CN111299796A - Dissimilar metal vacuum diffusion welding method for TC4 titanium alloy and 316L stainless steel - Google Patents
Dissimilar metal vacuum diffusion welding method for TC4 titanium alloy and 316L stainless steel Download PDFInfo
- Publication number
- CN111299796A CN111299796A CN202010158727.8A CN202010158727A CN111299796A CN 111299796 A CN111299796 A CN 111299796A CN 202010158727 A CN202010158727 A CN 202010158727A CN 111299796 A CN111299796 A CN 111299796A
- Authority
- CN
- China
- Prior art keywords
- foil
- titanium alloy
- stainless steel
- pressure
- welding
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- 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
- B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
- B23K20/001—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating by extrusion or drawing
-
- 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
- B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
- B23K20/22—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating taking account of the properties of the materials to be welded
- B23K20/227—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating taking account of the properties of the materials to be welded with ferrous layer
-
- 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
- B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
- B23K20/24—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
- B23K2103/00—Materials to be soldered, welded or cut
- B23K2103/18—Dissimilar materials
- B23K2103/24—Ferrous alloys and titanium or alloys thereof
Abstract
The invention discloses a dissimilar metal vacuum diffusion welding method of TC4 titanium alloy and 316L stainless steel, which belongs to the technical field of metal material welding and comprises the steps of sample surface cleaning, sample placement and diffusion welding, wherein a sample comprises TC4 titanium alloy to be welded, 316L stainless steel, intermediate layer vanadium foil, copper foil and cobalt foil; by adjusting parameters such as diffusion welding temperature, time, pressure and the like, the thickness of the interlayer and the type and the number of the interlayer, a transition solid solution can be formed at a welding seam, so that mutual diffusion of titanium and iron elements is prevented, and the formation of brittle ferrotitanium intermetallic compounds is avoided. The welded joint obtained by the method has the advantages of high tensile strength, good ductility, no pores or cracks and the like.
Description
Technical Field
The invention relates to the technical field of metal material welding, in particular to a vacuum diffusion welding method for dissimilar metals of TC4 titanium alloy and 316L stainless steel.
Background
316L stainless steel is a structural material with lower corrosion rate, reliability, high strength and low cost, has good corrosion resistance, excellent low-temperature performance, processability and welding performance, and is often applied to industrial manufacturing. Titanium and titanium alloy are widely applied to the fields of aerospace, petrochemical industry, transportation and the like due to excellent performances of high obdurability, high melting point, excellent corrosion performance, low density and the like.
When the satellite performs detection work, the infrared focal plane detector is main equipment, and the miniature Dewar is an encapsulation and protection device of the infrared focal plane detector, and provides a good optical, mechanical, electrical and thermal transmission channel when the satellite works at low temperature. In order to provide a micro-metallic dewar with a low parasitic thermal load and a long vacuum life, the main body material is stainless steel and titanium alloy. However, welding between titanium alloy and stainless steel has more problems, mainly because the difference of physical and chemical properties (such as the difference of expansion coefficient, specific heat capacity, thermal conductivity, melting point, chemical composition, etc.) of different metal materials can cause the welded joint to form larger residual stress. Moreover, Ti element in the titanium alloy and Fe, Cr and Ni element in the stainless steel are easy to form a great amount of TiCrFe, TiFe and TiFe2And the like, causing the weldment to fracture under the action of welding stress.
How to solve the welding problem between titanium alloy and stainless steel becomes the technical difficulty of improving the service performance and the stability of the low-temperature metal packaging material, if the problem of difficult combination between the titanium alloy and the stainless steel can be solved, and the combination performance is optimized, the stability, the accuracy and the like of related equipment and components can be improved, and the more excellent level can be achieved.
The chinese patent application CN102728937A discloses a welding method of dissimilar metals of titanium alloy and austenitic stainless steel, which comprises the following steps: and assembling the polished titanium alloy and stainless steel, welding, and heating to above 350 ℃ before welding. Meanwhile, pulsed argon tungsten-arc welding is carried out on the titanium alloy and the stainless steel under the protection of argon gas. However, the weld residual stress is high, and a large amount of brittle metal compounds are present, which is not favorable for obtaining a weld joint with stable performance.
In 2015, a document named pulse diffusion welding of titanium and stainless steel using a copper interlayer was published on rare metal materials and engineering, and as a result, it was found that intermetallic compounds with low brittleness, such as Ti atoms, were formed on the titanium alloy side due to interdiffusion of Ti atoms and Cu atoms2Cu，TiCu，Ti2Cu3And Cu4And (3) Ti. On the stainless steel side, no intermetallic compounds were found, and a solid solution with good ductility was produced. However, because brittle intermetallic compounds still exist in the weld, the performance of the joint still needs to be improved.
Vacuum diffusion welding refers to a solid state welding process in which workpieces are pressed at high temperatures without visible deformation and relative movement. The vacuum diffusion welding is particularly suitable for the bonding of new materials such as dissimilar metal materials, heat-resistant alloys, ceramics, intermetallic compounds, composite materials and the like, particularly for materials which are difficult to weld by a fusion welding method, has obvious advantages and increasingly draws attention of people. Vacuum diffusion welding is a process in which the surfaces of the same or different materials are plastically deformed through a contact surface at a high temperature, a high pressure and a diffusion time, and then atomic diffusion occurs at a high temperature to bond the materials together.
However, how to weld titanium alloy and stainless steel by diffusion welding to improve the weld performance has yet to be further studied.
In 2017, in 8 months, a dissimilar metal diffusion welding joint named as 'Ti-6 Al-4V titanium alloy and 316L stainless steel using Cu/Nb interlayer' is published in the research and report of VacuumTissue and mechanical properties. The diffusion welding step is as follows: firstly, prepressing a sample, pressing and stabilizing the sample with a pressure head, wherein the prepressing pressure is 15-30MPa, and then relieving the pressure; the vacuum degree is pumped to 5X 10-1Raising the temperature below Pa; heating at a speed of 10 ℃/min, and performing primary heat preservation and pressure maintaining when the temperature reaches 750 ℃ so that the metal is in close contact with the interlayer; and after the primary heat preservation and pressure maintenance is finished, reducing the pressure to the diffusion welding pressure, simultaneously increasing the temperature to the diffusion welding temperature, and maintaining the pressure under the diffusion welding pressure of 5MPa for 120 min. As a result, it was found that no significant intermetallic compound was generated in the weld of the welded joint, the welded joint was of good quality, and the highest tensile strength measured by the same method as that of the present invention was 489 MPa. However, when the welding temperature is too high or the holding time is too long, the copper interlayer is melted, so that brittle intermetallic compounds are formed in the welding seam, and the tensile strength of the welding joint is only 52 MPa.
