CN114473168B - Welding method of large-size NiTi shape memory alloy and stainless steel member - Google Patents
Welding method of large-size NiTi shape memory alloy and stainless steel member Download PDFInfo
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- CN114473168B CN114473168B CN202011167208.4A CN202011167208A CN114473168B CN 114473168 B CN114473168 B CN 114473168B CN 202011167208 A CN202011167208 A CN 202011167208A CN 114473168 B CN114473168 B CN 114473168B
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- 238000003466 welding Methods 0.000 title claims abstract description 106
- 229910001000 nickel titanium Inorganic materials 0.000 title claims abstract description 81
- 229910001220 stainless steel Inorganic materials 0.000 title claims abstract description 54
- 239000010935 stainless steel Substances 0.000 title claims abstract description 54
- 238000000034 method Methods 0.000 title claims abstract description 48
- 229910001285 shape-memory alloy Inorganic materials 0.000 title claims abstract description 45
- 238000005253 cladding Methods 0.000 claims abstract description 27
- 238000010894 electron beam technology Methods 0.000 claims abstract description 27
- 239000000463 material Substances 0.000 claims abstract description 23
- 238000004372 laser cladding Methods 0.000 claims abstract description 19
- 239000000956 alloy Substances 0.000 claims abstract description 17
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 16
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- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 8
- 229910052786 argon Inorganic materials 0.000 claims description 4
- 230000003446 memory effect Effects 0.000 claims description 4
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- 239000002932 luster Substances 0.000 claims description 2
- 230000000149 penetrating effect Effects 0.000 claims description 2
- 238000005457 optimization Methods 0.000 abstract description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 24
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 8
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- 229910000851 Alloy steel Inorganic materials 0.000 description 1
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K15/00—Electron-beam welding or cutting
- B23K15/06—Electron-beam welding or cutting within a vacuum chamber
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K15/00—Electron-beam welding or cutting
- B23K15/0033—Preliminary treatment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K15/00—Electron-beam welding or cutting
- B23K15/0046—Welding
- B23K15/0053—Seam welding
- B23K15/006—Seam welding of rectilinear seams
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/03—Alloys based on nickel or cobalt based on nickel
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C24/00—Coating starting from inorganic powder
- C23C24/08—Coating starting from inorganic powder by application of heat or pressure and heat
- C23C24/10—Coating starting from inorganic powder by application of heat or pressure and heat with intermediate formation of a liquid phase in the layer
- C23C24/103—Coating with metallic material, i.e. metals or metal alloys, optionally comprising hard particles, e.g. oxides, carbides or nitrides
- C23C24/106—Coating with metal alloys or metal elements only
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K2103/00—Materials to be soldered, welded or cut
- B23K2103/18—Dissimilar materials
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
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- Y02P10/25—Process efficiency
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Abstract
The invention relates to the field of welding of dissimilar materials of NiTi shape memory alloy and stainless steel, in particular to a welding method of a large-size NiTi shape memory alloy and stainless steel member. According to the method, a Ni cladding layer with a certain thickness is formed on the surface of the NiTi alloy through a laser cladding process. And polishing and cleaning the surface of the cladding layer, and then completing vacuum electron beam welding between the cladding layer and the stainless steel. According to the invention, the welding line area is completely austenitized by the method of laser cladding Ni on the surface of the NiTi alloy substrate, meanwhile, the generation of brittle phases such as Fe 2 Ti and the like is avoided, the plasticity of the welding line area is greatly improved, the welding residual stress is reduced, the reliability and strength of a weldment are ensured to the greatest extent, an effective solution is provided for a large-size NiTi/stainless steel welding member, and the highest welding strength after optimization can reach 280MPa.
Description
Technical Field
The invention relates to the field of welding of dissimilar materials of NiTi shape memory alloy and stainless steel, in particular to a welding method of a large-size NiTi shape memory alloy and stainless steel member.
