Intelligent laser 3D printing device and method

[0031] The present invention will be further described in detail below with reference to the drawings and embodiments.

[0032] The present invention provides an intelligent laser 3D printing device and printing method, such as figure 1 As shown, the printing device includes a housing 1, a semiconductor laser 2, a galvanometer X301, a galvanometer Y302, a scanning mirror X401, a scanning mirror Y402, a field lens 5, a molten pool 6, a workpiece table 7, a drive motor 8, a CCDA901, CCDB902, laser heterodyne interferometer 10 and computer 11. The workpiece table 7 and the drive motor 8 constitute a load six-axis parallel system, and the drive motor 8 drives the workpiece table 7 to move to realize the azimuth movement control of the physical objects on the workpiece table 7. The semiconductor laser 2, galvanometer X301, galvanometer Y302, scanning mirror X401, scanning mirror Y402, field lens 5, molten pool 6, work stage 7, drive motor 8, CCDA901, CCDB902 and laser heterodyne interferometer 10 are all It is fixed on the housing 1 by screws. The semiconductor laser 2, galvanometer X301, galvanometer Y302, scanning mirror X401, scanning mirror Y402, field lens 5, drive motor 8, CCDA901, CCDB902 and laser heterodyne interferometer 10 are respectively connected to the computer 11 through data lines. The maximum power of the semiconductor laser 2 is 100W, and the power can be adjusted from 0-100W. The focal distance of the field lens 5 is 50-300 mm, the processing scanning range is 200-500 mm, and the spot diameter is 10-50 μm. The repetition accuracy of the driving motor 8 is ±(2-10)μm, the stroke X/Y/Z is (30mm×30mm×10mm)-(400mm×400mm×300mm), and the angular stroke θX/θY/θZ is (20 °×20°×40°)-(40°×40°×80°). The CCDA901 and CCDB902 are preferably CCD cameras (charge coupled device image sensors, CCD) with a resolution of 1024×1024, an exposure time of 0.01-100 ms, and a frame rate of 0.1-5 s.

[0033] The computer uses Scan3DNow as the scanning software and CloudForm software as the image processing software.

[0034] The laser heterodyne interferometer 10 uses a helium-neon laser as a detection light source, a Bragg acousto-optic modulator, and a frequency difference of 80 MHz.

[0035] The laser light emitted by the semiconductor laser 2 passes through the galvanometer X301, the scanning mirror X401, the galvanometer Y302, the scanning mirror Y402, and the field lens 5 in sequence to reach the molten pool 6. The powder in the molten pool 6 is melted by the laser. The powder is sprayed on the workpiece through the nozzle to form a cladding layer corresponding to the contour of the workpiece.

[0036] The present invention is based on the intelligent laser 3D printing device. The present invention also provides an intelligent laser 3D printing method, which specifically includes the following steps:

[0037] Step 1: Establish the CAD model of the physical object, place the physical object to be printed on the workpiece table, and turn on the laser scanning imaging system, specifically:

[0038] The semiconductor laser 2 is turned on, the laser passes through the galvanometer X301, the scanning mirror X401, the galvanometer Y302, the scanning mirror Y402, and the field lens 5 in order to control the optical path to scan the physical objects of the workpiece stage 7 and drive the motor 8 to the workpiece stage 7 The physical objects on the upper part are moved in multiple directions, through the galvanometer X301, the galvanometer Y302, the scanning mirror X401, the scanning mirror Y402, and the field lens 5 to control the optical path to perform three-dimensional scanning of the physical objects. CCDA901 and CCDB902 receive the scan data, and the scan data passes through the data. After the data is processed by the scanning software Scan3DNow and the image processing software CloudForm of the computer 11, the CAD model is output on the computer 11.

[0039] Preferably, a sample table is generally set on the workpiece table, and the physical object is placed on the sample table; the cladding layer is also sprayed on the sample table during post-printing to avoid damage to the workpiece table.

[0040] Step 2: Laser 3D printing of physical objects.

[0041] According to the laser scanning imaging system to obtain the CAD model, the CAD model is divided, the printing process and working parameters are determined, after the powder is filled in the molten pool 6, the laser rapid prototyping system is turned on, specifically:

[0042] Turn on the semiconductor laser 2 and adjust the beam spot of the laser beam through the galvanometer X301, the scanning mirror X401, the galvanometer Y302, the scanning mirror Y402, and the field lens 5. The computer 11 drives the motor 8 according to the contour of the physical object through the data line command to control the workpiece table In the moving path of 7, the laser acts to melt the powder in the molten pool 6, and the melted powder is sprayed on the workpiece table 7 through the nozzle to form a cladding layer corresponding to the contour of the solid object.

[0043] Step 3: Nondestructive testing of the cladding layer, remove the molten pool 6, and turn on the laser photoacoustic nondestructive testing system, specifically:

[0044] Turn on the semiconductor laser 2 to generate a high-energy pulsed laser, and adjust the beam spot of the laser beam through the galvanometer X301, the scanning mirror X401, the galvanometer Y302, the scanning mirror Y402 and the field lens 5. The laser is irradiated on the cladding layer to generate laser ultrasonic waves; When the laser ultrasonic wave propagates through the tiny crack, the ultrasonic wave propagation variation will occur at the crack.

[0045] The laser heterodyne interferometer 10 is used to detect the ultrasonic signal, the data acquisition module collects the interference fringe changes, and the detection result is transmitted to the computer 11, and the structure damage feature data collection and internal defect detection are performed on the computer 11.

[0046] Step 4: According to the damage detection result, if there are defects in the cladding layer, repair the defects in the cladding layer.

[0047] The said repairing refers to repeating the step of printing the cladding layer in step 2, namely:

[0048] Turn on the semiconductor laser 2 and adjust the beam spot of the laser beam through the galvanometer X301, the scanning mirror X401, the galvanometer Y302, the scanning mirror Y402, and the field lens 5. The computer 11 drives the motor 8 according to the contour of the physical object through the data line command to control the workpiece table In the moving path of 7, the laser acts to melt the powder in the molten pool 6, and the melted powder is sprayed on the defective part on the cladding layer through the nozzle to repair the defect.

[0049] Step 5: The nozzle moves relative to the workpiece table 7 along the forming direction by a slice thickness, and then superimposes the previous cladding layer to form a subsequent cladding layer to ensure that the front and back layers are fused together.

[0050] Step 6: Repeat steps 3 to 5 until the entire workpiece is formed; after printing, turn off the intelligent laser 3D printing device.