Disclosure of Invention
The invention aims to provide a dissimilar metal vacuum diffusion welding method of TC4 titanium alloy and 316L stainless steel, which aims to solve the problems.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a dissimilar metal vacuum diffusion welding method of TC4 titanium alloy and 316L stainless steel comprises the following steps:
(1) cleaning the surface of the sample: cleaning the surfaces to be welded of TC4 titanium alloy and 316L stainless steel, and cleaning the surfaces of a vanadium foil, a copper foil and a cobalt foil which are intermediate interlayer materials; the thickness of the vanadium foil is 85-115 mu m, the thickness of the copper foil is 15-45 mu m, and the thickness of the cobalt foil is 35-65 mu m;
(2) placing a sample: and (2) butting the TC4 titanium alloy with the clean surface obtained in the step (1), 316L stainless steel, vanadium foil, copper foil and cobalt foil in sequence, wherein the sequence is as follows: TC4 titanium alloy-vanadium foil-copper foil-cobalt foil-316L stainless steel, or 316L stainless steel-cobalt foil-copper foil-vanadium foil-TC 4 titanium alloy; namely, the titanium alloy needs to be contacted with a vanadium foil, the vanadium foil is contacted with a copper foil, the copper foil is contacted with a cobalt foil, the stainless steel needs to be contacted with the cobalt foil, and the titanium alloy and the stainless steel metal are positioned at two sides of an interlayer;
(3) diffusion welding: placing the samples stacked in sequence obtained in the step (2) between an upper pressure head and a lower pressure head of a vacuum hot-pressing furnace, and then performing diffusion welding; in the step (3), good axial centering performance between the sample and a pressure head is kept, pre-pressure of 15-30MPa is applied to the sample to be welded through the upper pressure head, so that the interlayer is tightly contacted with metal, and then pressure relief is carried out; and carrying out heat preservation and pressure maintaining twice.
Aiming at the defects in the prior art, the inventor selects the thicknesses of special three-layer transition metal and special transition metal and adopts two heat-preservation and pressure-maintaining processes through a large number of tests, and the improved processes supplement each other, so that unexpected technical effects are obtained, the quality of a titanium alloy and stainless steel welding joint is remarkably improved, and the tensile strength of the welding joint reaches over 500 MPa.
Compared with the limitation of the common electronic welding, laser welding and friction stir welding processes, the diffusion welding method provided by the invention for dissimilar metal welding realizes diffusion connection by utilizing the three layers of transition metal interlayers under the action of high temperature and high pressure so as to optimize the welding quality between the TC4 titanium alloy and the 316L stainless steel, improve the utilization rate and the application range of metal, meet higher process quality requirements, meet different application conditions and achieve a better comprehensive material performance level, and particularly, the invention innovatively prevents the Cu interlayer from melting at high temperature or in a long-time welding process to damage the quality of a joint by virtue of the existence of the Co interlayer; meanwhile, the vanadium foil, the copper foil and the cobalt foil with the thicknesses can ensure that a solid solution with enough thickness is formed at a titanium alloy-vanadium foil interface, a vanadium foil-copper foil interface, a copper foil-cobalt foil interface and a cobalt foil-stainless steel interface, and the rest metal can prevent the aggregation of iron and titanium elements; then, the invention adopts two times of heat preservation and pressure maintaining in the diffusion welding process of the titanium alloy and the stainless steel, which is beneficial to the closure of a metal interface and promotes the diffusion welding; the titanium alloy and the stainless steel can be better welded by adopting the three metal interlayers as transition layers, because the vanadium foil, the copper foil and the cobalt foil have excellent plasticity, solid solutions can be formed between the titanium alloy and the vanadium foil, between the vanadium foil and the copper foil, between the copper foil and the cobalt foil, and between the cobalt foil and the stainless steel, and no brittle intermetallic compound is generated, a welding seam with better performance is obtained, excellent connection between the titanium alloy and the stainless steel is realized from two aspects of physical performance and chemical performance, a joint with good performance is facilitated to be obtained, and the titanium alloy and the stainless steel are more widely applied;
meanwhile, the slow cooling method is carried out after the diffusion welding is finished, so that the interface welding stress is eliminated, and the mechanical property of the titanium alloy and stainless steel composite component is improved. The invention adopts diffusion welding and adopts three layers of metal interlayers to carry out vacuum diffusion welding on the titanium alloy and the stainless steel, and the method has simple and efficient process, has less requirements on the shape and the size of a workpiece and excellent performance of obtaining a welding seam.
As a preferable technical scheme, in the step (1), the method for cleaning the surfaces to be welded of the TC4 titanium alloy and the 316L stainless steel comprises the following steps: taking titanium alloy, stainless steel, vanadium foil, copper foil and cobalt foil, grinding the surface by using abrasive paper, and polishing to ensure that the surface roughness Ra of the to-be-welded surface of the metal is less than or equal to 1.0 mu m, so that the to-be-welded surface can be in close contact conveniently, and the existence of pores is reduced; because the metal and the interlayer are arranged in the air, an oxide film is easily formed, the influence on welding is caused, impurities are introduced, and the diffusion behavior of atoms is not facilitated; at the same time, the introduction of oxygen atoms can be detrimental to the weld. Therefore, before diffusion welding, oxide films of the metal and the interlayer need to be removed, and the oxide films on the surface of the titanium alloy are removed by adopting a mixed solution of hydrofluoric acid and nitric acid; at the same time, dilute H is used2SO4The solution removes the oxide film on the surface of the copper foil, which is beneficial to the diffusion welding; and (3) putting the polished titanium alloy, stainless steel, vanadium foil, copper foil and cobalt foil into acetone for ultrasonic cleaning for 10-15min, wiping the surface to be welded with alcohol, removing residues of acetone water quality, oil stain and the like on the surface, and drying by cold air to obtain the titanium alloy, the stainless steel, the vanadium foil, the copper foil and the cobalt foil with clean surfaces so as to reduce the penetration of impurities in the experimental process.
