A research and development method for high temperature alloy interface metallurgical bonding suitable for extreme working conditions

Abstract

The application relates to the field of material processing and connecting technology, and provides a high-temperature alloy interface metallurgical bonding research and development method suitable for extreme working conditions, which comprises the following steps: arranging an acoustic response type reaction precursor containing main reaction components and an acoustic sensitive enhancer on the interface of workpieces to be connected; focusing acoustic energy on the local area of the precursor by using a focused acoustic energy transducer, so as to trigger in-situ self-propagating exothermic reaction of the precursor at a low energy threshold value, and form a transient high-temperature liquid phase; meanwhile or immediately after, a macroscopic ultrasonic transducer is used to apply an acoustic field to the whole interface area, and the solidification process of the transient high-temperature liquid phase is physically regulated. Through the synergistic effect of the double roles of acoustic energy, the accurate triggering of the reaction and the macroscopic regulation of the solidification process are combined, so that the interface grain refinement, the elimination of metallurgical defects and the relief of residual stress can be effectively realized, a high-quality metallurgical joint with high density, uniformity and high bonding strength can be obtained, and the method is suitable for the connection of dissimilar high-temperature alloys.

Description

Technical Field

[0001] This invention relates to the field of materials processing and joining technology, and in particular to a research and development method for metallurgical bonding of high-temperature alloy interfaces suitable for extreme working conditions. Background Technology

[0002] High-temperature alloys, also known as superalloys, are metallic materials capable of operating for extended periods at temperatures exceeding 600°C and under specific stresses. Due to their superior high-temperature strength, excellent resistance to oxidation and hot corrosion, and outstanding creep resistance, high-temperature alloys have become indispensable core materials for manufacturing critical hot-end components in aerospace engines, gas turbines in the energy sector, and nuclear reactors. Achieving high-quality, highly reliable metallurgical connections between high-temperature alloys is a crucial and extremely challenging core technology in the manufacturing and maintenance of these complex components.

[0003] Currently, the mainstream technologies for joining high-temperature alloys mainly revolve around fusion welding, brazing, and diffusion welding. Fusion welding technologies, represented by tungsten inert gas (TIG), laser welding, and electron beam welding, use concentrated high-energy input to locally melt the base material to form a joint. However, this melting-based mechanism has inherent drawbacks for high-temperature alloys that are sensitive to microstructure and properties. The large temperature gradient and rapid cooling rate inevitably create a wide heat-affected zone near the weld, causing the carefully controlled strengthening phases in the base material to dissolve or coarsen, severely weakening the mechanical properties of the joint. Simultaneously, the melting and resolidification processes of various elements in high-temperature alloys easily induce compositional segregation, leading to solidification and liquefaction cracks and the formation of coarse columnar crystal structures, all of which pose a serious threat to the reliability of the joint.

[0004] To avoid melting of the base metal, brazing is used to join high-temperature alloys. This technique achieves metallurgical bonding by filling the joint with an intermediate filler metal with a melting point lower than that of the base metal. Although the heat input of the brazing process is relatively small, its application is fundamentally limited. The presence of the filler metal layer dictates that the maximum service temperature of the joint must be lower than that of the base metal, which is unacceptable in advanced equipment requiring higher operating temperatures. Furthermore, the metallurgical reaction between the filler metal and the base metal can also generate brittle intermetallic compounds, becoming a weak point in the joint's performance.

[0005] Solid-state bonding technologies, such as diffusion bonding, avoid the problems associated with melting and the introduction of low-melting-point layers, but their process conditions are extremely demanding. They typically require prolonged exposure to high temperatures and pressures to drive slow atomic diffusion for interfacial bonding. This process is not only inefficient and expensive, but also places extremely high demands on the surface finish and fit of the workpieces, limiting its application in complex structures and large-scale production.

[0006] In summary, existing high-temperature alloy joining technologies generally face a core contradiction: achieving an ideal balance between effective metallurgical bonding at the interface and suppressing thermal damage to the base material. Whether it's high-heat-input fusion welding, brazing which introduces performance bottlenecks, or inefficient diffusion welding, none can perfectly meet the comprehensive requirements of high performance, high reliability, and high efficiency for high-temperature alloy joints in modern high-end equipment. Therefore, there is an urgent need to develop a new joining technology paradigm that can achieve rapid in-situ metallurgical reactions at the interface while strictly confining the thermal effects to the interface region, thereby fundamentally solving the aforementioned technical challenges. Summary of the Invention

[0007] The present invention aims to solve at least one of the problems existing in the prior art, and to provide a high-temperature alloy interface metallurgical bonding development method suitable for extreme working conditions that can overcome the problems of interface structure deterioration, residual and large residual stress caused by macroscopic heating in the prior art.

