add 10% to 30% by mass of uniformly mixed TiC powder to the alloy powder to improve the corrosion resistance and wear resistance of the cladding layer.

[0048] The alloy powder can be mixed using ultrasonic vibration, with an ultrasonic vibration time of 30–60 min, a frequency of 18–20 kHz, and a powder particle size of 50–150 μm. This setting can make the alloy powder mix more uniformly.

[0049] In addition, the alloy powder needs to be dried before being used in the laser cladding nozzle 2. Specifically, the alloy powder is placed in a vacuum drying oven, evacuated to below 0.2 MPa, then heated to 100℃-150℃ and held at that temperature for 1-2 hours, before being cooled to room temperature in the vacuum drying oven. This setting can improve the problem of bubbles appearing in the cladding layer.

[0050] S30: Make the jetting direction of the laser cladding nozzle 2 perpendicular to the surface to be repaired 11, move along the planned path of the surface to be repaired 11, and lay the cladding layer on the surface to be repaired 11.

[0051] The impact beam 3 of the laser shocker 3 and the cladding beam 2 of the laser cladding nozzle move synchronously. The impact beam 31 of the laser shocker 3 performs synchronous laser shock enhancement on the part above and below the interface between the cladding layer and the part 1 to be repaired, so as to form a repair layer 21 on the surface 11 to be repaired.

[0052] In this step, the cladding process uses a four-channel coaxial powder feeding method. The cladding process parameters are as follows: laser power 0.9–1.5 kW, scanning speed 4–7 mm / s, powder feeding rate 25–45 g / min, carrier gas flow rate 3–8 L / min, circular spot with a diameter of 3–3.5 mm, defocusing amount of 3–5 mm, and Gaussian energy distribution. The output mode is either continuous output or pulsed output. If pulsed output mode is used, the pulse width should be controlled between 10–15 ms, and the duty cycle should be 8:1–10:1. Argon gas is used as the protective gas for the molten pool and the powder feeding carrier gas, with a purity of 99.99%.

[0053] The process parameters for laser shock are: power density 6-8 gW / cm2, frequency 2-4 Hz, pulse width 12-15 ns, spot diameter 2.5-3 mm, and spot overlap rate 20-40%.

[0054] Optionally, S30 further includes: the cladding spot of the laser cladding nozzle 2 precedes the impact spot of the laser impactor 3 by 1-2 mm on the planned path. This step ensures that the cladding layer is impact-forged in the initial stage of solidification.

[0055] Optionally, S30 further includes: the impact spot of the laser shocker 3 is 0.8–1.5 mm above the interface between the cladding layer and the part to be repaired 1, and 0.7–1.5 mm below the interface between the cladding layer and the part to be repaired 1. In this step, the above settings ensure that, through forming path planning, the impact beam 31 can reach and cover the entire spatial position of the upper and lower parts of the interface, and minimizes the energy effect on non-remanufacturing parts.

[0056] The part to be repaired 1 is fixed by a robotic arm. The robotic arm holding the part to be repaired 1 is programmed to move in the opposite direction according to the planned path, so as to ensure that the interaction position, time interval and order of the cladding beam and the impact beam 31 remain unchanged during the laser cladding and laser shock composite remanufacturing process, thereby realizing impact forging in the initial stage of the cladding melting, transformation and solidification.

[0057] S40: Determine whether the repair layer 21 is flush with the surface of the part 1 to be repaired. If yes, execute S50; otherwise, execute S30.

[0058] In this step, after laying a repair layer 21 on the surface to be repaired, it is determined whether it is flush with the surface of the part 1 to be repaired. If it is flush, S50 is executed. If it is not flush, the repair layer 21 is laid on the surface to be repaired again through step S30 until the repair layer 21 is flush with the surface of the part 1 to be repaired.

[0059] Optionally, S60 can be executed before S40; S60: Stop the laser cladding nozzle 2 and the laser impactor 3, and clean and remove contaminants from the repair layer 21 on the surface to be repaired 11. After the laser cladding nozzle 2 lays the repair layer 21 on the surface to be repaired 11, there will be slag and other impurities on the repair layer 21, which will make it difficult to perform laser cladding again on the repair layer 21.

[0060] Optionally, S70 is executed before S40; S70: The impact beam 31 of the laser shocker 3 performs laser shock enhancement on the two sides of the repair layer 21 perpendicular to the surface to be repaired 11. The process parameters of the laser shock are a power density of not more than 3 gW / cm³. 2 The frequency is no higher than 2Hz, the pulse width is no greater than 10ns, the spot diameter is 2.5-3mm, and the spot overlap rate is no greater than 30%. In this step, the impact beam 31 of the laser shocker 3 performs laser shock strengthening on the two sides of the repair layer 21 perpendicular to the surface to be repaired 11, further improving the fatigue life strength of the repair layer 21, causing the material surface to undergo elastoplastic deformation, forming a deep residual compressive stress layer and a tissue reinforcement layer.

[0061] Optionally, S70 further includes: simultaneously forming a water-constraining layer on the surface of the repair layer 21, the water-constraining layer having a thickness of 2-3 mm. In this step, laser shock utilizes the good penetrability of laser in water. When the laser pulse acts on the surface of the repair layer 21, it generates a high-pressure, high-stress-rate plasma shock wave, and utilizes the surface tension of water to constrain the direction of the shock wave, thereby effectively increasing the duration and force of the shock wave on the surface of the repair layer 21.