Preferably, in the step (1), the purity of the vanadium foil is greater than 98 wt%, the purity of the copper foil is greater than 98 wt%, and the purity of the cobalt foil is greater than 98 wt%.
More preferably, the vanadium, copper and cobalt foils are more than 99.9 wt% pure.
More preferably, the thickness of the vanadium foil is 90-110 μm, the thickness of the copper foil is 20-40 μm, and the thickness of the cobalt foil is 40-60 μm.
As a further preferable technical scheme, the method for twice heat preservation and pressure maintaining comprises the following steps: then the vacuum hot pressing furnace is vacuumized until the vacuum degree reaches (1-6) multiplied by 10-1When Pa is needed, heating, raising the temperature to 750 ℃ at the speed of 10 ℃/min, and carrying out primary heat preservation and pressure maintaining to ensure that plastic deformation occurs between the titanium alloy-vanadium foil-copper foil-cobalt foil-stainless steel, so that the interfaces are in close contact, and the existence of pores is reduced; after the primary heat preservation and pressure maintenance is finished, reducing the pressure to the diffusion welding pressure, simultaneously increasing the temperature to the diffusion welding temperature, and carrying out secondary heat preservation and pressure maintenance (namely carrying out diffusion welding); and after the secondary heat preservation and pressure preservation is finished, releasing the pressure, simultaneously cooling the temperature to 700 ℃ at the speed of 5 ℃/min, and then cooling along with the furnace.
A typical temperature-time flow diagram for vacuum diffusion bonding according to the present invention is shown in fig. 2.
As a further preferable technical scheme, the heat preservation temperature is 600-800 ℃, the pressure is 10-30MPa, and the heat preservation time is 20-60min during the primary heat preservation and pressure maintaining. The interface pore can be closed by applying higher pressure at lower temperature without deforming the workpiece.
More preferably, the primary heat preservation temperature is 650-750 ℃, the pressure is 10-20MPa, and the heat preservation time is 20-40 min.
As a further preferable technical scheme, the heat preservation temperature is 800-.
More preferably, the heat preservation temperature of diffusion welding is 800-.
As a further preferable technical scheme, after the diffusion welding is finished, the temperature is reduced, the slow cooling rate is 3-20 ℃/min, the slow cooling rate is preferably controlled to be 5 ℃/min, and the slow cooling finishing temperature is 600-. In the cooling process, because the expansion coefficients of the titanium alloy and the stainless steel are different, the thermal stress caused by uneven expansion with heat and contraction with cold can be reduced by using a slower cooling speed. When the temperature of the furnace is reduced to 600 ℃, the temperature reduction rate in the furnace is slow, and furnace cooling can be directly adopted. More preferably, the slow cooling end temperature is 650-.
Furthermore, in the welding process, the pressure head generates welding pressure on the welding piece, the welding piece is in close contact under the action of the pressure head, the important effect is played in the stage of forming chemical bonds by activating surface atoms, and the influence on the diffusion of welding interface atoms is small; the temperature plays an important role in atomic diffusion, and the time is mainly used for regulating the diffusion degree. By reasonably matching diffusion temperature, pressure and time, the thickness of the compound layer is controlled within a proper range, and the mechanical property of the titanium alloy and stainless steel composite component is improved. Compared with other methods such as diffusion welding, the method has the advantages of simple and efficient process, less requirements on the shape and the size of the workpiece, capability of performing diffusion welding treatment on the workpiece even with a complex structure, and capability of being successfully applied to welding between titanium alloy and stainless steel metal.
The optimal technical scheme is that a vanadium foil, a copper foil and a cobalt foil are selected as metal interlayers, the thickness of the vanadium foil is 100 microns, the thickness of the copper foil is 30 microns, the thickness of the cobalt foil is 50 microns, the heat preservation temperature is 880 ℃, the heat preservation time is 120min, and the heat preservation pressure is 6MPa, and the optimal welding process parameters are set, wherein under the process parameters, the tensile strength of the welding joint reaches about unexpected 599 MPa.
Compared with the prior art, the invention has the advantages that:
(1) the invention adopts two times of heat preservation and pressure maintaining to ensure that the metal interface is in close contact with the interlayer, which is beneficial to interface closure and is convenient for subsequent atomic diffusion behavior.
(2) The three metal interlayers used in the invention are taken as transition layers, and the interlayers are respectively: the vanadium foil-copper foil-cobalt foil enables a solid solution to be formed between the titanium alloy and the stainless steel, so that a brittle intermetallic compound is prevented from being formed, and formation of a plastic welding line is facilitated;
(3) the invention adopts a slow cooling method after vacuum diffusion welding, which is beneficial to eliminating interface welding stress and improving the mechanical property of a welding joint;
(4) the method has simple and efficient process and less requirements on the shape and the size of the workpiece, and can be widely applied to welding between titanium alloy and stainless steel.
Drawings
FIG. 1 is a schematic view showing the order of titanium alloy, stainless steel, vanadium foil, copper foil and cobalt foil placement in the present invention;
FIG. 2 is a schematic temperature-time flow diagram of vacuum diffusion welding according to the present invention;
FIG. 3 is the microstructure of the weld zone in example 4.
In fig. 1: 1. a titanium alloy; 2. a vanadium foil; 3. copper foil; 4. a cobalt foil; 5. stainless steel.
Detailed Description
The present invention will be described in further detail with reference to test examples and specific embodiments. It should be understood that the scope of the above-described subject matter is not limited to the following examples, but is intended to include all technical aspects that can be achieved based on the present disclosure.
