Optimization method of temperature distribution uniformity of titanium-aluminum alloy plate under pulse current

Abstract

The present invention provides a method for optimizing the temperature distribution uniformity of a titanium-aluminum alloy plate under a pulse current, which relates to the field of heat treatment of titanium-aluminum alloy materials. The steps include: S1, determining the outer dimensions of the titanium-aluminum alloy plate, and obtaining the clamping length and plate thickness when the temperature distribution is optimally uniform; S2, changing the shape of the transition zone between the clamping portion and the middle portion of the plate; S3, performing thermoelectric coupling analysis on the plates in transition zones of different shapes, and obtaining a temperature distribution cloud map and path temperature distribution data of each plate; S4, using the length and proportion of the uniform temperature interval as evaluation indicators for the uniformity of the temperature distribution; S5, adjusting the outer dimension ratio of the plate, fitting the dimension ratio parameters under different ratios with the plate width, and obtaining the dimension parameters of the titanium-aluminum alloy plate with the optimal temperature distribution uniformity. The present invention improves the length of the uniform temperature interval and the temperature distribution uniformity of the titanium-aluminum alloy plate by optimizing the shape and dimension of the transition zone between the clamping portion and the middle portion of the plate, thereby making the microstructure more uniform and improving the utilization rate of the plate.

Description

Technical Field

[0001] The present invention relates to the technical field of heat treatment of titanium-aluminum alloy materials, and in particular to a method for optimizing the temperature distribution uniformity of a titanium-aluminum alloy plate under pulse current. Background Art

[0002] As the core component of aircraft, aircraft engines often operate under extremely harsh conditions. Titanium alloys have broad application prospects in the aerospace field due to their low density, high strength, high temperature resistance, corrosion resistance, stability and reliability in harsh service environments. Cast titanium alloys are often further processed with plastic deformation processes to refine the grain size and introduce a large number of dislocations to improve the strength of the alloy. Usually, the strength of the plates formed by rolling cast titanium alloys can be greatly improved, but the plasticity is still at a low level, making it difficult to directly apply them to the forming of engine parts. Heat treatment of the rolled plates is indispensable. By utilizing the phase transformation and static recrystallization phenomena accompanying the heat treatment process, the microstructure can be controlled, the morphology and size of the second phase can be adjusted, the dislocation density can be reduced, and fine recrystallized grains can be generated. This can improve both strength and plasticity simultaneously, thereby obtaining good comprehensive mechanical properties and machinability, providing important guarantees for the subsequent forming of engine parts.

[0003] Heat treatment of rolled alloys using the Joule heating and non-thermal effects present in pulsed current can rapidly control microstructure, refine grains, and reduce dislocation density to improve the material's comprehensive mechanical and machining properties. However, during pulsed current heat treatment, some heat flows to the electrodes via heat conduction, causing a significant temperature drop from the center to the sides of the specimen, resulting in uneven temperature distribution. Heat treatment temperatures in some areas are too low, failing to meet plate quality inspection standards and resulting in low material availability. Therefore, it is necessary to propose a method for optimizing the temperature distribution uniformity of titanium-aluminum alloy plates under pulsed current. Summary of the Invention

[0004] In response to the problems existing in the prior art, the present invention provides a method for optimizing the temperature distribution uniformity of titanium-aluminum alloy plates under pulsed current. By changing the shape of the transition zone between the clamping part and the middle part of the titanium-aluminum alloy plate, the resistance value at both ends of the plate is increased to increase heat generation, promote the temperature peak to shift toward the clamping part, extend the temperature uniformity range, improve the temperature distribution uniformity of the plate and the utilization rate of the plate, make the microstructure more uniform, and thus obtain titanium-aluminum alloy plates with better comprehensive mechanical properties.

[0005] The present invention provides a method for optimizing the temperature distribution uniformity of a titanium-aluminum alloy plate under pulse current, which comprises the following steps:

[0006] S1. Determine the dimensions of the titanium-aluminum alloy plate. Under a constant plate transition length, obtain the temperature distribution cloud map and path temperature distribution data of the alloy plate under different clamping lengths and plate thicknesses through finite element simulation to obtain the clamping length and plate thickness for optimal temperature distribution uniformity of the alloy plate.