[0008] One aspect of the present invention provides a method for developing metallurgical bonding of high-temperature alloy interfaces suitable for extreme working conditions, comprising the following steps: Step a: Set an acoustically responsive reactive precursor on the interface of the high-temperature alloy workpiece to be connected; Step b: Align the high-temperature alloy workpieces to be connected and apply preload; Step c: Focus the acoustic energy onto a predetermined region of the acoustically responsive reaction precursor using a focusing acoustic energy transducer to trigger a self-propagating exothermic reaction in the acoustically responsive reaction precursor, generating an instantaneous high-temperature liquid phase; Step d: At the same time or after the self-propagating exothermic reaction occurs, an ultrasonic field is applied to the interface region of the high-temperature alloy workpieces to be joined by a macroscopic ultrasonic transducer to control the solidification process of the instantaneous high-temperature liquid phase.

[0009] Optionally, the acoustically responsive reaction precursor in step a includes a main reaction component and an acoustically sensitive enhancer; the acoustically sensitive enhancer has a higher acoustic sensitivity than the main reaction component, and the acoustically sensitive enhancer is used to reduce the trigger energy threshold of the self-propagating exothermic reaction under the action of focused acoustic energy.

[0010] Optionally, the components of the acoustically responsive reactive precursor constitute satisfy: ; in, The main reactive components represent the nanoscale or submicron scale; Represents the aforementioned acoustic enhancement agent; It represents a dispersant or binder.

[0011] Optionally, step a specifically includes: The acoustically responsive reactive precursor is precisely deposited on the interface of the high-temperature alloy workpieces to be joined by at least one of micro-dispensing, aerosol printing, inkjet printing or screen printing.

[0012] Optionally, the condition for the focused acoustic energy to trigger the self-propagating exothermic reaction in step c is: ; in, This represents the effective energy instantaneously converted from focused acoustic energy within the predetermined area; This represents the critical triggering energy threshold at which the acoustically responsive precursor undergoes the self-propagating exothermic reaction.

[0013] Optionally, in step c, the focused acoustic energy acts on the acoustically sensitive enhancer, and through the acoustic cavitation effect or acoustic mechanical effect, local energy concentration is generated in the micro-region of the acoustically responsive reaction precursor, so as to achieve the conditions for triggering the self-propagating exothermic reaction.

[0014] Optionally, in step d, applying an ultrasonic field to the interface region of the high-temperature alloy workpieces to be joined using a macroscopic ultrasonic transducer to control the solidification process of the instantaneous high-temperature liquid phase includes: The acoustic flow effect or cavitation effect is used to break up the growth dendrites at the solidification front and increase the number of nucleation cores, so as to promote the formation of fine equiaxed crystal structures in the interfacial solidification structure.

[0015] Optionally, in step d, applying an ultrasonic field to the interface region of the high-temperature alloy workpieces to be joined using a macroscopic ultrasonic transducer to control the solidification process of the instantaneous high-temperature liquid phase includes: Ultrasonic vibration is used to enhance the atomic diffusion rate, and the acoustic flow effect or vibration pressure effect is used to remove the bubbles generated during the reaction to obtain a dense interfacial bond.

[0016] Optionally, in step d, applying an ultrasonic field to the interface region of the high-temperature alloy workpieces to be joined using a macroscopic ultrasonic transducer to control the solidification process of the instantaneous high-temperature liquid phase includes: Microscopic plastic deformation is introduced during the solidification and cooling process of the instantaneous high-temperature liquid phase to alleviate residual stress at the interface.

[0017] Optionally, the high-temperature alloy workpiece is a nickel-based high-temperature alloy workpiece, a cobalt-based high-temperature alloy workpiece, or an iron-based high-temperature alloy workpiece.

[0018] This invention solves a major problem in existing high-temperature alloy joining technologies by employing a novel energy application and conversion pathway. Instead of relying on an external macroscopic heat source to heat the workpiece as a whole or over a large area, this invention utilizes the chemical energy stored in acoustically responsive reaction precursors to generate heat in situ at the interface. Acoustic energy plays a dual role in this invention: firstly, focused acoustic energy acts as a non-thermodynamic, precisely controllable "trigger," triggering the chemical reaction at room temperature; secondly, the macroscopic sound field serves as a physical control mechanism, optimizing the microstructure during the instantaneous high-temperature liquid phase solidification process generated by the reaction. This synergistic effect of "in-situ triggering of the chemical reaction" and "synchronous control by the physical field" fundamentally avoids the formation of a large heat-affected zone and enables the active design and control of the interface microstructure.