Background
NiTi shape memory alloy (Shape Memory Alloy, SMA for short) has become the most practical shape memory material by virtue of its good shape memory effect (Shape Memory Effect, SME for short), superelasticity (Pseudoelasticity), and excellent biocompatibility and high damping. At present, the material has wide application prospect in the fields of aerospace, atomic energy, mechano-electronic, ocean development, instruments and meters, medical fields and the like, and is called as an ideal material for spanning 21 st century. Through decades of development, research work on component design and preparation technology, each phase crystal structure, thermoelastic martensitic transformation, porous SMA preparation and the like of NiTi alloy is becoming mature. With the wide application of NiTi SMA in various fields, research work on the NiTi SMA connection technology is becoming urgent and important.
The stainless steel and the NiTi are common biomedical materials, the NiTi and the stainless steel are connected, and the composite structure of the NiTi/the stainless steel can combine the high strength and high toughness and corrosion resistance of the stainless steel with the shape memory function and super elasticity of the SMA, so that the advantages of the two materials in performance can be fully exerted, and the member with excellent comprehensive performance can be obtained. At present, the material with the structure has good application prospect, and is particularly widely applied to the fields of orthopaedics (such as shape memory implants for treating joint fracture, arch active memory compression joint devices, shape memory double cups in hip prosthesis operation and the like), dentistry (such as orthodontic dental archwires, dental pulp needles, tension springs and pushing springs for orthodontic), interventional medicine (such as coronary heart disease interventional therapy and non-vascular stent interventional therapy) and the like.
When welding NiTi and stainless steel, the traditional fusion welding process often generates a large amount of brittle intermetallic compounds (such as Fe 2 Ti) in the welding line due to the huge difference in chemical composition of the base metal. Such brittle intermetallic compounds easily crack the weld under the action of the residual welding stress. In the prior art, precipitation of brittle intermetallic compounds in a weld zone is often inhibited by adding an intermediate layer, but this method is only applicable to welding wires and thin plates. When large-size NiTi and stainless steel components are welded, the welding residual stress is greatly increased due to the increase of the restraint dimension, the welding seam is prone to cracking, and the welding quality cannot be guaranteed by the traditional method. A method of joining large-sized NiTi alloys to stainless steel members has not been found to date. Therefore, the design of a welding process suitable for large-size NiTi/stainless steel components is a hot spot of current research and is an application bottleneck which needs to be solved urgently.
Disclosure of Invention
The invention aims to provide a welding method for a large-size NiTi shape memory alloy and a stainless steel member, wherein a layer of Ni cladding layer is formed on the surface of the prior NiTi alloy by utilizing a laser cladding process, and then welding is carried out by utilizing a vacuum electron beam.
The technical scheme of the invention is as follows:
a welding method of a large-size NiTi shape memory alloy and a stainless steel member is realized according to the following steps:
[A] polishing the surface of the NiTi shape memory alloy substrate with 1000# abrasive paper, respectively cleaning with acetone and alcohol to remove greasy dirt, and fixing on a workbench;
[B] Cladding a Ni cladding layer with the thickness of 1-4 mm on the prepared NiTi shape memory alloy substrate by using synchronous powder feeding laser forming equipment; the granularity of the Ni powder is 45-105 mu m, and the purity is more than 99wt%; the parameters of the laser cladding are as follows: the laser power is 1400-2500W, the powder feeding amount is 10-15 g/min, and the argon protection is 0.1-0.3 MPa;
[C] After the laser cladding procedure is finished, cooling the clad NiTi shape memory alloy base material to room temperature, taking out, fixing the NiTi shape memory alloy base material and a workpiece to be welded, which is formed by stainless steel, on a clamp, and applying compressive stress at two ends of the clamp to ensure that the workpiece to be welded is tightly attached;
[D] C, placing the workpiece to be welded in the step C and the clamp into a vacuum chamber of an electron beam welding machine, vacuumizing the vacuum chamber to 10 -2～10-3 Pa, and performing vacuum electron beam welding;
[E] After the vacuum electron beam welding procedure is completed, cooling for 5-15 min under vacuum, removing vacuum and taking out the workpiece to finish the welding of the NiTi shape memory alloy and the stainless steel member.
