Device for laser-inducing cavitation strengthening with multi-system automatic coordination work

Abstract

A device and a method for laser-inducing cavitation strengthening with multi-system automatic coordination work. The device comprises a plurality of systems, including a clamping system, a lifting system, an imaging system, a computer control system, a laser system and an energy density amplifying system, etc. The device for laser-inducing cavitation strengthening comprises a laser cavitation device and a fixing platform.

Claims

1. A multi-system automatic coordinating apparatus for laser induced cavitation strengthening, comprising: a laser cavitation device and a fixing station, wherein the fixing station has a water tank with a cushion block inside, a temperature sensor on a side wall of the water tank, and the temperature sensor is connected to a computer; and wherein the fixing station is on a lifting system and the lifting system is on a two-axis platform, a laser emitted from the laser cavitation device passes through a wall of the water tank and focuses in the tank, and further comprising a guide rod at the upper end of the fixing station and a movable plate mounted on the guide rod, wherein the movable plate is connected with the guide rod in the form of a moving pair, the movable plate is connected to a piston rod of a cylinder, and the cylinder is connected to a nitrogen tank through an electromagnetic valve; and wherein the laser cavitation device is connected to the computer, and the lifting system and two-axis platform are both connected to the computer through a CNC servo system.

2. The multi-system automatic coordinating apparatus for laser induced cavitation strengthening according to claim 1, wherein the lifting system has a lifting platform, the fixing station is on the lifting platform and the lifting platform is connected to the CNC servo system through a shaft, a coupling, and a servo motor in turn.

3. The multi-system automatic coordinating apparatus for laser induced cavitation strengthening according to claim 1, wherein: the laser cavitation device includes a laser controller, a YAG laser, a 45 mirror, a beam expanding lens, and a focusing lens, and wherein the laser controller controls the YAG laser to emit the laser, and the laser focuses in the water tank after passing the 45 mirror, the beam expanding lens, the focusing lens, and the back side wall of water tank.

4. The multi-system automatic coordinating apparatus for laser induced cavitation strengthening according to claim 3, further comprising a hydrophone above the water tank, wherein the hydrophone is connected to the computer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is the main view of the apparatus.

(2) FIG. 2 is the top view of the apparatus.

(3) In the drawings: (1) lifting platform, (2) cylinder, (3) movable plate, (4) hydrophone, (5) guide rod, (6) water tank, (7) fixing station, (8) target, (9) temperature sensor, (10) cushion block, (11) coupling, (12) servo motor, (13) two-axis platform, (14) shaft, (15) lighting flash, (16) high speed camera, (17) CCD, (18) CNC servo system, (19) computer, (20) laser controller, (21) YAG laser, (22) 45 mirror, (23) beam expanding lens, (24) focusing lens, (25) nitrogen tank, (26) electromagnetic valve.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(4) As shown in FIGS. 1 and 2, the above apparatus includes laser cavitation device and fixing station (7). The laser cavitation device includes laser controller (20), YAG laser (21), 45 mirror (22), beam expanding lens (23), focusing lens (24). The laser controller (20) controls YAG laser (21) to emit laser. The laser beam passes the 45 mirror (22), beam expanding lens (23), focusing lens (24), and side wall of water tank (6) to focus in the water tank (6). The water tank (6) is on the fixing station (7) and a cushion block (10) is put in the water tank (6). A guide rod (5) is mounted on the upper end of the fixing station (7) and a movable plate (3) is mounted on the guide rod (5). The movable plate (3) is connected to the moving pair of guide rod (5) and the piston rod of the cylinder (2). The cylinder (2) is connected to nitrogen tank (25) though electromagnetic valve (26). There is a temperature sensor (9) on the side wall of water tank (6). The temperature sensor (9) is connected to computer (19). Above the water tank (6), there is a hydrophone (4) connected to computer (19), which is used for recording acoustic signal of cavitation. The imaging system includes flash light (15), high speed camera (16), and CCD (17). The flash light (15), high speed camera (16), and CCD (17) are all connected to computer (19) to record the pulsating and collapse of the cavitation bubbles. The fixing station (7) is on the lifting system. The lifting system includes lifting platform (1) and the fixing station (7) is on the lifting platform (1). The lifting platform is connected to CNC servo system (18) through shaft (14), coupling (11), and servo motor (12). The lifting system is on the two-axis platform (13). The laser beam emitted from laser cavitation device is focused in water tank (6) after passing through the side wall of it. The above device is connected to computer (19). The above lifting system and two-axis platform (13) are connected to computer (19) through CNC servo system (18).

(5) During the operation, the target (8) and cushion block (10) are cleaned with ethanol or acetone and put into the right place of water tank (6). The water tank is put on the fixing station (7) and the purified water is filled into the water tank until the target (8) and cushion block (10) are submerged. The water temperature obtained from temperature sensor (9) during laser cavitation can be seen on computer screen in real time. Computer (19) is controlling the fixing system and lifting system. The YAG laser (21) emits laser after the laser parameters (laser energy, laser wavelength, beam spot size) are set on laser controller (20). The cavitation is generated after amplifying the laser energy. The experiment data are analyzed and the residual stress distribution is measured after cleaning the target (8) surface. Adjust the lifting system and change the water temperature to repeat the above operation until the optimal strengthening distance ds is obtained (ds is the distance between target (8) surface and laser focus point in the water tank (6)). Keep the ds unchanged and process the whole target (8) surface with control of two-axis platform (13) by computer (19). In order for further study of the laser cavitation process with optimal situation, the hydrophone and imaging system send signals to computer (19) so that the researchers can make observation and research to cavitation process in details.

(6) It should be noticed that the above content is only illustrating the technical scheme rather than limit the scope of protection of the current invention. The simple modification or equivalent replacement of the technical scheme made by technicians in this field does not separate from the nature and extent of the technical scheme of this invention.