[0007] S2. Changing the shape of the transition zone between the clamping portion and the middle portion of the titanium-aluminum alloy plate, and ensuring that the cross-sectional area S1 of the transition zone near the clamping portion is less than or equal to the cross-sectional area S2 of the transition zone near the middle portion, selecting constant function, linear function, trigonometric function inward concave shape, and trigonometric function outward convex shape for the transition zone, optimizing the end width of the plate, and establishing titanium-aluminum alloy plate models with transition zones of different shapes;

[0008] S3. Perform thermoelectric coupling analysis on titanium-aluminum alloy plates in transition zones of different shapes using the thermoelectric coupling module in the finite element simulation to obtain temperature distribution cloud maps and path temperature distribution data for each titanium-aluminum alloy plate. The specific steps are as follows:

[0009] S31, setting the resistivity, thermal conductivity and specific heat parameters of the titanium-aluminum alloy plate and the clamping electrode, and meshing the alloy plate model using free tetrahedrons;

[0010] S32. Setting boundary conditions and loads, setting the natural convection heat transfer coefficient between the alloy plate and the air, the emissivity of the alloy plate for radiation heat transfer, the shrinkage thermal conductivity and shrinkage electrical conductivity parameters of the contact portion between the alloy plate and the clamping electrode, and applying different pulse currents to the clamping electrode;

[0011] S33. Analyzing and processing the simulation data to obtain temperature distribution cloud maps and path temperature distribution data of the titanium-aluminum alloy plates in transition zones of different shapes;

[0012] S4. The adjacent continuous intervals that meet the central temperature of the titanium-aluminum alloy plate within ±10°C are defined as the uniform temperature intervals. The length and proportion of the uniform temperature intervals are used as evaluation indicators for the uniformity of the temperature distribution of the titanium-aluminum alloy plate. The end width of the titanium-aluminum alloy plate when the temperature distribution uniformity is optimal is obtained.

[0013] S5. Adjust the dimensional ratio of the titanium-aluminum alloy plate, perform finite element simulation analysis on alloy plates with the same transition zone shape but different dimensional ratios, and obtain the dimensional parameters of the titanium-aluminum alloy plate with the best temperature distribution uniformity under different dimensional ratios. The dimensional ratio parameters of the titanium-aluminum alloy plate are:

[0014]

[0015] Where L is the length of the plate, W is the width of the plate, a is the clamping length, b is the transition length, c is the end width, x, y, and z are the plate size ratio parameters, x and y remain unchanged, while z changes;

[0016] The alloy plate size ratio parameter is fitted with the alloy plate width. The polynomial fitting equation of the size ratio parameter z and the plate width W is:

[0017] z=a0+a1W+a2W 2 +a3W 3 +a4W 4 +…+a n W n

[0018] Where a0, a1, a2…a n It is obtained by fitting the simulation analysis data;

[0019] Obtain the dimensional parameters of titanium-aluminum alloy plates when the temperature distribution uniformity is optimal.

[0020] Preferably, the end length L of the titanium aluminum alloy plate in step S1 is R The relationship with the terminal resistance R is:

[0021]

[0022] Where R is the resistance value, ρ is the resistivity, L R is the length of the plate end, and S is the cross-sectional area of ​​the plate end.

[0023] Preferably, the transition zone in step S2 is in the shape of a constant function, a linear function, a concave trigonometric function, or a convex trigonometric function.

[0024] Preferably, the relationship between the resistivity and temperature of the titanium-aluminum alloy plate at low temperature in step S31 is:

[0025] ρ=ρ0(1+kT)

[0026] Where ρ is the resistivity, ρ0 is the resistivity at 0°C, k is the temperature coefficient, and T is the temperature.

[0027] Preferably, the natural convection heat transfer coefficient in step S32 is:

[0028] L1=A / B

[0029] N u =C(G r ·P r ) n ,

[0030] Where α is the convection heat transfer coefficient, β is the volume expansion coefficient, ΔT is the temperature difference, V is the kinematic viscosity, G r is the Grashof number, P r is the Prandtl number, Nu is the Nusselt number, λ is the thermal conductivity, L1 is the standard size, A is the plate area, B is the plate perimeter, C and n are constants related to the shape and position of the heat transfer surface, heat transfer boundary conditions and flow factors.