The welding method of the large-size NiTi shape memory alloy and the stainless steel member comprises the steps that the NiTi shape memory alloy comprises a near-equiatomic ratio of NiTi, and the atomic ratio of Ni to Ti is (50-55) (45-50); the NiTi shape memory alloy has B2-B19' martensitic transformation to obtain shape memory effect and super elasticity, and the performance indexes are as follows: the yield strength reaches 340-360 MPa at room temperature, and the tensile strength reaches 800-830 MPa.
In the welding method of the large-size NiTi shape memory alloy and the stainless steel member, in the step C, after the laser cladding of the Ni cladding layer is completed on the surface of the NiTi shape memory alloy substrate, the surface of the Ni cladding layer is required to be ground, so that the surface of the Ni cladding layer is smooth and flat, and the metallic luster is shown.
In the welding method of the large-size NiTi shape memory alloy and the stainless steel member, in the step D, electron beam current with strong penetrating capacity, high energy conversion rate and high heating and cooling speed is selected as a welding heat source, so that the generation of a precipitated phase is effectively inhibited.
In the welding method of the large-size NiTi shape memory alloy and the stainless steel member, in the step D, the vacuum electron beam welding parameters range is as follows:
The welding speed is 300-2000 mm/min; the accelerating voltage is 30 KV-60 KV; the focusing current is 1500 mA-5000 mA; the current of the electron beam is 5 mA-50 mA; the working distance is 100 mm-400 mm.
According to the welding method of the large-size NiTi shape memory alloy and the stainless steel member, after the welding of the NiTi shape memory alloy and the stainless steel member is completed, the tensile strength of the welding part reaches 240-280 MPa at room temperature.
The design idea of the invention is as follows:
In the prior art, precipitation of brittle intermetallic compounds in a weld zone is often inhibited by adding an intermediate layer, but this method is only applicable to welding wires and thin plates. When large-size NiTi alloy and stainless steel components are welded, the welding residual stress is greatly increased due to the increase of the restraint dimension, and the welding seam is prone to cracking. Ni with a certain thickness is clad on the surface of the NiTi alloy base material through a laser cladding process, so that brittle Fe 2 Ti phase generated by direct contact of two base materials during welding can be avoided, meanwhile, the method can fully austenitize a welding seam area, greatly improve the plasticity of the welding seam area and effectively reduce welding residual stress.
The invention has the advantages and beneficial effects that:
1. According to the invention, after Ni with a certain thickness is laser-clad on the surface of the NiTi alloy substrate, the contact of Ti element in the NiTi base material and Fe element in the stainless steel during welding can be avoided, and the possibility of generating Fe 2 Ti phase in a welding line is thoroughly broken.
2. The Ni cladding layer can fully austenitize a welding seam area, improve the plasticity of the welding seam area and reduce the welding residual stress.
3. The laser cladding process adopted by the invention can be suitable for various large-size and complex components, and can greatly widen the application range of the dissimilar material welding components.
4. The NiTi shape memory alloy prepared by the invention has good molding with stainless steel welding heads, and the room temperature tensile strength can reach 240-280 MPa.
Drawings
Fig. 1 is a schematic diagram of welding.
FIG. 2 is a structure morphology after laser cladding Ni on a NiTi substrate.
FIG. 3 is a tissue morphology of a dilution zone of a cladding sample.
Fig. 4 is a photograph of a weld tensile fracture.
Detailed Description
In a specific implementation process, when welding NiTi and stainless steel, a large amount of brittle intermetallic compounds (such as Fe 2 Ti) often appear in a welding line due to the large difference in chemical composition of a base metal. Such brittle intermetallic compounds easily crack the weld under the action of the residual welding stress. In the prior art, precipitation of brittle intermetallic compounds in a weld zone is mostly inhibited by adding an intermediate layer, however, the method is only applicable to welding wires and plates with very thin thickness. When large-size NiTi and stainless steel components with the thickness larger than 1mm are welded, the welding residual stress is greatly increased due to the increase of the restraint dimension, the welding seam is prone to cracking, and the welding quality cannot be guaranteed by the traditional method.
