Ultra-large titanium alloy blank construction forming method based on TRIZ theory

Abstract

The invention relates to the field of metal material processing, in particular to an ultra-large titanium alloy blank construction forming method based on the TRIZ theory, according to the TRIZ segmentation and nesting principle, a one-time formed ultra-large part is converted into a plurality of high-quality small units to be accurately combined, the capacity limitation of ultra-large equipment is thoroughly eliminated, and the construction efficiency of the ultra-large titanium alloy blank is improved. Ultra-large titanium alloy blanks of any size can be prepared, and the large-scale requirement of high-end equipment is met; meanwhile, through pre-acting and composite material principle synergistic interface treatment in cooperation with multi-field coupling and phase change promotion, the interface bonding strength reaches the base material strength, the defects of oxidation, air holes, cracks and the like are avoided, and the structure and performance continuity of an interface and a base body is achieved; and finally, through multi-zone heating control, feedback type parameter adjustment and differential post-treatment of a local quality principle, the grain size and mechanical property deviation of different zones of the ultra-large blank is controlled within 5%, and the performance consistency is remarkably superior to that of a traditional method.

Description

Technical Field

[0001] This invention relates to the field of metal material processing, specifically a method for constructing and forming ultra-large titanium alloy billets based on TRIZ theory. Background Technology

[0002] As aerospace, marine engineering, and defense equipment continue to develop towards larger size, lighter weight, and higher performance, the demand for integral ultra-large titanium alloy structural components is becoming increasingly urgent. Titanium alloys have advantages such as high specific strength and good corrosion resistance; therefore, ultra-large titanium alloy structural components are needed for construction.

[0003] Current technologies for overcoming size limitations often employ a segmented manufacturing approach followed by subsequent joining. This involves first preparing small unit blanks, then assembling them into ultra-large blanks through welding, diffusion bonding, and other methods. However, due to the high reactivity of titanium alloys, the interfaces are prone to oxidation during the joining process, forming brittle phases such as TiO2. Furthermore, welding / diffusion bonding is susceptible to defects such as porosity, cracks, and incomplete penetration, resulting in low interfacial bonding strength that fails to meet the load-bearing requirements of high-end equipment. Therefore, this paper proposes a method for constructing ultra-large titanium alloy blanks based on TRIZ theory to address these issues. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies and solve at least one of the technical problems mentioned in the background art, this invention proposes a method for constructing and forming ultra-large titanium alloy billets based on TRIZ theory.

[0005] The technical solution adopted by this invention to solve other technical problems is: a method for constructing and forming ultra-large titanium alloy billets based on TRIZ theory, comprising the following steps:

[0006] S1. Based on the TRIZ segmentation and nesting principles, the ultra-large titanium alloy billet is decomposed into multiple regular modular unit billets, and nesting interfaces are designed and microtextures are processed.

[0007] S2. Based on the TRIZ pre-action principle and composite material principle, an active intermediate layer and a functional gradient transition layer are pre-placed on the interface surface and then activated by plasma.

[0008] S3. Based on the TRIZ dynamic principle, the mechanical system substitution principle and the pneumatic and hydraulic structure principle, a multi-zone control heating / pressure system is adopted, and electromagnetic fields and ultrasonic multi-physics fields are introduced to assist in the construction and shaping.

[0009] S4. Based on the TRIZ phase transition principle and feedback principle, the interface bonding is promoted by temperature cycling phase transition, and the process parameters are monitored and dynamically adjusted in real time by combining a sensor network.

[0010] S5. Based on the TRIZ local quality principle, differentiated heat treatment processes are applied to the interface region and the matrix region to optimize the microstructure properties.

[0011] Preferably, the modular unit blank in S1 has a single weight controlled at 5-10t, a size ≤1.5m×1.5m×1m, and a nesting interface that is wedge-shaped, stepped, or curved.

[0012] Preferably, the interface mating gap in S1 is 0.05-0.1mm, and the microtexture is a cross-shaped mesh groove with a depth of 0.1-0.2mm and a width of 0.2-0.3mm.

