9 results about "Laser power density" patented technology

The application provides a high-performance composite femtosecond laser processing variable cross-section hole forming precision control method, relates to the technical field of laser processing, and first discretizes a target hole into a plurality of processing layers along a depth direction, and establishes a Cartesian coordinate system; the effective radius of a spot and a projection area of each layer are calculated in combination with hole taper; on this basis, a reference power density decay model is constructed, a laser incidence angle is further introduced, and a mapping model between hole taper, laser incidence angle and laser power density is established. Finally, according to the target hole taper and the target removal efficiency, the laser incidence angle required by each processing layer is inversely solved, and the dynamic regulation and control of the rotary cutting head and the cradle turntable are realized accordingly. The method can realize layer-by-layer closed-loop control of the variable cross-section hole forming precision, effectively compensate for the laser power decay in the depth direction, and improve the precision of laser processing.

This invention discloses a method for CO2 continuous laser cutting of CFRP material. The method employs a CO2 continuous laser engraving and cutting system to cut CFRP material. After adjusting the corresponding working parameters, a portion of the CFRP material to be cut is taken as a sample, and a rectangle is obtained through trial cutting. The diameters of the pits generated by the spot laser are measured horizontally and vertically twice, and the average diameter is calculated. Simultaneously, the continuous laser power density is calculated, and the height difference between the four corners and the center of the rectangle is measured to obtain the surface fluctuation value (Fv). Different scanning speeds, number of consecutive processing cycles, and Z-axis scale values ​​are selected, and trial cutting is repeated on the sample. When the measured Fv is at its minimum value, the thermal damage to the material is minimized. The scanning speed, number of consecutive processing cycles, and Z-axis scale value at this minimum value are used as the working parameters for cutting the CFRP material. This invention effectively controls the thermal damage to the CFRP material during processing and improves the processing effect of laser-processed CFRP material.

The application provides a coating material and a laser cladding process for steam turbine blade water erosion resistance, and the mass percentage of each component of the coating material is as follows: C: 0.65-0.80wt%, Cr: 3.00-6.50wt%, Mn: 0.22-0.55wt%, Nb: 0.30-0.80wt%, Mo: 4.00-8.50wt%, Si: 0.1-0.3wt%, W: 5.00-8.00wt%, V: 1.50-2.50wt%, Al: 0.40-0.60wt%, and the balance is Fe and a small amount of impurity elements. The laser power density in the cladding process is 100-150W / mm 2 , argon is used to protect the molten pool, the powder feeding amount is 40-60r / min, and the multi-pass lap rate is 30-50%. The coating material provided by the application has the characteristics of high toughness, not easy to produce pores and excellent water erosion resistance. The cladding layer prepared from the coating material has high water erosion resistance and good comprehensive mechanical properties.

A method for the laser welding of two conductor pieces includes providing an elongated first conductor piece having a first end section and a first end face, and providing an elongated second conductor piece having a second end section and a second end face. The first end face is arranged adjacent to the second end face. The method further includes generating at least two laser spots on the first end face and / or the second end face. Each of the at least two laser spots has a core region and a ring region. An average laser power density in the core region is higher than an average laser power density in the ring region. The method further includes moving the at least two laser spots. The at least two laser spots generate a common melt pool that extends at least partially over the first end face and the second end face.

This application provides a laser thermal coma effect simulation method and system, belonging to the field of laser thermal coma effect simulation technology, including the following steps: dividing the atmospheric space along the laser transmission path into a two-layer structure of macroscopic and microscopic grids; calculating the absorbed laser power density in each macroscopic grid cell based on the initial temperature field at the current moment, and transferring the laser power density in the macroscopic grid cell containing the activated microscopic grid to the corresponding microscopic grid; within the activated microscopic grid region, using the received laser power density as the heat source, solving the heat-fluid coupling equation system to obtain local temperature field data, and returning the local temperature field data to the macroscopic grid node through volume weighted averaging to update the temperature field at the current moment; based on the updated temperature field, using pre-determined spatial basis functions, obtaining the modal coefficients at the current moment through eigenorthogonal decomposition; achieving improved computational efficiency while ensuring physical accuracy.

The application provides a diabetic foot rehabilitation physiotherapy device and method, wherein scattering interference caused by tissue exudate is compensated by distribution characteristics of the tissue exudate extracted from a physiotherapy image in a laser physiotherapy process, and a compensation image of the diabetic foot physiotherapy is obtained; laser absorption of laser energy at each position is determined according to optical structure characteristics in each local lesion area in the compensation image and brightness changes of each corresponding area in a contrast image; a plurality of physiotherapy areas are divided according to density accessibility of skin characteristics at each position in the physiotherapy image, and physiotherapy uniformity of each physiotherapy area is determined by all laser absorptions in each physiotherapy area; and laser irradiation parameters of each lesion area in the laser therapy are adjusted according to each physiotherapy uniformity of the diabetic foot surface of the patient and real-time laser power density. By using the scheme of the application, it can be ensured that the optical power density received by the skin of the patient at each position is uniform in the laser physiotherapy process.

The application provides a high-performance composite femtosecond laser processing variable cross-section hole forming precision control method, relates to the technical field of laser processing, and first discretizes a target hole into a plurality of processing layers along a depth direction, and establishes a Cartesian coordinate system; the effective radius of a spot and a projection area of each layer are calculated in combination with hole taper; on this basis, a reference power density decay model is constructed, a laser incidence angle is further introduced, and a mapping model between hole taper, laser incidence angle and laser power density is established. Finally, according to the target hole taper and the target removal efficiency, the laser incidence angle required by each processing layer is inversely solved, and the dynamic regulation and control of the rotary cutting head and the cradle turntable are realized accordingly. The method can realize layer-by-layer closed-loop control of the variable cross-section hole forming precision, effectively compensate for the laser power decay in the depth direction, and improve the precision of laser processing.

The application discloses a kind of brittle material optical element laser damage evaluation method considering stress concentration, it includes the following steps: determining strong laser irradiation target target material element type, obtains material fracture strength parameter;Microscope is used to detect the surface or subsurface defect point topography and size of optical element, obtains the transverse size w and longitudinal size d of defect point;Determine target laser power density, and determine laser wavelength and irradiation time, for pulsed laser, further determine pulse width and frequency;Based on optical and thermodynamic theory, establish the simulation model of defect structure induced optical material internal stress concentration, comparative analysis the stress caused by defect structure of different shape and size in laser action area;Select the maximum value of material internal stress and material fracture strength parameter comparison, according to brittle material fracture criterion, judge the element damage failure state under the irradiation of this laser parameter.The method of the application is reliable and has strong guidance.

This invention discloses a method for improving the mechanical properties of welded joints in laser welding and laser-welded plates, relating to the field of welding technology. The method for improving the mechanical properties of welded joints in laser welding utilizes a 3D-printed eutectic high-entropy alloy as an intermediate layer material. By precisely adjusting the line energy and laser power density and controlling the temperature field distribution, the laser beam temperature reaches above the liquidus temperature of both the eutectic high-entropy alloy and the steel plate, forming a molten weld on the steel plate side. On the aluminum alloy plate side, a brazing weld is formed due to the lower melting point of aluminum. A second laser process is applied to the weld to achieve a heat treatment effect. The high-entropy alloy intermediate layer increases the entropy of the welded joint, suppressing the formation of brittle Fe-Al intermetallic compounds and reducing the brittleness of the joint. The second laser processing eliminates residual stress, improving the mechanical properties of the joint, thereby achieving an effective connection between the aluminum alloy and the steel.