As shown in FIG. 1, according to the invention, ni with a certain thickness is clad on the surface of the NiTi alloy through a laser cladding process to form a Ni cladding layer, and after the surface of the Ni cladding layer is polished and cleaned, vacuum electron beam welding with stainless steel is completed. Therefore, the method for cladding Ni on the surface of the NiTi alloy by laser can avoid brittle Fe 2 Ti phase caused by direct contact of two base metals during welding, and simultaneously the method can fully austenitize a welding seam area, greatly improve the plasticity of the welding seam area, effectively reduce the welding residual stress, furthest ensure the reliability and strength of a weldment, provide an effective solution for a large-size NiTi/stainless steel welding member, and ensure that the highest welding strength after optimization can reach 280MPa.
In the invention, the experimental material is a near-equiatomic ratio NiTi alloy, wherein the atomic ratio of Ni to Ti is 50.8:49.2; the stainless steel is 304 austenitic Stainless Steel (SS), and comprises the following components in percentage by mass: 18.01%, nickel: 8.06%, mn: 1.01%, silicon: 0.62%, carbon: 0.039% and the balance of iron.
The invention is further elucidated below by means of examples and figures.
Example 1
In this embodiment, the welding method of the large-size NiTi shape memory alloy and the stainless steel member is as follows:
Firstly polishing and finishing the surface of a NiTi alloy block sample with the size of 40 multiplied by 30 multiplied by 20mm, then respectively using acetone and alcohol solvents to carry out ultrasonic cleaning to remove greasy dirt, and fixing the sample on a laser cladding triaxial workbench. Ni powder with granularity of 60 mu m and purity of more than 99wt percent is selected, and a Ni cladding layer with the thickness of 3mm is clad on the surface of the NiTi alloy by utilizing laser synchronous powder feeding equipment. The parameters selected are: laser power 1400W, powder feeding amount 10g/min, and argon protection 0.1MPa. And after the laser cladding procedure is finished, cooling the clad sample, taking out, grinding the surface of the cladding layer to make the cladding layer smooth and clean, and cutting the cladding layer into plates with the thickness of 2.8 mm. And the workpiece to be welded is fixed on a clamp together with stainless steel which is subjected to surface treatment (grinding processing is carried out to enable the workpiece to be smooth and clean), and certain compressive stress is applied to the two ends of the clamp so as to ensure that the welding piece is tightly attached.
And placing the workpiece to be welded and the clamp into a vacuum chamber of an electron beam welding machine, vacuumizing the vacuum chamber to 2X 10 - 3 Pa, and performing vacuum electron beam welding. The vacuum electron beam welding parameters are as follows: the welding speed is 1000mm/min, the accelerating voltage is 60KV, the focusing current is 2325mA, the electron beam current is 13mA, and the working distance is 260mm. After the vacuum electron beam welding procedure is completed, cooling for 10min under vacuum, removing vacuum and taking out the workpiece to finish the welding of the NiTi shape memory alloy and the stainless steel member.
In this embodiment, after the welding of the NiTi shape memory alloy and the stainless steel member is completed, the tensile strength of the welded portion can reach 240MPa at room temperature.
Example 2
In this embodiment, the welding method of the large-size NiTi shape memory alloy and the stainless steel member is as follows:
firstly polishing and finishing the surface of a NiTi alloy block sample with the size of 40 multiplied by 30 multiplied by 20mm, then respectively using acetone and alcohol solvents to carry out ultrasonic cleaning to remove greasy dirt, and fixing the sample on a laser cladding triaxial workbench. Ni powder with granularity of 90 mu m and purity of more than 99wt% is selected, and a Ni cladding layer with the thickness of 2mm is clad on the surface of the NiTi alloy by utilizing laser synchronous powder feeding equipment. The parameters selected are: laser power is 1800W, powder feeding amount is 12g/min, and argon gas is used for protecting 0.2MPa. And after the laser cladding procedure is finished, cooling the clad sample, taking out, grinding the surface of the cladding layer to make the cladding layer smooth and clean, and cutting the cladding layer into plates with the thickness of 3.4 mm. And the workpiece to be welded is fixed on a clamp together with stainless steel which is subjected to surface treatment (grinding processing is carried out to enable the workpiece to be smooth and clean), and certain compressive stress is applied to the two ends of the clamp so as to ensure that the welding piece is tightly attached.
