WO2015101103A1

WO2015101103A1 - Laser shock peening device and water spray pipe thereof

Info

Publication number: WO2015101103A1
Application number: PCT/CN2014/090378
Authority: WO
Inventors: 孙帮成; 李明高; 李国清; 高峰; 李欣伟; 李明
Original assignee: 唐山轨道客车有限责任公司
Priority date: 2013-12-31
Filing date: 2014-11-05
Publication date: 2015-07-09
Also published as: CN103740894A

Abstract

A laser shock peening device and a water spray pipe (10) thereof. The laser shock peening device comprises a clamping assembly (5) for clamping a lens seat (6) and the water spray pipe (10). The water spray pipe (10) comprises a pipe body (1) that is provided with a water inlet and a water outlet, a nozzle (2) that is connected to the water outlet of the pipe body (1) has a spray opening with a rectangular cross section, and grooves (21) with arc-shaped cross sections are oppositely provided at two ends of the spray opening. The laser shock peening device can form a stable water restraint layer, and can adapt to workpieces in various situations by means of adjustment of the spray position and spray angle.

Description

Laser shock reinforced device and water spray pipe thereof

Technical field

The invention relates to the technical field of laser shock peening, in particular to a laser shock reinforced device and a water spray pipe thereof.

Background technique

Laser shock peening technology, also known as laser peening technology, is the energy applied by a laser with a high power density (on the order of GW/cm ² ) and a short pulse (on the order of 10 to 30 ns) through a transparent constraining layer on the surface of a metal workpiece. When absorbing the coating, the coating absorbs the laser energy and rapidly vaporizes and forms a large number of dense high-temperature (>10K), high-pressure (>1GPa) plasmas at the same time. The plasma continues to absorb the laser energy and rapidly expands and then expands to form high intensity. The shock wave acts on the surface of the metal workpiece. When the peak pressure of the shock wave exceeds the dynamic yield strength of the metal material, the metal material is plastically deformed and generates tensile stress parallel to the surface of the metal material in the surface layer. The mechanical effect of the reaction of metal materials is that the surface of the metal material obtains high residual compressive stress, which reduces the level of tensile stress in the alternating load and reduces the average stress level, thereby improving the fatigue crack initiation life. At the same time, the existence of residual compressive stress can cause the crack closing effect, thereby effectively reducing the driving force of fatigue crack growth and prolonging the fatigue crack growth life.

In the laser shock treatment process, the laser needs to reach the absorption layer through the water layer as the constraining layer, and the laser energy is absorbed by the absorption layer to generate a high-temperature and high-pressure plasma, thereby generating a shock wave. Especially in the case of continuous laser shock treatment, the flatness of the constraining layer will affect whether the laser shock treatment can be carried out or whether it can be continuously implemented.

The existing implementation of the water layer as the constraining layer mainly includes two types, one is to place the workpiece in the water tank for underwater processing, and the other is to form flowing water on the surface of the workpiece through an external circular water pipe. screen. The first implementation method is not flexible enough in the actual operation process, and the processing range is not only limited by the size of the water tank, but also needs to wait for the water surface to be smoothed after each impact, and the processing efficiency is low; the second implementation method is difficult to control the water layer. Thickness and stability of water flow, and when the distance between the laser and the surface of the workpiece changes, it is difficult to adjust the position of the water sprinkler head, and further, it is difficult to form a stable water flow for impact strengthening of the space, and the spout of the circular water pipe It also affects the distribution of water flow.

Summary of the invention

The present invention provides a laser shock reinforced device and a water spray pipe thereof, which are capable of forming a water confinement layer which is smooth and controllable in thickness, and is also applicable to a workpiece in various situations by adjusting an injection position and an injection angle, and has high applicability.

The invention provides a water spray pipe for laser shock strengthening, comprising:

a tubular body having a water inlet and a water outlet;

The spray head communicating with the water outlet of the pipe body has a water spray port having a rectangular cross section, and a groove having a curved cross section is oppositely opened at both ends of the water spray port.

