Ti-si eutectic ribbon solder, and preparation method and application thereof

Abstract

The present application relates to a Ti-Si eutectic ribbon solder and a preparation method and application thereof. The components of the Ti-Si eutectic ribbon solder include Ti-Si eutectic powder, a binder, a dispersant and a plasticizer.

Description

TECHNICAL FIELD

[0001] The present application relates to a Ti-Si eutectic strip solder applied to silicon carbide ceramic welding and a preparation method and application thereof, and belongs to the field of ceramic material welding. BACKGROUND

[0002] Silicon carbide ceramics are widely used in aerospace, nuclear power, machinery, petroleum, optics, integrated circuits, semiconductors and other fields due to their excellent properties such as high temperature strength, good wear resistance, good thermal stability, small coefficient of thermal expansion (CTE), high hardness and excellent thermal shock resistance, and are increasingly valued by people. Due to the limitations of existing preparation technologies of silicon carbide ceramic materials, it is very difficult to manufacture large-size and complex-shaped parts, and welding technology is an effective technical route to solve the problem of engineering manufacturing of complex and large-size silicon carbide ceramic parts.

[0003] As one of the most widely used methods in ceramic joining, brazing has a good engineering application background. In the brazing process, the welding stress caused by the mismatch of the coefficients of thermal expansion between the ceramic base material and the metal solder has always been one of the technical problems that have plagued silicon carbide ceramic brazing. The Ti-Si eutectic solder has good chemical compatibility with the silicon carbide base material, in addition, the coefficient of thermal expansion of the Ti-Si eutectic solder is close to that of the silicon carbide ceramic, which brings great benefits to the reduction of welding joint stress, so the Ti-Si eutectic solder has been valued by many researchers in the brazing of silicon carbide-based ceramic materials. For example, Chinese Patent No. CN 108274086B discloses a method for high-temperature brazing of carbon fiber reinforced carbon-based composite materials using a two-step Ti-Si soldering method, but the patent uses a Ti-Si solder ingot after smelting and thinning method as solder. The preparation of solder by this method will seriously limit the size and shape of the solder. In addition, due to the brittleness of the solder, the Ti-Si sheet that has been cut and thinned cannot be processed again according to the shape of the welding surface. The complex and inefficient solder preparation technology leads to poor engineering application prospects. SUMMARY

[0004] In view of the defects of the above Ti-Si eutectic solder preparation technology, the present application first proposes to use a tape-shaped solder with flexible characteristics and any shape by using a tape casting method to prepare the Ti-Si eutectic solder, which is convenient and simple in process, low in cost, easy to operate, high in efficiency and has good industrial application prospects.

[0005] In one aspect, the present application provides a Ti-Si eutectic strip solder, the components of the Ti-Si eutectic strip solder comprising Ti-Si eutectic powder, binder, dispersant and plasticizer.

[0006] The Ti-Si eutectic ribbon solder prepared in the application has simple process, unrestricted shape and size, high preparation efficiency, and good industrial application prospect. The application can be widely applied in the welding of normal pressure sintered silicon carbide ceramics, reaction sintered silicon carbide ceramics, hot-pressed silicon carbide ceramics and chemical vapor deposition silicon carbide ceramics.

[0007] Preferably, the atomic ratio of Ti element to Si element in the Ti-Si eutectic powder is (16-30):(84-70); and the particle size of the Ti-Si eutectic powder is ≤25 μm, preferably ≤15 μm.

[0008] Preferably, the dispersant is at least one of castor oil phosphate, triolein glycerol, benzene phosphoric acid and fish oil; and the mass ratio of the dispersant to the Ti-Si eutectic powder is (1.2-3.5):(50-60).

[0009] Preferably, the binder is at least one of polyvinyl butyral, polymethyl acrylate, polyvinyl alcohol and polymethyl methacrylate; and the mass ratio of the binder to the Ti-Si eutectic powder is (2.5-5.5):(50-60). The appropriate amount of binder can bring the following beneficial effects: 1) enhancing the cohesiveness of the ceramic powder, improving the strength and toughness after forming; 2) improving the flowability of the ceramic powder, reducing the energy consumption in the forming process; and 3) enhancing the oxidation resistance, reducing the color and performance changes caused by oxidation reaction. It should be noted that excessive binder will cause a large number of pores after sintering of the ceramic, and thus the amount of the binder needs to be controlled appropriately.

[0010] Preferably, the plasticizer is at least one of dimethyl phthalate, dimethyl phenyl phosphate, polyethylene glycol and titanium acid ester mixture; and the mass ratio of the plasticizer to the Ti-Si eutectic powder is (1.3-6):(50-60). In the tape casting method, the amount of the plasticizer has an important influence on the forming performance of the green body and the performance of the sintered ceramic. The common beneficial effects include: 1) improving the plasticity of the green body: the addition of the plasticizer can increase the plasticity and plasticity of the green body, making the forming easier and more accurate; 2) promoting the dispersion of the forming agent: the plasticizer can act as a dispersant to connect the forming agent and the powder, so that the forming agent is better dispersed in the ceramic powder; 3) improving the flowability of the forming agent: the plasticizer can improve the flowability of the forming agent, improving the filling property and uniformity of the green body; and 4) improving the density of the ceramic: the appropriate amount of the plasticizer can promote the densification of the green body, so that the sintered ceramic has higher density and strength. It should be noted that the amount of the plasticizer should also be controlled within a certain range, and excessive addition will cause high viscosity of the forming agent, which is not easy to handle and will affect the performance of the ceramic.

