301 results about "Dissimilar metal" patented technology

The invention relates to the technical field of metal powder processing, and discloses a high-performance dissimilar metal powder precision forming process which comprises the following steps: filling powder into a mold cavity, applying vibration disturbance, monitoring the change rate of a phase lag angle, judging that the powder is dense when the change rate is lower than an offset threshold value, outputting a pressing mode switching signal, an induction heating device is used for applying transient thermal load to induce cracks of an oxide film on the surfaces of particles, the pressure load is applied, the side wall is adjusted to generate shear displacement to peel off the oxide film, and metallurgical bonding is achieved through fresh metal surface contact. An interface is activated through thermal expansion mismatch and mechanical friction synergistically, a high-density uniform green body is obtained at low temperature, generation of brittle intermetallic compounds is inhibited, and the fatigue resistance of a formed part is enhanced.

The invention discloses a method for predicting the mechanical property of a dissimilar metal friction stir lap joint welded joint by fusing physical information, and belongs to the technical field of crossing of material processing and artificial intelligence. The method comprises the following steps that firstly, welding samples under different technological parameters are prepared through experiments, and the mechanical properties of the welding samples are tested; meanwhile, establishing a finite element simulation model, and extracting physical field data such as a temperature field and a stress-strain field; fusing the process parameters and the physical field data to serve as input features, taking the measured mechanical property data as output features, and forming a machine learning training data set; a prediction model is trained by adopting algorithms such as a gradient lifting decision tree and limit gradient lifting; and finally, new process parameters and physical field data obtained through finite element simulation are input, and the mechanical property of the joint can be efficiently and precisely predicted through the model. According to the method, the defects that a traditional trial and error method is high in cost and long in period are overcome, and key technical support is provided for optimization and intelligent design of the dissimilar metal friction stir lap welding process.

The invention discloses an intermediate layer for resistance spot welding of aluminum / steel dissimilar metals and a resistance spot welding method, the intermediate layer is a FeMnCuNi medium-entropy alloy, and the intermediate layer comprises the following components by atomic percent: 20-30% of Fe, 20-30% of Cu, 5-10% of Ni, 5-10% of Ni, and the balance of Fe and inevitable impurities. 20%-30% of Mn; 20%-30% of Cu; the sum of the atomic percentages of all the components is 100%. The method comprises the steps that (1) the aluminum alloy plate and the steel plate serve as welding base materials to be assembled in a lap joint mode, and the middle layer is added to the lap joint area; and (2) through resistance spot welding, a part of the middle layer and the base metal are melted through resistance heat at the lap joint interface, high entropy of nuggets is achieved through atomic diffusion and the high entropy effect, a welding joint with a solid solution as the main part is formed, and the aluminum / steel dissimilar metal composite structure is obtained. Compared with an existing aluminum / steel resistance spot welding technology, high entropy of nuggets is achieved by applying the high entropy effect, generation of brittle-hard phase intermetallic compounds in a welding joint is remarkably reduced, and a high-performance aluminum-steel composite structure is easily obtained.

The invention discloses a dissimilar metal laser arc hybrid welding regulation and control system and method based on multi-source information fusion, and belongs to the technical field of welding monitoring and regulation and control. The dissimilar metal laser arc hybrid welding regulation and control system comprises a welding subsystem (1), a monitoring subsystem (2), a control subsystem (3), an execution subsystem (4) and the like. The multi-dimensional monitoring subsystem is combined with a special data preprocessing mechanism, comprehensive data collection in the dissimilar metal welding process is achieved, the problem that an existing system is single in monitoring dimension is solved, and data support is provided for follow-up defect recognition and parameter regulation and control.

The invention discloses an aluminum alloy and galvanized aluminum magnesium steel CMT dissimilar metal connection method. The method comprises the following steps that S11, a galvanized aluminum magnesium steel plate to be welded and an aluminum alloy plate to be welded are cleaned before welding; s12, laser etching is conducted on the surface of the cleaned zinc-aluminum-magnesium-plated steel plate, a surface microstructure is prepared, and the depth of the surface microstructure is smaller than the thickness of a plating layer on the zinc-aluminum-magnesium-plated steel plate; and S2, the galvanized aluminum magnesium steel plate with the surface microstructure and the cleaned aluminum alloy plate are placed in a lap joint mode, and welding is carried out. According to the method, the surface microstructure is prepared on the surface of the galvanized aluminum-magnesium steel plate, so that the coating restraint degree of the galvanized aluminum-magnesium steel surface is changed, the contact area of brazing filler metal and a base material is remarkably increased, the coating restraint stress of the surface of the base material is reduced, the flowing resistance of a molten pool is reduced, and the wettability is improved; the surface microstructure can promote evaporation of Zn in the coating and reduce the temperature of a molten pool, so that the thickness of an intermetallic compound is reduced, and the performance of a welded joint is remarkably improved.

