CN113102893A - Material surface modification method suitable for thermal composite laser impact in atmospheric environment - Google Patents
Material surface modification method suitable for thermal composite laser impact in atmospheric environment Download PDFInfo
- Publication number
- CN113102893A CN113102893A CN202110524044.4A CN202110524044A CN113102893A CN 113102893 A CN113102893 A CN 113102893A CN 202110524044 A CN202110524044 A CN 202110524044A CN 113102893 A CN113102893 A CN 113102893A
- Authority
- CN
- China
- Prior art keywords
- laser
- processed
- laser beam
- area
- defocusing amount
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/352—Working by laser beam, e.g. welding, cutting or boring for surface treatment
- B23K26/356—Working by laser beam, e.g. welding, cutting or boring for surface treatment by shock processing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/04—Automatically aligning, aiming or focusing the laser beam, e.g. using the back-scattered light
- B23K26/046—Automatically focusing the laser beam
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
- B23K26/062—Shaping the laser beam, e.g. by masks or multi-focusing by direct control of the laser beam
- B23K26/0622—Shaping the laser beam, e.g. by masks or multi-focusing by direct control of the laser beam by shaping pulses
Abstract
The invention provides a material surface modification method suitable for thermal composite laser impact in atmospheric environment, which comprises the following steps: setting the pulse width, the laser energy and the shape and the size of a laser beam of the laser; setting the surface of a material to be processed to keep negative defocusing amount; carrying out single-point laser shock treatment on the surface of the material to be processed by adopting the laser parameters and the negative defocusing amount; adjusting the negative defocusing amount or adjusting the negative defocusing amount and the side length or the diameter of the laser beam until the area of the modified area of the surface of the material to be processed is less than or equal to 120% of the irradiation area of the laser beam on the surface of the material to be processed, so that the negative defocusing amount and the diameter or the side length of the laser beam are determined; setting the lap joint rate of laser shock treatment of a multipoint region; and carrying out laser shock treatment on the surface of the material to be processed by adopting the determined process parameters. The method effectively realizes the surface modification of the material under the condition of no absorption layer and no constraint layer, so that the material has a mechanical property distribution state of hard outside and tough inside.
Description
Technical Field
The invention relates to a material surface modification method suitable for thermal composite laser impact in an atmospheric environment, and belongs to the technical field of laser surface strengthening and modification of metal structure materials.
Background
Laser shock is a material surface strengthening and modifying technique developed based on the force effect of pulsed laser. In the conventional laser impact material surface treatment process, an absorption layer and a constraint layer material are respectively coated on the surface of a material to be processed. The absorption layer is used for forming high-temperature high-pressure plasma and preventing the surface of the material from being ablated due to heat influence, and the restraint layer is used for limiting the forming space of the high-temperature high-pressure plasma and guiding to form GPa-level impact pressure acting on the surface of the material.
At present, researchers propose an underwater laser shock technology without an absorption layer, and the technology is suitable for the application fields of surface service life prolonging and the like of nuclear power pressure vessels with underwater service environments. When the underwater service component is generally difficult to coat an absorbing layer material such as black paint or black adhesive tape, when the laser beam acts on the surface of the material, the surface of the material is melted and ablated to form plasma, and the plasma forms pressure load impacting the surface of the material under the action of a liquid environment. With the continuous expansion of the application field of the laser impact technology, the laser impact treatment in narrow spaces such as turbine disc mortises of aero-engines is restricted by the space structure of the component, and the absorption layer and the constraint layer are difficult to be applied to the to-be-processed area of the material.