[0011] Preferably, the thickness of the Ti-Si eutectic ribbon solder is 0.05-0.3 mm; the Ti-Si eutectic ribbon solder is folded over 150° without breaking. The thickness of the Ti-Si eutectic ribbon solder will affect the performance and properties of the final composite material, specifically in the following aspects: 1) strength and toughness: appropriately increasing the thickness of the ribbon solder can improve the strength and toughness of the composite material, because the ribbon solder can provide strength and toughness enhancement; 2) tensile properties: when the thickness of the ribbon solder increases, the tensile properties of the composite material will decrease, because the ribbon solder will affect the tensile properties of the composite material; 3) thermal expansion: the thickness of the ribbon solder will also affect the thermal expansion of the composite material, because the thermal expansion coefficient of the ribbon solder and the thermal expansion coefficient of the matrix material may be different. Therefore, it is important to select the appropriate thickness of the ribbon solder in the tape casting method, considering the specific application and requirements of the composite material.

[0012] In another aspect, the present application provides a preparation method of a Ti-Si eutectic ribbon solder, comprising:

[0013] (1) mixing Ti-Si eutectic powder, solvent, binder, dispersant and plasticizer to obtain a mixed slurry;

[0014] (2) vacuum degassing and tape casting the mixed slurry to obtain the Ti-Si eutectic ribbon solder.

[0015] Preferably, the preparation method of the Ti-Si eutectic powder comprises: mechanically mixing Ti powder particles and Si powder particles, then placing them in a water-cooled copper crucible, using a vacuum arc melting equipment to melt 5-7 times under vacuum conditions, and controlling the ingot to be turned over 180° after each melting, and finally naturally cooling to room temperature to obtain a Ti-Si eutectic ingot;

[0016] putting the Ti-Si eutectic ingot into a vibrating mill for vibration crushing, and then sieving to obtain the Ti-Si eutectic powder;

[0017] Preferably, the purity of the Ti powder particles is ≥99.99%, and the purity of the Si powder particles is ≥99.999%;

[0018] Preferably, the vacuum degree in the vacuum arc melting equipment is ≤8×10 -3 Pa, and the current range is 120-260 A;

[0019] Preferably, the thermal expansion coefficient of the prepared Ti-Si eutectic ingot is 5.5×10 -6 -6.14×10 -6 ℃-1;

[0020] Preferably, the sieving is through a 400-mesh sieve.

[0021] Preferably, the solid content of the mixed slurry is 50-60wt%;

[0022] The solvent is a binary azeotropic solvent; the binary azeotropic solvent is methyl ethyl ketone / n-propyl ketone binary azeotropic solvent or n-propyl alcohol / butyl acetate binary azeotropic solvent;

[0023] Preferably, the mass ratio of methyl ethyl ketone and n-propyl ketone in the methyl ethyl ketone / n-propyl ketone binary azeotropic solvent is (2-4):(6-8), more preferably 3:7;

[0024] Preferably, the mass ratio of n-propyl alcohol and butyl acetate in the n-propyl alcohol / butyl acetate binary azeotropic solvent is (10-17):(8-15), more preferably 13:12.

[0025] Preferably, the vacuum degree of the vacuum degassing is ≤5×10 -1 Pa, and the time is 30-60min;

[0026] The parameters of the flow casting include that the height of the doctor blade is 0.05mm-0.3mm.

[0027] In still another aspect, the application provides a use of Ti-Si eutectic ribbon solder in ceramic welding, and the ceramic is silicon carbide ceramic or silicon carbide ceramic matrix composite, preferably normal pressure sintered silicon carbide ceramic, reaction sintered silicon carbide ceramic, hot-pressed silicon carbide ceramic or chemical vapor deposition silicon carbide ceramic.

[0028] Preferably, the application comprises:

[0029] (1) After the Ti-Si eutectic ribbon solder is cut according to the shape of the welding surface, it is placed flat between the two ceramic end surfaces to be welded to form a sandwich structure base material;

[0030] (2) The sandwich structure base material is fixed with a graphite mold and placed in a high-temperature brazing furnace to complete the vacuum brazing process and realize the connection of the ceramic;

[0031] Preferably, the vacuum brazing process comprises: vacuum condition of ≤5×10 -3 Pa, temperature of 1300-1330℃, and time of 10-30min;

[0032] More preferably, the vacuum brazing process comprises: under the vacuum condition of ≤5×10 -3 Pa, heating to 650℃ at a rate of 5-10℃ / min and holding for 30min, then heating to 1300-1330℃ at a rate of 5-10℃ / min and holding for 10-30min, and finally cooling to 600℃ at a rate of 5℃ / min and then cooling to room temperature in the furnace.

[0033] Advantages:

[0034] In the present application, the obtained Ti-Si eutectic strip-shaped solder is applied under the conditions of a vacuum degree of ≤5*10 -3 Pa, a welding temperature of 1300-1330 DEG C, and a holding time of 10-30 min. The Ti-Si eutectic strip-shaped solder prepared in the present application has the advantages of simple process, unrestricted shape and size, high preparation efficiency, and good industrial application prospect. The problems of complex preparation process, high cost, difficulty in preservation, restricted shape and size, and inability to realize industrial production of the existing solder are effectively solved, and technical support is provided for the wide application and industrial production of the Ti-Si eutectic strip-shaped solder. The present application can be widely applied in the welding of normal-pressure sintered silicon carbide ceramics, reaction sintered silicon carbide ceramics, hot-pressed silicon carbide ceramics, and chemical vapor deposition silicon carbide ceramics. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 The micro-morphology diagram of the Ti-Si eutectic ingot prepared in Example 1 shows that the Ti-Si solder is successfully prepared by arc melting, and the rod-shaped and micro-matrix arranged spherical TiSi2 eutectic colonies are uniformly distributed in the Si matrix;