[0019] The present invention provides a method for developing metallurgical bonding of high-temperature alloy interfaces suitable for extreme working conditions, which has the following advantages compared with the prior art: 1. Minimal thermal damage to the base material, effectively preserving the original material properties. This invention triggers an in-situ self-propagating exothermic reaction solely within the interface precursor layer by focusing acoustic energy. Heat is instantaneously generated at the interface and effectively utilized for metallurgical bonding, rather than being introduced in large quantities by an external high-energy beam. This "endogenous" heating method strictly confines the heat-affected zone to the micron level at the interface, maximizing the protection of the carefully controlled microstructure and mechanical properties of the high-temperature alloy base material.

[0020] 2. This invention enables precise control of the interfacial solidification structure, significantly improving joint quality. Following the self-propagating reaction, the invention innovatively utilizes a macroscopic acoustic field to physically control the instantaneously formed liquid phase. The cavitation and acoustic flow effects of the acoustic field effectively break up growing dendrites, increase nucleation sites, and promote bubble escape, fundamentally inhibiting the formation of coarse columnar crystals and solidification defects. This results in a fine, dense equiaxed crystal structure, significantly improving the overall mechanical properties of the joint.

[0021] 3. The reaction triggering process is precisely controllable, with high process stability and repeatability. This invention uses focused acoustic energy as the triggering method, and both the energy transfer path and the focal position can be precisely controlled. Simultaneously, the introduction of a sound-sensitive enhancer in the precursor significantly reduces the reaction excitation threshold, making the reaction initiation insensitive to minor energy disturbances. This ensures stable and reliable triggering at the set focal position, greatly improving process reliability.

[0022] 4. Excellent adaptability and design freedom for joining dissimilar high-temperature alloys. The core of this invention lies in the acoustically responsive reactive precursor at the interface. By designing a gradient in the composition of this acoustically responsive reactive precursor, the in-situ generated bonding zone can achieve a smooth transition in key properties such as chemical composition and coefficient of thermal expansion, effectively alleviating the huge residual stress caused by performance mismatch during the joining of dissimilar materials, and solving the technical bottleneck that is difficult to overcome by traditional methods.

[0023] 5. The connection process is highly efficient and energy-saving, with low requirements for equipment environment. Once the self-propagating exothermic reaction of this invention is triggered, its propagation speed is extremely fast, and the entire interface bonding process can usually be completed within a few seconds, with production efficiency far exceeding that of diffusion welding. In addition, the total energy required for acoustic triggering is much lower than that for fusion welding, and the entire process usually does not require a vacuum or high-pressure environment, simplifying equipment configuration, reducing manufacturing costs, and showing good prospects for industrial applications. Attached Figure Description

[0024] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0025] Figure 1 A flowchart illustrating a method for developing a high-temperature alloy interface metallurgical bonding system suitable for extreme operating conditions, as provided in an embodiment of the present invention; Figure 2 A schematic diagram of a system device corresponding to a high-temperature alloy interface metallurgical bonding development method suitable for extreme working conditions, provided for another embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the principle of the synergistic effect of focused sound energy triggering and sound field modulation, provided for another embodiment of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the embodiments of the present invention to facilitate a better understanding of the invention. However, the technical solutions claimed in the present invention can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of the present invention. The various embodiments can be combined with and referenced by each other without contradiction.

[0027] Combined Figure 1One embodiment of the present invention provides a method for developing metallurgical bonding of high-temperature alloy interfaces suitable for extreme working conditions, comprising the following steps: Step a: Set an acoustically responsive reactive precursor on the interface of the high-temperature alloy workpiece to be connected; Step b: Align the high-temperature alloy workpieces to be connected and apply preload; Step c: Focus the acoustic energy onto a predetermined region of the acoustically responsive reaction precursor using a focusing acoustic energy transducer to trigger a self-propagating exothermic reaction in the acoustically responsive reaction precursor, generating an instantaneous high-temperature liquid phase; Step d: Simultaneously or after the self-propagating exothermic reaction, an ultrasonic field is applied to the interface region of the high-temperature alloy workpieces to be joined using a macroscopic ultrasonic transducer to control the solidification process of the instantaneous high-temperature liquid phase. After the instantaneous high-temperature liquid phase cools and solidifies, the joint of the high-temperature alloy workpieces to be joined can be obtained.

[0028] For example, the acoustically responsive reaction precursor in step a includes a main reactive component and an acoustically sensitive enhancer. The acoustically sensitive enhancer has a higher acoustic sensitivity than the main reactive component, and is used to reduce the trigger energy threshold of the self-propagating exothermic reaction under focused acoustic energy.