In the process of carrying out vacuum diffusion welding on titanium alloy and stainless steel, the invention needs to adjust vacuum, and further adjusts parameters such as diffusion welding temperature, pressure, time and the like, the placing sequence of the titanium alloy, the stainless steel, the vanadium foil, the copper foil and the cobalt foil is placed in a vacuum diffusion furnace according to the figure 1, an upper cushion block is placed between an upper pressure head and a sample to be welded, a lower cushion block is placed between a lower pressure head and the sample to be welded, and a thermocouple is used for measuring the temperature of the sample to be welded. The whole equipment is in a vacuum environment. In short, experiments that can adjust the diffusion welding temperature, time, pressure and vacuum degree belong to the protection scope of the present application.
The present invention will be described in further detail with reference to test examples and specific embodiments. It should be understood that the scope of the above-described subject matter is not limited to the following examples, but is intended to include all technical aspects that can be achieved based on the present disclosure.
The titanium alloy, the stainless steel, the vanadium foil, the copper foil and the cobalt foil related in the embodiment of the invention are provided by Shanghai technical physics of Chinese academy of sciences.
Example 1
Grinding and polishing the surfaces to be welded of the TC4 titanium alloy and the 316L stainless steel by using abrasive paper to ensure that the roughness Ra of the surfaces is less than or equal to 1.0 mu m so as to carry out subsequent diffusion welding experiments and ensure that the metal and the interlayer can be tightly attached; for the oxide film on the surface of the titanium alloy, a mixed solution of hydrofluoric acid and nitric acid is adopted to remove the oxide film on the surface; at the same time, dilute H is used2SO4The solution removes the oxide film on the surface of the copper foil, is beneficial to the diffusion welding and avoids the impurity oxygen from permeating into the welding line to damage the performance of the welding line; finally, removing oil and dirt on the surface of the sample, simultaneously placing the titanium alloy, the stainless steel, the vanadium foil, the copper foil and the cobalt foil into acetone for ultrasonic cleaning for 10-15min so as to clean up oil dirt and dust on the surface of the sample, then wiping the surface to be welded with alcohol, and drying the surface with cold air to obtain the cleaned titanium alloy, the stainless steel, the vanadium foil, the copper foil and the cobalt foil; wherein the vanadium foil is selected to be 100 μm, the copper foil is selected to be 30 μm, the cobalt foil is selected to be 50 μm, and the purity is more than 98 wt%;
the above cleaning methods are all known in the art;
and (3) sequentially butting and placing the titanium alloy, the stainless steel, the vanadium foil, the copper foil and the cobalt foil with the cleaned surfaces according to the titanium alloy-vanadium foil-copper foil-cobalt foil-stainless steel. Specifically, as shown in fig. 1, a titanium alloy 1, a vanadium foil 2, a copper foil 3, a cobalt foil 4 and stainless steel 5 are sequentially arranged and fixed between an upper pressure head and a lower pressure head in a hearth of a vacuum diffusion furnace to ensure that a gap between a metal material and an interlayer is less than 0.1 mm;
after the fixing is finished, operating according to a standard flow, and firstly applying pre-pressure of 10MPa to the to-be-welded piece through an upper pressure head and a lower pressure head to stably fix the to-be-welded piece between the pressure heads; then vacuumizing until the vacuum degree reaches (1-6) multiplied by 10-1The vacuum diffusion welding process is carried out when Pa is reached, the diffusion welding time selected in the embodiment is 90min, the diffusion welding pressure is 5MPa, and the diffusion is carried outThe welding temperature is 800 ℃, and a vacuum diffusion machine is adopted for diffusion welding;
specifically, the temperature is increased to 750 ℃ at the heating rate of 10 ℃/min, and the pressure is maintained for 30min under the pressure of 20MPa, so that the metal is in full contact with the interlayer, and the gap is reduced; after the primary heat preservation and pressure maintenance is finished, the temperature is raised to the diffusion welding temperature of 800 ℃, meanwhile, the pressure is reduced to 5MPa, and diffusion welding time of 90min, namely secondary heat preservation and pressure maintenance, is carried out; after diffusion welding is finished, pressure relief is carried out, the temperature is reduced to 700 ℃ at the speed of 5 ℃/min, and furnace cooling is carried out; after welding, waiting for the sample to be cooled to room temperature, opening the hearth of the equipment, and taking out the sample to obtain the TC4 titanium alloy and 316L stainless steel dissimilar welding composite member.
Example 2
The welding of the titanium alloy and the stainless steel was performed by the same process as in example 1. The conditions were the same as in example 1 except that the diffusion bonding temperature (i.e., the secondary soaking temperature) was 840 ℃.
Example 3
The welding of the titanium alloy and the stainless steel was performed by the same process as in example 1. The conditions were the same as in example 1 except that the selected diffusion welding temperature (i.e., the secondary soak temperature) was 880 ℃.
Example 4
The welding of the titanium alloy and the stainless steel was performed by the same process as in example 1. The same conditions as in example 1 were used except that the selected diffusion welding temperature (i.e., the secondary soak temperature) was 920 ℃.
The microstructure and morphology of the obtained weld zone are shown in figure 3, and in figure 3, according to a Ti-V phase diagram, a solid solution of titanium and vanadium is formed on the side surface of the titanium alloy; according to a Fe-Co binary phase diagram, a cobalt solid solution and FeCo with certain thickness are mainly formed; meanwhile, according to the binary phase diagrams of V-Cu and Cu-Co, a V-Cu solid solution and a Cu-Co solid solution are respectively formed at the V-Cu and Cu-Co interfaces.
Example 5
The welding of the titanium alloy and the stainless steel was performed by the same process as in example 1. The conditions were the same as in example 1 except that the diffusion welding temperature (i.e., the secondary soak temperature) was 960 ℃.
Examples 1-5, the effect of different diffusion welding temperatures on the performance of the weld between the titanium alloy and stainless steel vacuum diffusion welds was compared and the results are given in table 1 below.
The invention is regulated according to the national standard GB/T228-2002, and the tensile test is carried out on the welding sample at room temperature, and the loading rate is 0.5 mm/min. And observing the tensile fracture by using a scanning electron microscope, and judging the fracture property according to the existence of the characteristics of the tough pits, the river floriform and the like.