[0036] Figure 2 The Ti-Si eutectic powder diagram prepared in Example 1 shows that the Ti-Si eutectic ingot is put into a vibration mill for vibration crushing, and then passes through a 400-mesh sieve to obtain the uniformly dispersed Ti-Si eutectic powder;

[0037] Figure 3 The Ti-Si eutectic powder particle size distribution diagram prepared in Example 1 shows that the Ti-Si eutectic powder particle size mainly concentrates near 0.03 μm, 0.06 μm and 13 μm, and is relatively uniformly dispersed;

[0038] Figure 4 The Ti-Si strip-shaped solder diagram prepared in Example 1 by the flow casting method shows that the Ti-Si strip-shaped solder prepared by the flow casting method has a uniformly dispersed thickness, can be folded by more than 150 DEG without breaking, and is convenient to store and cut;

[0039] Figure 5 The welding interface photo in Example 1 shows that the silicon carbide ceramic interface connected by the Ti-Si strip-shaped solder has good bonding, no pollution and no defects, and has high bonding strength;

[0040] Figure 6 The welding interface photo in Comparative Example 1 shows that the silicon carbide ceramic connection cannot be realized by the direct brazing connection of the Ti-Si eutectic powder, and there are obvious defects in the connection interface. DETAILED DESCRIPTION

[0041] The present application is further illustrated by the following examples, which should not be construed as limiting the present application.

[0042] The present application relates to Ti-Si eutectic ribbon solder applied to silicon carbide ceramic welding, and a preparation method and application thereof.

[0043] The preparation method of the Ti-Si eutectic ribbon solder is exemplarily described below.

[0044] Ti-Si eutectic ingots are prepared by arc melting with Ti and Si as raw materials. As an example, according to the Ti-Si binary phase diagram, Ti particles (16-30 at.%) and Si particles are weighed and mechanically mixed according to the atomic ratio (totaling 100 at.%), placed in a water-cooled copper crucible, and melted 5-7 times by a vacuum arc melting device, each time the ingot is turned over 180°, and cooled to room temperature under vacuum conditions, to complete the preparation of the Ti-Si eutectic ingot. The purity of the Ti particles used is ≥99.99%. The purity of the silicon particles is ≥99.999%. The vacuum degree of the arc melting furnace is better than 8×10 -3 Pa, the current range is 120-260 A, the cooling water temperature of the copper crucible is 22-24℃, and the cooling water pressure is 0.1-0.2 MPa.

[0045] The Ti-Si eutectic ingot is crushed into powder using a vibration mill and sieved to obtain Ti-Si eutectic powder. After crushing, the Ti-Si eutectic powder is sieved through a 400 mesh screen.

[0046] A solvent, a dispersant, a binder and a plasticizer are added to the Ti-Si eutectic powder, and ball milling is performed to obtain a dispersion uniform, suspension stable casting slurry (or mixed slurry). The solid (Ti-Si eutectic powder) content of the suspension slurry is 50-60 wt.%.

[0047] The mixed slurry is prepared into a uniform thickness film using a casting method (with synchronous drying), and a Ti-Si eutectic ribbon solder is prepared. Preferably, after the suspension slurry is treated by vacuum degassing, it is poured into the trough of the casting machine to control the height by a doctor blade, and a uniform thickness ribbon Ti-Si eutectic solder ribbon is formed by synchronous drying. After synchronous drying, the thickness of the ribbon solder after casting is 0.05-0.3 mm, and it can be folded more than 150° without breaking.

[0048] In the present application, the Ti-Si eutectic ribbon solder can be used for the welding of normal pressure sintered silicon carbide ceramics, reaction sintered silicon carbide ceramics, hot-pressed silicon carbide ceramics and chemical vapor deposition silicon carbide ceramics. The prepared Ti-Si eutectic ribbon solder is cut according to the shape of the welding surface, and then is placed flat between the end faces of the ceramics or ceramic matrix composites to be welded to form a "sandwich" structure. The graphite mold is used to fix the base material of the sandwich structure, and the sandwich structure is placed in a high-temperature brazing furnace. Specifically, the temperature is raised to 650℃ at a rate of 5-10℃ / min under a vacuum condition of 5×10 -3 Pa, and the temperature is kept for 10-30 min. Then the temperature is raised to a welding temperature of 1300-1330℃ at a rate of 5-10℃ / min, and the temperature is kept for 10-30 min. Finally, the temperature is reduced to 600℃ at a rate of 5℃ / min, and the furnace is cooled to room temperature. The whole brazing process is completed.

[0049] The following examples are further illustrated to explain the present application. It should be understood that the following examples are only used to further illustrate the present application, and cannot be understood as limiting the protection scope of the present application. Some non-essential improvements and adjustments made by those skilled in the art according to the above content of the present application are within the protection scope of the present application. The specific process parameters in the following examples are only one example in the appropriate range, i.e. those skilled in the art can select within the appropriate range according to the description herein, and are not limited to the specific values in the following examples.

[0050] Example 1:

[0051] (1) Preparation of eutectic ingot: according to the Ti-Si binary phase diagram, Ti particles and Si particles are weighed and mechanically mixed according to the atomic ratio of Ti:Si=16:84, and are placed in a water-cooled copper crucible. The vacuum arc melting equipment is used for melting 5-7 times, and each time the ingot is turned over 180°. Under vacuum condition, the temperature is naturally cooled to room temperature to complete the preparation of the Ti-Si eutectic ingot.