According to the water spray pipe for laser shock reinforced provided by the present invention, the groove has a semicircular cross-sectional shape.

According to the water spray pipe for laser shock reinforcement provided by the present invention, the water spray port has a width of 2 to 3 cm.

According to the water spray pipe for laser shock reinforcement provided by the present invention, the pipe body and the spray head are connected by a connector, and the connector can rotate the spray head relative to the axial direction of the pipe body 15~ 90 degrees.

Further, the connector is a universal serpentine connector.

Further, a rotating disk with a handle is fixedly mounted on the connector, which is capable of manually driving the nozzle to rotate in the axial direction of the tube.

According to the water spray pipe for laser shock reinforcement provided by the present invention, the water spray port end of the spray head is bent.

Further, when the nozzle is vertically disposed, the degree of bending of the lower pipe wall of the water spout end is greater than the bending degree of the pipe wall at the spout end.

The present invention also provides a laser shock reinforced device comprising a clamping set, a lens holder having a protective lens at one end, and a spray pipe for laser shock reinforced according to any of the above,

The clamping set includes a first jig and a second jig, and a first groove and a second groove are oppositely opened on the first jig and the second jig, and the lens mount is mounted on the first In a recess, the water spray pipe is installed in the second groove, and both ends of the first jig and the second jig are fixed by bolts and nuts.

Further, opposite to the outside of the second groove of the first jig and the second jig More than one groove is opened.

The water spray pipe for laser shock reinforced by the invention can form a water confinement layer with smooth and controllable thickness, and the water constraining layer is evenly distributed on the surface of the workpiece, which not only facilitates the continuous implementation of the laser impact strengthening treatment, but also can enhance the performance. The more excellent workpiece; the laser impact reinforced device of the invention can conveniently adjust the position of the mirror base and the water spray pipe and the spray angle of the water spray pipe in an all-round manner, thereby being beneficial to meet various practical process requirements.

DRAWINGS

1 is a plan view of a laser shock peening apparatus according to an embodiment of the present invention;

Figure 2 is a cross-sectional view taken along line A-A of Figure 1;

Figure 3 is a left side elevational view of a water spray pipe according to an embodiment of the present invention;

4 is a schematic view showing the working principle of a laser shock absorbing device according to an embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described in the following with reference to the accompanying drawings. It is obvious that the described embodiments are a part of the embodiments of the present invention, instead of All embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

As shown in FIG. 1 and FIG. 2, a laser shock reinforced device according to an embodiment of the present invention includes a clamping set 5, a lens holder 6 having a protective lens 61 at one end, and a water spray pipe 10, and the clamping set 5 includes a first The first clamp 53 and the second clamp 54 are oppositely disposed on the first clamp 51 and the second clamp 52. The mirror base 6 is mounted in the first recess 53 and the water spray pipe 10 is installed. Mounted in the second recess 54, both ends of the first jig 51 and the second jig 52 are fixed by bolts 57 and nuts 58.

The laser shock reinforced device of the present invention can adjust the vertical distance between the lens holder 6 and the water spout pipe 10 and the workpiece 7 according to the needs of the implementation. Specifically, the lens holder 6 can be moved up and down by loosening the nut 58 and water sprayed. The tube 10 is such that the vertical distance between the mirror holder 6 and the water spout tube 10 and the workpiece 7 is suitable, for example, the vertical distance may be 40-100 mm.

In one of the embodiments, the second groove 54 of the first jig 51 and the second jig 52 The outer side is also relatively open with more than one groove for installing the water spray pipe 10, so that the water spray pipe 10 can be disposed at different horizontal positions to better meet the requirements of the laser shock reinforced process. Specifically, the third groove 55 and the fourth groove 56 may be oppositely opened outside the second groove 54 of the first jig 51 and the second jig 52, and the spacing between the grooves may be adjusted according to actual needs, for example, It may be 5 cm, and the distance between the water spout pipe 10 and the mirror base 6 may be selected as needed in 5 cm, 10 cm, and 15 cm. In other embodiments, more than three grooves may be formed outside the second recess 54 of the first jig 51 and the second jig 52.