[0013] Preferably, the active intermediate layer in S2 is a Ti-Zr-Nb alloy foil with a thickness of 0.1-0.2 mm; the functional gradient transition layer is prepared by plasma spraying and is composed of titanium alloy powder and TiC particles in a gradient ratio with a thickness of 0.3-0.5 mm.

[0014] Preferably, the plasma activation treatment in S2 uses argon plasma with a power of 3-5kW and a time of 5-10min.

[0015] Preferably, the construction temperature in S3 is controlled at 950-1050℃, the pressure range is 5-15MPa, the electromagnetic field is a low-frequency alternating magnetic field with a frequency of 50-100Hz and an intensity of 0.1-0.2T, and the ultrasonic wave is a power ultrasonic wave with a power of 1-2kW and a frequency of 20-40kHz.

[0016] Preferably, the temperature cycle in S4 is to cool down to 850-900℃, hold for 15-20 minutes, then heat up to 950-1050℃, and repeat 2-3 times.

[0017] Preferably, the interface region in S5 is subjected to low-temperature tempering at 550-600℃ and stress relief treatment, and the matrix region is subjected to solution treatment at 920-950℃ and aging treatment at 500-550℃. The fluctuation of mechanical properties in each region of the billet is controlled within 5%, and the interface bonding strength reaches more than 90% of the strength of the matrix.

[0018] The advantages of this invention are:

[0019] This invention utilizes the TRIZ segmentation and nesting principle to transform a single-piece ultra-large component into multiple high-quality small units that are precisely combined, completely overcoming the limitations of ultra-large equipment capabilities. It can prepare ultra-large titanium alloy billets of any size, meeting the large-scale requirements of high-end equipment. Simultaneously, through pre-treatment and composite material principle-based interface treatment, combined with multi-field coupling and phase transformation promotion, the interface bonding strength reaches the strength of the substrate, achieving a continuous effect in the microstructure and properties of the interface and the matrix. This solves the problem that due to the high reactivity of titanium alloys, the interface is prone to oxidation during the joining process, forming brittle phases such as TiO2, and welding / diffusion joints are prone to defects such as porosity, cracks, and incomplete penetration, resulting in low interface bonding strength that cannot meet the load-bearing requirements of high-end equipment. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The following is in conjunction with the appendix Figure 1 This application will be described in further detail.

[0024] This application discloses a method for constructing and forming ultra-large titanium alloy billets based on TRIZ theory, including the following steps:

[0025] S1. Based on the TRIZ segmentation and nesting principles, the ultra-large titanium alloy billet is decomposed into multiple regular modular unit billets, and nesting interfaces are designed and microtextures are processed.

[0026] S2. Based on the TRIZ pre-action principle and composite material principle, an active intermediate layer and a functional gradient transition layer are pre-placed on the interface surface and then activated by plasma.

[0027] S3. Based on the TRIZ dynamic principle, the mechanical system substitution principle and the pneumatic and hydraulic structure principle, a multi-zone control heating / pressure system is adopted, and electromagnetic fields and ultrasonic multi-physics fields are introduced to assist in the construction and shaping.

[0028] S4. Based on the TRIZ phase transition principle and feedback principle, the interface bonding is promoted by temperature cycling phase transition, and the process parameters are monitored and dynamically adjusted in real time by combining a sensor network.

[0029] S5. Based on the TRIZ local quality principle, differentiated heat treatment processes are applied to the interface region and the matrix region to optimize the microstructure properties.

[0030] Reference Figure 1 The S1 uses the TRIZ segmentation and nesting principles to break down ultra-large billets into precisely manufactured unit billets, while ensuring the integrity of the assembled billets through interface design.