Research has shown that laser beams with faster pulse widths such as fs can still form high-strength pressure loads on the surface of a material without depending on the restriction of a liquid confinement layer due to extremely short action time. However, the pulse laser with ns-order pulse width cannot form high-intensity shock wave effectively acting on the surface of the material in the atmospheric environment without a constrained layer, and the high-intensity shock wave propagates in the reverse direction of the surface of the material, so that the application of the laser shock technology in the surface processing field in narrow and complex spaces such as a slot is directly restricted. The conventional laser impact surface processing technology adopts ns-magnitude pulse laser beams as energy sources, so that how to break through the technical limitation is limited, and the development of a new laser force effect technology suitable for the atmospheric environment under the condition of no absorption layer and no constraint layer is an application problem which needs to be solved by technical personnel.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a material surface modification method suitable for the thermal-mechanical composite laser impact in the atmospheric environment. The biggest technical problem of laser shock treatment of metal materials in an atmospheric environment without a constrained layer is that the plasma shock wave formed on the surface of the material cannot form a pressure load acting in the direction of the surface of the material, but propagates in the opposite direction of the surface of the material. The technical obstacle of the backward propagation of the laser-induced shock wave is broken through, and the remarkable surface processing effect of laser shock can be formed. The technical scheme provided by the invention is a new way for solving the scientific problem of laser shock wave back propagation in the atmospheric environment without a specific constraint layer material, and the surface modification of the material is effectively realized by adopting a thermal composite laser shock method under the condition without an absorption layer and a constraint layer, so that the material has a mechanical property distribution state of 'hard outside and tough inside'.
The technical scheme of the invention is as follows:
a surface modification method of a material suitable for thermal-mechanical composite laser impact in an atmospheric environment comprises the following steps:
(1) setting the pulse width of the laser to be ns magnitude and the laser energy to be 5J-10J; setting the laser beam to be a round or square laser beam; the diameter of the round laser beam is more than 0.1mm and less than 1mm, and the side length of the square laser beam is more than 0.1mm and less than 1 mm;
(2) setting the surface of a material to be processed to keep a negative defocusing amount, wherein the negative defocusing amount is set to be 0.7mm-1.2 mm;
(3) carrying out single-point laser shock treatment on the surface of the material to be processed by adopting the laser parameters and the negative defocusing amount in the steps (1) to (2); adjusting the negative defocusing amount or adjusting the negative defocusing amount and the side length or the diameter of the laser beam until the area of the modified area of the surface of the material to be processed is less than or equal to 120% of the irradiation area of the laser beam on the surface of the material to be processed, so that the negative defocusing amount and the diameter or the side length of the laser beam when the surface of the material to be processed is subjected to actual laser shock treatment are determined;
(4) setting the lap joint rate of laser shock treatment of a multipoint region to be 10-30%;
(5) and (4) carrying out laser shock treatment on the surface of the material to be processed by adopting the process parameters determined in the steps (1) to (4).
According to the invention, in the step (1), the ns-magnitude pulse width laser beam is adopted, and the larger pulse width can improve the action time of the laser heat effect, thereby improving the depth of the micro-molten pool. The laser energy is more than 5J, so that the surface of the material has enough thermal effect to perform rapid melting; the laser energy needs to be proper, the micro-melting pool vaporization is easily aggravated when the laser energy is too large, and sufficient melting depth cannot be formed when the laser energy is too small.
Preferably, in step (1), the pulse width of the laser is 10ns to 50 ns.
According to the present invention, in step (1), the area of the laser beam needs to be appropriate. The maximum depth of the micro-molten pool on the surface of the material needs to consider the area size of the action area of the laser beam. When a circular laser beam is used as an energy source, the larger the diameter of the laser beam is, the smaller the allowable depth of the micro-molten pool is; namely, the larger the area of the laser beam is, the smaller the allowable depth of the micro-molten pool is; therefore, in order to ensure that the micro-molten pool has a certain thickness, the area size of the laser beam needs to be appropriate. Since the micro-pools that are too deep are likely to cause splashing of the droplets, the depth of the micro-pools needs to be under processing conditions that keep the droplets from splashing.
According to the invention, in the step (2), the surface of the material to be processed is set to keep a negative defocusing amount, namely the focal point of the laser beam is positioned in the material to be processed, and the extension of the focal point of the laser beam to the interior of the material causes the increase of the penetration depth of the surface of the material. The negative defocus amount of 0.7mm-1.2mm was set so that the laser beam focus was located within the material surface layer to a depth of about 1 mm. After the laser beam is incident to the liquid micro-molten pool on the surface of the material from the air, the change of the refractive index causes the laser focusing position to extend further to the interior of the material. Therefore, during the laser impact process under the full action time, the depth of the liquid micro-molten pool on the surface of the material is greater than the action depth determined by the negative defocusing amount value. The negative defocusing amount needs to be proper, and if the negative defocusing amount is too large, the splashing of the liquid molten pool is difficult to control; if the negative defocusing amount is too small, a liquid restraint layer with a certain thickness cannot be formed.