[0062] Specifically, the water confinement layer is provided by the water confinement layer transmitter 4.

[0063] The S50 specifically includes:

[0064] S51: Use penetrant testing to test the surface of the repair layer 21. If it passes, proceed to S52; otherwise, proceed to S10.

[0065] In this step, penetrant testing is used to monitor the surface of the repair layer 21 formed by the remanufacturing of the titanium alloy blade for defects such as cracks, porosity, and poor fusion. If it passes, proceed to step S52; if it fails, proceed to step S10.

[0066] S52: Use X-ray flaw detection to inspect the repair layer 21 and the surface to be repaired 11. If it passes, proceed to S53; if it fails, proceed to S10.

[0067] In this step, X-ray flaw detection is used to monitor for defects such as cracks and porosity on the repair layer 21 and the surface 11 to be repaired in the remanufactured titanium alloy blade. If the defects are acceptable, proceed to step S53; otherwise, proceed to step S10.

[0068] S53: Repair complete.

[0069] Alloy powder is melted and sprayed onto the surface 11 to be repaired using a laser cladding nozzle 2 to form a cladding layer. This repairs volumetric damage such as pitting, cracks, and fractures on the part 1 to be repaired. Simultaneously, a laser shock absorber 3 is used to strengthen the cladding layer with laser shock, improving its fatigue life strength. This device does not require a large amount of heat input, thus reducing the impact on the mechanical properties of the original part to be repaired. The laser shock absorber 3 strengthens the cladding layer with laser shock, preventing the repair layer 21 from exhibiting coarse microstructure and uneven distribution of residual stress.

[0070] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A laser composite additive remanufacturing process, characterized in that, Includes the following steps: S10: Clean the surface (11) to be repaired of the part (1) to be repaired and grind the surface (11) to be repaired flat; S20: Prepare alloy powder for use in laser cladding nozzle (2), wherein the ratio of each element in the alloy powder is the same as the ratio of each element in the material used in the part to be repaired (1); S30: Make the spraying direction of the laser cladding nozzle (2) perpendicular to the surface to be repaired (11), move along the planned path of the surface to be repaired (11), and lay the cladding layer on the surface to be repaired (11); The impact spot of the laser shocker (3) and the cladding spot of the laser cladding nozzle (2) move synchronously. The impact beam (31) of the laser shocker (3) performs synchronous laser shock enhancement on the part above the interface and the part below the interface between the cladding layer and the part to be repaired (1), so as to form a repair layer (21) on the surface to be repaired (11). S40: Determine whether the repair layer (21) is flush with the surface of the part to be repaired (1). If yes, execute S50; otherwise, execute S30. S50: Determine whether the repair layer (21) of the part to be repaired (1) is qualified; Execute S60 before executing S40; S60: Stop the laser cladding nozzle (2) and the laser shocker (3), and clean and remove dirt from the repair layer (21) on the surface to be repaired (11); Execute S70 first, after S60 has been executed and before S40 has been executed; S70: The impact beam (31) of the laser shocker (3) performs laser shock strengthening on the two sides of the repair layer (21) perpendicular to the surface to be repaired (11). The process parameters of the laser shock are a power density of not more than 3 gW / cm³. 2 The frequency is not higher than 2Hz, the pulse width is not greater than 10ns, the spot diameter is 2.5~3mm, and the spot overlap rate is not greater than 30%. S30 further includes: the impact spot of the laser shocker (3) is 0.8~1.5mm above the interface between the cladding layer and the part to be repaired (1), and 0.7~1.5mm below the interface between the cladding layer and the part to be repaired (1).

2. The laser composite additive remanufacturing process method according to claim 1, characterized in that, S70 further includes: simultaneously forming a water constraint layer on the surface of the repair layer (21), the water constraint layer having a thickness of 2~3mm.

3. The laser composite additive remanufacturing process method according to claim 1, characterized in that, The S50 specifically includes: S51: Use penetrant testing to test the surface of the repair layer (21). If it passes, proceed to S52; otherwise, proceed to S10. S52: Use X-ray flaw detection to test the repair layer (21) and the surface to be repaired (11). If it is qualified, proceed to S53; if it is not qualified, proceed to S10. S53: Repair complete.

4. The laser composite additive remanufacturing process method according to claim 1, characterized in that, S30 also includes: the cladding spot of the laser cladding nozzle (2) precedes the impact spot of the laser shocker (3) by 1~2 mm on the planned path.

5. The laser composite additive remanufacturing process method according to claim 1, characterized in that, S20 further includes: the alloy powder is spherical, and the particle size of the alloy powder is 50-150μm.

6. The laser composite additive remanufacturing process method according to claim 1, characterized in that, S20 also includes: the alloy powder is mixed by ultrasonic vibration, the ultrasonic vibration time is 30~60min, and the frequency is 18~20KHz.

7. The laser composite additive remanufacturing process method according to claim 1, characterized in that, S20 further includes: placing the alloy powder into a vacuum drying oven, evacuating it to below 0.2 MPa, then heating it to 100℃-150℃, holding it at that temperature for 1-2 hours, and then cooling it to room temperature with the vacuum drying oven.

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