Glass-metal laser composite welding method

Abstract

A glass-metal laser composite welding method, the present invention relates to the field of laser welding, and specifically to a glass-metal connection process based on ultrafast laser technology. The present invention is to solve the technical problem of poor reliability of existing glass-metal connections. Method: 1. Fix the light emitter of the continuous laser and the light emitter of the ultrafast laser; 2. Adjust the focus of the continuous laser and the focus of the ultrafast laser to be located on the contact surface of the base material; 3. Turn on the continuous laser and the ultrafast laser to weld the base material. The present invention utilizes the thermal effect and impact effect of the continuous laser, the high processing accuracy and nonlinear absorption phenomenon of the ultrafast laser, to overcome the problems such as the difficulty in processing the base material contact surface in the ultrafast laser welding process, and is of great significance to the development of laser welding and the nuclear industry. The present invention is used for welding glass-metal dissimilar materials.

Description

Technical Field

[0001] The invention relates to the field of laser welding, and in particular to a glass-metal connection process based on ultrafast laser technology. Background Art

[0002] Glass is a transparent material with a mature production process. It plays an important role in scientific research, military, aerospace and daily life due to its high hardness, high strength, wear resistance, corrosion resistance and beautiful appearance. There are many types of glass materials, among which quartz glass has good high temperature performance and resistance to neutron radiation, and can be used as the shell material of containers for irradiation environment research. Due to its high hardness and low thermal expansion coefficient, it is very difficult to process quartz glass into containers with complex shapes. Welding and connection processes can combine simple parts into complete instruments. Zirconium metal, as the main structural material of nuclear fuel rods, has low cost and is easy to machine, making it very suitable for combination with quartz glass to become an irradiation container.

[0003] At present, the methods for connecting dissimilar materials between glass and metal include gluing, high-temperature sintering, and welding. The life of the glued joint is short and the reliability is poor, while the high-temperature sintering has poor uniformity, the device is fragile, and it is easy to cause pollution. Welding methods are widely used in the field of dissimilar material connection. Among them, laser welding has the advantages of high energy density, little damage to the parent material, and high automation. However, as a transparent material, glass has an unsatisfactory energy absorption rate for lasers. It is difficult for traditional continuous or long-pulse lasers to produce enough thermal effects on glass to form welded joints. Ultrafast lasers have the characteristics of short pulse time (picoseconds or even femtoseconds), high power density, and low average power. They have extremely high processing accuracy and can accurately control the heat input to the workpiece to avoid cracking caused by excessive local heat input. At the same time, because they can induce nonlinear absorption of laser energy by glass, ultrafast lasers can cause glass and metal to melt directly at the interface to form joints. Therefore, ultrafast laser technology is of great significance for the connection of glass and metal. However, compared with continuous laser, due to the short action time of a single pulse and the extremely small action radius, the single pulse heat input of ultrafast laser is relatively small. The use of ultrafast laser for welding often requires precise control of the spacing of the workpieces, and the spacing should not exceed 0.1μm. This places extremely high demands on the smoothness of the contact surface of the workpiece, which will greatly extend the production cycle and increase production costs. At present, there is an urgent need for a process that can overcome the difficulties in contact surface processing and achieve reliable connection between glass and metal. Summary of the invention

[0004] In order to solve the technical problem of poor reliability of existing glass-metal connection, the present invention provides a glass-metal laser composite welding method.

[0005] A glass-metal laser composite welding method, the welding method is carried out according to the following steps:

[0006] 1. Combine the continuous laser light emitter and the ultrafast laser light emitter on a fixed structure;

[0007] 2. Adjust the focus of the continuous laser and the focus of the ultrafast laser to be located on the contact surface of the base material, and keep the focuses on the same straight line. Control the distance between the focus of the continuous laser and the focus of the ultrafast laser to be 5 to 20 mm;

[0008] 3. Turn on the continuous laser and ultrafast laser to weld the base material;

[0009] The process parameters for controlling the ultrafast laser are: wavelength 1030nm, pulse width 700ns~5ps, average power 1~5W, pulse repetition frequency 100kHz~2MHz;

[0010] The process parameters of continuous laser are: wavelength 1030nm, power 50~150W.

[0011] In the welding process of the present invention, ultrafast laser is the main heat input means for realizing laser welding of two base materials, and continuous laser is the auxiliary heat input means for deforming the metal base material at the weld bead position to reduce the spacing between the base materials.

[0012] The beneficial effects of the present invention are as follows:

[0013] (1) The thermal effect and impact effect of continuous laser are used to deform the metal base material at a specific position, reducing the spacing between the base materials to nanometer level, thus overcoming the processing difficulties of the base material contact surface.