[0031] Modular unit disassembly: Based on the final size and shape of the ultra-large titanium alloy billet, it is decomposed into multiple geometrically regular modular unit billets according to the TRIZ segmentation principle. The weight of each unit billet is controlled within 5-10t, and the size is controlled within 1.5m×1.5m×1m to ensure that existing equipment can achieve high-quality preparation. The number of unit billets is determined according to the final billet size. For example, to prepare an ultra-large billet of 5m×2m×1m, it can be disassembled into 12 unit billets of 1.5m×1.5m×1m, with a 0.1m splicing allowance reserved.

[0032] Nested Interface Design: Applying the TRIZ nesting principle, wedge-shaped, stepped, or curved surface nested interfaces are designed between unit blanks. The interface clearance is controlled within 0.05-0.1mm to ensure positioning accuracy. Simultaneously, micro-textures are machined on the interface surface, such as cross-shaped mesh grooves. The grooves are 0.1-0.2mm deep, 0.2-0.3mm wide, and spaced 1-2mm apart. This increases the interface bonding area and disperses stress, preventing stress concentration.

[0033] Unit blank pretreatment: The prepared unit blanks are ground and cleaned to remove surface oxide scale, oil and impurities. After grinding, the surface roughness of the interface is controlled to Ra≤0.8μm, which lays the foundation for subsequent interface treatment.

[0034] The S2 applies the TRIZ pre-action principle and composite material principle, improving the interfacial bonding quality through pre-placed intermediate layers and plasma activation, while avoiding excessive reliance on complex equipment.

[0035] Pre-placed active interlayer: Applying the principle of pre-action, an active interlayer material is pre-placed on the surface of the nested interface of the unit blank. The interlayer is made of Ti-Zr-Nb alloy foil, with a gold foil thickness of 0.1-0.2 mm. Its melting point is lower than that of the titanium alloy substrate, and it has good compatibility with the substrate. It can preferentially melt during subsequent heating to fill the interface gap and inhibit interface oxidation. The interlayer must be tightly adhered to the interface surface during installation, without bubbles or wrinkles.

[0036] Functionally graded transition layer design: Applying composite material principles, a functionally graded transition layer is designed between the active interlayer and the substrate. This transition layer is prepared using plasma spraying and is formed by spraying titanium alloy powder and TiC particles in a gradient ratio. The gradient ratio of titanium alloy powder to TiC particles transitions from 100% titanium alloy powder on the substrate side to 70% titanium alloy powder + 30% TiC particles on the interlayer side, with a thickness of 0.3-0.5 mm. This transition layer can mitigate abrupt changes in composition and properties at the interface, further improving the interfacial bonding strength and stability.

[0037] Plasma activation treatment: The interface surface between the laid intermediate and transition layers is subjected to plasma activation treatment using argon plasma at a power of 3-5 kW for 5-10 minutes and a distance of 50-80 mm. The plasma bombardment removes residual trace oxide films from the interface surface, while simultaneously activating surface atoms and enhancing interfacial reactivity, creating conditions for subsequent interfacial bonding. After treatment, the unit blanks are immediately assembled and positioned to prevent secondary oxidation.

[0038] S33 applies the TRIZ dynamic principle, the mechanical system substitution principle, and the pneumatic and hydraulic structure principle to achieve high-quality construction through multi-zone control and multi-physics field assistance.

[0039] Construction of a multi-zone independently controlled heating / pressure system: Applying the principle of dynamics, a multi-zone independently controlled heating and pressure system was designed. The heating system uses induction heating coils arranged in zones, with each zone corresponding to 2-3 billet units. Each zone can independently control the heating temperature, achieving gradient heating of different areas of the billet and avoiding coarsening of the microstructure caused by concentrated heat. The pressure system uses flexible pressure heads arranged in zones, with each pressure head corresponding to the splicing area of ​​a billet unit. The pressure can be independently adjusted, with a pressure range of 5-15 MPa.