As shown in FIG. 3, a water spray pipe 10 for laser shock peening according to an embodiment of the present invention includes a pipe body 1 and a spray head 2. The pipe body 1 has a water inlet and a water outlet, and one end of the nozzle 2 and the pipe body 1 are discharged. The nozzle is connected to the other end, and the other end is a water jet port having a rectangular cross section, and a groove 21 having an arc shape in cross section is oppositely opened at both ends of the water spray port, wherein the curved groove 21 is favorable for forming a smooth shape. The water confinement layer (ie, the jet water flow), and the rectangular water spout facilitates the uniform distribution of the water confinement layer on the surface of the workpiece, thereby facilitating the continuous implementation of the laser impact strengthening treatment, and further, by controlling the width of the spout Water confinement layers of different thicknesses to meet various practical needs. Specifically, the cross-sectional shape of the groove 21 may be semicircular, and the width of the water spout may be 2 to 3 cm, thereby forming a smooth water constraining layer having a thickness of 2 to 3 cm.

In one embodiment, the tube body 1 and the head 2 are connected by a connector 3, for example, a gimbal connector can be used, and the connector 3 can make the head 2 opposite The tubular body 1 is rotated by 15 to 90 degrees in the axial direction, as can be rotated clockwise and/or counterclockwise with respect to the axial direction of the tubular body 1. The water spout pipe 10 of this embodiment can adjust the spray angle as needed, which is advantageous for meeting various practical operations.

Referring to FIG. 4, further, a rotating disk 4 with a handle 41 can be fixedly disposed on the connector 3, which can manually drive the nozzle 2 to rotate in the axial direction of the tubular body 1 and rotate the disk 4. The angle coincides with the angle at which the head 2 rotates in the axial direction of the tube 1 to facilitate practical operation. In addition, a dial with a scale (not shown) may be fixedly disposed at the water outlet end of the tubular body 1, and the dial may be disposed below the rotating disc 4 to rotate the rotating disc 4. The angle at which the nozzle 2 is rotated can be clearly determined by the scale on the dial, that is, the angle of rotation of the nozzle 2 with respect to the axial direction of the tube 1 is confirmed, so that the operator can perform the actual operation.

In the water spray pipe 10 for laser shock reinforcement according to any of the above embodiments, the spray of the spray head 2 The nozzle end is bent, and the water spout is disposed toward the mirror base 6, and the angle of the bend is less than 90 degrees with respect to the axial direction of the pipe body 1, so that the flow velocity of the water flow in the water spout pipe 10 can be slowed to facilitate formation. Water constraint layer. Further, when the nozzle 2 is vertically disposed, the degree of bending of the nozzle wall of the nozzle end is greater than the degree of bending of the tube wall of the nozzle end, that is, the nozzle wall of the nozzle is opposite to the nozzle. The upper tube wall is bent upwards to make the water flow more gradual.

As shown in FIG. 4, when the workpiece is subjected to laser strengthening treatment using the laser impact tensing device of any of the above embodiments, the lens holder 6 is first mounted in the first recess 51 of the clamping set 5, and the lens holder is made 6 is located above the workpiece 7, and after adjusting its vertical distance from the workpiece 7 as needed, the water spout 10 is mounted in the second recess 52, the third recess 53 or the fourth recess 54 as needed, and The water spout of the sprinkler pipe 10 faces the mirror mount 6, and after the vertical distance from the workpiece 7 is adjusted as needed, the clamp kit 5 is fixed by the bolt 57 and the nut 58. After the laser shock reinforced device is installed and adjusted, a laser of a certain power density is passed through the upper focusing device and then enters the lens holder 6, and the laser passes through the protective lens 61 at the lower end of the lens holder 6 to form a desired laser spot, which is covered with a laser spot. At the same time, the water is sprayed through the water spout pipe 10 under a certain pressure, and when it reaches the surface of the workpiece 7, a water-constrained layer having a smooth thickness and the same width as the nozzle spout is formed. Further, when it is necessary to adjust the injection angle of the head 2, it can be realized by the rotation of the rotating disk 4 fixed to the connector 3 by the handle 41.