[0029] Acoustic enhancers are materials with special physical properties, exhibiting a higher sensitivity to sound waves than the main reactant components. The mechanism of action of acoustic enhancers lies in the preferential response of the enhancer when focused acoustic energy acts on the acoustically responsive precursor. Through acoustic cavitation or acoustic-mechanical effects, the enhancer generates localized energy concentration in a microscopic region (e.g., instantaneous high temperature and pressure or high-speed microjets), significantly reducing the apparent activation energy required for the entire system to undergo a self-propagating exothermic reaction, thus lowering the critical triggering energy threshold. This makes the triggering of self-propagating exothermic reactions more efficient, stable, and easier to control.

[0030] For example, the composition of acoustically responsive reaction precursors satisfy: .

[0031] in, Representing the main reactive components at the nanoscale or submicron scale, used to generate the target binding phase through chemical reactions; Represents acoustic enhancement agents; Dispersants or binders used to adjust the physical morphology of acoustically responsive reactive precursors.

[0032] For example, step a specifically includes: precisely depositing a layer of acoustically responsive reaction precursor on the interface of the high-temperature alloy workpieces to be bonded using at least one of micro-dispensing, aerosol spraying, inkjet printing, or screen printing. The micro-dispensing, aerosol spraying, inkjet printing, or screen printing technologies can ensure uniform thickness and controllable morphology of the acoustically responsive reaction precursor, thus guaranteeing uniform propagation of the subsequent reaction and uniformity of the interface bonding quality.

[0033] For example, the condition for the focused acoustic energy to trigger the self-propagating exothermic reaction in step c is: .

[0034] in, It represents the effective energy instantaneously converted from focused acoustic energy within a predetermined region of the acoustically responsive precursor, and its magnitude is related to the intensity, frequency, and duration of the focused acoustic wave. This represents the critical trigger energy threshold for the self-propagating exothermic reaction of acoustically responsive precursors. The technical solution of this invention effectively reduces this threshold by introducing an acoustically sensitive enhancer. This allows for reliable triggering of the self-propagating exothermic reaction with relatively low input acoustic energy.

[0035] For example, in step c, the focused acoustic energy acts on the acoustically sensitive enhancer, and through the acoustic cavitation effect or acoustic mechanical effect, local energy concentration is generated in the micro-region of the acoustically responsive reaction precursor, so as to achieve the conditions for triggering the self-propagating exothermic reaction.

[0036] For example, in step d, an ultrasonic field is applied to the interface region of the high-temperature alloy workpieces to be joined by a macroscopic ultrasonic transducer to control the solidification process of the instantaneous high-temperature liquid phase, including: using the acoustic flow effect or cavitation effect to break up the growth dendrites at the solidification front and increase the number of nucleation cores to promote the formation of a fine equiaxed crystal structure in the interface solidification structure.

[0037] Specifically, in step d, applying an ultrasonic field to regulate the solidification process of the instantaneously high-temperature liquid phase has the following physical mechanism: the acoustic flow effect generated by the macroscopic ultrasonic field in the liquid phase can create strong macroscopic and microscopic stirring, effectively breaking up the naturally growing coarse columnar crystals or dendrites at the solidification front; at the same time, the cavitation effect generated by the pressure fluctuations caused by the sound waves can provide a large number of non-spontaneous nucleation nuclei. The synergistic effect of these two effects leads to the final solidification structure of the interface being a fine, uniform equiaxed crystal structure, thereby optimizing the mechanical properties of the interface.

[0038] For example, in step d, an ultrasonic field is applied to the interface region of the high-temperature alloy workpieces to be joined by a macroscopic ultrasonic transducer to control the solidification process of the instantaneous high-temperature liquid phase, including: using ultrasonic vibration to enhance the atomic diffusion rate, and using acoustic flow effect or vibration pressure effect to drive away the bubbles generated during the reaction to obtain a dense interface bond.

[0039] Specifically, the ultrasonic field modulation effect in step d is also reflected in the following aspects: ultrasonic vibration, as a form of mechanical energy, can significantly enhance the diffusion rate of atoms in the liquid phase and solid-liquid interface. This helps to form a metallurgical bonding zone with a smoother compositional transition and stronger bonding between the reaction products and the parent materials on both sides. In addition, the acoustic flow effect or periodic vibration pressure effect generated by the ultrasonic field can effectively "squeeze" or "carry" out the interface region of any tiny bubbles that may be generated during the reaction, thereby obtaining a denser bonding interface free of pores and defects.

[0040] For example, in step d, an ultrasonic field is applied to the interface region of the high-temperature alloy workpieces to be joined by a macroscopic ultrasonic transducer to regulate the solidification process of the instantaneous high-temperature liquid phase, including: introducing microscopic plastic deformation during the solidification and cooling process of the instantaneous high-temperature liquid phase to alleviate the residual stress at the interface.