TABLE 1 mechanical Properties of titanium alloy/stainless Steel Metal welded parts
From the test results in table 1, it can be seen that when the welding scheme of the invention is adopted to weld stainless steel and titanium alloy, the selection of the vacuum diffusion welding temperature has a great influence on the mechanical properties of the welded parts. When the diffusion welding temperature is lower, the performance of the joint is poorer after vacuum diffusion welding, the diffusion of elements at the interface is not facilitated, and the performance of the formed joint is poorer. When the diffusion welding temperature is higher, the elements perform sufficient diffusion action to form solid solution between the titanium alloy and the stainless steel metal, and the obtained welding line has better performance. When the temperature is too high, the strength of the welded joint is reduced due to the growth of crystal grains. Therefore, there is a significant relationship between the structural stability of the joint and the soldering temperature, so a diffusion soldering temperature of 880 ℃ is preferred.
Example 6
Grinding and polishing the surfaces to be welded of the TC4 titanium alloy and the 316L stainless steel by using abrasive paper to ensure that the roughness Ra of the surfaces is less than or equal to 1.0 mu m so as to carry out subsequent diffusion welding experiments and ensure that the metal and the interlayer can be tightly attached; for the oxide film on the surface of the titanium alloy, a mixed solution of hydrofluoric acid and nitric acid is adopted to remove the oxide film on the surface; at the same time, dilute H is used2SO4The solution removes the oxide film on the surface of the copper foil, is beneficial to the diffusion welding and avoids the impurity oxygen from permeating into the welding line to damage the performance of the welding line; finally, the surface of the sample is degreasedAnd (3) removing dirt, meanwhile, putting the titanium alloy, the stainless steel, the vanadium foil, the copper foil and the cobalt foil into acetone for ultrasonic cleaning for 10-15min so as to clean up oil dirt and dust on the surface of the sample, then wiping the surface to be welded with alcohol, and drying by cold air to obtain the cleaned titanium alloy, stainless steel metal, vanadium foil, copper foil and cobalt foil.
And (3) sequentially butting and placing the titanium alloy, the stainless steel, the vanadium foil, the copper foil and the cobalt foil with the cleaned surfaces according to the titanium alloy-vanadium foil-copper foil-cobalt foil-stainless steel. Specifically, as shown in fig. 1, titanium alloy-1, vanadium foil-2, copper foil-3, cobalt foil-4 and stainless steel metal-5 are sequentially arranged and fixed between an upper pressure head and a lower pressure head in a hearth of a vacuum diffusion furnace to ensure that a gap between a metal material and an interlayer is less than 0.1 mm;
after the fixing is finished, the operation is carried out according to a standard flow, and firstly, the prepressing force of 10MPa is applied to the to-be-welded piece through the upper pressure head and the lower pressure head, so that the to-be-welded piece is stably fixed between the pressure heads. Then vacuumizing until the vacuum degree reaches (1-6) multiplied by 10-1And carrying out vacuum diffusion welding process at Pa. The diffusion welding time is 90min, the diffusion welding pressure is 5MPa, and the diffusion welding temperature is 880 ℃. Carrying out diffusion welding by using a vacuum diffusion machine;
specifically, the temperature is increased to 750 ℃ at the heating rate of 10 ℃/min, and the pressure is maintained for 30min under the pressure of 20MPa, so that the metal is in full contact with the interlayer, and the gap is reduced; after the pressure holding is finished, the temperature is raised to 880 ℃, meanwhile, the pressure is reduced to 4MPa, and diffusion welding is carried out for 30min (namely, the secondary temperature holding time is 30 min); and (4) after the diffusion welding is finished, releasing the pressure, reducing the temperature to 700 ℃ at the same time at the speed of 5 ℃/min, and cooling along with the furnace. After welding, waiting for the sample to be cooled to room temperature, opening the hearth of the equipment, and taking out the sample to obtain the TC4 titanium alloy and 316L stainless steel dissimilar welding composite member.
Examples 7 to 10
Influence of vacuum diffusion welding holding time
The welding of the titanium alloy and the stainless steel was performed by the same process as in example 6. The conditions were the same as in example 6 except that the diffusion bonding pressure was reduced to 4MPa, the temperature was raised to 880 ℃ and the secondary heat and pressure was maintained for 60min, 90min, 120min and 150min, respectively.
Examples 7 to 10 were compared in the effects of different heat-insulating times for diffusion welding on the performance of the weld joints in vacuum diffusion welding of titanium alloy and stainless steel, and a plurality of heat-insulating times were set as comparative examples for study by controlling the secondary heat-insulating and pressure-maintaining time, and the results are shown in table 2 below.
TABLE 2 mechanical Properties of titanium alloy/stainless Steel welded parts
| Test specimen | Tensile strength (MPa) | Fracture properties |
| Example 6(30min) | 242.89 | Toughness of |
| Example 7(60min) | 376.39 | Toughness of |
| Example 8(90min) | 489.76 | Toughness of |
| Example 9(120min) | 591.31 | Toughness of |
| Example 10(150min) | 498.69 | Toughness of |
As can be seen from the results of Table 2, the secondary soak time has a significant effect on the weld quality when the weld joint is made using the welding scheme of stainless steel and titanium alloys of the present invention. Along with the prolonging of the heat preservation time, the tensile strength of the weldment shows a trend of increasing first and then decreasing. This is because the interface atoms perform a sufficient diffusion behavior with a sufficient diffusion soldering time. Therefore, as the soldering time is prolonged, the degree of interfacial atomic diffusion increases. Meanwhile, the copper-cobalt interface generates a copper-cobalt solid solution, and the grain boundary of the cobalt is completely or partially surrounded by the copper. In other words, the grain boundaries of the second solid phase are fully or partially wetted by copper, promoting interfacial bonding, thereby improving the weld strength. However, when the welding time exceeds 120min, the atomic diffusion distance further increases, resulting in the gradual formation of a small amount of brittle phases at the interface, and at the same time, the grains start to grow, weakening the joint welding strength. Through the heat preservation for 120min, no brittle compound is generated in the joint, no defects such as air holes and cracks are generated, the tensile strength of the joint reaches 330.80MPa, and the joint is in ductile fracture.