[0040] Multiphysics-assisted construction: Applying the principle of mechanical system substitution, this method introduces electromagnetic and ultrasonic multiphysics-assisted construction processes to replace traditional single mechanical pressure. The electromagnetic field uses a low-frequency alternating magnetic field (50-100Hz, 0.1-0.2T), generating eddy currents through electromagnetic induction to promote interfacial atomic diffusion. The ultrasonic field uses high-power ultrasound (1-2kW, 20-40kHz), which breaks down residual oxide films at the interface through ultrasonic vibration, promoting the fusion of the intermediate layer and the substrate, while refining grain size. The multiphysics field works synergistically with heating and pressure systems to control the construction temperature at 950-1050℃, with the holding time determined by the number of units, each unit holding for 30-60 minutes.

[0041] Flexible pressure transmission and adaptive adjustment: Utilizing the principles of pneumatic and hydraulic structures, a flexible pressure transmission system is designed. The pressure head employs a hydraulic drive + pneumatic buffer structure, which can adaptively adjust the pressure distribution according to the splicing deformation of the unit blanks, avoiding blank deformation or joint cracking caused by excessive local pressure. Simultaneously, displacement sensors monitor the splicing displacement of the unit blanks in real time to ensure overall dimensional accuracy.

[0042] S4 applies the TRIZ phase transition principle and feedback principle, promotes interface bonding through temperature cycling phase transition, and achieves dynamic adjustment of process parameters by combining real-time monitoring.

[0043] Phase transformation promotes interfacial bonding: Applying the principle of phase transformation, in the later stage of thermal insulation construction, by precisely controlling the temperature cycle, for example, cooling to 850-900℃ in the α+β dual-phase region of titanium alloy, holding for 15-20 minutes, and then heating to 950-1050℃ in the β phase region, repeating 2-3 times, the volume change and atomic rearrangement during the α-β phase transformation of titanium alloy are utilized to promote the full diffusion and fusion of atoms at the interface, eliminate interfacial gaps and micro-defects, and improve the interfacial bonding strength.

[0044] Built-in sensor network for real-time monitoring: Applying the feedback principle, multiple types of sensors, such as temperature sensors, pressure sensors, and ultrasonic flaw detection sensors, are built into the interface area and matrix area of ​​the unit billet to form a sensor network, which monitors the interface bonding status and the evolution of the internal structure of the billet in real time, and the monitoring data is transmitted to the central control system in real time.

[0045] Dynamic adjustment of process parameters: The central control system dynamically adjusts the heating temperature, pressure, holding time, and multi-physical field parameters of each zone based on sensor monitoring data. For example, when an abnormal ultrasonic reflection signal is detected at a certain interface, the heating temperature of that area is automatically increased by 5-10℃, the holding time is extended by 10-15 minutes, and the ultrasonic power is increased until the defect is eliminated, ensuring the interface bonding quality and microstructure uniformity.

[0046] The S5 applies the TRIZ local quality principle to optimize the overall microstructure and properties of the billet through differentiated heat treatment, while avoiding the inefficiency caused by overall heat treatment.

[0047] Differentiated heat treatment process design: Applying the principle of local mass, a graded heat treatment regime is designed based on the different microstructure characteristics of the interface region and the matrix region. Due to the multi-field coupling and phase transformation cycles, the interface region exhibits easily refined grains but may have residual stress. Therefore, a low-temperature tempering + stress relief treatment is employed at 550-600℃, held for 2-3 hours, and then air-cooled. The matrix region has a relatively uniform microstructure and is treated with solution treatment + aging. The solution treatment temperature is 920-950℃, held for 1 hour, and then water-cooled; the aging temperature is 500-550℃, held for 4-5 hours, and then air-cooled, thus improving the mechanical properties of the matrix.

[0048] Local finishing and quality inspection: After post-heat treatment, the ultra-large billets undergo overall dimensional finishing to remove splicing allowances and ensure that the final dimensional accuracy meets design requirements. Simultaneously, non-destructive testing methods such as ultrasonic and radiographic testing are used to comprehensively inspect the interface and substrate areas to ensure the absence of internal defects. Mechanical property testing is performed on samples to verify the consistency of performance across different areas of the billet.