The invention provides a friction solid-phase additive manufacturing method for improving the bonding strength of dissimilar alloys through interlayer interface texturing. The method comprises the following steps that an aluminum alloy or magnesium alloy plate serves as a base body; depositing a first metal layer on the polished to-be-added area by adopting a friction solid-phase additive process; processing a preset micron-sized three-dimensional texture on the surface of the first metal layer by adopting a laser scanning system so as to form a textured interface, and meanwhile, removing new oxides on the surface of the first metal layer; on the textured interface, a second metal layer which is made of a material different from that of the first metal layer is deposited again through the friction solid-phase additive process, so that a bonding interface which is characterized by micromechanical interlocking is formed between the first metal layer and the second metal layer; layer-by-layer additive manufacturing of a stacked dissimilar alloy having a plurality of dissimilar metal bonding interfaces. According to the method, the interlayer bonding mode of the dissimilar alloy is changed, and the problems of layering and cracking of dissimilar alloy fusion welding additive manufacturing components are effectively solved.

The invention provides an anti-overheating expansion welding method for a tube plate and a heat exchange tube and a tube plate heat exchanger, and relates to the technical field of heat exchanger manufacturing, the method comprises the following steps: planning a welding sequence according to a plurality of to-be-welded tube plate joints on the tube plate, and enabling the continuous tube plate joints on the welding sequence to be non-adjacent in spatial positions; welding is conducted according to the welding sequence, and meanwhile a heat conduction tool is used for making contact with the tube plate connector to conduct heat away; after welding of the preset number of tube plate joints is completed every time, the weld joint temperature is detected and compared with a preset temperature threshold value, and if the weld joint temperature is smaller than or equal to the preset temperature threshold value, welding of the next set of tube plate joints continues; and if the weld joint temperature is larger than the preset temperature threshold value, welding is suspended, and cooling is conducted till the weld joint temperature falls back to be lower than or equal to the preset temperature threshold value. Through a collaborative mechanism of path dispersion, active heat conduction and closed-loop temperature control, the problems of welding seam overheating oxidation, structure deterioration and poor process stability caused by heat conduction difference of dissimilar metals and heat accumulation of batch welding are solved.

The invention relates to the technical field of metal connection, and discloses a welding forming process of an aluminum alloy copper bar and a terminal, which comprises the following steps: sequentially carrying out mechanical cleaning, chemical oil removal and chemical activation pretreatment on the surfaces to be welded of an aluminum alloy base material and a brass terminal; the aluminum-based brazing filler metal foil and the potassium fluoroaluminate scaling powder are sequentially arranged between the aluminum alloy base material and the brass terminal, and an assembly to be welded is assembled; and finally, placing the assembly in hot pressing equipment under vacuum or inert atmosphere protection, carrying out constant-temperature and constant-pressure treatment at the temperature of 600-630 DEG C and under the pressure of 5-15 MPa, cooling, relieving the pressure, and molding. According to the method, a metallurgical bonding transition layer which is compact in structure and free of welding defects is formed at an aluminum-copper dissimilar metal interface under the combined action of liquid-phase filling and solid-phase diffusion, and a prepared welding joint has mechanical shear strength superior to that of an aluminum alloy base material and extremely low interface contact resistance; and reliable connection with high strength and high conductivity is realized.

The invention discloses a high-entropy alloy foil strip and a laser welding method of a titanium alloy and an aluminum alloy, and belongs to the technical field of dissimilar metal laser welding machining, the high-entropy alloy foil strip is used as a dissimilar metal welding middle layer, and the chemical formula of the high-entropy alloy foil strip is TiaFe2aCo2aNi2aCub; wherein a and b both represent atomic proportionality coefficients, b is a continuous adjustable real number parameter in a [1, 3] interval, and 7a + b = 10. The high-entropy alloy foil strip system has uniqueness in element selection, the proportion of Ti, Fe, Co, Ni and Cu is optimized by combining a Miema model and the metallurgical compatibility of base metal, a stable FCC solid solution can be formed in the welding process, the wettability and the structure stability can be improved, and therefore it is ensured that the performance of a welded joint is improved. A high-entropy alloy foil strip middle layer is introduced between two base materials, the high-entropy effect and the hysteresis diffusion effect are utilized, chemical components of a joint are regulated and controlled, generation of brittle Ti-Al intermetallic compounds in a weld joint is restrained, and therefore the mechanical property of the welded joint is improved.

The invention provides an ultrathin-wall niobium-tungsten alloy and titanium alloy dissimilar metal electron beam welding method which comprises the following steps: step 1, cleaning the to-be-welded parts of niobium-tungsten alloy and titanium alloy by using absolute ethyl alcohol, and then drying; step 2, assembling; the niobium-tungsten alloy and the titanium alloy part are in butt joint and fixed; 3, vacuum electron beam welding is used for positioned welding; and 4, formal welding is conducted. After welding, the surface of a welding seam is formed well, good metallurgical fusion is achieved, and the welding seam welded through a vacuum electron beam meets the QJ 20622-2016 I-level standard; under the room temperature condition, the tensile strength of the welding seam reaches 80% of that of titanium alloy base metal; a hydraulic strength test is carried out on a welding seam, and the welding seam is free of leakage and deformation when the pressure is maintained for 5 minutes under 4.1 MPa. An airtight test is carried out on a welding seam, the requirement that air leakage is avoided under the pressure of 3 MPa for 5 min is met, and the design structure size is promoted to continuously break through in the miniaturization and precision direction.

The invention belongs to the technical field of dissimilar metal welding, and particularly relates to a laser welding-brazing method for titanium steel dissimilar metal connection. According to the laser welding-brazing method, the laser is adopted as a welding heat source, and laser welding combining brazing and fusion welding is achieved by comprehensively regulating and controlling the filling material, the laser beam position and welding parameters. By the adoption of the welding mode, metallurgical regulation and control of welding seams can be effectively achieved, generation of brittle intermetallic compounds is restrained, a high-quality welding joint with excellent strength and plasticity is obtained, the tensile strength of the welded joint is 317.6 MPa and reaches 82.71% of that of steel base metal and 75.44% of that of titanium base metal, the joint coefficient is 0.83, equal-strength matching is basically achieved, and the welding quality is improved. The welding problem of the titanium steel dissimilar metal is effectively solved, technical support can be provided for matched use of titanium alloy and traditional steel and iron materials, and development of the transportation tool lightweight technology is further promoted.

The invention provides a precision casting and friction welding digital manufacturing method for a basic part of an aero-engine, which specifically comprises the following steps of: 1, preparing a blade by adopting a high-temperature alloy material through a precision single crystal casting process; 2, a titanium alloy / high-temperature alloy / carbon fiber composite material is adopted for preparing a blisk / turbine disk; 3, the blades and the blisk / turbine disc are connected through a linear friction welding technology, and connection of homogeneous or heterogeneous metal or nonmetal is achieved; 4, in the linear friction welding process, data of vibration and force-heat multi-frequency key factors are collected, and support is provided for construction of a digital twinborn model; and 5, a digital twinborn model of the linear friction welding process is constructed based on the collected data. According to the method, key factors such as vibration and force heat in the linear friction welding process are collected and reconstructed, the digital twinborn model is constructed, the welding process can be monitored in real time, the welding quality can be predicted, and a basis is provided for welding process optimization and component performance evaluation.

The invention discloses a near-net forming friction welding method for a dissimilar metal stud based on a middle layer, which comprises the following steps of: pre-processing a similar T-shaped boss with a thread or a circular truncated cone-shaped boss without a thread section on the end surface of a workpiece with high hardness, and pre-processing a corresponding similar T-shaped groove or a circular truncated cone-shaped groove on the end surface of a workpiece with low hardness; and before welding, middle-layer alloy is placed at the upper end and the bottom of the T-like groove or the bottom of the circular-truncated-cone-shaped groove, and the welding steps comprise rotary pressing, rotary pressing and friction, sudden stop and upsetting. The intermediate layer alloy is used as a medium, direct contact friction of a welded workpiece is avoided, surface oxidation films of adjacent base metal are broken and gaps are filled through severe plastic deformation of the intermediate layer under rotary extrusion of the workpiece, and effective welding under the conditions of low upsetting friction pressure and no obvious deformation of the workpiece is achieved. And a dissimilar metal welding interface is prevented from being overheated to generate an overthick intermetallic compound, subsequent machining is omitted, near-net forming of a friction welding joint is achieved, and the production efficiency is improved.

The invention provides a cover plate, a cover plate assembly and a battery cell, and relates to the technical field of batteries. The cover plate comprises a first metal piece and a second metal piece, and the first metal piece and the second metal piece are both annular; wherein the first metal piece is sleeved on the second metal piece, the first metal piece is provided with a first circumferential part close to the second metal piece, the second metal piece is provided with a second circumferential part close to the first metal piece, and the first circumferential part is riveted with the second circumferential part. By riveting the first metal piece and the second metal piece, on the basis of realizing direct connection of dissimilar metals, interlocking in mechanical structure can be formed between the first metal piece and the second metal piece based on plastic deformation for realizing riveting, so that the first metal piece and the second metal piece can be stably connected into a whole; the reliability of connection between the first metal piece and the second metal piece is improved.

The invention discloses a laser hybrid welding device for dissimilar metal connection, and relates to the technical field of laser welding, the laser hybrid welding device comprises a supporting mechanism, the supporting mechanism comprises a welding table and a protective cover, and the top of the welding table is fixedly connected with the bottom of the protective cover; and the clamping and positioning mechanism comprises a first motor. Through the arrangement of the pretreatment mechanism, the cleanliness of the to-be-welded surface is remarkably improved, the dissimilar metal welding quality is guaranteed, a steel wire brush driven by a fourth motor is matched with a first double-shaft displacement assembly, precise and uniform grinding of compact oxide layers on the surfaces of aluminum and copper can be achieved, the local residue problem caused by single mechanical grinding is avoided, and the welding quality of the dissimilar metal is improved. Thorough removal of the oxide layer is ensured; and meanwhile, alcohol is accurately conveyed through the alcohol spraying opening through a conveying pump, machining residual oil stains can be efficiently removed, cleaning dead corners caused by traditional simple wiping are prevented, blocking of molten pool fusion is eliminated through thorough removal of an oxidation layer, and air holes generated by high-temperature decomposition are avoided through efficient cleaning of the oil stains.

The application discloses a brazing method of magnesium / aluminum dissimilar metals, which comprises the following steps: pre-electroplating nickel on a magnesium alloy base material, connecting the prepared magnesium alloy with a nickel plating layer and an aluminum alloy by using an ultrasonic-assisted brazing method, and using a brazing filler metal SAC305. The method prevents the generation of Mg-Sn intermetallic compounds (IMCs) in the process of magnesium / aluminum dissimilar metal low-temperature brazing using a Sn-based brazing filler metal. After welding, the position of the original nickel plating layer is changed into a Cu-Ni solid solution, and no large block-shaped Mg2Sn IMC is found in the brazing seam. Compared with a joint without a plating layer, the shear strength of the magnesium / aluminum dissimilar metal brazing joint based on the nickel plating layer is greatly improved, and the joint strength is strengthened by the diffusion of the nickel element into the brazing seam in the welding process. In addition, the corrosion resistance of the magnesium alloy can be improved by plating nickel on the surface of the magnesium alloy, and the service life of the magnesium / aluminum component is prolonged.

This invention provides an engine valve and a method for manufacturing the same, which can suppress galvanic corrosion even when dissimilar metals are joined, and which exhibits excellent wear resistance and corrosion resistance, for use in engines that use CNG, LPG, or alcohol as fuel. [Solution] The engine valve 10 of the present invention is a joint member in which a shaft portion 14 made of martensitic heat-resistant steel SUH11 and a umbrella portion 12 made of austenitic heat-resistant steel SUH35 are joined. A nitride layer is formed only on the surface of the base material on the shaft portion 14 side from the joint portion 13 between the shaft portion 14 and the umbrella portion 12, leaving the surface of the base material exposed on the umbrella portion 12 side from the joint portion 13.

The present invention relates to a high-temperature superconducting magnet and, more specifically, to: a high-temperature superconducting magnet achieving uniform critical current density using dissimilar metal wire materials; and a design parameter determination method thereof. To this end, in a high-temperature superconducting (HTS) magnet (100) formed by stacking an HTS coil (50) having a tape-type HTS conductor wire material wound thereon, the HTS coil (50) comprises: a first metal wire material (110) wound on the HTS coil (50); and a second metal wire material (130) that is made of a different metal from the first metal wire material (110) and wound while at least partially overlapping the first metal wire material (110) in the longitudinal direction of the first metal wire material (110), thereby forming a composite winding portion (140). Accordingly, the HTS magnet achieving uniform critical current density using dissimilar metal wire materials is provided, wherein the uniformity of the critical current density increases on the longitudinal cross-section of the HTS magnet (100).

The application discloses a hot isostatic pressing diffusion connection synchronous aging treatment method for high-temperature alloy and copper alloy, relates to the field of dissimilar metal solid-phase welding, and can improve the strength of the high-temperature alloy, inhibit size distortion caused by stress change in the aging process, improve machining precision, shorten the process cycle of finished products and greatly improve production efficiency. Step 1: high-temperature alloy with a predetermined structure is prepared, and solid solution treatment is carried out; step 2: copper alloy with a predetermined structure is prepared, the surfaces of the high-temperature alloy and the copper alloy are polished smooth and cleaned; step 3: the copper alloy and the high-temperature alloy structure are attached to the surfaces to be connected, and vacuum sealing is carried out; step 4: the structure after sealing is sent into a hot isostatic pressing furnace to carry out hot isostatic pressing diffusion connection and in-furnace aging treatment, so that a final product is obtained. According to the hot isostatic pressing diffusion connection synchronous aging treatment method, the strength of the high-temperature alloy is improved, size distortion is inhibited, machining precision is improved, the process cycle of finished products is shortened, and production efficiency is improved.

The invention discloses a titanium dioxide nanorod / dissimilar metal MOFs heterojunction material and a preparation method and application thereof, and belongs to the technical field of photoelectrochemistry seawater hydrogen production. Soluble nickel salt, soluble cadmium salt or soluble cobalt salt and ammonium molybdate are adopted as metal sources, spherical dissimilar metal MOFs grow on the surface of a TiO2 nanorod in situ, and the TiO2 nanorod / dissimilar metal MOFs heterojunction material is prepared. According to the present invention, the oxygen deficiency-regulated dissimilar metal MOFs material (i.e., the titanium dioxide nanorod / dissimilar metal MOFs heterojunction material) is obtained through subsequent acid etching and annealing treatment, the material is subjected to in-situ reconstruction during the OER process to spontaneously form the active hydroxide (NiOOH) of anion protection (MoO4 < 2->), and the excellent stability is represented; only small Faraday efficiency loss (1.2-2.3%) occurs in a high chloride ion environment (3.5 wt%-7wt% of NaCl), and an extensible path is provided for industrial-scale solar hydrogen production by using seawater.

This invention relates to a method for preparing a layered composite material, comprising the following steps: S1, pretreating the surfaces of an aluminum plate and a dissimilar metal plate; S2, coating the surfaces of the aluminum plate and the dissimilar metal plate treated in S1 with a paste-like aluminum flux, wherein the melting point and minimum activity temperature of the aluminum flux are both lower than the diffusion reaction temperature of the aluminum plate and the dissimilar metal plate; S3, alternately stacking the aluminum plate and the dissimilar metal plate treated in S2 to form a stack, wherein aluminum flux is present between adjacent aluminum plates and dissimilar metal plates, and subjecting the stack to vacuum heating surface treatment; S4, subjecting the stack treated in S3 to further vacuum hot-press diffusion treatment, thereby obtaining an aluminum flux-assisted metal / aluminide layered composite material. This method significantly improves the diffusion reaction rate and reduces the probability of Kirkendal voids; it avoids the "centerline" defect that easily forms in the original technology, which leads to incomplete conversion of the aluminum layer into aluminides, allowing the layered composite material to be used under conditions higher than the melting point of aluminum.

This invention relates to a method for preparing high-throughput diffusion couples using friction forming. The method utilizes friction welding equipment to bring two metal materials into contact and form a friction pair. The frictional heat and plastic deformation heat generated by the friction pair cause mutual diffusion between metal atoms, forming a diffusion layer and thus completing the diffusion connection of the components. The diffusion joint core is then removed by machining, ultimately completing the preparation of the diffusion couple. This method can be used to prepare binary and ternary diffusion couples. The method of this invention has low requirements for component surface treatment, does not require a vacuum environment, and does not require long diffusion times. The diffusion couple preparation method of this invention has high success rate and efficiency and can be used to prepare binary and multi-component diffusion couples of dissimilar metal materials.

A method of forming a shaped article wherein said article comprises at least two parts which are chemically bonded, the method comprising: assembling at least two non chemically bonded parts in a weld cavity of a tool to form an assembly of the at least two parts, wherein said weld cavity is adapted to receive the assembly of at least two parts in the form of the shaped article; sealing the weld cavity of the tool; melting the assembly of at least two parts to chemically bond the at least two parts together to form the shaped article, wherein the shape of the weld cavity is matched to the outer circumference of the assembly of parts such that thermal expansion forces the polymer parts against the weld cavity surface and the pressure leads to full surface bonds between all parts, and wherein the tool forming the weld cavity comprises two halves forming a piston which fits into the bore of a bolster component and the plane of the split line between the two piston halves is parallel to the axis of the bore such that the pressure from the thermal expansion of the assembly of parts within the weld cavity is opposed by the surface of the bore preventing the weld cavity split line from opening and therefore preventing leakage of polymer from within the pressurised weld cavity volume, and wherein the two piston components are made from a dissimilar metal with higher coefficient of thermal expansion than the bolster component ensuring that at the welding temperature the piston is larger in diameter than the bore diameter of the bolster component leading to an interference fit which makes forces the weld cavity split line to close at the weld temperature but which still allows for a clearance gap between piston and bore at room temperature for the tool to be assembled and disassembled.

The invention discloses a forced cooling assisted double-heat-source aluminum steel dissimilar metal joint additive manufacturing device and a forced cooling assisted double-heat-source aluminum steel dissimilar metal joint additive manufacturing method. The device comprises a CMT welding gun, a CMT power source, a TIG welding gun, a TIG wire feeding device, a TIG power source, a first liquid carbon dioxide cooling device, a second liquid carbon dioxide cooling device, a first mechanical arm, a second mechanical arm, a first argon bottle, a second argon bottle, a first liquid carbon dioxide bottle and a second liquid carbon dioxide bottle. The CMT heat source and the TIG heat source are adopted for conducting independent deposition on the aluminum steel, welding heat input is optimized, the problems that a single heat source easily causes brittle IMCs, welding wires are frequently replaced and the like are solved, the welding-following carbon dioxide gas-solid mixture forced cooling technology is adopted, in-situ rapid cooling is achieved, the cooling rate of a molten pool is effectively increased, element segregation is restrained, generation of the brittle IMCs is avoided, and the welding quality is improved. And the thickness of an interface layer is reduced, and a solution is provided for efficient and high-quality preparation of the aluminum steel dissimilar metal joint.

The invention discloses a titanium / steel welding method based on a laser cladding transition layer, and belongs to the technical field of titanium alloy and stainless steel dissimilar metal connection manufacturing. The method comprises the steps that vanadium powder serves as a cladding material, a vanadium metal transition layer is prepared on the end face of the titanium alloy through the laser cladding technology, and then a workpiece obtained after cladding is completed is subjected to pretreatment including stress relief treatment, surface machining and cleaning; and finally, the titanium alloy and vanadium transition layer and stainless steel are subjected to laser assembly welding. The transition layer interface prepared through laser cladding is in a metallurgical bonding mode, the compatibility of dissimilar materials on the two sides is achieved through the component gradient structure of the transition layer, and then the weldability of titanium alloy and stainless steel and the performance of a connector are greatly improved; and meanwhile, the method has certain general applicability, has a relatively good reference value in the field of connection of other heterogeneous materials, and provides an effective breakthrough for realizing industrial and marketization application.

The invention discloses a galvanic corrosion risk assessment method and device for a dissimilar metal lap joint structure, and relates to the technical field of corrosion protection, and the method comprises the steps: obtaining standard polarization curves of a plurality of metal materials for the power system design of aviation equipment, so as to form a polarization curve library; determining a first metal material and a second metal material which form the to-be-evaluated dissimilar metal lap joint structure; acquiring a first standard polarization curve of the first metal material and a second standard polarization curve of the second metal material from a polarization curve library to determine the standard galvanic corrosion current density of the lap joint structure of the galvanic anode metal material and the dissimilar metal to be evaluated; determining a target corrosion rate of the galvanic couple anode metal material; and based on the target corrosion rate, determining a galvanic corrosion risk assessment result of the to-be-assessed dissimilar metal lap joint structure. The technical problem of low efficiency of a galvanic corrosion risk assessment mode in related technologies is solved, and the technical effect of improving the efficiency of galvanic corrosion risk assessment is achieved.

The application relates to the technical field of metal material processing, and discloses a layered sintering preparation method of a composite layer titanium pot, which comprises the following steps: laying, from bottom to top, stainless steel powder, aluminum powder, active transition layer composite powder and titanium powder in a forming die in sequence, and compacting to obtain a composite green body; placing the green body in a variable pressure sintering furnace, first heating and keeping a low vacuum state; continuously heating to a second set temperature, starting a vacuum pump to instantaneously reduce to a deep vacuum state to discharge gas phase by-products; when heating to a third set temperature, filling argon into the furnace to establish a micro-positive pressure state and constant temperature preservation, inhibiting metal element volatilization and promoting liquid phase filling densification, and finally, cooling at a predetermined rate and naturally cooling out of the furnace. Through a temperature and pressure time sequence coupling process, the application eliminates interface oxide films and hole defects, realizes high-strength metallurgical combination of dissimilar metal materials, and improves the interlayer shear strength, thermal conductivity and thermal shock fatigue life of the composite pot.

This invention provides a method and apparatus for interface control in steel-aluminum dissimilar metal additive manufacturing, relating to the field of additive manufacturing technology. The method mainly includes: acquiring current process parameters and performing additive manufacturing based on these parameters; acquiring interface temperature field data during the manufacturing process; determining temperature characteristic parameters based on the interface temperature field data; inputting the temperature characteristic parameters into a prediction model to obtain interface brittle phase characteristics; determining the interface bonding strength based on the interface brittle phase characteristics; responding to the interface bonding strength not meeting a preset threshold, calling a reverse adjustment model to determine the process parameter adjustment amount; and adjusting the additive manufacturing process parameters based on the process parameter adjustment amount. This invention enables proactive and precise control of the morphology and layer thickness of the interface brittle phase, thereby improving the interface bonding strength.

The present application belongs to the field of dissimilar metal laser welding, and particularly relates to a method for improving the gap adaptability of dissimilar metal butt joint laser brazing by alternating magnetic field. By setting the butt joint part of the dissimilar metal test plate with assembly gap suspended at the bottom, applying transverse alternating magnetic field and inert gas protection below it, and setting the laser welding head above the sample and the magnetic field generating device below the sample to remain stationary during the welding process, and the laser beam is offset to the low melting point metal side, the molten low melting point material wets and spreads on the surface of the un-molten high melting point material, and then interface metallurgical bonding occurs to form a brazing joint. The present application improves the assembly gap adaptability of dissimilar metal butt joint laser brazing based on the effect of transverse alternating magnetic field lifting the molten pool, suppresses the generation of aluminum alloy weld side heat cracks and other defects caused by the increase of assembly gap, improves the weld forming, and improves the adaptability of dissimilar metal butt joint laser brazing in engineering.

The invention relates to the technical field of solid oxide fuel cell (SOFC) system high-temperature pipelines, in particular to a high-temperature pipeline flange sealing structure which comprises a flange, a high-temperature-resistant bolt, a metal gasket, a ceramic fiber check ring, a high-temperature-resistant nut, a cone and a thin mica pad. The flange is provided with a boss and a conical step, the metal gasket is provided with a sealing boss, the metal gasket and the flange are made of dissimilar high-temperature-resistant metal, the thin mica pad is arranged between the metal gasket and the flange, the ceramic fiber check ring achieves dust prevention, and the cone is matched with the conical step to facilitate disassembly. According to the flange sealing structure for the high-temperature pipeline, the high-temperature moderate sintering characteristic of dissimilar metal is utilized, the thin mica pad is combined to prevent excessive sintering, under the high-temperature working condition, long-term sealing reliability is guaranteed, overhauling is convenient, and the metal gasket can be repeatedly used.