And placing the workpiece to be welded and the clamp into a vacuum chamber of an electron beam welding machine, vacuumizing the vacuum chamber to 3X 10 - 3 Pa, and performing vacuum electron beam welding. The vacuum electron beam welding parameters are as follows: the welding speed is 800mm/min, the accelerating voltage is 40KV, the focusing current is 2325mA, the electron beam current is 15mA, and the working distance is 150mm. After the vacuum electron beam welding procedure is completed, cooling for 15min under vacuum, removing vacuum and taking out the workpiece to finish the welding of the NiTi shape memory alloy and the stainless steel member.
In this embodiment, after the welding of the NiTi shape memory alloy and the stainless steel member is completed, the tensile strength of the welded portion can reach 280MPa at room temperature.
As shown in fig. 2, the sample was laser clad in microscopic morphology in the examples. In the figure, the lower part is a NiTi substrate, the upper part is a Ni cladding layer, and a dilution zone (drawn by white dotted lines) exists between the two parts.
As shown in fig. 3, the tissue morphology of the dilution zone in the examples. As can be seen from the figure, the dilution zone consists mainly of two phases: the B2 phase (dark color) and Ni 3 Ti phase were light color, and the two phases were present in the form of coagulated dendrites.
As shown in fig. 4, in the example, the NiTi base material and the stainless steel base material weld were subjected to a tensile test. It can be seen from the figure that the location where the fracture occurs is within the dilution zone rather than the weld, and that the weld strength is greatly improved.
The weld strength obtained by the two processes of example 1 and example 2 is shown in the following table:
TABLE 1
| Example 1 | Example 2 | NiTi base material | Stainless steel base material | |
| Rp0.2(MPa) | - | - | 340 | 316 |
| Rm(MPa) | 240 | 280 | 816 | 779 |
The implementation result shows that the method realizes the welding of two materials, namely NiTi and stainless steel by laser cladding the Ni intermediate layer on the surface of the NiTi alloy substrate and then utilizing vacuum electron beam welding. The precipitation of brittle phases in the welding line is avoided, the mechanical property of the welding joint is guaranteed to the greatest extent, and the room temperature strength of the electron beam welding joint after parameter optimization can reach 240-280 MPa.
Claims (5)
1. A welding method of a large-size NiTi shape memory alloy and a stainless steel member is characterized by comprising the following steps:
[A] polishing the surface of the NiTi shape memory alloy substrate with 1000# abrasive paper, respectively cleaning with acetone and alcohol to remove greasy dirt, and fixing on a workbench;
[B] Cladding a Ni cladding layer with the thickness of 1-4 mm on the prepared NiTi shape memory alloy substrate by using synchronous powder feeding laser forming equipment; the granularity of the Ni powder is 45-105 mu m, and the purity is more than 99wt%; the parameters of the laser cladding are as follows: the laser power is 1400-2500W, the powder feeding amount is 10-15 g/min, and the argon protection is 0.1-0.3 MPa; ni is clad on the surface of the NiTi alloy base material through a laser cladding process, so that brittle Fe 2 Ti phase generated by direct contact of two base materials during welding is avoided, and a welding line zone is completely austenitized;
[C] After the laser cladding procedure is finished, cooling the clad NiTi shape memory alloy base material to room temperature, taking out, fixing the NiTi shape memory alloy base material and a workpiece to be welded, which is formed by stainless steel, on a clamp, and applying compressive stress at two ends of the clamp to ensure that the workpiece to be welded is tightly attached;
[D] C, placing the workpiece to be welded in the step C and the clamp into a vacuum chamber of an electron beam welding machine, vacuumizing the vacuum chamber to 10 -2～10-3 Pa, and performing vacuum electron beam welding;
[E] After the vacuum electron beam welding procedure is finished, firstly cooling for 5-15 min under vacuum, then removing the vacuum and taking out the workpiece to finish the welding of the NiTi shape memory alloy and the stainless steel member;
After the welding of the NiTi shape memory alloy and the stainless steel member is completed, the tensile strength of the welding part reaches 240-280 MPa at room temperature.