[0049] Working principle: When constructing and forming ultra-large titanium alloy billets, the 60t ultra-large TC4 billet is divided into 12 unit billets of 1.5m×1.5m×1m according to the principle of segmentation. Each billet weighs approximately 5t. The unit billets are prepared using vacuum arc remelting + precision forging. The forging deformation is controlled within 40%-50% to ensure uniform microstructure and no segregation defects in the unit billets. The interface is designed as a stepped nested structure with a step height of 0.5m. The interface surface is machined with a cross-mesh microtexture, which consists of grooves with a depth of 0.15mm, a width of 0.25mm, and a spacing of 1.5mm. After grinding, the surface roughness Ra=0.6μm.

[0050] A 0.15 mm thick Ti-Zr-Nb active intermediate layer is pre-placed on the stepped interface surface, and the intermediate layer is tightly bonded to the interface surface. A functional gradient transition layer is prepared by plasma spraying, with 100% TC4 powder on the substrate side and 70% TC4 powder + 30% TiC particles on the intermediate layer side, and the transition layer thickness is 0.4 mm. Argon plasma activation treatment is used with a power of 4 kW, a treatment time of 8 min, and a treatment distance of 60 mm. After treatment, the parts are immediately spliced ​​and positioned, and the interface mating gap is 0.08 mm.

[0051] Four heating zones and four pressure zones were constructed. The heating system adopted induction heating, and the pressure system was a hydraulic drive + pneumatic buffer flexible pressure head. A low-frequency alternating magnetic field and power ultrasound were introduced, with the alternating magnetic field having a frequency of 80Hz and a magnetic field strength of 0.15T, and the power ultrasound having a frequency of 1.5kW and a frequency of 30kHz. The construction temperature was controlled at 1000℃, and the pressure of each zone was adjusted to 10MPa and held for 40 minutes. During this period, two temperature cycles were performed, with the temperature controlled to drop to 880℃ and hold for 18 minutes, and then rise to 1000℃ and hold for 10 minutes.

[0052] Meanwhile, three temperature sensors, two pressure sensors, and one ultrasonic flaw detection sensor are built into the interface area and the matrix area of ​​each of the 12 unit blanks to monitor the data in real time. When an abnormal ultrasonic reflection signal is detected at interface #3, the heating temperature of that area is automatically increased to 1010℃, the heat preservation time is extended by 12 minutes, the ultrasonic power is increased to 1.8kW, and the monitoring continues until the signal is normal to ensure that there are no defects at the interface.

[0053] Finally, the interface area was subjected to low-temperature tempering at 580℃ with stress relief treatment, held for 2.5 hours, and then air-cooled; the matrix area was subjected to solution treatment at 930℃, including holding for 1 hour, water cooling, followed by aging treatment at 520℃, holding for 4.5 hours, and then air-cooled; the finished blank size was 5m×2m×1m, with a dimensional accuracy of ±0.5mm; non-destructive testing showed no internal defects, the interface bonding strength reached 1100MPa, and the matrix strength was 1210MPa, reaching 90.9% of the matrix strength; the tensile strength and yield strength deviation of each area were ≤4%, and the performance fluctuation was controlled within 5%.

[0054] Therefore, compared with the traditional integral forming method, this embodiment does not require ultra-large melting and forging equipment, thus reducing equipment investment, energy consumption, and material utilization. Compared with the existing segmented welding scheme, the interface bonding strength is improved, performance fluctuation is reduced, and production efficiency is increased, fully meeting the requirements for the use of ultra-large titanium alloy components in the aerospace field.

[0055] This application utilizes the TRIZ segmentation and nesting principle to transform a single-piece ultra-large component into multiple high-quality small units that are precisely combined, completely overcoming the capability limitations of ultra-large equipment. It can prepare ultra-large titanium alloy billets of any size to meet the large-scale requirements of high-end equipment. Simultaneously, through pre-treatment and composite material principle-based interface treatment, combined with multi-field coupling and phase transformation promotion, the interface bonding strength reaches the strength of the substrate, free from defects such as oxidation, porosity, and cracks, achieving continuity in the microstructure and properties of the interface and the matrix. Finally, through multi-zone heating control, feedback parameter adjustment, and differentiated post-treatment based on the principle of local quality, the grain size and mechanical property deviations in different regions of the ultra-large billet are controlled within 5%, and the performance consistency is significantly better than traditional methods.