The laser shock peening device of any of the above embodiments of the present invention can not only form a stable and controllable water confinement layer, but also a vertical distance between the mirror base 6 and the workpiece 7, a vertical distance between the spray pipe 10 and the workpiece 7, and a spray. The distance between the water pipe 10 and the mirror base 6 and the spray angle of the water spray pipe 10 are all-roundly adjusted to meet various process requirements, and the operation is convenient and the applicability is strong.

When the laser impact strengthening treatment is performed on the aluminum alloy workpiece by the laser impact strengthening device of the present invention, the lens holder 6 is vertically disposed at 100 cm above the workpiece 7, and the water spout pipe 10 is vertically installed in the third groove 55 even if it is The spacing of the mirror base 6 is 10 cm, and the spray head 10 of the spray pipe 10 is vertically disposed below and in communication with the pipe body 1. The width of the water spray port is 2.5 cm, and the cross-sectional shape is semicircular at the opposite ends of the water spray port. The groove is formed with a bend at the end of the water spout, and the pipe wall of the spout end is bent by 75 degrees with respect to the pipe wall of the pipe body 1, and the pipe wall of the spout end is bent by 45 degrees with respect to the pipe wall of the pipe body 1. The aluminum alloy workpiece is reinforced by a laser having a power density of 1.5 GW/cm ² .

Compared with the prior art, an external circular water pipe is used to form a 2-3 cm flow water curtain on the same aluminum alloy workpiece surface to perform laser shock peening treatment (laser power density is 1.5 GW/cm ² ). After the laser shock absorbing device of the present invention processes the aluminum alloy workpiece, the fatigue crack growth life of the aluminum alloy workpiece is remarkably prolonged.

Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that The technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the technical solutions of the embodiments of the present invention. range.

Claims

A water spray pipe for laser shock strengthening, characterized in that it comprises:

a tubular body having a water inlet and a water outlet;

The spray head communicating with the water outlet of the pipe body has a water spray port having a rectangular cross section, and a groove having a curved cross section is oppositely opened at both ends of the water spray port.
A water spray pipe for laser shock reinforced according to claim 1, wherein the groove has a semicircular cross section.
The water spray pipe for laser shock reinforced according to claim 1, wherein the water spout has a width of 2 to 3 cm.
The water spray pipe for laser shock reinforced according to claim 1, wherein the pipe body and the spray head are connected by a connector, and the connector enables the spray head to face the pipe The body axis direction is rotated by 15 to 90 degrees.
A water spray pipe for laser shock reinforced according to claim 4, wherein said connector is a universal serpentine connector.
A water spray pipe for laser shock reinforced according to claim 5, wherein a rotating disk with a handle is fixedly mounted on the connector, which is capable of manually driving the nozzle relative to the axis of the pipe body Turn.
A water spray pipe for laser shock reinforced according to claim 4, wherein the water spray port end of the spray head is bent.
The water spray pipe for laser shock reinforced according to claim 7, wherein when the nozzle is vertically disposed, the wall of the lower end of the water spout is bent more than the upper wall of the spout end. The degree of bending.
A laser impact reinforced device, comprising: a clamping set, a lens holder having a protective lens at one end; and a water jet pipe for laser shock reinforced according to any one of claims 1 to 8.

The clamping set includes a first jig and a second jig, and a first groove and a second groove are oppositely opened on the first jig and the second jig, and the lens mount is mounted on the first In a recess, the water spray pipe is installed in the second groove, and both ends of the first jig and the second jig are fixed by bolts and nuts.
The laser shock peening apparatus according to claim 9, wherein one or more grooves are further provided outside the second grooves of the first jig and the second jig.