2. The method for welding a large-size NiTi shape memory alloy and a stainless steel member according to claim 1, wherein the NiTi shape memory alloy composition is a near-equiatomic ratio of NiTi, and the atomic ratio of Ni to Ti is (50-55): (45-50); the NiTi shape memory alloy has B2-B19' martensitic transformation to obtain shape memory effect and super elasticity, and the performance indexes are as follows: the yield strength reaches 340-360 MPa at room temperature, and the tensile strength reaches 800-830 MPa.
3. The welding method of large-size NiTi shape memory alloy and stainless steel member according to claim 1, wherein in step C, after the laser cladding of the Ni cladding layer is completed on the surface of the NiTi shape memory alloy substrate, grinding processing is required to be performed on the surface of the Ni cladding layer to make it smooth and flat, and metallic luster is developed.
4. The welding method of the large-size NiTi shape memory alloy and the stainless steel member according to claim 1, wherein in the step D, electron beam current with strong penetrating power, high energy conversion rate and high heating and cooling speed is selected as a welding heat source, and the generation of precipitated phases is effectively inhibited.
5. The method of welding a large size NiTi shape memory alloy to a stainless steel member according to claim 1, wherein in step D, vacuum electron beam welding parameters range as follows:
the welding speed is 300-2000 mm/min;
The accelerating voltage is 30 KV-60 KV;
the focusing current is 1500 mA-5000 mA;
The current of the electron beam is 5 mA-50 mA;
The working distance is 100 mm-400 mm.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3560700A (en) * | 1967-07-18 | 1971-02-02 | Kernforschung Gmbh Ges Fuer | Electron beam welding of two dissimilar metals |
| US5863360A (en) * | 1994-03-05 | 1999-01-26 | The University Of Dundee | Surface treatment of shape memory alloys |
| CN101428371A (en) * | 2008-12-05 | 2009-05-13 | 南昌航空大学 | Connecting method for TiNi shape memory alloy and stainless steel dissimilar material |
| CN101768719A (en) * | 2010-01-30 | 2010-07-07 | 深圳市欧帝光学有限公司 | Ti-Ni shape memory alloy glasses manufacturing process |
| CN109465532A (en) * | 2018-11-22 | 2019-03-15 | 中国科学院金属研究所 | A kind of NiTi marmem and stainless steel electron beam welding method |
| CN109570762A (en) * | 2018-12-29 | 2019-04-05 | 宝鸡文理学院 | A kind of niti-shaped memorial alloy and the connection method of stainless steel dissimilar welded joint |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9399262B2 (en) * | 2011-12-15 | 2016-07-26 | Lake Region Manufacturing, Inc. | Method of joining titanium and titanium-based alloys to ferrous metals using tantalum |
-
2020
- 2020-10-27 CN CN202011167208.4A patent/CN114473168B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3560700A (en) * | 1967-07-18 | 1971-02-02 | Kernforschung Gmbh Ges Fuer | Electron beam welding of two dissimilar metals |
| US5863360A (en) * | 1994-03-05 | 1999-01-26 | The University Of Dundee | Surface treatment of shape memory alloys |
| CN101428371A (en) * | 2008-12-05 | 2009-05-13 | 南昌航空大学 | Connecting method for TiNi shape memory alloy and stainless steel dissimilar material |
| CN101768719A (en) * | 2010-01-30 | 2010-07-07 | 深圳市欧帝光学有限公司 | Ti-Ni shape memory alloy glasses manufacturing process |
| CN109465532A (en) * | 2018-11-22 | 2019-03-15 | 中国科学院金属研究所 | A kind of NiTi marmem and stainless steel electron beam welding method |
| CN109570762A (en) * | 2018-12-29 | 2019-04-05 | 宝鸡文理学院 | A kind of niti-shaped memorial alloy and the connection method of stainless steel dissimilar welded joint |
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