[0041] Specifically, the ultrasonic field modulation effect in step d further includes: during the solidification and cooling stage, the continuously or intermittently applied ultrasonic field can introduce microscopic plastic deformation in the interface region through its mechanical vibration effect. This dynamic disturbance introduced during stress formation helps alleviate the residual stress at the interface caused by the mismatch of the material's thermal expansion coefficients and solidification shrinkage, and has a positive effect on improving the service reliability of the structure.

[0042] For example, the high-temperature alloy workpiece is a nickel-based high-temperature alloy workpiece, a cobalt-based high-temperature alloy workpiece, or an iron-based high-temperature alloy workpiece.

[0043] Specifically, the high-temperature alloy interface metallurgical bonding development method for extreme working conditions provided in this embodiment of the invention is applicable to the same or different types of difficult-to-weld materials such as nickel-based high-temperature alloys, cobalt-based high-temperature alloys or iron-based high-temperature alloys, and has significant technical advantages, especially in application scenarios where there are strict limitations on thermal damage to the base material.

[0044] The high-temperature alloy interface metallurgical bonding research and development method for extreme working conditions provided by the embodiments of the present invention can accurately execute each step in the acoustic trigger adaptive reaction interface fusion method through a system device composed of highly integrated functional modules, thereby achieving active and precise control of the interface bonding process.

[0045] Combined Figure 2The system apparatus for implementing the high-temperature alloy interface metallurgical bonding research and development method for extreme working conditions provided in this embodiment of the invention may include: a material deposition module, a workpiece clamping and alignment module, a core acoustic system module, and a central control module. The central control module is electrically connected to the material deposition module, the workpiece clamping and alignment module, and the core acoustic system module, respectively, and is used to coordinate and control the synchronous operation of each module to ensure the automation and accuracy of the entire metallurgical bonding process.

[0046] The material deposition module is used to precisely and uniformly deposit a layer of acoustically responsive reactive precursor on the interface of high-temperature alloy workpieces to be joined. The material deposition module can be a high-precision material delivery and positioning system, such as a pneumatically or piezoelectrically driven micro-dispensing system, or an aerosol printing system equipped with a high-resolution printhead. The material deposition module can deliver the acoustically responsive reactive precursor at a controlled thickness according to a preset program. The morphology is coated onto the workpiece interface.

[0047] The workpiece clamping and alignment module features high-precision multi-axis displacement and attitude adjustment capabilities. It is used to precisely align two high-temperature alloy workpieces to be joined after acoustically responsive reactive precursor deposition, and to apply a controllable, minute preload. This preload ensures physical contact between the workpiece interfaces and creates a stable mechanical environment for subsequent acoustic coupling and reaction propagation.

[0048] The core acoustic system module is a key component in realizing the high-temperature alloy interface metallurgical bonding research and development method suitable for extreme working conditions provided in this embodiment of the invention. It integrates two acoustic subsystems with different functions but working in concert. The core acoustic system module includes a focusing sound energy triggering subsystem and a macroscopic sound field control subsystem. Figure 3 This demonstrates the principle of the synergistic effect of focused sound energy triggering and sound field modulation. The following section combines... Figure 3 The principle of the synergistic effect of focused sound energy triggering and sound field modulation is explained in detail.

[0049] The focused acoustic triggering subsystem is used to achieve in-situ reaction triggering in step c of the research and development method for metallurgical bonding of high-temperature alloy interfaces suitable for extreme working conditions. The focused acoustic triggering subsystem includes a high-intensity focused ultrasonic transducer (HIFU transducer), a high-frequency power supply, and a precision positioning mechanism. The HIFU transducer can be a concave piezoelectric ceramic transducer with a specific radius of curvature, capable of converting high-frequency electrical energy into mechanical vibration and naturally focusing the acoustic energy into a very small focal region through its own geometry. In some embodiments, a phased array transducer can also be used, flexibly adjusting the position and shape of the focal point by precisely controlling the phase of each unit in the array.

[0050] During operation, a high-frequency power supply provides the drive signal to the HIFU transducer, while a precision positioning mechanism accurately aligns the focus of the HIFU transducer with the predetermined starting region of the acoustically responsive precursor on the workpiece interface. To ensure efficient acoustic energy transmission, the workpiece and the HIFU transducer are typically coupled via an acoustic coupling medium (such as deionized water). The focused acoustic energy generated by the focused acoustic energy triggering subsystem represents the effective energy instantaneously converted in the focal region. The critical condition for triggering the reaction must be met, namely: .in, The critical triggering energy threshold represents the self-propagating exothermic reaction of an acoustically responsive precursor under specific conditions.