[0056] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for constructing and forming ultra-large titanium alloy billets based on TRIZ theory, characterized in that: Includes the following steps: S1. Based on the TRIZ segmentation and nesting principles, the ultra-large titanium alloy billet is decomposed into multiple regular modular unit billets, and nesting interfaces are designed and microtextures are processed. S2. Based on the TRIZ pre-action principle and composite material principle, an active intermediate layer and a functional gradient transition layer are pre-placed on the interface surface and then activated by plasma. S3. Based on the TRIZ dynamic principle, the mechanical system substitution principle and the pneumatic and hydraulic structure principle, a multi-zone control heating / pressure system is adopted, and electromagnetic fields and ultrasonic multi-physics fields are introduced to assist in the construction and shaping. S4. Based on the TRIZ phase transition principle and feedback principle, the interface bonding is promoted by temperature cycling phase transition, and the process parameters are monitored and dynamically adjusted in real time by combining a sensor network. S5. Based on the TRIZ local quality principle, differentiated heat treatment processes are applied to the interface region and the matrix region to optimize the microstructure properties.

2. The method for constructing and forming ultra-large titanium alloy billets based on TRIZ theory according to claim 1, characterized in that: The modular unit blank in S1 has a single weight controlled at 5-10t and a size ≤1.5m×1.5m×1m, and the nesting interface is a wedge-shaped, stepped, or curved surface structure.

3. The method for constructing and forming ultra-large titanium alloy billets based on TRIZ theory according to claim 2, characterized in that: The interface mating gap in S1 is 0.05-0.1mm, and the microtexture is a cross-shaped mesh groove with a depth of 0.1-0.2mm and a width of 0.2-0.3mm.

4. The method for constructing and forming ultra-large titanium alloy billets based on TRIZ theory according to claim 1, characterized in that: The active intermediate layer in S2 is a Ti-Zr-Nb alloy foil with a thickness of 0.1-0.2 mm; the functional gradient transition layer is prepared by plasma spraying and is composed of titanium alloy powder and TiC particles in a gradient ratio with a thickness of 0.3-0.5 mm.

5. The method for constructing and forming ultra-large titanium alloy billets based on TRIZ theory according to claim 4, characterized in that: The plasma activation treatment in S2 uses argon plasma with a power of 3-5 kW and a time of 5-10 min.

6. The method for constructing and forming ultra-large titanium alloy billets based on TRIZ theory according to claim 1, characterized in that: The construction temperature in S3 is controlled at 950-1050℃, the pressure range is 5-15MPa, the electromagnetic field is a low-frequency alternating magnetic field with a frequency of 50-100Hz and an intensity of 0.1-0.2T, and the ultrasonic wave is a power ultrasonic wave with a power of 1-2kW and a frequency of 20-40kHz.

7. The method for constructing and forming ultra-large titanium alloy billets based on TRIZ theory according to claim 1, characterized in that: The temperature cycle in S4 is to cool down to 850-900℃, hold for 15-20 minutes, then raise the temperature to 950-1050℃, and repeat 2-3 times.

8. The method for constructing and forming ultra-large titanium alloy billets based on TRIZ theory according to claim 7, characterized in that: The sensor network in S4 includes temperature, pressure, and ultrasonic flaw detection sensors, which monitor the interface bonding state and tissue evolution in real time.

9. The method for constructing and forming ultra-large titanium alloy billets based on TRIZ theory according to claim 1, characterized in that: The interface region in S5 is subjected to low-temperature tempering at 550-600℃ and stress relief treatment, while the matrix region is subjected to solution treatment at 920-950℃ and aging treatment at 500-550℃. The mechanical property fluctuation of each region of the billet is controlled within 5%, and the interface bonding strength reaches more than 90% of the strength of the matrix.

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