[0031] Preferably, the heat dissipated by the alloy plate through radiation heat exchange in step S32 is:

[0032]

[0033] Where Q is the radiative heat dissipation, σ is the Stefan-Boltzmann constant, T1 is the alloy plate temperature, T0 is the ambient temperature, A is the plate area, and ε is the emissivity, which depends on the alloy type, surface state, and surface temperature and is determined experimentally.

[0034] Preferably, the shrinkage thermal conductivity and shrinkage electrical conductivity of the contact portion between the plate and the clamping electrode in step S32 are specifically:

[0035]

[0036]

[0037] Where h c is the shrinkage thermal conductivity or shrinkage electrical conductivity, k contact is the contact surface thermal conductivity or contact surface electrical conductivity, k a 、k b is the thermal conductivity or electrical conductivity of the titanium-aluminum alloy plate and the clamping electrode, m is the average roughness slope, m h is the average roughness height, p is the surface normal pressure, H c For microhardness.

[0038] Preferably, the pulse current in step S32 is simulated by an equivalent direct current, specifically:

[0039]

[0040] Where, I e is the equivalent current, I p (t) is the pulse current, T r is the pulse period.

[0041] Compared with the prior art, the present invention has the following beneficial technical effects:

[0042] The method for optimizing the temperature distribution uniformity of titanium-aluminum alloy plates under pulse current of the present invention changes the shape of the transition zone between the clamping portion and the middle portion of the titanium-aluminum alloy plate, thereby increasing the resistance value at both ends of the plate and thus increasing heat generation, promoting the temperature peak to shift toward the clamping portion, extending the temperature uniformity interval, improving the temperature distribution uniformity of the plate and the utilization rate of the plate, making the microstructure more uniform, thereby obtaining a titanium-aluminum alloy plate with better comprehensive mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a flow chart of the method for optimizing the temperature distribution uniformity of titanium-aluminum alloy plates under pulse current of the present invention;

[0044] Figure 2 It is a schematic structural diagram of the titanium aluminum alloy plate of the present invention;

[0045] Figure 3 It is a schematic diagram of the cooperation between the titanium aluminum alloy plate and the clamping electrode in the present invention;

[0046] Figure 4 The shape and temperature distribution cloud diagram of the titanium aluminum alloy plate in the constant function shape transition zone of the present invention;

[0047] Figure 5 The shape and temperature distribution cloud diagram of the titanium aluminum alloy plate in the linear function shape transition zone of the present invention;

[0048] Figure 6 The shape and temperature distribution cloud diagram of the titanium aluminum alloy plate in the concave shape transition zone of the trigonometric function in the present invention;

[0049] Figure 7 The shape and temperature distribution cloud diagram of the titanium-aluminum alloy plate in the convex shape transition zone of the trigonometric function in the present invention;

[0050] Figure 8a Schematic diagram of the clamping length and path temperature distribution of the titanium aluminum alloy plate in the present invention;

[0051] Figure 8b Schematic diagram of the plate thickness and path temperature distribution of the titanium aluminum alloy plate in the present invention;

[0052] Figure 9 1 is a temperature distribution curve diagram of the titanium-aluminum alloy plate in different shapes of transition zones in the present invention;

[0053] Figure 10 It is a curve diagram showing the relationship between the plate width and the size ratio parameters of the titanium aluminum alloy plate in the present invention. DETAILED DESCRIPTION

[0054] To fully describe the technical content, structural features, objectives and effects of the present invention, the following is a detailed description with reference to the accompanying drawings.

[0055] like Figure 1 As shown, the method for optimizing the temperature distribution uniformity of a titanium aluminum alloy plate under pulse current of the present invention comprises the following steps:

[0056] S1. Determine the external dimensions of the titanium-aluminum alloy plate. Under a certain plate transition length, obtain the temperature distribution cloud map and path temperature distribution data of the alloy plate under different clamping lengths and plate thicknesses through finite element simulation, and obtain the clamping length and plate thickness for the optimal temperature distribution uniformity of the alloy plate.