According to the invention, in the step (2), the material to be processed is a light metal material, stainless steel or an aviation alloy material; preferably, the light metal material is aluminum, magnesium or copper, and the aviation alloy material is titanium alloy or high-temperature alloy.
According to the invention, in the step (3), the adjustment of the negative defocusing amount is carried out in the range of 0.7mm-1.2 mm; the adjustment of the laser beam area is realized by adjusting the beam diameter or the side length, and the adjustment range is as described in the step (1).
The method for determining the negative defocusing amount and the diameter or side length of the laser beam when the surface of the material to be processed is subjected to actual laser shock treatment comprises the following steps of:
i. firstly, fixing the diameter or side length of a laser beam, and then adjusting the negative defocusing amount within the range of 0.7mm-1.2 mm; if the area of the modified area of the surface of the material to be processed is larger than 120% of the irradiation area of the laser beam on the surface of the material to be processed, the negative defocusing amount is reduced until the area of the modified area of the surface of the material to be processed is smaller than or equal to 120% of the irradiation area of the laser beam on the surface of the material to be processed;
ii. If the area of the area, in which the surface modification of the material to be processed cannot be realized, of the negative defocusing amount in the step i is less than or equal to 120% of the irradiation area of the laser beam on the surface of the material to be processed, the diameter or the side length of the laser beam is adjusted, the negative defocusing amount is adjusted again according to the method, and the step i is repeated;
and iii, repeating the steps i-ii until the area of the modified area of the surface of the material to be processed is less than or equal to 120% of the irradiation area of the laser beam on the surface of the material to be processed, thereby determining the negative defocusing amount and the diameter or side length of the laser beam when the actual laser impact treatment is carried out on the surface of the material to be processed.
The above purpose is to avoid splashing and flowing of the liquid metal in the micro-molten pool to the periphery of the molten pool as much as possible. The remelting area of the stable micro-molten pool after solidification approximately corresponds to the laser beam irradiation area, so that the laser surface strengthening range is easier to control.
According to the invention, in the step (4), the focusing position of the laser beam is positioned at a certain depth below the surface layer of the material, and the irradiation range of the laser beam at the bottom of the micro-molten pool is lower than that at the outermost surface layer of the material, so that the minimum value of the lap joint rate is set by multi-point laser impact. The lower limit of the lap joint rate is set to be 10%, and the target of uniform surface modification of areas under different working conditions can be met. In addition, the laser impact surface modification method leads the surface of the material to be a remelting modification layer, and the remelting modification layer is easy to cause the formation of a coarse grain structure under the action of multiple long-time thermal effects, so that the maximum value of the lap joint rate is set by multipoint laser impact. The upper limit of the lap joint rate is set to be 30%, and repeated remelting of a light beam irradiation area can be avoided.
The invention has the technical characteristics and beneficial effects that:
1. the focus of the laser beam is the position with the maximum laser energy density, and the surface of the material to be processed is placed at the focus of the laser beam in the conventional laser shock treatment, so that the maximum laser shock processing effect is obtained. Aiming at a newly proposed double-effect stress light impact processing method of 'plasma impact-cavitation', a technician places a surface to be processed at a positive defocusing amount position of a laser beam. The invention provides a method for submerging the focusing position of a laser beam into the surface layer of a material, namely, the surface of the material keeps negative defocusing amount relative to the laser beam, and further a liquid melting layer with larger depth on the surface of the material is obtained (Chaiyu beads, research on the influence of focusing and environmental parameters on the mechanical effect of laser plasma shock waves, Nanjing university of science and technology, 2007, when a target has negative defocusing amount, the effect of the laser on the material is mainly ablation). The laser beam focus is positioned in the material surface layer, so that the bottom of a micro molten pool on the material surface has the greatest tendency to form high-temperature and high-pressure plasma, and the liquid melting layer with larger thickness also plays a role of a restraint layer in the atmospheric environment, and can play a role of promoting the plasma explosion shock wave to be transmitted to the interior of the material. While the above process occurs in an atmospheric environment, the larger thickness of the liquid micro-puddle acts as both an absorber layer and a constraining layer during conventional laser shock. Namely, high-temperature high-pressure plasma is formed at the bottom of the micro melting tank where the focus of the laser beam is positioned, and the high-temperature high-pressure plasma plays a role of an absorption layer; and the surface micro-molten pool plays a role in restraining the expansion of plasma and plays a role in restraining the layer. The method effectively overcomes the defect that the pressure load acting on the surface of the material cannot be formed under the conditions of no absorption layer and no constraint layer in the atmospheric environment, and effectively realizes the modification of the surface of the material to be processed under the conditions of no absorption layer and no constraint layer in the atmospheric environment.
