Tantalum alloy welding method

Abstract

The invention relates to a tantalum alloy welding method which comprises the following steps: splicing two tantalum alloy plates A1 and A2 to be welded to obtain a gap B1 to be welded; a tantalum alloy plate A1 and a tantalum alloy plate A2 are preprocessed along the position of a to-be-welded gap B1, and the preprocessing method comprises the following steps that the width of the to-be-welded gap between the tantalum alloy plate A1 and the tantalum alloy plate A2 is adjusted, a hole is drilled in the splicing face of the tantalum alloy plate A1 and the tantalum alloy plate A2 in the thickness direction, the diameter of the drilled hole is 0.5 mm-1 mm larger than the width of an adjusted welding seam, and the depth of the drilled hole is equal to the thickness of the tantalum alloy plate A1 and the tantalum alloy plate A2; a tantalum alloy welding rod made of the same material is embedded into the drilled gap, the width between the welding rod and the plate is reduced, and a new to-be-welded gap B2 is obtained; the new to-be-welded gap B2 is welded through electron beams; and after welding is completed, a tantalum alloy plate welding part is obtained. The method has the advantages of being high in welding strength, good in sealing performance, low in residual stress and the like, and reliable connection of the tantalum alloy can be achieved.

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 that affect the application of tantalum alloys. Compared with general metals, tantalum alloys have the characteristics of high melting point, good thermal conductivity, and easy oxidation. During the welding process, it is easy to produce insufficient penetration, poor sealing, and high residual stress, resulting in high-temperature thermal structures that are difficult to meet the needs of engineering applications. Summary of the invention

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

[0005] The solution to the technical problem of the present invention is: a tantalum alloy welding method, comprising the following steps:

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

[0007] Pre-processing two tantalum alloy plates A1 and A2 along the position of the gap B1 to be welded, and 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 on the joint surfaces of the tantalum alloy plates A1 and A2 along the thickness direction, the diameter of the holes is slightly larger than the width of the adjusted weld, and the depth of the holes is the thickness of the tantalum alloy plates A1 and A2; embedding a tantalum alloy welding rod of the same material into the gap after drilling, reducing the width between the welding rod and the plate, and obtaining 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 sheet weldment 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 selected from Ta10W, Ta15W or Ta20W.

[0011] Furthermore, after the tantalum alloy plates A1 and A2 are spliced, the width of the welding 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 drilled hole is 0.5 mm-1 mm 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 1.5 mm-3 mm, and the diameter of the drilled hole is 2 mm-4 mm.

[0014] Furthermore, the drill holes are evenly distributed along the weld direction, and the spacing between the drill holes is 1.2 mm-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 electrode and the tantalum alloy plate is no more than 0.2 mm.

[0017] Furthermore, the electron beam is welded along the welding gap direction, and the welding parameters are: the welding vacuum degree is less than 5.0×10 -2 Pa, acceleration voltage 60kV-70kV, welding current 30mA-44mA, welding line 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 in the embodiment of the invention changes the weld from a straight line to a zigzag shape, has a high welding depth, effectively releases the residual stress during the welding process, and can ensure 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 electrode. After melting, the welding fills the welding gap through the surface expansion effect, which effectively improves 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 welding method of tantalum alloy is provided for an embodiment of the present invention;

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

[0025] FIG3( b ) is a schematic diagram of the position distribution of temperature measurement points on the surface 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-original weld; B2-pretreated weld; C-electron beam. DETAILED DESCRIPTION

[0029] The present invention provides 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, and the pre-processing method is as follows: first, adjusting the width of the gap to be welded between the tantalum alloy plates A1 and A2, and then drilling holes on the joint surfaces of the tantalum alloy plates A1 and A2 along the thickness direction, the diameter of the drilled hole is 0.5 mm-1 mm larger than the width of the adjusted weld, and the depth of the drilled hole is the thickness of the tantalum alloy plates A1 and A2, and finally, a tantalum alloy welding rod of the same material is embedded in the gap after drilling, reducing the width between the welding rod and the plate, and obtaining a new gap to be welded B2; Figure 1 shown.

[0032] (3) The new gap B2 to be welded formed in step (2) is welded by electron beam C; Figure 2 shown.

[0033] (4) After welding is completed, a tantalum alloy sheet weldment is obtained.

[0034] Specifically, in step (1), the thickness of the tantalum alloy plates A1 and A2 is 1.2 mm-8 mm, and the material of the tantalum alloy plates is selected from 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 weld direction, and the spacing between the drill holes is 1.2 mm-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 welding gap B2 described in step (2), the distance between the tantalum alloy electrode and the tantalum alloy plate is no more than 0.2 mm.

[0040] In step (3), the electron beam C is welded along the welding gap direction, 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 line 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] Embodiment 1:

[0043] According to the tantalum alloy welding method of the present invention, Ta10W is used as the raw material of the tantalum alloy sheet 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 electrode was embedded in the drilled gap to reduce the width between the electrode and the plate, and a new gap to be welded B2 was obtained; then, electron beam welding B2 was used, and the welding parameters were: welding vacuum degree 3.0×10 -2 Pa, acceleration voltage 60kV, welding current 35mA, welding line speed 12mm / 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, 8 atmospheres of air were 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, the helium mass spectrometer leak test 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] In order to further illustrate the superiority of the present invention, in this embodiment, lithium working fluid is filled into the above-mentioned tantalum alloy heat pipe shell to obtain a lithium working fluid / tantalum alloy heat pipe sample, and 8 temperature measuring points are arranged on the sample, see Figure 3 (a) and Figure 3 (b) for details. Figure 3 (a) shows a schematic diagram of the structure of the tantalum alloy heat pipe, and Figure 3 (b) shows a top view of the heat pipe, and the positions of the 8 temperature measuring points T1, T2, T3, T4, T5, T6, T7, and T8 are marked.

[0051] Figure 4 The temperature-time diagram of the tantalum alloy heat pipe sample in the ground heating test is given. It can be seen from the figure that the operating temperature of the tantalum alloy heat pipe at the 8 temperature measurement points T0, T1, T2, T3 and T4 is about 900°C. After the test, no visible deformation occurs in the heat pipe, indicating that the residual stress in the tantalum alloy welded by the present invention is very low.

[0052] It can be seen from the above that 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 as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution 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 solution of the present invention shall fall within the protection scope of the technical solution 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: Splicing two tantalum alloy plates A1 and A2 to be welded to obtain a welding gap B1; Pre-processing two tantalum alloy plates A1 and A2 along the position of the gap B1 to be welded, and 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 on the joint surfaces of the tantalum alloy plates A1 and A2 along the thickness direction, the diameter of the holes is slightly larger than the width of the adjusted weld, and the depth of the holes is the thickness of the tantalum alloy plates A1 and A2; embedding a tantalum alloy welding rod of the same material into the gap after drilling, reducing the width between the welding rod and the plate, and obtaining 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 sheet weldment 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 selected from Ta10W, Ta15W or Ta20W.

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

4. A 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 drilled 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 drilled hole is 2mm-4mm.

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

7. A tantalum alloy welding method according to claim 1, characterized in that: The tantalum alloy welding rod of the same material is in 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.

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

9. A tantalum alloy welding method according to claim 1, characterized in that: The electron beam is welded along the welding gap direction, 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 line speed 10mm / s-15mm / s.

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