[0057] The end length L of the titanium aluminum alloy plate in step S1 R The relationship with the terminal resistance R is:

[0058]

[0059] Where R is the resistance value, ρ is the resistivity, L R is the length of the plate end, and S is the cross-sectional area of ​​the plate end.

[0060] S2. Change the shape of the transition zone between the clamping part and the middle part of the titanium-aluminum alloy plate, and the cross-sectional area S1 of the transition zone close to the clamping part is ≤ the cross-sectional area S2 of the transition zone close to the middle part. The transition zone selects constant function, linear function, trigonometric function concave and trigonometric function convex shapes, optimizes the end width of the plate, and establishes titanium-aluminum alloy plate models with transition zones of different shapes.

[0061] The transition region in step S2 is in the shape of a constant function, a linear function, a concave trigonometric function, or a convex trigonometric function.

[0062] S3. Perform thermoelectric coupling analysis on titanium-aluminum alloy plates in transition zones of different shapes using the thermoelectric coupling module in the finite element simulation to obtain temperature distribution cloud maps and path temperature distribution data for each titanium-aluminum alloy plate. The specific steps are as follows:

[0063] S31. Set the resistivity, thermal conductivity, and specific heat parameters of the titanium-aluminum alloy plate and the clamping electrode, and use free tetrahedrons to mesh the alloy plate model.

[0064] The relationship between the resistivity and temperature of the titanium-aluminum alloy plate at low temperature in step S31 is:

[0065] ρ=ρ0(1+kT)

[0066] Where ρ is the resistivity, ρ0 is the resistivity at 0°C, k is the temperature coefficient, and T is the temperature.

[0067] S32. Set boundary conditions and loads, set the natural convection heat transfer coefficient between the alloy plate and the air, the emissivity of the alloy plate's radiation heat transfer, the shrinkage thermal conductivity and shrinkage electrical conductivity parameters of the contact area between the alloy plate and the clamping electrode, and apply different pulse currents to the clamping electrode.

[0068] The natural convection heat transfer coefficient in step S32 is:

[0069] L1=A / B

[0070] N u =C(G r ·P r ) n ,

[0071] Where α is the convection heat transfer coefficient, β is the volume expansion coefficient, ΔT is the temperature difference, V is the kinematic viscosity, G r is the Grashof number, P r is the Prandtl number, N u is the Nusselt number, λ is the thermal conductivity, L1 is the standard size, A is the plate area, B is the plate perimeter, C and n are constants related to the shape and position of the heat transfer surface, heat transfer boundary conditions and flow factors.

[0072] The heat dissipated by the alloy plate through radiation heat exchange in step S32 is:

[0073]

[0074] Where Q is the radiative heat dissipation, σ is the Stefan-Boltzmann constant, T1 is the alloy plate temperature, T0 is the ambient temperature, A is the plate area, and ε is the emissivity, which depends on the alloy type, surface state, and surface temperature and is determined experimentally.

[0075] The shrinkage thermal conductivity and shrinkage electrical conductivity of the contact portion between the plate and the clamping electrode in step S32 are specifically:

[0076]

[0077]

[0078] Where h c is the shrinkage thermal conductivity or shrinkage electrical conductivity, k contact is the contact surface thermal conductivity or contact surface electrical conductivity, k a 、k b is the thermal conductivity or electrical conductivity of the titanium-aluminum alloy plate and the clamping electrode, m is the average roughness slope, m h is the average roughness height, p is the surface normal pressure, H c For microhardness.

[0079] In step S32, the pulse current is simulated by an equivalent DC current, specifically:

[0080]

[0081] Where, I e is the equivalent current, I p (t) is the pulse current, T r is the pulse period.

[0082] S33. The temperature distribution cloud diagram and path temperature distribution data of the titanium-aluminum alloy plates in transition zones of different shapes are obtained by analyzing and processing the simulation data.

[0083] S4. The adjacent continuous intervals that meet the central temperature of the titanium-aluminum alloy plate by ±10°C are defined as the uniform temperature intervals. The length and proportion of the uniform temperature intervals are used as evaluation indicators of the temperature distribution uniformity of the titanium-aluminum alloy plate, and the end width of the titanium-aluminum alloy plate when the temperature distribution uniformity is optimal is obtained.