2. After the surface of the material is processed by the laser processing method, a residual compressive stress field induced by laser shock waves is formed below the depth of a micro molten pool on the surface layer of the material, and a remelting modification layer forms higher hardness, so that the material has a mechanical property distribution state of hard outside and tough inside.
3. The laser impact method simultaneously utilizes the heat effect and the force effect formed by the action of the pulse laser on the surface of the material, the heat effect is mainly expressed by the formation of a liquid micro-molten pool on the surface of the material, and the force effect is mainly expressed by the introduction of residual stress in the material caused by the plasma impact wave. The method of the invention belongs to a laser surface processing method of thermal compounding, and is particularly suitable for surface modification treatment in slits such as turbine disc mortises, gear tooth roots and the like or in complex space structures with shielding because the method does not need coating of specific absorption layers and constraint layer materials.
Drawings
FIG. 1 is a schematic physical schematic diagram of a thermal composite laser shock surface modification method in an atmospheric environment in example 1 of the present invention;
wherein, 1 is the material to be processed, 2 is the laser beam with ns-magnitude pulse width, and 3 is the micro-molten pool formed by the laser beam acting on the surface of the material to be processed.
Detailed Description
The present invention will be further described with reference to the following examples, but is not limited thereto.
Meanwhile, the experimental methods described in the following examples are all conventional methods unless otherwise specified; the reagents, materials and equipment are commercially available, unless otherwise specified.
Example 1
A surface modification method of a material suitable for thermal-mechanical composite laser impact in an atmospheric environment comprises the following steps:
taking a high-temperature alloy material for processing certain aviation engine blades as an example, the specification of a sample is 20mm multiplied by 5mm, and the surface to be processed is a plane determined by 20mm multiplied by 20 mm. The surface of the material is polished by a mechanical grinding method before laser shock treatment.
1. Setting laser parameters of laser shock treatment;
setting the laser beam to be a circular laser beam with the diameter of 0.8 mm; laser energy 6J; the laser pulse width was 18 ns.
2. Setting the relative distance between the surface of the material to be processed and a laser emission device;
and (3) setting the surface of the material to be processed to keep a negative defocusing amount, setting the negative defocusing amount to be 0.9mm, and performing single-point laser shock treatment on the surface of the material by using the laser parameters determined in the step (1). Observing the impact area by using a metallographic microscope, determining that the diameter of a molten pool solidification area on the surface of the material subjected to laser impact treatment is about 0.9mm, and calculating to obtain the remelting area of the surface of the material, namely the area (pi multiplied by 0.45) of the surface modification area of the material to be processed2mm2) Exceeds the irradiation area (pi x 0.4) of the laser beam2mm2) 120% of the total.
Adjusting the negative defocusing amount to be 0.8mm, and carrying out single-point laser shock treatment on the surface of the material. Observing the impact area by using a metallographic microscope, determining that the diameter of a molten pool solidification area on the surface of the material subjected to laser impact treatment is about 0.86mm, and calculating to obtain the remelting area of the surface of the material, namely the area (pi multiplied by 0.43) of the surface modification area of the material to be processed2mm2) Not exceeding the irradiation area (pi x 0.4) of the laser beam2mm2) 120% of the total.