[0014] (2) With the assistance of continuous laser, the high precision, low damage and nonlinear absorption of ultrafast laser are utilized to achieve effective connection between glass and metal, solving the problems of difficult connection of the two materials, long processing cycle and high cost in actual production.

[0015] (3) The present invention has been tested in practice and is capable of producing containers for irradiation environment research, which is of great significance to the development of nuclear industry such as nuclear power plants.

[0016] The invention is used for welding glass-metal dissimilar materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the welding structure of Example 1;

[0018] Figure 2 Schematic diagram of the structure of a square container made of a flat quartz glass plate and metal zirconium as the base material of Example 1, wherein 1 represents the quartz glass plate and 2 represents the metal zirconium;

[0019] Figure 3 Schematic diagram of welding bead in Example 1. DETAILED DESCRIPTION

[0020] Specific implementation method 1: This implementation method is a glass-metal laser composite welding method, which is carried out according to the following steps:

[0021] 1. Combine the continuous laser light emitter and the ultrafast laser light emitter on a fixed structure;

[0022] 2. Adjust the focus of the continuous laser and the focus of the ultrafast laser to be located on the contact surface of the base material, and keep the focuses on the same straight line. Control the distance between the focus of the continuous laser and the focus of the ultrafast laser to be 5 to 20 mm;

[0023] 3. Turn on the continuous laser and ultrafast laser to weld the base material;

[0024] The process parameters for controlling the ultrafast laser are: wavelength 1030nm, pulse width 700ns~5ps, average power 1~5W, pulse repetition frequency 100kHz~2MHz;

[0025] The process parameters of continuous laser are: wavelength 1030nm, power 50~150W.

[0026] Specific implementation method 2: This implementation method is different from specific implementation method 1 in that: in step 1, a welding robot is used to connect and fix the continuous laser light emitter and the ultrafast laser light emitter. The rest is the same as specific implementation method 1.

[0027] Specific implementation method 3: This implementation method is different from specific implementation method 1 or 2 in that the base material in step 2 is a composite structure formed by glass and metal. The rest is the same as specific implementation method 1 or 2.

[0028] Specific implementation mode 4: This implementation mode is different from specific implementation modes 1 to 3 in that the glass is quartz glass and the metal is metal zirconium. The rest is the same as specific implementation modes 1 to 3.

[0029] Specific implementation example 5: This implementation example is different from specific implementation examples 1 to 4 in that: in step 2, the distance between the focus of the continuous laser and the focus of the ultrafast laser is controlled to be 8 to 15 mm. The rest is the same as specific implementation examples 1 to 4.

[0030] Specific implementation method 6: This implementation method is different from specific implementation methods 1 to 5 in that: step 3 is to weld multiple welds. The rest is the same as specific implementation methods 1 to 5.

[0031] Specific implementation method 7: This implementation method is different from specific implementation methods 1 to 6 in that: step 3 is to weld three welds. The rest is the same as specific implementation methods 1 to 6.

[0032] Specific embodiment 8: This embodiment differs from specific embodiments 1 to 7 in that the process parameters of controlling the ultrafast laser in step 3 are: wavelength 1030nm, pulse width 800ns, average power 1.5W, pulse repetition frequency 400kHz. Others are the same as specific embodiments 1 to 7.

[0033] Specific embodiment 9: This embodiment differs from specific embodiments 1 to 8 in that the welding speed of the continuous laser light emitter and the ultrafast laser light emitter in step 3 are both 200 μm / s to 1000 μm / s. The rest is the same as specific embodiments 1 to 8.

[0034] Specific embodiment 10: This embodiment differs from specific embodiments 1 to 9 in that the welding speed of the continuous laser light emitter and the ultrafast laser light emitter are both 300 μm / s. The rest is the same as specific embodiments 1 to 9.

[0035] The content of the present invention is not limited to the content of the above-mentioned embodiments. The combination of one or several specific embodiments can also achieve the purpose of the invention.

[0036] Embodiment 1:

[0037] This embodiment provides a glass-metal laser composite welding method, which is performed according to the following steps:

[0038] 1. Use a connection welding robot to connect and fix the continuous laser light emitter and the ultrafast laser light emitter;

[0039] 2. Adjust the focus of the continuous laser and the focus of the ultrafast laser to be on the same straight line, control the distance between the focus of the continuous laser and the focus of the ultrafast laser to be 10mm, and the focus of the continuous laser is at the interface between the glass and the metal container.