[0084] S5. Adjust the dimensional ratio of the titanium-aluminum alloy plate, perform finite element simulation analysis on alloy plates with the same transition zone shape but different dimensional ratios, and obtain the dimensional parameters of the titanium-aluminum alloy plate with the best temperature distribution uniformity under different dimensional ratios. The dimensional ratio parameters of the titanium-aluminum alloy plate are:

[0085]

[0086] Where L is the length of the plate, W is the width of the plate, a is the clamping length, b is the transition length, c is the end width, x, y, and z are the plate size ratio parameters, x and y remain unchanged, while z changes.

[0087] The alloy plate size ratio parameter is fitted with the alloy plate width. The polynomial fitting equation of the size ratio parameter z and the plate width W is:

[0088] z=a0+a1W+a2W 2 +a3W 3 +a4W 4 +…+a n W n

[0089] Where a0, a1, a2…a n Obtained through simulation analysis data fitting.

[0090] Obtain the dimensional parameters of titanium-aluminum alloy plates when the temperature distribution uniformity is optimal.

[0091] In step S4, by comparing the length and proportion of the uniform temperature interval when the transition zone is a constant function, a linear function, a concave trigonometric function, and a convex trigonometric function, it is found that the temperature distribution uniformity of the titanium-aluminum alloy plate when the transition zone is a convex trigonometric function is relatively better than that of the constant function, the linear function, and the concave trigonometric function.

[0092] The following is a further description of the method for optimizing the temperature distribution uniformity of a titanium-aluminum alloy plate under pulse current of the present invention in conjunction with the embodiments:

[0093] like Figure 2 and Figure 3 As shown, the length L of the titanium-aluminum alloy plate is 100 mm, the width W of the plate is 30 mm, the thickness t is 2 mm, the clamping length a is 9 mm, the transition length b is 6 mm, the end width c is a variable, the transition zone of the titanium-aluminum alloy plate is a constant shape, a linear shape, a triangular concave shape, and a triangular convex shape, and the clamping electrode includes a fixed plate and a bottom plate. The fixed plate has a length of 160 mm, a width of 40 mm, and a thickness of 4 mm. The bottom plate has a length of 160 mm, a width of 160 mm, and a thickness of 8 mm.

[0094] like Figures 4 to 7 As shown in the figure, after the pulse current is passed through the titanium aluminum alloy plate, the red area in the temperature distribution cloud diagram exists in most areas of the plate, and the temperature distribution uniformity is significantly improved. The temperature distribution uniformity of the alloy plates in the four shape transition zones is at a relatively good level.

[0095] like Figure 8a As shown in the figure, the temperature distribution curve of the titanium-aluminum alloy sheet shows an overall upward trend as the clamping length decreases. That is, the temperature of the sheet with a shorter clamping length is generally higher than that of the sheet with a longer clamping length. Although the temperature at the center is nearly the same for different clamping lengths, the temperature at the end surface gradually increases as the clamping length decreases, and the rising gradient gradually widens. The maximum value is close to 450°C for the titanium-aluminum alloy sheet with a clamping length a of 3mm. This shows that adjusting the clamping length can initially optimize the temperature distribution uniformity of the titanium-aluminum alloy sheet, with minimal impact on the center temperature.

[0096] like Figure 8bAs shown in the figure, as the thickness of the titanium-aluminum alloy plate decreases, the temperature distribution curve shows an overall upward trend, that is, the temperature of the thinner plate is generally higher than that of the thicker plate. This is because the increase in plate thickness leads to a decrease in resistance. Under the condition of a constant current, the heat generated decreases and the temperature drops significantly. The temperature difference in the middle area is more obvious, while the temperature difference in the end area is not much, almost overlapping. The temperature distribution curves of different plate thicknesses are relatively close in shape and do not produce obvious differences. This shows that the influence of plate thickness on temperature distribution is different from the influence of end width and clamping length, and will not cause the curve to change from "concave" to "convex", and the degree of temperature distribution uniformity is almost the same. This shows that changing the plate thickness within the deviation range of the national standard has a greater impact on the center temperature. It is necessary to strictly measure the plate thickness before pulse current treatment. It is recommended that the actual thickness of the plate meet the nominal thickness ±0.05mm.