Therefore, the surface of the material to be processed is determined to keep 0.8mm of negative defocusing amount, and the area of the solidified material surface micro-molten pool, namely the area of the modified area of the surface of the material to be processed is ensured not to exceed 120% of the irradiation area of the laser beam on the surface of the material;
3. single-point laser shock treatment of the material to be processed;
carrying out single-point laser shock treatment on the material to be processed by adopting the determined laser parameters and the defocusing amount parameters of the material surface so as to verify; it was measured and confirmed that the single point laser shock treatment resulted in a diameter of the surface modified region of the material of about 0.86mm, which was consistent with the diameter of the surface modified region of the material in step 2 above.
4. Setting the lap joint rate of laser shock treatment of a multipoint region;
the overlap ratio of the laser shock treatment of the multi-spot area was set to 20%.
5. And (3) carrying out thermal composite laser impact surface processing treatment on the to-be-processed area of the to-be-processed material.
The laser impact surface processing treatment is carried out on the area to be processed of the material to be processed by adopting the determined surface modification process parameters of the single laser beam (the diameter of the laser beam is 0.8mm, the laser energy is 6J, the pulse width is 18ns, and the negative defocusing amount of the surface of the material to be processed is 0.8mm) and the numerical value (20%) of the lap joint rate of the adjacent laser beams during area processing.
Example 2
A surface modification method of a material suitable for thermal-mechanical composite laser impact in an atmospheric environment comprises the following steps:
taking a high-temperature alloy material for processing certain aviation engine blades as an example, the specification of a sample is 20mm multiplied by 5mm, and the surface to be processed is a plane determined by 20mm multiplied by 20 mm. The surface of the material is polished by a mechanical grinding method before laser shock treatment.
1. Setting laser parameters of laser shock treatment;
setting the laser beam as a square laser beam, wherein the side length of the beam is 0.7 mm; laser energy 6J; the laser pulse width was 18 ns.
2. Setting the relative distance between the surface of the material to be processed and a laser emission device;
and (3) setting the surface of the material to be processed to keep a negative defocusing amount, setting the negative defocusing amount to be 0.9mm, and performing single-point laser shock treatment on the surface of the material by using the laser parameters determined in the step (1). Observing the impact area by using a metallographic microscope, determining that the side length of a molten pool solidification area on the surface of the material subjected to laser impact treatment is about 0.72mm, and calculating to obtain the remelting area of the surface of the material, namely the area (0.72) of the surface modification area of the material to be processed2mm2) Not exceeding the irradiation area (0.7) of the laser beam2mm2) 120% of the total.
Therefore, the surface of the material to be processed is determined to keep 0.9mm of negative defocusing amount, and the area of the solidified material surface micro-molten pool, namely the area of the modified area of the surface of the material to be processed is ensured not to exceed 120% of the irradiation area of the laser beam on the surface of the material;
3. single-point laser shock treatment of the material to be processed;
carrying out single-point laser shock treatment on the material to be processed by adopting the determined laser parameters and the defocusing amount parameters of the material surface so as to verify; it was measured and confirmed that the single-point laser shock treatment resulted in a material surface-modified region having an edge length of about 0.72mm, which was consistent with the edge length of the material surface-modified region in step 2 above.
4. Setting the lap joint rate of laser shock treatment of a multipoint region;
the overlap ratio of the laser shock treatment of the multi-spot area was set to 10%.
5. And (3) carrying out thermal composite laser impact surface processing treatment on the to-be-processed area of the to-be-processed material.
The laser impact surface processing treatment is carried out on the area to be processed of the material to be processed by adopting the determined single laser beam surface modification process parameters (the laser beam side length is 0.7mm, the laser energy is 6J, the pulse width is 18ns, and the negative defocusing amount of the surface of the material to be processed is 0.9mm) and the numerical value (10%) of the lap joint rate of the adjacent beams during area processing.
Example 3
A surface modification method of a material suitable for thermal-mechanical composite laser impact in an atmospheric environment comprises the following steps:
taking a high-temperature alloy material for processing certain aviation engine blades as an example, the specification of a sample is 20mm multiplied by 5mm, and the surface to be processed is a plane determined by 20mm multiplied by 20 mm. The surface of the material is polished by a mechanical grinding method before laser shock treatment.
1. Setting laser parameters of laser shock treatment;
setting the laser beam to be a circular laser beam with the diameter of 0.9 mm; laser energy 6J; the laser pulse width was 18 ns.