[0051] The macroscopic acoustic field control subsystem is used to physically control the instantaneous high-temperature liquid phase solidification process in step d of the research and development method for metallurgical bonding of high-temperature alloy interfaces suitable for extreme working conditions. The macroscopic acoustic field control subsystem includes one or more macroscopic ultrasonic transducers and a corresponding power supply. The type and layout of these macroscopic ultrasonic transducers can be designed according to the geometry and size of the workpiece. For example, flat transducers can be placed on both sides of the workpiece, or annular transducers can be used to surround the bonding area to ensure a uniformly distributed ultrasonic field throughout the entire interface region.

[0052] Operating frequency of the macroscopic sound field control subsystem and power The selection is based on the desired control objective (such as grain refinement, defect removal, or stress relief). Its operating timing is precisely controlled by the central control module, allowing it to be activated simultaneously with the triggering of the self-propagating reaction or after the reaction wave has propagated to a specific region, and to continuously operate throughout the entire solidification and cooling process. The operation of the macroscopic acoustic field control subsystem provides a key technical means for actively optimizing the microstructure and properties of the interface at the physical level.

[0053] The following specific embodiment will provide a detailed description of the high-temperature alloy interface metallurgical bonding development method for extreme working conditions provided by this invention. This embodiment aims to achieve the same interface metallurgical bonding of two nickel-based high-temperature alloy (e.g., Inconel 718 alloy) workpieces.

[0054] In this embodiment, the acoustically responsive reactive precursor is first designed and prepared. The core objective is to construct a composite material system that can generate an interface layer compatible with the parent material through an exothermic reaction, and also produce a highly efficient response to external acoustic energy excitation. For this purpose, nanoscale nickel (Ni) powder and aluminum (Al) powder are selected as the main reactive components. Their chemical reaction (Ni+Al→NiAl) can release a large amount of heat energy and generate NiAl intermetallic compounds with excellent high-temperature performance.

[0055] Furthermore, to optimize the efficiency of acoustic triggering, this embodiment introduces nanoscale tin (Sn) powder as a sound-sensitive enhancer into the acoustically responsive reactive precursor. Tin has a low melting point and readily generates strong cavitation effects in an acoustic field. Under focused acoustic energy, nano-tin particles preferentially melt or undergo violent physical oscillations, generating localized high-temperature, high-pressure hotspots and high-speed microjets around them. These localized energy concentration points greatly promote the contact and reaction of surrounding Ni and Al particles, thereby effectively reducing the critical triggering energy threshold for self-propagating reactions in the entire system. .

[0056] Component composition of acoustically responsive reaction precursors Follow the following relationship: .

[0057] in, and These represent nano-sized Ni powder and Al powder, respectively, and their stoichiometric ratio is close to the ratio of NiAl produced. This represents nanoscale Sn powder, the amount of which has been optimized to maximize the acoustic effect without significantly affecting the performance of the final interfacial product. Representing an aqueous solution of polyvinyl alcohol (PVA), it is used as a dispersant and binder to uniformly mix solid powders into a "reactive paste" with suitable rheological properties. The specific preparation process includes: placing the above-mentioned powder components and PVA solution in a planetary ball mill, and performing high-energy ball milling and mixing under an inert atmosphere until a uniform, non-agglomerated precursor is formed.

[0058] Subsequently, interface treatment and precision deposition of acoustically responsive reactive precursors are performed. The mating surfaces of the Inconel 718 workpieces to be joined are polished, followed by ultrasonic cleaning in acetone and anhydrous ethanol, and finally low-temperature baking in a vacuum environment to completely remove surface adsorbates. Next, using screen printing technology and a custom-designed mask, the prepared reactive paste is precisely coated onto the clean interface of one of the workpieces, forming a thickness... A uniform reactive precursor layer is an acoustically responsive reactive precursor.

[0059] Next, the coordinated process of acoustic triggering and sound field modulation begins. A workpiece coated with an acoustically responsive precursor is precisely aligned with another clean workpiece in the workpiece clamping and alignment module, and a small preload is applied. Then, the core acoustic system module is activated. The HIFU transducer of the focused acoustic energy triggering subsystem is activated, its focus precisely aligned with the predetermined starting point at the interface edge. The effective energy converted from the applied focused acoustic energy... Reaching or exceeding the critical triggering energy threshold At that time, acoustic responsiveness enhancers in acoustic response precursors The first response triggers a violent self-propagating exothermic reaction in the Ni and Al particles.

[0060] The self-propagating exothermic reaction propagates rapidly along the interface in the form of a reaction wave, transforming the acoustically responsive reaction precursor into a transiently high-temperature liquid phase in an extremely short time. Simultaneously with or immediately following the triggering of the self-propagating exothermic reaction, the central control module immediately activates the macroscopic acoustic field modulation subsystem. The macroscopic ultrasonic transducer applies a specific frequency to the entire interface region. and power The ultrasonic field.