[0097] As shown in Table 1, the dimensions, current value, temperature, and size ratio parameters of the titanium aluminum alloy plate are as follows: The aspect ratio of titanium aluminum alloy plate is fixed at 10:3.

[0098] like Figure 10 As shown, the polynomial function of the size ratio parameter z and the plate width W is:

[0099] z=4.35524-1.4424×10 (-1) ×W+4.4×10 (-3) ×W 2 -2.66831×10 (-5) ×W 3 +5.3291×10 (-8) ×W 4

[0100] Table 1

[0101]

[0102]

[0103] like Figure 9 As shown in the figure, the temperature distribution of the dotted path in the alloy plates in the transition zone of the four shapes, the length of the uniform temperature interval of the alloy plate whose transition zone is in the form of a convex trigonometric function is significantly longer than that of the other three shapes.

[0104] As shown in Table 2, the length and proportion of the uniform temperature interval are given. For the alloy plate with a convex trigonometric function transition zone, the uniform temperature interval length was 65.22 mm, accounting for 65.22% of the uniform temperature interval. For the alloy plate with a constant function transition zone, the uniform temperature interval length was 60.18 mm, accounting for 60.18% of the uniform temperature interval. Using the uniform temperature interval length and proportion as evaluation indicators for temperature distribution uniformity, the plate with a convex trigonometric function transition zone exhibited the best temperature distribution uniformity among the four alloy plates with transition zones.

[0105] Table 2 Length and proportion of average temperature interval

[0106]

[0107] The method for optimizing the temperature distribution uniformity of titanium-aluminum alloy plates under pulse current of the present invention processes the titanium alloy rolled plates by pulse current, quickly induces the formation of recrystallized grains and reduces the recrystallization temperature and recrystallization time, significantly reduces energy consumption, and changes the shape of the transition zone between the clamping part and the middle part of the titanium-aluminum alloy plate, thereby increasing the resistance value at both ends of the plate and thereby increasing heat generation, promoting the temperature peak to shift toward the clamping part, extending the temperature uniformity interval, improving the temperature distribution uniformity of the plate and the utilization rate of the plate, making the microstructure more uniform, thereby obtaining a titanium-aluminum alloy plate with better comprehensive mechanical properties.

[0108] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A method for optimizing the temperature distribution uniformity of titanium aluminum alloy plates under pulse current, characterized in that: It includes the following steps: S1. Determine the dimensions of the titanium-aluminum alloy plate. Under a constant plate transition length, obtain the temperature distribution cloud map and path temperature distribution data of the alloy plate under different clamping lengths and plate thicknesses through finite element simulation to obtain the clamping length and plate thickness for optimal temperature distribution uniformity of the alloy plate. S2. Changing the shape of the transition zone between the clamping portion and the middle portion of the titanium-aluminum alloy plate, and ensuring that the cross-sectional area S1 of the transition zone near the clamping portion is less than or equal to the cross-sectional area S2 of the transition zone near the middle portion, optimizing the end width of the plate, and establishing titanium-aluminum alloy plate models with transition zones of different shapes; S3. Perform thermoelectric coupling analysis on titanium-aluminum alloy plates in transition zones of different shapes using the thermoelectric coupling module in the finite element simulation to obtain temperature distribution cloud maps and path temperature distribution data for each titanium-aluminum alloy plate. The specific steps are as follows: S31, setting the resistivity, thermal conductivity and specific heat parameters of the titanium-aluminum alloy plate and the clamping electrode, and meshing the alloy plate model using free tetrahedrons; S32. Setting boundary conditions and loads, setting the natural convection heat transfer coefficient between the alloy plate and the air, the emissivity of the alloy plate for radiation heat transfer, the shrinkage thermal conductivity and shrinkage electrical conductivity parameters of the contact portion between the alloy plate and the clamping electrode, and applying different pulse currents to the clamping electrode; S33. Analyzing and processing the simulation data to obtain temperature distribution cloud maps and path temperature distribution data of the titanium-aluminum alloy plates in transition zones of different shapes; S4. The adjacent continuous intervals that meet the central temperature of the titanium-aluminum alloy plate within ±10°C are defined as the uniform temperature intervals. The length and proportion of the uniform temperature intervals are used as evaluation indicators for the uniformity of the temperature distribution of the titanium-aluminum alloy plate. The end width of the titanium-aluminum alloy plate when the temperature distribution uniformity is optimal is obtained. S5. Adjust the dimensional ratio of the titanium-aluminum alloy plate, perform finite element simulation analysis on alloy plates with the same transition zone shape but different dimensional ratios, and obtain the dimensional parameters of the titanium-aluminum alloy plate with the best temperature distribution uniformity under different dimensional ratios. The dimensional ratio parameters of the titanium-aluminum alloy plate are: Where L is the length of the plate, W is the width of the plate, a is the clamping length, b is the transition length, c is the end width, x, y, and z are the plate size ratio parameters, x and y remain unchanged, while z changes; The alloy plate size ratio parameter is fitted with the alloy plate width. The polynomial fitting equation of the size ratio parameter z and the plate width W is: z=a0+a1W+a2W 2 +a3W 3 +a4W 4 +…+a n IN n Where a0, a1, a2…a n It is obtained by fitting the simulation analysis data; Obtain the dimensional parameters of titanium-aluminum alloy plates when the temperature distribution uniformity is optimal.