2. Setting the relative distance between the surface of the material to be processed and a laser emission device;
and (3) setting the surface of the material to be processed to keep a negative defocusing amount, setting the negative defocusing amount to be 0.9mm, and performing single-point laser shock treatment on the surface of the material by using the laser parameters determined in the step (1). Observing the impact area by using a metallographic microscope, determining that the diameter of a molten pool solidification area on the surface of the material subjected to laser impact treatment is about 1.1mm, and calculating to obtain the remelting area of the surface of the material, namely the area (pi multiplied by 0.55) of the surface modification area of the material to be processed2mm2) Exceeds the irradiation area (pi x 0.45) of the laser beam2mm2) 120% of the total.
Adjusting the negative defocusing amount to be 0.7mm, and carrying out single-point laser shock treatment on the surface of the material. Observing the impact area by using a metallographic microscope, determining that the diameter of a molten pool solidification area on the surface of the material subjected to laser impact treatment is about 1mm, and calculating to obtain the remelting area of the surface of the material, namely the area (pi multiplied by 0.5) of the surface modification area of the material to be processed2mm2) Still exceeds the irradiation area (pi x 0.45) of the laser beam2mm2) 120% of the total.
The change of the negative defocusing amount can only be in the range of 0.7mm-1.2mm, and the defocusing amount can not be adjusted to meet the processing requirement at the moment.
Changing the diameter of the laser beam to be 0.7mm, setting the surface of the material to be processed to keep negative defocusing amount, setting the negative defocusing amount to be 0.9mm, and carrying out single-point laser shock treatment on the surface of the material. Observing the impact area by using a metallographic microscope, determining that the diameter of a molten pool solidification area on the surface of the material subjected to laser impact treatment is about 0.72mm, and calculating to obtain the remelting area of the surface of the material, namely the area (pi multiplied by 0.36) of the surface modification area of the material to be processed2mm2) Not exceeding the irradiation area (pi x 0.35) of the laser beam2mm2) 120% of the total.
Therefore, the diameter of the laser beam is determined to be 0.7mm, the negative defocusing amount of 0.9mm is kept on the surface of the material to be processed, and the area of the solidified material surface micro-molten pool, namely the area of the modified area of the surface of the material to be processed, is ensured not to exceed 120% of the irradiation area of the laser beam on the material surface;
3. single-point laser shock treatment of the material to be processed;
performing single-point laser shock treatment on the material to be processed by adopting the determined laser parameters (the diameter of the laser beam is adjusted to be 0.7mm, the laser beam is a circular laser beam; the laser energy is 6J; the laser pulse width is 18ns) and the defocusing amount parameter of the surface of the material so as to verify; it was measured and confirmed that the single point laser shock treatment resulted in a diameter of the surface modified region of the material of about 0.72mm, which was consistent with the diameter of the surface modified region of the material in step 2 above.
4. Setting the lap joint rate of laser shock treatment of a multipoint region;
the overlap ratio of the laser shock treatment of the multi-spot area was set to 15%.
5. And (3) carrying out thermal composite laser impact surface processing treatment on the to-be-processed area of the to-be-processed material.
The laser impact surface processing treatment is carried out on the area to be processed of the material to be processed by adopting the determined surface modification process parameters of the single laser beam (the diameter of the laser beam is 0.7mm, the laser energy is 6J, the pulse width is 18ns, and the negative defocusing amount of the surface of the material to be processed is 0.9mm) and the numerical value (15%) of the lap joint rate of the adjacent laser beams during area processing.
Claims (5)
1. A surface modification method of a material suitable for thermal-mechanical composite laser impact in an atmospheric environment comprises the following steps:
(1) setting the pulse width of the laser to be ns magnitude and the laser energy to be 5J-10J; setting the laser beam to be a round or square laser beam; the diameter of the round laser beam is more than 0.1mm and less than 1mm, and the side length of the square laser beam is more than 0.1mm and less than 1 mm;
(2) setting the surface of a material to be processed to keep a negative defocusing amount, wherein the negative defocusing amount is set to be 0.7mm-1.2 mm;
(3) carrying out single-point laser shock treatment on the surface of the material to be processed by adopting the laser parameters and the negative defocusing amount in the steps (1) to (2); adjusting the negative defocusing amount or adjusting the negative defocusing amount and the side length or the diameter of the laser beam until the area of the modified area of the surface of the material to be processed is less than or equal to 120% of the irradiation area of the laser beam on the surface of the material to be processed, so that the negative defocusing amount and the diameter or the side length of the laser beam when the surface of the material to be processed is subjected to actual laser shock treatment are determined;
(4) setting the lap joint rate of laser shock treatment of a multipoint region to be 10-30%;
(5) and (4) carrying out laser shock treatment on the surface of the material to be processed by adopting the process parameters determined in the steps (1) to (4).