[0061] Under the influence of an ultrasonic field, intense acoustic flow and cavitation effects are generated within the instantaneously high-temperature liquid phase. The shear force of the acoustic flow effectively breaks up the dendrite arms forming at the solidification front, preventing the growth of coarse columnar crystals. Simultaneously, the collapse of cavitation bubbles generates numerous nucleation sites in the liquid phase, promoting the formation of fine, uniform equiaxed crystals. This process physically reshapes the solidification structure, avoiding the coarsening problem commonly found in traditional welding methods.

[0062] Furthermore, the continuous action of the ultrasonic field brings other beneficial effects. Its intense mechanical vibration significantly accelerates atomic diffusion within the liquid phase and at the liquid-solid interface, resulting in a more robust metallurgical transition zone between the generated NiAl phase and the Inconel 718 base material on both sides. Simultaneously, the vibrational pressure and "pumping" effect of the acoustic waves effectively drive any trace gases or unreacted PVA decomposition products that may be generated during the reaction to the interface edge, ensuring a highly compact final interface. In the subsequent cooling stage, the continuously applied low-power ultrasonic field, by introducing micro-vibrations, helps alleviate localized residual stresses caused by rapid cooling, improving the structural integrity of the interface. In another embodiment of the invention, a method for developing high-temperature alloy interfacial metallurgical bonding suitable for extreme operating conditions is applied to the interfacial metallurgical bonding of dissimilar high-temperature alloys, such as the connection of a nickel-based high-temperature alloy (e.g., Inconel 718) and a cobalt-based high-temperature alloy (e.g., Haynes 188). Due to significant differences in chemical composition, thermophysical properties (especially the coefficient of thermal expansion) between the two base materials, direct bonding easily generates enormous residual stress at the interface and forms brittle intermetallic compounds.

[0063] To address this technical problem, this embodiment makes adaptive adjustments to the design of the acoustically responsive reaction precursor. Instead of using a single-component reaction precursor layer, a composition-gradient reaction precursor layer is constructed using multiple or multi-channel precision deposition techniques. The design of this composition-gradient reaction precursor layer aims to generate a functionally graded bonding region at the interface through in-situ reaction, where the chemical composition and material properties smoothly transition from the nickel-based alloy side to the cobalt-based alloy side. Specifically, on the side closer to the Inconel 718 workpiece interface, the precursor composition is dominated by a nickel-rich reaction system; on the side closer to the Haynes 188 workpiece interface, it is dominated by a cobalt (Co)-rich reaction system. Between the two layers, continuous variation in the content of key elements such as Ni and Co is achieved through precise control of deposition parameters. Acoustic enhancer. It is then evenly distributed throughout the gradient reaction layer to ensure that the self-propagating reaction of the entire interface can be reliably triggered from any side or the middle position.

[0064] The subsequent steps in implementing acoustic triggering and acoustic field modulation are basically the same as those in the aforementioned embodiments. However, through this gradient precursor design, the phase composition and thermal expansion coefficient of the metallurgical bonding zone synthesized in situ at the interface exhibit a gradient distribution. This smooth structural transition effectively alleviates the stress concentration at the interface caused by thermal mismatch between dissimilar materials, thereby significantly improving the structural reliability and high-temperature service stability of dissimilar high-temperature alloy joints.

[0065] It should be noted that the technical solutions disclosed in this invention are not limited to the specific components or process parameters described above. In other embodiments, the main reactive components of the acoustically responsive reactive precursor... Depending on the type of base material to be joined and the interface performance requirements, other systems capable of undergoing self-propagating exothermic reactions can be selected, such as Ti-Al systems, Ni-Ti systems, or composite reaction systems with added ceramic reinforcing phases (such as TiC and B4C).

[0066] Similarly, sound-sensitive enhancers The selection of materials is also diverse. In addition to nano-tin powder, other materials with similar physical effects can be used, such as nanoparticles with low acoustic impedance and matrix mismatch, or materials that easily undergo phase transitions under ultrasonic action. The core selection criterion is the ability to efficiently convert acoustic energy into local excitation energy sufficient to trigger a chain of exothermic reactions under focused acoustic energy.

[0067] Furthermore, the various process parameters in this invention include, but are not limited to, the thickness of the acoustically responsive reactive precursor. Preload Size, intensity of focused sound energy With frequency, and the power of macroscopically controlling the sound field Both the contact time and the interaction duration can be adjusted and optimized within a reasonable range to adapt to the connection requirements of workpieces of different materials and sizes, and to obtain the best interface bonding quality. These adjustments and optimizations do not deviate from the core technical concepts revealed in this invention.