Examples 11 to 15
Influence of vacuum diffusion welding heat preservation pressure intensity
The welding of the titanium alloy and the stainless steel was performed by the same procedure as in example 9. The parameters were kept as in example 9, except that the diffusion welding holding pressure was changed. The secondary heat preservation pressure intensity is respectively 5MPa, 5.5MPa, 6MPa, 6.5MPa and 7 MPa.
Examples a plurality of holding pressures were set as comparative examples and investigated by controlling the secondary holding pressure, and the results are shown in table 3 below.
TABLE 3 mechanical Properties of titanium alloy/stainless Steel welded parts
As can be seen from the results of Table 3, the secondary holding pressure did not have a significant effect on the weld quality when the weld joint was made using the welding scheme of stainless steel and titanium alloy of the present invention. Along with the increase of the heat preservation pressure, the tensile strength of the welding piece slightly rises. This is because atoms can diffuse tightly under sufficient diffusion welding pressure. However, it has been found that the strength of the welded joint is not significantly increased, since the welding pressure acts to promote the fracture of the material surface in contact with the interface, thus favouring atomic diffusion, and this pressure reaches a certain value to achieve this purpose.
Example 16
Only vanadium foil and cobalt foil are used as transition layers
Titanium alloy, stainless steel, vanadium foil and cobalt foil were prepared in the same manner as in example 3. Arranging 100-micron vanadium foil and 50-micron cobalt foil between titanium alloy and stainless steel metal, then putting the titanium alloy-vanadium foil-cobalt foil-stainless steel into a hearth of a vacuum diffusion machine in sequence, and performing pre-pressing operation, wherein the pre-pressing pressure is 15 MPa.
Then welding operation is carried out according to the standard flow, and vacuum pumping is carried out to reach (1-6) multiplied by 10-1Pa vacuum degree, starting diffusion welding process parameter setting, and then welding; firstly, heating to 750 ℃ at a heating rate of 10 ℃/min, maintaining the pressure for 30min under the pressure of 20MPa so as to be in full contact, heating to a heat preservation temperature of 880 ℃ after the pressure maintaining is finished, reducing the pressure to 5MPa, maintaining the pressure for 90min, reducing the temperature to 700 ℃ at 5 ℃/min after the pressure maintaining is finished, and cooling along with the furnace. And after welding, waiting for the cooling of the sample, opening the hearth of the vacuum diffusion machine, and taking out the sample.
Example 17
Only vanadium foil and copper foil are used as transition layers
Titanium alloy, stainless steel, vanadium foil and cobalt foil were prepared in the same manner as in example 3. Arranging 100 μm vanadium foil and 30 μm copper foil between titanium alloy and stainless steel metal, placing in the order of titanium alloy-vanadium foil-copper foil-stainless steel into the hearth of vacuum diffusion machine, pre-pressing, and pre-pressingThe force is 10 MPa; then welding operation is carried out according to the standard flow, and vacuum pumping is carried out to reach (1-6) multiplied by 10-1Pa vacuum degree, starting to set diffusion welding technological parameters, and then welding. Firstly, heating to 750 ℃ at a heating rate of 10 ℃/min, maintaining the pressure for 30min under the pressure of 20MPa so as to be in full contact, heating to a heat preservation temperature of 880 ℃ after the pressure maintaining is finished, reducing the pressure to 5MPa, maintaining the pressure for 90min, reducing the temperature to 700 ℃ at 5 ℃/min after the pressure maintaining is finished, and cooling along with the furnace. After welding, the test sample is cooled, and then the furnace chamber of the vacuum diffusion machine is opened, and the test sample is taken out.
Example 18
The transition layer only uses cobalt foil and copper foil
Titanium alloy, stainless steel, vanadium foil and cobalt foil were prepared in the same manner as in example 3; arranging a 30-micron copper foil and a 50-micron cobalt foil between titanium alloy and stainless steel metal, then putting the titanium alloy-cobalt foil-copper foil-stainless steel into a hearth of a vacuum diffusion machine in sequence, and performing pre-pressing operation, wherein the pre-pressing pressure is 10 MPa; then welding operation is carried out according to the standard flow, and vacuum pumping is carried out to reach (1-6) multiplied by 10-1Pa vacuum degree, starting diffusion welding process parameter setting, and then welding. Firstly, heating to 750 ℃ at a heating rate of 10 ℃/min, maintaining the pressure for 30min under the pressure of 20MPa so as to be in full contact, heating to a heat preservation temperature of 880 ℃ after the pressure maintaining is finished, reducing the pressure to 5MPa, maintaining the pressure for 90min, reducing the temperature to 700 ℃ at 5 ℃/min after the pressure maintaining is finished, and cooling along with the furnace. And after welding, waiting for the cooling of the sample, opening the hearth of the vacuum diffusion machine, and taking out the sample.
Examples the effect on joint performance was investigated by varying the interlayer type, and the results are given in table 4 below.
TABLE 4 mechanical Properties of welded parts of titanium alloy/stainless Steel Metal
From the test results, it can be known that when the welding scheme of the stainless steel and the titanium alloy is adopted for welding, if the transition layer only adopts vanadium foil and cobalt foil, some brittle intermetallic compounds still exist in the welding seam, which can damage the strength of the joint; when the transition layer only adopts vanadium foil and copper foil, a joint with better mechanical property is obtained; when copper foil and cobalt foil are used, titanium-copper phase is generated, and a joint with excellent mechanical properties cannot be obtained. Therefore, vanadium foil, copper foil and cobalt foil are selected as metal interlayers, the heat preservation temperature is 880 ℃, the heat preservation time is 120min, and the heat preservation pressure is 6MPa as the optimal welding process parameters.
The invention is not limited to the foregoing embodiments. The invention extends to any novel feature or any novel combination of features disclosed in this specification and any novel method or process steps or any novel combination of features disclosed.