2. The method for modifying the surface of a material subjected to the thermal composite laser shock under the atmospheric environment according to claim 1, wherein in the step (1), the pulse width of the laser is 10 ns-50 ns.
3. The method for modifying the surface of a material subjected to the thermal mechanical composite laser shock in the atmospheric environment as claimed in claim 1, wherein in the step (2), the material to be processed is a light metal material, stainless steel or an aviation alloy material.
4. The method for modifying the surface of a material subjected to the thermal mechanical composite laser shock in the atmospheric environment as claimed in claim 3, wherein the light metal material is aluminum, magnesium or copper, and the aviation alloy material is a titanium alloy or a high-temperature alloy.
5. The method for modifying the surface of a material through thermal compound laser shock suitable for the atmospheric environment as claimed in claim 1, wherein in the step (3), the method for determining the negative defocusing amount and the diameter or side length of the laser beam when the actual laser shock treatment is performed on the surface of the material to be processed comprises the steps of:
i. firstly, fixing the diameter or side length of a laser beam, and then adjusting the negative defocusing amount; if the area of the modified area of the surface of the material to be processed is larger than 120% of the irradiation area of the laser beam on the surface of the material to be processed, the negative defocusing amount is reduced until the area of the modified area of the surface of the material to be processed is smaller than or equal to 120% of the irradiation area of the laser beam on the surface of the material to be processed;
ii. If the area of the area, in which the negative defocusing amount cannot be adjusted to realize the surface modification of the material to be processed, in the step i is less than or equal to 120% of the irradiation area of the laser beam on the surface of the material to be processed, the diameter or the side length of the laser beam is adjusted, and then the step i is repeated;
and iii, repeating the steps i-ii until the area of the modified area of the surface of the material to be processed is less than or equal to 120% of the irradiation area of the laser beam on the surface of the material to be processed, thereby determining the negative defocusing amount and the diameter or side length of the laser beam when the actual laser impact treatment is carried out on the surface of the material to be processed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110524044.4A CN113102893B (en) | 2021-05-13 | 2021-05-13 | Material surface modification method suitable for thermal composite laser impact in atmospheric environment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110524044.4A CN113102893B (en) | 2021-05-13 | 2021-05-13 | Material surface modification method suitable for thermal composite laser impact in atmospheric environment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113102893A true CN113102893A (en) | 2021-07-13 |
| CN113102893B CN113102893B (en) | 2022-01-18 |
Family
ID=76722488
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110524044.4A Active CN113102893B (en) | 2021-05-13 | 2021-05-13 | Material surface modification method suitable for thermal composite laser impact in atmospheric environment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113102893B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113740319A (en) * | 2021-09-06 | 2021-12-03 | 山东大学 | Nondestructive implementation method for laser-induced breakdown spectroscopy component detection and application thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105658372A (en) * | 2013-09-05 | 2016-06-08 | 萨澳激光有限公司 | Method for machining workpiece by means of laser beam, laser tool, laser machine, machine control |
| CN107378235A (en) * | 2017-09-11 | 2017-11-24 | 中南大学 | Femtosecond laser system of processing and method |
| CN109226970A (en) * | 2018-11-01 | 2019-01-18 | 徐州工程学院 | A kind of micro/nano-scale high-temperature laser impact imprinting apparatus and method |
| CN109778177A (en) * | 2017-11-10 | 2019-05-21 | 中国科学院沈阳自动化研究所 | The composite surface treatment method of laser induced plasma impact cladding layer |