2. The method for optimizing the temperature distribution uniformity of a titanium-aluminum alloy plate under pulse current according to claim 1, characterized in that: The end length L of the titanium aluminum alloy plate in step S1 R The relationship with the terminal resistance R is: Where R is the resistance value, ρ is the resistivity, L R is the length of the plate end, and S is the cross-sectional area of ​​the plate end.

3. The method for optimizing temperature distribution uniformity of titanium aluminum alloy plate under pulse current according to claim 1, characterized in that: The transition region in step S2 is in the shape of a constant function, a linear function, a concave trigonometric function, or a convex trigonometric function.

4. The method for optimizing temperature distribution uniformity of titanium-aluminum alloy plate under pulse current according to claim 1, characterized in that: The relationship between the resistivity and temperature of the titanium-aluminum alloy plate at low temperature in step S31 is: ρ=ρ0(1+kT) Where ρ is the resistivity, ρ0 is the resistivity at 0°C, k is the temperature coefficient, and T is the temperature.

5. The method for optimizing temperature distribution uniformity of titanium aluminum alloy plate under pulse current according to claim 1, characterized in that: The natural convection heat transfer coefficient in step S32 is: Where α is the convection heat transfer coefficient, β is the volume expansion coefficient, ΔT is the temperature difference, V is the kinematic viscosity, G r is the Grashof number, P r is the Prandtl number, N u is the Nusselt number, λ is the thermal conductivity, L1 is the standard size, A is the plate area, B is the plate perimeter, C and n are constants related to the shape and position of the heat transfer surface, heat transfer boundary conditions and flow factors.

6. The method for optimizing temperature distribution uniformity of titanium-aluminum alloy plate under pulse current according to claim 1, characterized in that: The heat dissipated by the alloy plate through radiation heat exchange in step S32 is: Where Q is the radiative heat dissipation, σ is the Stefan-Boltzmann constant, T1 is the alloy plate temperature, T0 is the ambient temperature, A is the plate area, and ε is the emissivity, which depends on the alloy type, surface state, and surface temperature and is determined experimentally.

7. The method for optimizing temperature distribution uniformity of titanium-aluminum alloy plate under pulse current according to claim 1, characterized in that: The shrinkage thermal conductivity and shrinkage electrical conductivity of the contact portion between the plate and the clamping electrode in step S32 are specifically: Where h c is the shrinkage thermal conductivity or shrinkage electrical conductivity, k contact is the contact surface thermal conductivity or contact surface electrical conductivity, k a 、k b is the thermal conductivity or electrical conductivity of the titanium-aluminum alloy plate and the clamping electrode, m is the average roughness slope, m h is the average roughness height, p is the surface normal pressure, H c For microhardness.

8. The method for optimizing temperature distribution uniformity of titanium-aluminum alloy plate under pulse current according to claim 1, characterized in that: In step S32, the pulse current is simulated by an equivalent DC current, specifically: Where, I e is the equivalent current, I p (t) is the pulse current, T r is the pulse period.

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