[0068] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for developing metallurgical bonding of high-temperature alloy interfaces suitable for extreme working conditions, characterized in that, Includes the following steps: Step a: Set an acoustically responsive reactive precursor on the interface of the high-temperature alloy workpiece to be connected; Step b: Align the high-temperature alloy workpieces to be connected and apply preload; Step c: Focus the acoustic energy onto a predetermined region of the acoustically responsive reaction precursor using a focusing acoustic energy transducer to trigger a self-propagating exothermic reaction in the acoustically responsive reaction precursor, generating an instantaneous high-temperature liquid phase; Step d: At the same time or after the self-propagating exothermic reaction occurs, an ultrasonic field is applied to the interface region of the high-temperature alloy workpieces to be joined by a macroscopic ultrasonic transducer to control the solidification process of the instantaneous high-temperature liquid phase.

2. The method for developing high-temperature alloy interface metallurgical bonding suitable for extreme working conditions according to claim 1, characterized in that, The acoustically responsive reaction precursor in step a includes a main reaction component and an acoustically sensitive enhancer; the acoustically sensitive enhancer has a higher acoustic sensitivity than the main reaction component, and the acoustically sensitive enhancer is used to reduce the trigger energy threshold of the self-propagating exothermic reaction under the action of focused acoustic energy.

3. The method for developing high-temperature alloy interface metallurgical bonding suitable for extreme working conditions according to claim 2, characterized in that, The components of the acoustically responsive reaction precursor constitute satisfy: ； in, The main reactive components represent the nanoscale or submicron scale; Represents the aforementioned acoustic enhancement agent; It represents a dispersant or binder.

4. The method for developing high-temperature alloy interface metallurgical bonding suitable for extreme working conditions according to claim 1, characterized in that, Step a specifically includes: The acoustically responsive reactive precursor is precisely deposited on the interface of the high-temperature alloy workpieces to be joined by at least one of micro-dispensing, aerosol printing, inkjet printing or screen printing.

5. The method for developing high-temperature alloy interface metallurgical bonding suitable for extreme working conditions according to claim 1, characterized in that, The condition for focusing acoustic energy to trigger the self-propagating exothermic reaction in step c is: ； in, This represents the effective energy instantaneously converted from focused acoustic energy within the predetermined area; This represents the critical triggering energy threshold at which the acoustically responsive precursor undergoes the self-propagating exothermic reaction.

6. The method for developing high-temperature alloy interface metallurgical bonding suitable for extreme working conditions according to claim 2, characterized in that, In step c, the focused acoustic energy acts on the acoustically sensitive enhancer, and through the acoustic cavitation effect or acoustic mechanical effect, local energy concentration is generated in the micro-region of the acoustically responsive reaction precursor, so as to achieve the conditions for triggering the self-propagating exothermic reaction.

7. The method for developing high-temperature alloy interface metallurgical bonding suitable for extreme working conditions according to claim 1, characterized in that, In step d, an ultrasonic field is applied to the interface region of the high-temperature alloy workpieces to be joined using a macroscopic ultrasonic transducer to control the solidification process of the instantaneous high-temperature liquid phase, including: The acoustic flow effect or cavitation effect is used to break up the growth dendrites at the solidification front and increase the number of nucleation cores, so as to promote the formation of fine equiaxed crystal structures in the interfacial solidification structure.

8. The method for developing high-temperature alloy interface metallurgical bonding suitable for extreme working conditions according to claim 1, characterized in that, In step d, an ultrasonic field is applied to the interface region of the high-temperature alloy workpieces to be joined using a macroscopic ultrasonic transducer to control the solidification process of the instantaneous high-temperature liquid phase, including: Ultrasonic vibration is used to enhance the atomic diffusion rate, and the acoustic flow effect or vibration pressure effect is used to remove the bubbles generated during the reaction to obtain a dense interfacial bond.

9. The method for developing high-temperature alloy interface metallurgical bonding suitable for extreme working conditions according to claim 1, characterized in that, In step d, an ultrasonic field is applied to the interface region of the high-temperature alloy workpieces to be joined using a macroscopic ultrasonic transducer to control the solidification process of the instantaneous high-temperature liquid phase, including: Microscopic plastic deformation is introduced during the solidification and cooling process of the instantaneous high-temperature liquid phase to alleviate residual stress at the interface.

10. The method for developing high-temperature alloy interface metallurgical bonding suitable for extreme working conditions according to any one of claims 1 to 9, characterized in that, The high-temperature alloy workpiece is a nickel-based high-temperature alloy workpiece, a cobalt-based high-temperature alloy workpiece, or an iron-based high-temperature alloy workpiece.

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