| CN111485235A (en) * | 2020-04-07 | 2020-08-04 | 江苏大学 | Method for promoting fine particles to realize intra-crystal distribution in laser shock melt injection process |
-
2021
- 2021-05-13 CN CN202110524044.4A patent/CN113102893B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105658372A (en) * | 2013-09-05 | 2016-06-08 | 萨澳激光有限公司 | Method for machining workpiece by means of laser beam, laser tool, laser machine, machine control |
| CN107378235A (en) * | 2017-09-11 | 2017-11-24 | 中南大学 | Femtosecond laser system of processing and method |
| CN109778177A (en) * | 2017-11-10 | 2019-05-21 | 中国科学院沈阳自动化研究所 | The composite surface treatment method of laser induced plasma impact cladding layer |
| CN109226970A (en) * | 2018-11-01 | 2019-01-18 | 徐州工程学院 | A kind of micro/nano-scale high-temperature laser impact imprinting apparatus and method |
| CN111485235A (en) * | 2020-04-07 | 2020-08-04 | 江苏大学 | Method for promoting fine particles to realize intra-crystal distribution in laser shock melt injection process |
Non-Patent Citations (1)
| Title |
|---|
| 章玉珠: "聚焦和环境参数对激光等离子体冲击波力学效应影响的研究", 《中国优秀博硕士学位论文全文数据库(博士) 基础科学辑》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113740319A (en) * | 2021-09-06 | 2021-12-03 | 山东大学 | Nondestructive implementation method for laser-induced breakdown spectroscopy component detection and application thereof |
| CN113740319B (en) * | 2021-09-06 | 2023-02-21 | 山东大学 | Nondestructive implementation method for laser-induced breakdown spectroscopy component detection and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113102893B (en) | 2022-01-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2986410B1 (en) | Process diagnostic system for and method of performing laser shock peening on a target with a fluid flow path sandwiched beteen a transparent to laser light solid medium and the target | |
| Tangwarodomnukun et al. | An investigation of hybrid laser–waterjet ablation of silicon substrates | |
| Guo et al. | Effect of water depth on weld quality and welding process in underwater fiber laser welding | |
| KR101625948B1 (en) | Ultrasonic vibration and laser-induced backside wet etching drilling apparatus | |
| CN101537534B (en) | Superimposing method of circular light spot laser shock strengthening tracks | |
| Fu et al. | Underwater wire-feed laser deposition of the Ti–6Al–4V titanium alloy | |
| Caiazzo et al. | Investigation and optimization of laser welding of Ti-6Al-4 V titanium alloy plates | |
| Zhang et al. | Progress in applications of shockwave induced by short pulsed laser on surface processing | |
| JPH07246483A (en) | Laser peening method | |
| CN111074061B (en) | Uniform surface strengthening method based on laser shock wave | |
| CN113102893B (en) | Material surface modification method suitable for thermal composite laser impact in atmospheric environment | |
| CN109117553B (en) | Light beam energy distribution determination method suitable for equal-intensity laser impact | |
| Mei et al. | Effects of Cr2O3 active agent on the weld process dynamic behavior and joint comprehensive properties of fiber laser welded stainless steel thick plate | |
| Fu et al. | In-situ formation of laser-cladded layer on Ti-6Al-4 V titanium alloy in underwater environment | |
| CN113102884A (en) | Material surface modification method by thermal composite underwater laser shock | |
| Tsuyama et al. | Effects of laser peening parameters on plastic deformation in stainless steel | |
| Brandt et al. | Laser cladding with a pulsed Nd: YAG laser and optical fibers | |
| Fabbro et al. | Physics and applications of laser shock processing of materials | |
| Wang et al. | Mechanism and parametric control of laser-layered paint removal for aircraft skin | |
| JP5172191B2 (en) | Laser shock hardening processing method and laser shock hardening processing apparatus | |
| CN106624353A (en) | Laser shotblast product surface fabrication system | |
| Hou et al. | A review of thermal effects and substrate damage control in laser cleaning | |
| Yilbas et al. | Study into the effect of beam waist position on hole formation in the laser drilling process | |
| Elgazzar et al. | Laser Surface Texturing of 304 Stainless Steel. | |
| Baptista et al. | Fatigue crack growth behavior of laser-shock processed aluminum alloy 2024-T3 |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |