Tantalum alloy welding method

Abstract

The present invention relates to a tantalum alloy welding method, comprising: splicing two tantalum alloy plates A1 and A2 to be welded to obtain a gap B1 to be welded; pre-processing the two tantalum alloy plates A1 and A2 along the position of the gap B1 to be welded, wherein the pre-processing method is as follows: adjusting the width of the gap to be welded between the tantalum alloy plates A1 and A2, drilling holes in the splicing surfaces of the tantalum alloy plates A1 and A2 along the thickness direction, wherein the diameter of the drilled holes is 0.5 mm to 1 mm larger than the adjusted width of the weld, and the depth of the drilled holes is equal to the thickness of the tantalum alloy plates A1 and A2; inserting a tantalum alloy welding rod of the same material into the drilled gap, reducing the width between the welding rod and the plates, thereby obtaining a new gap B2 to be welded; using electron beam welding to weld the new gap B2 to be welded; and completing the welding to obtain a tantalum alloy plate welded part. The present invention has the advantages of high welding strength, good sealing performance, and low residual stress, and can achieve reliable connection of tantalum alloys.

Description

Technical Field

[0001] The invention belongs to the technical field of high-temperature structural material welding and relates to a tantalum alloy welding method. Background Art

[0002] Refractory metals represented by tantalum alloys, such as Ta10W, Ta15W, and Ta20W, have the advantages of high operating temperature and good structural strength. They are the main materials for high-temperature thermal structures and thermal protection designs, and show good application prospects in high-speed aircraft, thermal energy storage, and nuclear thermal power generation.

[0003] Welding is one of the key technologies affecting the application of tantalum alloys. Compared to common metals, tantalum alloys have high melting points, good thermal conductivity, and are easily oxidized. However, the welding process is prone to insufficient penetration, poor sealing, and high residual stress, resulting in high-temperature thermal structures that are difficult to meet the requirements of engineering applications. Summary of the Invention

[0004] The technical problem solved by the present invention is to overcome the shortcomings of the existing technology and propose a tantalum alloy welding method, which has the advantages of high welding strength, good sealing performance, low residual stress, etc. and can achieve reliable connection of tantalum alloy.

[0005] The present invention solves the technical problem by providing a tantalum alloy welding method, comprising the following steps:

[0006] Splice two tantalum alloy plates A1 and A2 to be welded to obtain a welding gap B1;

[0007] Two tantalum alloy plates A1 and A2 are pre-processed along the position of the gap B1 to be welded. The pre-processing method is as follows: the width of the gap to be welded between the tantalum alloy plates A1 and A2 is adjusted, and holes are drilled in the joint surface of the tantalum alloy plates A1 and A2 along the thickness direction. The diameter of the drilled hole is slightly larger than the adjusted width of the weld, and the depth of the drilled hole is equal to the thickness of the tantalum alloy plates A1 and A2. A tantalum alloy welding rod of the same material is inserted into the gap after drilling, and the width between the welding rod and the plates is reduced to obtain a new gap to be welded B2.

[0008] Using electron beam welding to weld the new gap B2 to be welded;

[0009] After welding is completed, a tantalum alloy plate welded part is obtained.

[0010] Furthermore, the thickness of the tantalum alloy plates A1 and A2 is 1.2 mm to 8 mm, and the material of the tantalum alloy plates is Ta10W, Ta15W or Ta20W.

[0011] Furthermore, after the tantalum alloy plates A1 and A2 are joined together, the width of the weld gap B1 is less than 0.05 mm.

[0012] Furthermore, the parallelism of the joint surfaces of the tantalum alloy plates A1 and A2 is less than / / 0.1 mm.

[0013] Furthermore, in the pre-processing method, the diameter of the drill hole is 0.5mm-1mm larger than the width of the adjusted weld, the width of the gap to be welded between the tantalum alloy plates A1 and A2 is adjusted to 1.5mm-3mm, and the diameter of the drill hole is 2mm-4mm.

[0014] Furthermore, the drill holes are evenly distributed along the weld direction, and the spacing between the drill holes is 1.2 mm to 4 mm.

[0015] Furthermore, the tantalum alloy welding rod of the same material has a rectangular shape, the welding rod is 10mm-30mm longer than the weld, the welding rod height is 0.5mm-0.8mm greater than the thickness of the tantalum alloy plate, and the welding rod width is 0.5mm-1mm.

[0016] Furthermore, in the new gap B2 to be welded, the distance between the tantalum alloy welding rod and the tantalum alloy plate is no more than 0.2 mm.

[0017] Furthermore, the electron beam is welded along the direction of the welding gap, and the welding parameters are: the welding vacuum is less than 5.0×10 -2 Pa, acceleration voltage 60kV-70kV, welding current 30mA-44mA, welding linear speed 10mm / s-15mm / s.

[0018] The beneficial effects of the present invention compared with the prior art are:

[0019] (1) The tantalum alloy welding method provided by the embodiment of the invention changes the weld from a straight line to a zigzag shape, achieves high welding penetration, effectively releases residual stress during welding, and ensures good bonding strength of the tantalum alloy plate;

[0020] (2) The tantalum alloy welding method provided by the embodiment of the invention mainly melts the tantalum alloy welding rod. After melting, the welding fills the welding gap through the surface expansion effect, effectively improving the sealing of the weld;

[0021] (3) The tantalum alloy welding method provided in the embodiment of the invention preferably uses electron beam vacuum welding, which effectively avoids the problem of oxidation of the tantalum alloy welding plate during the welding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the component structure in steps (1) and (2) of the tantalum alloy welding method provided in an embodiment of the present invention;

[0023] Figure 2 A schematic diagram of the component structure in step (3) of the tantalum alloy welding method is provided in an embodiment of the present invention;

[0024] FIG3( a ) is a schematic structural diagram of a tantalum alloy high-temperature heat pipe provided by an embodiment of the present invention;

[0025] FIG3( b ) is a schematic diagram showing the position distribution of temperature measurement points in a surface test of a tantalum alloy high-temperature heat pipe according to an embodiment of the present invention;

[0026] Figure 4 A temperature-time diagram of a tantalum alloy heat pipe provided by an embodiment of the present invention in a ground heating test;

[0027] Figure 5 This is a flow chart of a tantalum alloy welding method of the present invention;

[0028] In the figure: A1 and A2 are tantalum alloy plates to be welded; B1 is the original weld; B2 is the weld after pretreatment; C is the electron beam. DETAILED DESCRIPTION

[0029] The present invention proposes a tantalum alloy welding method, such as Figure 5 As shown, the following steps are included:

[0030] (1) Splicing two tantalum alloy plates A1 and A2 to be welded to obtain a welding gap B1;

[0031] (2) Pre-processing two tantalum alloy plates A1 and A2 along the position of the gap B1 to be welded. The pre-processing method is as follows: first, adjust the width of the gap to be welded between the tantalum alloy plates A1 and A2, then drill holes in the joint surface of the tantalum alloy plates A1 and A2 along the thickness direction. The diameter of the drilled hole is 0.5mm-1mm larger than the width of the adjusted weld seam, and the depth of the drilled hole is the thickness of the tantalum alloy plates A1 and A2. Finally, a tantalum alloy welding rod of the same material is embedded in the gap after drilling, and the width between the welding rod and the plate is reduced to obtain a new gap to be welded B2; Figure 1 shown.

[0032] (3) Using electron beam C to weld the new gap B2 to be welded formed in step (2); Figure 2 shown.

[0033] (4) Welding is completed, and a tantalum alloy plate welded part is obtained.

[0034] Specifically, in step (1), the thickness of the tantalum alloy plates A1 and A2 is 1.2 mm to 8 mm, and the material of the tantalum alloy plates is Ta10W, Ta15W or Ta20W.

[0035] In step (1), after the two tantalum alloy plates A1 and A2 are spliced ​​together, the width of the welding gap B1 is less than 0.05 mm, and the parallelism of the splicing surfaces of the tantalum alloy plates A1 and A2 is less than / / 0.1 mm.

[0036] In the pre-processing method of step (2), the width of the gap to be welded between the tantalum alloy plates A1 and A2 is adjusted to 1.5 mm-3 mm, and the diameter of the drilled hole is 2 mm-4 mm.

[0037] In the pre-processing method of step (2), the drill holes are evenly distributed along the direction of the weld, and the spacing between the drill holes is 1.2 mm to 4 mm.

[0038] In step (2), the tantalum alloy welding rod of the same material has a rectangular shape, the welding rod is 10mm-30mm longer than the weld, the welding rod height is 0.5mm-0.8mm greater than the thickness of the tantalum alloy plate, and the welding rod width is 0.5mm-1mm.

[0039] In the new gap B2 to be welded described in step (2), the distance between the tantalum alloy welding rod and the tantalum alloy plate is no more than 0.2 mm.

[0040] In step (3), the electron beam C is welded along the direction of the welding gap, and the welding parameters are: welding vacuum degree is less than 5.0×10 -2 Pa, acceleration voltage 60kV-70kV, welding current 30mA-44mA, welding linear speed 10mm / s-15mm / s.

[0041] The following is a specific embodiment of the present invention, which specifically illustrates the tantalum alloy welding method of the present invention.

[0042] Example 1:

[0043] According to the above-mentioned tantalum alloy welding method of the present invention, Ta10W is used as the raw material of the tantalum alloy plate to prepare the tantalum alloy heat pipe shell by welding.

[0044] The relevant technical parameters for welding the tantalum alloy heat pipe shell are as follows:

[0045] The thickness of Ta10W plates A1 and A2 is 2.5 mm, the width of the welding gap B1 is 0.02 mm, and the parallelism of the joint surfaces of Ta10W plates A1 and A2 is less than 0.1 mm.

[0046] First, the welding gap B1 was enlarged to 1.5 mm. Then, holes were drilled along the center line of the gap B1 with a diameter of 2.0 mm, a depth of 2.5 mm, and a spacing of 4 mm. Finally, a 0.5 mm wide tantalum alloy welding rod was inserted into the drilled gap to reduce the width between the welding rod and the plate, thus obtaining a new welding gap B2. Next, electron beam welding B2 was performed with the following welding parameters: welding vacuum degree 3.0 × 10 -2 Pa, accelerating voltage 60 kV, welding current 35 mA, welding linear speed 12 mm / s.

[0047] After welding is completed, a tantalum alloy heat pipe shell welded part is obtained.

[0048] Then, the performance of the tantalum alloy heat pipe shell welded parts prepared above was tested:

[0049] First, air at 8 atmospheres of pressure was passed into the tantalum alloy heat pipe shell for 1 hour. No visible deformation occurred in the tantalum alloy heat pipe shell, indicating that the heat pipe shell obtained by this welding method has high welding strength. Then, further helium mass spectrometer leak detection results showed that the leakage rate of the tantalum alloy heat pipe shell was 5.0×10 -10 Pa·m 3 / s, which is the same as the leakage rate of Ta10W substrate, indicating that the tantalum alloy heat pipe shell obtained by the tantalum alloy welding method of the present invention has good sealing performance.

[0050] To further illustrate the advantages of the present invention, in this example, lithium was filled into the tantalum alloy heat pipe housing to produce a lithium / tantalum alloy heat pipe sample. Eight temperature measurement points were arranged on the sample, as shown in Figures 3(a) and 3(b). Figure 3(a) shows a schematic diagram of the tantalum alloy heat pipe structure, while Figure 3(b) shows a top view of the heat pipe, with the locations of the eight temperature measurement points, T1, T2, T3, T4, T5, T6, T7, and T8, marked.

[0051] Figure 4 A temperature-time graph of a tantalum alloy heat pipe sample during a ground heating test is shown. The graph shows that the operating temperature of the tantalum alloy heat pipe at eight measurement points (T0, T1, T2, T3, and T4) was approximately 900°C. No visible deformation was observed after the test, demonstrating that the residual stress within the tantalum alloy welded in this invention is very low.

[0052] As can be seen from the above, the tantalum alloy welding method of the present invention has the advantages of high welding strength, good sealing performance and low residual stress.

[0053] Although the present invention has been disclosed above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solutions of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the scope of protection of the technical solutions of the present invention.

[0054] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A tantalum alloy welding method, characterized in that: The following steps are involved: Splice two tantalum alloy plates A1 and A2 to be welded to obtain a welding gap B1; Two tantalum alloy plates A1 and A2 are pre-processed along the position of the gap B1 to be welded. The pre-processing method is as follows: the width of the gap to be welded between the tantalum alloy plates A1 and A2 is adjusted, and holes are drilled in the joint surface of the tantalum alloy plates A1 and A2 along the thickness direction. The diameter of the drilled hole is slightly larger than the adjusted width of the weld, and the depth of the drilled hole is equal to the thickness of the tantalum alloy plates A1 and A2. A tantalum alloy welding rod of the same material is inserted into the gap after drilling, and the width between the welding rod and the plates is reduced to obtain a new gap to be welded B2. Using electron beam welding to weld the new gap B2 to be welded; After welding is completed, a tantalum alloy plate welded part is obtained.

2. A tantalum alloy welding method according to claim 1, characterized in that: The thickness of tantalum alloy plates A1 and A2 is 1.2mm-8mm, and the material of tantalum alloy plates is Ta10W, Ta15W or Ta20W.

3. The tantalum alloy welding method according to claim 1, characterized in that: After the tantalum alloy plates A1 and A2 are spliced ​​together, the width of the welding gap B1 is less than 0.05 mm.

4. The tantalum alloy welding method according to claim 1, characterized in that: The parallelism of the joint surfaces of the tantalum alloy plates A1 and A2 is less than / / 0.1 mm.

5. The tantalum alloy welding method according to claim 1, characterized in that: In the pre-processing method, the diameter of the drill hole is 0.5mm-1mm larger than the width of the adjusted weld, the width of the gap to be welded between the tantalum alloy plates A1 and A2 is adjusted to 1.5mm-3mm, and the diameter of the drill hole is 2mm-4mm.

6. The tantalum alloy welding method according to claim 1, characterized in that: The drill holes are evenly distributed along the weld direction, and the spacing between the drill holes is 1.2 mm to 4 mm.

7. The tantalum alloy welding method according to claim 1, characterized in that: The tantalum alloy welding rod of the same material has a rectangular shape, is 10mm-30mm longer than the weld, is 0.5mm-0.8mm higher than the thickness of the tantalum alloy plate, and has a width of 0.5mm-1mm.

8. The tantalum alloy welding method according to claim 1, characterized in that: In the new gap B2 to be welded, the distance between the tantalum alloy welding rod and the tantalum alloy plate is no more than 0.2 mm.

9. The tantalum alloy welding method according to claim 1, characterized in that: The electron beam is welded along the direction of the welding gap, and the welding parameters are: the welding vacuum is less than 5.0×10 -2 Pa, acceleration voltage 60kV-70kV, welding current 30mA-44mA, welding linear speed 10mm / s-15mm / s.

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