[0040] The parent material is a flat quartz glass plate and a square container structure, the quartz glass plate is on the top and the metal container is on the bottom, the side lengths of the two are 20 mm, and the side length of the metal box is 16 mm;

[0041] 3. Turn on the continuous laser and ultrafast laser to weld the base material. The welding method is transmission welding. Three welds are welded with a weld spacing of 0.5 mm.

[0042] The process parameters for controlling the ultrafast laser are: wavelength 1030nm, pulse width 800ns, average power 1.5W, and pulse repetition frequency 400kHz;

[0043] The process parameters of continuous laser are: wavelength 1030nm, power 150W;

[0044] The welding speed of the continuous laser emitter and the ultrafast laser emitter is 300μm / s.

[0045] Figure 1 This is a schematic diagram of the welding structure of Example 1;

[0046] Figure 2 Schematic diagram of the structure of a square container made of a flat quartz glass plate and metal zirconium as the base material of Example 1, wherein 1 represents the quartz glass plate and 2 represents the metal zirconium;

[0047] Figure 3 This is a schematic diagram of the welding path of Example 1.

[0048] The welding process is as follows: Press the continuous laser and ultrafast laser emitters Figure 1 As shown in the figure, adjust the laser focus of the two so that they are on the same horizontal line. Figure 2 Place it on a horizontal platform as shown. Adjust the position of the light emitter so that the focus of the continuous laser is at the interface between the glass and the metal container, and start the welding operation. The welding path is as follows Figure 3 As shown, in this embodiment, there are three welds, and the weld distance is 0.5 mm. During the welding process, it should be ensured that the continuous laser emits light first, and the ultrafast laser then emits light in the area irradiated by the continuous laser.

[0049] In this embodiment, since the continuous laser emits light first, its thermal effect and impact effect will cause local deformation of the metal. After testing, the distance between the deformation area and the quartz glass plate is less than 0.05μm, which meets the distance requirement for ultrafast laser welding. Then the ultrafast laser emits light in the deformed area, thereby achieving effective connection between glass and metal. The process method involved in the present invention successfully realizes the welding of quartz glass and zirconium alloy container.

[0050] After welding testing, the shear strength can reach 40MPa, the sealing is good, and the shear fracture is at the weld where the glass and metal are connected together.

Claims

1. A glass-metal laser composite welding method, characterized in that The welding method is carried out in the following steps:

1. Combine the continuous laser light emitter and the ultrafast laser light emitter on a fixed structure; 2. Adjust the focus of the continuous laser and the focus of the ultrafast laser to be located on the contact surface of the base material, and keep the focus on the same straight line. Control the distance between the focus of the continuous laser and the focus of the ultrafast laser to be 5~20mm; 3. Turn on the continuous laser and ultrafast laser to weld the base material. The continuous laser emits light first, and its thermal and impact effects will cause local deformation of the metal. Then the ultrafast laser emits light in the deformed area, thus achieving effective connection between glass and metal. The process parameters for controlling ultrafast lasers are: wavelength 1030nm, pulse width 700ns~5ps, average power 1~5W, and pulse repetition frequency 100kHz~2MHz; The process parameters of continuous laser are: wavelength 1030nm, power 50~150W; The base material in step 2 is a composite structure formed by glass and metal; Step 3: The welding speeds of the continuous laser emitter and the ultrafast laser emitter are both 200 μm / s to 1000 μm / s.

2. A glass-metal laser hybrid welding method according to claim 1, characterized in that Step 1: Use a welding robot to connect and fix the continuous laser light emitter and the ultrafast laser light emitter.

3. The glass-metal laser hybrid welding method according to claim 1, characterized in that The glass is quartz glass; the metal is metallic zirconium.

4. The glass-metal laser hybrid welding method according to claim 1, characterized in that Step 2: Control the distance between the focus of the continuous laser and the focus of the ultrafast laser to be 8-15 mm.

5. The glass-metal laser hybrid welding method according to claim 1, characterized in that Step 3: Weld multiple welds to perform welding.

6. A glass-metal laser hybrid welding method according to claim 5, characterized in that Step 3: Weld three weld passes.

7. The glass-metal laser hybrid welding method according to claim 1, characterized in that Step 3: Control the process parameters of the ultrafast laser as follows: wavelength 1030 nm, pulse width 800 ns, average power 1.5 W, and pulse repetition frequency 400 kHz.

8. The glass-metal laser hybrid welding method according to claim 1, characterized in that The welding speed of the continuous laser emitter and the ultrafast laser emitter is 300μm / s.

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