Claims (5)
1. A dissimilar metal vacuum diffusion welding method of TC4 titanium alloy and 316L stainless steel is characterized by comprising the following steps:
(1) cleaning the surface of the sample: cleaning the surfaces to be welded of TC4 titanium alloy and 316L stainless steel, and cleaning the surfaces of a vanadium foil, a copper foil and a cobalt foil which are intermediate interlayer materials; the thickness of the vanadium foil is 85-115 mu m, the thickness of the copper foil is 15-45 mu m, and the thickness of the cobalt foil is 35-65 mu m;
(2) placing a sample: and (2) butting the TC4 titanium alloy with the clean surface obtained in the step (1), 316L stainless steel, vanadium foil, copper foil and cobalt foil in sequence, wherein the sequence is as follows: TC4 titanium alloy-vanadium foil-copper foil-cobalt foil-316L stainless steel, or 316L stainless steel-cobalt foil-copper foil-vanadium foil-TC 4 titanium alloy;
(3) diffusion welding: placing the samples stacked in sequence obtained in the step (2) between an upper pressure head and a lower pressure head of a vacuum hot-pressing furnace, and then performing diffusion welding; in the step (3), good axial centering performance between the sample and a pressure head is kept, pre-pressure of 15-30MPa is applied to the sample to be welded through the upper pressure head, so that the interlayer is tightly contacted with metal, and then pressure relief is carried out; and carrying out heat preservation and pressure maintaining twice.
2. The dissimilar metal vacuum diffusion welding method for the TC4 titanium alloy and 316L stainless steel according to claim 1, wherein the step of vacuum diffusion welding is performed by using a vacuum gas welding method(1) The cleaning method of the surfaces to be welded of the TC4 titanium alloy and the 316L stainless steel comprises the following steps: sanding and polishing by using sand paper to ensure that the roughness Ra is less than or equal to 1.0 mu m; removing an oxide film on the surface of the titanium alloy by adopting a mixed solution of hydrofluoric acid and nitric acid; by dilute H2SO4Solution, removing an oxide film on the surface of the copper foil: and then, putting the TC4 titanium alloy, the 316L stainless steel, the vanadium foil, the copper foil and the cobalt foil into an acetone solution, ultrasonically cleaning for 10-15min, wiping the metal surface to be welded and the two surfaces of the interlayer with alcohol, and drying by cold air to obtain the clean and dustless TC4 titanium alloy, the 316L stainless steel, the vanadium foil, the copper foil and the cobalt foil.
3. A dissimilar metal vacuum diffusion welding method of TC4 titanium alloy and 316L stainless steel according to claim 1, wherein the two heat and pressure maintaining method comprises the following steps: vacuum-pumping to (1-6) x 10 in vacuum hot-pressing furnace-1When Pa is needed, the temperature is increased at the speed of 10 ℃/min, the furnace temperature is increased to be lower than the diffusion welding temperature by 100-200 ℃, the primary heat preservation and pressure maintaining are carried out, then the pressure is reduced to the diffusion welding pressure, meanwhile, the temperature is increased to the diffusion welding temperature, and the secondary heat preservation and pressure maintaining are carried out; and (4) after the heat preservation and pressure maintenance are finished, releasing the pressure, cooling to 700 ℃ at the temperature of 5 ℃/min, and then cooling along with the furnace.
4. The vacuum diffusion welding method for dissimilar metals of TC4 titanium alloy and 316L stainless steel according to claim 3, wherein the initial heat preservation and pressure maintaining are carried out at a temperature of 600-800 ℃, a pressure of 10-30MPa and a heat preservation time of 20-60 min.
5. The vacuum diffusion welding method for dissimilar metals of TC4 titanium alloy and 316L stainless steel according to claim 4, wherein the temperature and pressure are 800-1100 ℃, 5-10MPa and 20-180min during the secondary heat preservation and pressure maintaining.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010158727.8A CN111299796A (en) | 2020-03-09 | 2020-03-09 | Dissimilar metal vacuum diffusion welding method for TC4 titanium alloy and 316L stainless steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010158727.8A CN111299796A (en) | 2020-03-09 | 2020-03-09 | Dissimilar metal vacuum diffusion welding method for TC4 titanium alloy and 316L stainless steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111299796A true CN111299796A (en) | 2020-06-19 |
Family
ID=71151079
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010158727.8A Pending CN111299796A (en) | 2020-03-09 | 2020-03-09 | Dissimilar metal vacuum diffusion welding method for TC4 titanium alloy and 316L stainless steel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111299796A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113020737A (en) * | 2021-03-25 | 2021-06-25 | 哈尔滨工业大学 | Method for diffusion connection of skutterudite and copper electrode through cobalt intermediate layer |
| CN113415063A (en) * | 2021-06-22 | 2021-09-21 | 西安理工大学 | Preparation method of tin-lead bronze/titanium alloy bimetal |
| CN114367731A (en) * | 2022-02-09 | 2022-04-19 | 中国工程物理研究院材料研究所 | Method for connecting tungsten and steel |
| CN114577841A (en) * | 2022-02-08 | 2022-06-03 | 首钢集团有限公司 | Steel-aluminum welding simulation method |
| CN115079750A (en) * | 2022-08-11 | 2022-09-20 | 中国核动力研究设计院 | Heating control method and device for welding equipment and computer readable storage medium |
| US20220388090A1 (en) * | 2021-06-04 | 2022-12-08 | The Boeing Company | Fabrication of thick stock via diffusion bonding of titanium alloys |
| CN115570252A (en) * | 2022-12-09 | 2023-01-06 | 西部金属材料股份有限公司 | Hot-pressing creep compounding method for oversized metal blank |
| CN115647555A (en) * | 2022-12-13 | 2023-01-31 | 杭州沈氏节能科技股份有限公司 | Welding method and welding product of high-temperature alloy micro-channel heat exchanger |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6310088A (en) * | 1986-06-28 | 1988-01-16 | Tobata Seisakusho:Kk | Joining method for titanium material and austenite stainless steel |
| JPH0623570A (en) * | 1992-07-02 | 1994-02-01 | Kobe Steel Ltd | Manufacture of joined material of different kinds of metal |
| CN101244483A (en) * | 2008-03-20 | 2008-08-20 | 重庆大学 | Self-nano-structure diffusion welding technique for titanium alloy and stainless steel surface |
| CN103920987A (en) * | 2014-04-23 | 2014-07-16 | 哈尔滨工业大学 | Method for vacuum micro-diffusion connection of titanium alloy and stainless steel |
| CN107030367A (en) * | 2017-04-10 | 2017-08-11 | 西南交通大学 | The dissimilar metal diffusion welding method of titanium alloy and stainless steel |
-
2020
- 2020-03-09 CN CN202010158727.8A patent/CN111299796A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6310088A (en) * | 1986-06-28 | 1988-01-16 | Tobata Seisakusho:Kk | Joining method for titanium material and austenite stainless steel |
| JPH0623570A (en) * | 1992-07-02 | 1994-02-01 | Kobe Steel Ltd | Manufacture of joined material of different kinds of metal |
| CN101244483A (en) * | 2008-03-20 | 2008-08-20 | 重庆大学 | Self-nano-structure diffusion welding technique for titanium alloy and stainless steel surface |
| CN103920987A (en) * | 2014-04-23 | 2014-07-16 | 哈尔滨工业大学 | Method for vacuum micro-diffusion connection of titanium alloy and stainless steel |
| CN107030367A (en) * | 2017-04-10 | 2017-08-11 | 西南交通大学 | The dissimilar metal diffusion welding method of titanium alloy and stainless steel |
Non-Patent Citations (1)
| Title |
|---|
| LIU YANG等: "Interfacial reaction and microstructure investigation of TC4/V/Cu/Co/316L diffusion-bonded joints", 《MATERIALS LETTERS》 * |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113020737A (en) * | 2021-03-25 | 2021-06-25 | 哈尔滨工业大学 | Method for diffusion connection of skutterudite and copper electrode through cobalt intermediate layer |
| US20220388090A1 (en) * | 2021-06-04 | 2022-12-08 | The Boeing Company | Fabrication of thick stock via diffusion bonding of titanium alloys |
| CN113415063A (en) * | 2021-06-22 | 2021-09-21 | 西安理工大学 | Preparation method of tin-lead bronze/titanium alloy bimetal |
| CN114577841A (en) * | 2022-02-08 | 2022-06-03 | 首钢集团有限公司 | Steel-aluminum welding simulation method |
| CN114367731A (en) * | 2022-02-09 | 2022-04-19 | 中国工程物理研究院材料研究所 | Method for connecting tungsten and steel |
| CN114367731B (en) * | 2022-02-09 | 2023-05-09 | 中国工程物理研究院材料研究所 | Tungsten and steel connecting method |
| CN115079750A (en) * | 2022-08-11 | 2022-09-20 | 中国核动力研究设计院 | Heating control method and device for welding equipment and computer readable storage medium |
| CN115570252A (en) * | 2022-12-09 | 2023-01-06 | 西部金属材料股份有限公司 | Hot-pressing creep compounding method for oversized metal blank |
| CN115647555A (en) * | 2022-12-13 | 2023-01-31 | 杭州沈氏节能科技股份有限公司 | Welding method and welding product of high-temperature alloy micro-channel heat exchanger |
| CN115647555B (en) * | 2022-12-13 | 2023-04-21 | 杭州沈氏节能科技股份有限公司 | Welding method and welding product of high-temperature alloy microchannel heat exchanger |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111299796A (en) | Dissimilar metal vacuum diffusion welding method for TC4 titanium alloy and 316L stainless steel | |
| CN106808079B (en) | TiAl alloy and Ti2Diffusion bonding method of AlNb alloy | |
| JP5846868B2 (en) | Manufacturing method of stainless steel diffusion bonding products | |
| CN101254572B (en) | Method for diffusion welding titanium alloy and copper alloy using niobium central layer | |
| WO2014184890A1 (en) | Process for producing stainless steel diffusion-joined product | |
| CN107030367A (en) | The dissimilar metal diffusion welding method of titanium alloy and stainless steel | |
| CN106271015B (en) | A kind of stainless steel and kovar alloy dissimilar metal diffusion welding method | |
| CN111347146B (en) | Tungsten and heat sink material connector and preparation method thereof | |
| Wu et al. | Vacuum diffusion bonding of TC4 titanium alloy and T2 copper by a slow cooling heat treatment | |
| CN108637447B (en) | Electron beam welding method for dissimilar metals of titanium alloy and kovar alloy | |
| CN111468815B (en) | Aluminum alloy diffusion bonding method without intermediate layer | |
| CN109014549B (en) | Diffusion welding connection method adopting Cu foil and Ti foil as composite intermediate layer | |
| CN113478062B (en) | Reaction diffusion connection method for titanium-zirconium-molybdenum alloy high-temperature-resistant joint | |
| CN111421218A (en) | Hydrogen-containing Ti2Low-temperature diffusion welding method for AlNb-based alloy and TC4 titanium alloy | |
| CN111347147B (en) | Hot isostatic pressing connection method of tungsten and heat sink material | |
| CN112605518B (en) | Diffusion connection method of molybdenum and copper metals without solid solution by adopting consumable intermediate layer | |
| CN113968749A (en) | Method for connecting high-entropy ceramics and metal | |
| Yeh et al. | Low-pressure diffusion bonding of SAE 316 stainless steel by inserting a superplastic interlayer | |
| CN110900037B (en) | Brazing filler metal and method for welding molybdenum-rhenium alloy and steel | |
| CN108724894B (en) | Method for preparing zirconium steel composite board by using copper as intermediate layer | |
| CN111299833A (en) | Dissimilar metal pulse laser welding method for titanium alloy and stainless steel | |
| CN113182631B (en) | Method for preparing high-strength C/C composite material and TC4 alloy joint | |
| CN108480838B (en) | Diffusion welding connection method adopting Ti foil and titanium-based brazing filler metal foil as intermediate layer | |
| CN111687530B (en) | Method for compounding hydrogen absorption expansion substance and other materials | |
| CN114012234A (en) | Vacuum diffusion welding method for dissimilar metals of titanium alloy and magnesium alloy |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200619 |
|
| RJ01 | Rejection of invention patent application after publication |