[0052] The purity of the Ti particles used is ≥99.99%, and the purity of the silicon particles is ≥99.999%. The vacuum degree of the arc melting furnace is 5×10 -3 Pa, the current is 120A, the cooling water temperature of the copper crucible is 22℃, the cooling water pressure is 0.1MPa, and the thermal expansion coefficient of the prepared Ti-Si eutectic ingot is 5.5×10 -6 ℃ -1 .

[0053] (2) Preparation of Ti-Si ribbon solder: Put the Ti-Si eutectic ingot prepared in step (1) into a vibrating mill to crush, and then pass the crushed raw material through a 400-mesh sieve to obtain Ti-Si eutectic powder with a certain particle size; ball mill the Ti-Si eutectic powder, solvent, dispersant, binder and plasticizer to obtain a suspension slurry for casting (wherein the solvent is a binary azeotropic mixture of n-propanol and butyl acetate, the dispersant is castor oil phosphate, the binder is polyvinyl butyral, and the plasticizer is dibutyl phthalate); after vacuum degassing treatment, pour the suspension slurry into the trough of the casting machine to control the height by a doctor blade, and then dry synchronously to form a Ti-Si eutectic solder ribbon with a thickness of 0.05 mm.

[0054] The raw materials and their proportions used in the casting formulation in this example 1 are shown in Table 1:

[0055] Name Class Proportion (wt. %) Ti-Si Ceramic powder 50 Methyl ethyl ketone Solvent 12 n-Propyl acetone Solvent 28 Castor oil phosphate Dispersant 2.5 Polyvinyl butyral Binder 3.5 Dibutyl phthalate Plasticizer 4 .

[0056] (3) Ti-Si eutectic ribbon solder brazing connection: after cutting the prepared Ti-Si eutectic ribbon solder according to the shape of the welding surface, place it flat between the end faces of the ceramic or ceramic matrix composite to be welded to form a "sandwich" structure, use a graphite mold to fix the base material of the sandwich structure, and place it in a high-temperature brazing furnace; under a vacuum of 3.5 x 10 -3 Pa, heat to 650℃ at a rate of 10℃ / min and keep for 30 min, then heat to a welding temperature of 1330℃ at a rate of 10℃ / min and keep for 30 min, and finally cool to 600℃ at a rate of 5℃ / min and then cool to room temperature with the furnace, to complete the entire brazing process. The ribbon solder after casting in this example 1 can be folded by more than 150° without breaking, and the interface bonding effect of the joint after brazing connection is good, and the shear strength of the silicon carbide ceramic connecting joint prepared reaches 76 MPa.

[0057] Example 2:

[0058] (1) Preparation of eutectic ingot: according to the Ti-Si binary phase diagram, weigh and mechanically mix Ti particles and Si particles according to the atomic ratio Ti:Si = 30:70, place them in a water-cooled copper crucible, and use a vacuum arc melting equipment to melt 5-7 times, each time turning the ingot by 180°, and then naturally cool to room temperature under vacuum conditions to complete the preparation of the Ti-Si eutectic ingot.

[0059] The purity of the Ti particles used is ≥ 99.99%, and the purity of the silicon particles is ≥ 99.999%. The vacuum degree of the arc melting furnace is 3 x 10 -3Pa, current 240 A, cooling water temperature of copper crucible 23℃, cooling water pressure 0.2 MPa, the thermal expansion coefficient of the prepared Ti-Si eutectic ingot is 6.14 x 10 -6 ℃ -1 .

[0060] (2) Preparation of Ti-Si ribbon solder: the Ti-Si eutectic ingot prepared in step (1) is put into a vibration mill for vibration crushing, and the crushed raw material is obtained after passing through a 400-mesh sieve to obtain Ti-Si eutectic powder of a certain particle size; the Ti-Si eutectic powder, solvent, dispersant, binder and plasticizer are ball-milled and mixed to obtain a suspension slurry for casting (wherein the solvent is a binary azeotropic mixture of methyl ethyl ketone and n-propanone, the dispersant is castor oil phosphate, the binder is polyvinyl butyral, and the plasticizer is dibutyl phthalate); the suspension slurry is treated by vacuum degassing, then poured into the trough of the casting machine to control the height by a doctor blade, and then dried synchronously to form a Ti-Si eutectic solder ribbon with a thickness of 0.1 mm. The raw materials and proportions used in the casting formula of Example 2 are shown in Table 2.

[0061] Table 2 is the raw materials and proportions used in the casting formula of Example 2:

[0062] Name Class Proportion (wt. %) Ti-Si Ceramic powder 50 n-Propyl alcohol Solvent 19.5 Butyl acetate Solvent 18 Castor oil phosphate Dispersant 3.5 Polyvinyl butyral Binder 4.5 Dibutyl phthalate Plasticizer 4.5 .

[0063] (3) Ti-Si eutectic ribbon solder brazing connection: the prepared Ti-Si eutectic ribbon solder is cut according to the shape of the welding surface, then placed flat between the end faces of the ceramic or ceramic matrix composite to be welded to form a "sandwich" structure, the base material of the sandwich structure is fixed with a graphite mold, and then placed in a high-temperature brazing furnace; under a vacuum condition of 5 x 10 -3 Pa, heated to 650℃ at a rate of 10℃ / min and kept for 30 min, then heated to a welding temperature of 1330℃ at a rate of 10℃ / min and kept for 30 min, and finally cooled to 600℃ at a rate of 5℃ / min and then cooled to room temperature in the furnace, to complete the entire brazing process. The ribbon solder after casting in Example 2 can be folded more than 150° without breaking, and the interface bonding effect of the joint after brazing connection is good, and the shear strength of the prepared silicon carbide ceramic connecting joint reaches 68 MPa.

[0064] Example 3

[0065] (1) Preparation of eutectic ingot: according to the Ti-Si binary phase diagram, Ti particles and Si particles are weighed and mechanically mixed according to the atomic ratio of Ti: Si = 20: 80, placed in a water-cooled copper crucible, and melted 5-7 times by a vacuum arc melting device, each time the ingot is turned over 180°, and cooled to room temperature under vacuum to complete the preparation of the Ti-Si eutectic ingot.

[0066] The purity of the Ti particles used is ≥ 99.99%, and the purity of the silicon particles is ≥ 99.999%. The vacuum degree of the arc melting furnace is 3.5 x 10 -3 Pa, the current is 260 A, the cooling water temperature of the copper crucible is 24°C, the cooling water pressure is 0.2 MPa, and the thermal expansion coefficient of the prepared Ti-Si eutectic ingot is 5.86 x 10 -6 -1 .

[0067] (2) Preparation of Ti-Si ribbon solder: the Ti-Si eutectic ingot prepared in step (1) is placed in a vibration mill for vibration crushing, and the crushed raw material is obtained after passing through a 400-mesh sieve to obtain Ti-Si eutectic powder of a certain particle size; the Ti-Si eutectic powder, solvent, dispersant, binder and plasticizer are ball-milled and mixed to obtain a suspension slurry for casting (wherein the solvent is a binary azeotropic mixture of n-propanol and butyl acetate, the dispersant is castor oil phosphate, the binder is polyvinyl butyral, and the plasticizer is dibutyl phthalate); the suspension slurry is subjected to vacuum degassing treatment, then poured into the trough of the casting machine to control the height by a doctor blade, and then dried synchronously to form a Ti-Si eutectic solder ribbon with a thickness of 0.2 mm.

[0068] Table 3 is the raw materials and proportions used in the casting formulation in Example 3:

[0069] Name Class Proportion (wt. %) Ti-Si Ceramic powder 55 Methyl ethyl ketone Solvent 9 n-Propyl acetone Solvent 21 Castor oil phosphate Dispersant 3.5 Polyvinyl butyral Binder 5.5 Dibutyl phthalate Plasticizer 6 .

[0070] (3) Ti-Si eutectic ribbon solder brazing connection: the prepared Ti-Si eutectic ribbon solder is cut according to the shape of the welding surface, then placed flat between the end faces of the ceramic or ceramic matrix composite to be welded to form a “sandwich” structure, the base material of the sandwich structure is fixed with a graphite mold, and then placed in a high-temperature brazing furnace; under a vacuum condition of 5 x 10 -3 Pa, the temperature is raised to 650°C at a rate of 10°C / min and held for 30 min, then raised to a welding temperature of 1330°C at a rate of 10°C / min and held for 30 min, and finally cooled to 600°C at a rate of 5°C / min and then cooled to room temperature with the furnace, to complete the entire brazing process. The ribbon solder after casting in Example 3 can be folded by more than 150° without breaking, and the interface bonding effect of the joint after brazing connection is good, and the shear strength of the prepared silicon carbide ceramic connecting joint reaches 73 MPa.

[0071] Example 4

[0072] ​(1) Preparation of eutectic ingot: according to Ti-Si binary phase diagram, Ti particles and Si particles are weighed and mechanically mixed according to the atomic ratio of Ti: Si = 25: 75, placed in a water-cooled copper crucible, and melted 5-7 times by using a vacuum arc melting equipment, each time the ingot is turned over 180°, and cooled to room temperature under vacuum conditions to complete the preparation of Ti-Si eutectic ingot.

[0073] Among them, the purity of the Ti particles used is ≥99.99%, and the purity of the silicon particles is ≥99.999%. The vacuum degree of the arc melting furnace is 5x10 -3 Pa, the current is 220 A, the cooling water temperature of the copper crucible is 23℃, the cooling water pressure is 0.2 MPa, and the thermal expansion coefficient of the prepared Ti-Si eutectic ingot is 6.03x10 -6 ℃ -1 .

[0074] (2) Preparation of Ti-Si ribbon solder: the Ti-Si eutectic ingot prepared in step (1) is put into a vibration mill for vibration crushing, and the crushed raw materials are obtained after passing through a 400 mesh sieve to obtain Ti-Si eutectic powder of a certain particle size; the Ti-Si eutectic powder, solvent, dispersant, binder and plasticizer are ball milled and mixed to obtain a suspension slurry for casting (wherein the solvent is a binary azeotropic mixture of methyl ethyl ketone and n-propanone, the dispersant is castor oil phosphate, the binder is polyvinyl butyral, and the plasticizer is dibutyl phthalate); the suspension slurry is treated by vacuum degassing, then poured into the trough of the casting machine by controlling the height with a doctor blade, and dried synchronously to form a Ti-Si eutectic solder ribbon with a thickness of 0.3 mm.

[0075] Table 4 is the raw materials and proportions used in the casting formula of Example 4:

[0076] Name Class Proportion (wt. %) Ti-Si Ceramic powder 55 n-Propyl alcohol Solvent 19.5 Butyl acetate Solvent 18 Castor oil phosphate Dispersant 1.5 Polyvinyl butyral Binder 3.5 Dibutyl phthalate Plasticizer 2.5 .

[0077] (3) Ti-Si eutectic ribbon solder brazing connection: the prepared Ti-Si eutectic ribbon solder is cut according to the shape of the welding surface, then placed flat between the end faces of the ceramic or ceramic matrix composite to be welded to form a “sandwich” structure, the graphite mold is used to fix the base material of the sandwich structure, and the sandwich structure is placed in a high-temperature brazing furnace; under the condition of 5x10 -3The whole brazing process is completed by heating to 650°C at a rate of 10°C / min under vacuum, holding for 30 min, then heating to 1330°C at a rate of 10°C / min, holding for 30 min, and finally cooling to 600°C at a rate of 5°C / min and then cooling to room temperature in the furnace. The tape-shaped solder prepared in Example 4 can be folded by more than 150° without breaking, and the interface bonding effect of the joint after brazing connection is good, and the shear strength of the prepared silicon carbide ceramic connecting piece joint reaches 67 MPa.

[0078] Example 5

[0079] (1) Preparation of eutectic ingot: according to the Ti-Si binary phase diagram, Ti particles and Si particles are weighed and mechanically mixed according to the atomic ratio of Ti: Si = 16: 84, placed in a water-cooled copper crucible, and melted 5-7 times by using a vacuum arc melting equipment, and each time the ingot is turned over by 180°. Under vacuum, it is naturally cooled to room temperature to complete the preparation of Ti-Si eutectic ingot. Among them, the purity of the Ti particles used is ≥99.99%, and the purity of the silicon particles is ≥99.999%. The vacuum degree of the arc melting furnace is 5.8 x 10 -3 Pa, current 160 A, cooling water temperature of copper crucible 22°C, cooling water pressure 0.1 MPa, and the thermal expansion coefficient of the prepared Ti-Si eutectic ingot is 5.5 x 10 -6 °C -1 .

[0080] (2) Preparation of Ti-Si tape-shaped solder: the Ti-Si eutectic ingot prepared in step (1) is put into a vibration mill for vibration crushing, and the crushed raw materials are obtained after passing through a 400 mesh sieve to obtain Ti-Si eutectic powder of a certain particle size; the Ti-Si eutectic powder, solvent, dispersant, binder and plasticizer are ball milled and mixed to obtain a suspension slurry for casting (wherein the solvent is a binary azeotropic mixture of n-propanol and butyl acetate, the dispersant is castor oil phosphate, the binder is polyvinyl butyral, and the plasticizer is dibutyl phthalate); the suspension slurry is treated by vacuum degassing, then poured into the trough of the casting machine by controlling the height with a doctor blade, and then dried synchronously to form a tape-shaped Ti-Si eutectic solder tape with a thickness of 0.15 mm.

[0081] Table 5 is the raw materials and proportions used in the casting formula in Example 5:

[0082] Name Class Proportion (wt. %) Ti-Si Ceramic powder 60 Methyl ethyl ketone Solvent 10.5 n-Propyl acetone Solvent 24.4 Castor oil phosphate Dispersant 1.2 Polyvinyl butyral Binder 2.5 Dibutyl phthalate Plasticizer 1.3 .

[0083] (3) Ti-Si eutectic ribbon solder brazing connection: the prepared Ti-Si eutectic ribbon solder is cut according to the shape of the welding surface, and then is placed flat between the end faces of the ceramics or ceramic matrix composites to be welded to form a "sandwich" structure. The sandwich structure is fixed by a graphite mold, and is placed in a high-temperature brazing furnace. The brazing is carried out under a vacuum condition of 3.5 x 10 -3 Pa, and the temperature is raised to 650°C at a rate of 10°C / min, is kept for 30 min, is raised to a welding temperature of 1330°C at a rate of 10°C / min, is kept for 30 min, and is finally cooled to 600°C at a rate of 5°C / min, and is then cooled to room temperature in the furnace. The entire brazing process is completed. The ribbon solder prepared in Example 5 can be folded by more than 150° without breaking, and the interface bonding effect of the joint after brazing connection is good. The shear strength of the prepared silicon carbide ceramic connecting joint reaches 73 MPa.

[0084] Example 6

[0085] (1) Preparation of eutectic ingot: according to the Ti-Si binary phase diagram, Ti particles and Si particles are weighed and mechanically mixed according to the atomic ratio of Ti: Si = 25: 75, and are placed in a water-cooled copper crucible. A vacuum arc melting device is used for melting 5-7 times, and each time the ingot is turned over 180°. The Ti-Si eutectic ingot is prepared by natural cooling to room temperature under a vacuum condition.

[0086] The purity of the Ti particles used is ≥ 99.99%, and the purity of the silicon particles is ≥ 99.999%. The vacuum degree of the arc melting furnace is 4.5 x 10 -3 Pa, the current is 180 A, the cooling water temperature of the copper crucible is 23°C, the cooling water pressure is 0.2 MPa, and the thermal expansion coefficient of the prepared Ti-Si eutectic ingot is 6.03 x 10 -6 ℃ -1 .

[0087] (2) Preparation of Ti-Si ribbon solder: the Ti-Si eutectic ingot prepared in step (1) is placed in a vibration mill for vibration crushing. The crushed raw materials are sieved through a 400-mesh sieve to obtain Ti-Si eutectic powder of a certain particle size. The Ti-Si eutectic powder, a solvent, a dispersant, a binder and a plasticizer are ball-milled and mixed to obtain a suspension slurry for casting (the solvent is a binary azeotropic mixture of methyl ethyl ketone and n-propanone, the dispersant is castor oil phosphate, the binder is polyvinyl butyral, and the plasticizer is dibutyl phthalate). After vacuum degassing treatment, the suspension slurry is poured into the trough of the casting machine through the control of the height by a doctor blade, and is dried synchronously to form a ribbon Ti-Si eutectic solder ribbon with a thickness of 0.05 mm.

[0088] Table 6 shows the raw materials and proportions used in the casting formulation in Example 6:

[0089] Name Class Proportion (wt. %) Ti-Si Ceramic powder 60 n-Propyl alcohol Solvent 15.6 Butyl acetate Solvent 14.4 Castor oil phosphate Dispersant 2.5 Polyvinyl butyral Binder 4.5 Dibutyl phthalate Plasticizer 3.0 .

[0090] (3) Ti-Si eutectic ribbon solder brazing connection: the prepared Ti-Si eutectic ribbon solder is cut according to the shape of the welding surface, and then is placed flat between the end faces of the ceramics or ceramic matrix composites to be welded to form a "sandwich" structure. The graphite mold is used to fix the base material of the sandwich structure, and the sandwich structure is placed in a high-temperature brazing furnace. Under the vacuum condition of 5x10 -3 Pa, the temperature is raised to 650℃ at a rate of 10℃ / min and kept for 30min, then the temperature is raised to 1330℃ at a rate of 10℃ / min, and kept for 30min. Finally, the temperature is reduced to 600℃ at a rate of 5℃ / min, and then the furnace is cooled to room temperature. The whole brazing process is completed. The ribbon solder prepared in this embodiment 6 can be folded more than 150° without breaking, and the interface bonding effect of the joint after brazing connection is good. The shear strength of the prepared silicon carbide ceramic connecting joint reaches 76MPa.

[0091] Embodiment 7

[0092] (1) Preparation of eutectic ingot: according to the Ti-Si binary phase diagram, Ti particles and Si particles are weighed and mechanically mixed according to the atomic ratio of Ti:Si = 20:80, and are placed in a water-cooled copper crucible. The vacuum arc melting equipment is used for melting 5-7 times, and each time the ingot is turned over 180°. Under the vacuum condition, the temperature is naturally cooled to room temperature to complete the preparation of the Ti-Si eutectic ingot.

[0093] Among them, the purity of the Ti particles used is ≥99.99%, and the purity of the silicon particles is ≥99.999%. The vacuum degree of the arc melting furnace is 5.5x10 -3 Pa, the current is 240A, the cooling water temperature of the copper crucible is 24℃, the cooling water pressure is 0.2MPa, and the thermal expansion coefficient of the prepared Ti-Si eutectic ingot is 5.86x10 -6 ℃ -1 .

[0094] (2) Preparation of Ti-Si ribbon solder: the Ti-Si eutectic ingot prepared in ① is put into a vibrating mill for vibration crushing. After the crushed raw materials pass through a 400-mesh sieve, Ti-Si eutectic powder with a certain particle size is obtained. The Ti-Si eutectic powder, solvent, dispersant, binder and plasticizer are ball-milled and mixed to obtain a suspension slurry for casting (wherein the solvent is a binary azeotropic mixture of n-propanol and butyl acetate, the dispersant is castor oil phosphate, the binder is polyvinyl butyral, and the plasticizer is dibutyl phthalate). After the suspension slurry is treated by vacuum degassing, it is poured into the trough of the casting machine through the scraper to control the height, and then is dried synchronously to form a ribbon-shaped Ti-Si eutectic solder ribbon with a thickness of 0.08mm.

[0095] Table 7 is the raw materials and their proportions used in the tape casting formulation of Example 7:

[0096] Name Class Proportion (wt. %) Ti-Si Ceramic powder 60 Methyl ethyl ketone Solvent 9 n-Propyl acetone Solvent 21 Castor oil phosphate Dispersant 2.5 Polyvinyl butyral Binder 3.5 Dibutyl phthalate Plasticizer 4 .

[0097] (3) Ti-Si eutectic ribbon solder brazing connection: the prepared Ti-Si eutectic ribbon solder is cut according to the shape of the welding surface, then is placed flat between the end faces of the ceramics or ceramic matrix composites to be welded to form a "sandwich" structure, the base material of the sandwich structure is fixed with a graphite mold, and the sandwich structure is placed in a high-temperature brazing furnace; under a vacuum condition of 5 x 10 -3 Pa, the temperature is raised to 650 °C at a rate of 10 °C / min, and the temperature is kept for 30 min, then the temperature is raised to a welding temperature of 1330 °C at a rate of 10 °C / min, and the temperature is kept for 30 min, finally the temperature is reduced to 600 °C at a rate of 5 °C / min, and the furnace is cooled to room temperature, thus completing the entire brazing process. The ribbon solder after tape casting in Example 7 can be folded by more than 150° without breaking, and the interface bonding effect of the joint after brazing connection is good, and the shear strength of the prepared silicon carbide ceramic connecting joint reaches 71 MPa.

[0098] Example 8

[0099] (1) Preparation of eutectic ingot: according to the Ti-Si binary phase diagram, Ti particles and Si particles are weighed and mechanically mixed according to the atomic ratio of Ti: Si = 16: 84, and are placed in a water-cooled copper crucible, and are melted 5-7 times by using a vacuum arc melting device, and the ingot is turned over 180° each time, and is naturally cooled to room temperature under vacuum conditions, thus completing the preparation of the Ti-Si eutectic ingot.

[0100] Among them, the purity of the Ti particles used is ≥ 99.99%, and the purity of the silicon particles is ≥ 99.999%. The vacuum degree of the arc melting furnace is 5 x 10 -3 Pa, the current is 120 A, the cooling water temperature of the copper crucible is 22 °C, the cooling water pressure is 0.1 MPa, and the thermal expansion coefficient of the prepared Ti-Si eutectic ingot is 5.5 x 10 -6 ℃ -1 .

[0101] (2) Preparation of Ti-Si ribbon solder: the Ti-Si eutectic ingot prepared in step (1) is put into a vibration mill for vibration pulverization, and the pulverized raw material is obtained in a certain particle size after passing through a 400-mesh sieve; the Ti-Si eutectic powder, a solvent, a dispersant, a binder and a plasticizer are ball-milled and mixed to obtain a suspension slurry for casting (wherein the solvent is a binary azeotropic mixture of n-propanol and butyl acetate, the dispersant is castor oil phosphate, the binder is polyvinyl butyral, and the plasticizer is dibutyl phthalate); the suspension slurry is treated by vacuum degassing, then poured into a trough of a casting machine to control the height by a doctor blade, and dried synchronously to form a Ti-Si eutectic solder ribbon with a thickness of 0.12 mm.

[0102] Table 8 is the raw materials and their proportions used in the casting formulation in Example 8:

[0103] Name Class Proportion (wt. %) Ti-Si Ceramic powder 60 n-Propyl alcohol Solvent 16.9 Butyl acetate Solvent 15.6 Castor oil phosphate Dispersant 1.5 Polyvinyl butyral Binder 3.5 Dibutyl phthalate Plasticizer Name Class Proportion (wt. %) Ti-Si Ceramic powder Methyl ethyl ketone Solvent n-Propyl acetone Solvent Castor oil phosphate Dispersant Polyvinyl butyral Binder Dibutyl phthalate Plasticizer Name Class Proportion (wt. %) Ti-Si Ceramic powder n-Propyl alcohol Solvent Butyl acetate Solvent Castor oil phosphate Dispersant Polyvinyl butyral Binder Dibutyl phthalate Plasticizer Name Class Proportion (wt. %) Ti-Si Ceramic powder Methyl ethyl ketone Solvent n-Propyl acetone Solvent Castor oil phosphate Dispersant Polyvinyl butyral Binder Dibutyl phthalate Plasticizer Name Class Proportion (wt. %) Ti-Si Ceramic powder n-Propyl alcohol Solvent Butyl acetate Solvent Castor oil phosphate Dispersant Polyvinyl butyral Binder Dibutyl phthalate Plasticizer 2.5 .

[0104] (3) Ti-Si eutectic ribbon solder brazing connection: the prepared Ti-Si eutectic ribbon solder is cut according to the shape of the welding surface, then placed flat between the end faces of the ceramic or ceramic matrix composite to be welded to form a “sandwich” structure, the base material of the sandwich structure is fixed with a graphite mold, and the sandwich structure is placed in a high-temperature brazing furnace; under a vacuum condition of 3.5 x 10 -3 Pa, the temperature is raised to 650℃ at a rate of 10℃ / min, kept for 30 min, then raised to a welding temperature of 1330℃ at a rate of 10℃ / min, kept for 30 min, and finally cooled to 600℃ at a rate of 5℃ / min, and then cooled to room temperature in the furnace, to complete the entire brazing process.

[0105] The ribbon solder after casting in this example can be folded more than 150° without breaking, and the interface bonding effect of the joint after brazing connection is good, and the shear strength of the silicon carbide ceramic connector joint prepared reaches 78 MPa.

[0106] Example 9

[0107] The difference between this example 9 and the specific example 1 is that in step (2), the plasticizer of the Ti-Si ribbon solder is trimethylphenyl phosphate, and the others are the same as in the specific example 1. The ribbon solder after casting in this example 9 can be folded more than 150° without breaking, and the interface bonding effect of the joint after brazing connection is good, and the shear strength of the silicon carbide ceramic connector joint prepared reaches 68 MPa.

[0108] Example 10

[0109] The embodiment 10 is different from the specific embodiment 1 in that the Ti-Si eutectic solder ribbon with a thickness of 0.12 mm is formed by synchronous drying in step (2). The other steps are the same as those in the specific embodiment 1. The ribbon solder after the casting in the embodiment 10 can be folded over 150° without breaking, and the interface bonding effect of the joint after the brazing connection is good, and the shear strength of the silicon carbide ceramic connecting piece joint prepared reaches 75 MPa.

[0110] Embodiment 11

[0111] The embodiment 11 is different from the specific embodiment 1 in that the Ti-Si eutectic solder ribbon with a thickness of 0.3 mm is formed by synchronous drying in step (2). The other steps are the same as those in the specific embodiment 1. The ribbon solder after the casting in the embodiment 11 can be folded over 150° without breaking, and the interface bonding effect of the joint after the brazing connection is good, and the shear strength of the silicon carbide ceramic connecting piece joint prepared reaches 69 MPa.

[0112] Embodiment 12

[0113] The embodiment 12 is different from the specific embodiment 1 in that the Ti-Si eutectic solder ribbon with a thickness of 0.25 mm is formed by synchronous drying in step (2). The other steps are the same as those in the specific embodiment 1. The ribbon solder after the casting in the embodiment 12 can be folded over 150° without breaking, and the interface bonding effect of the joint after the brazing connection is good, and the shear strength of the silicon carbide ceramic connecting piece joint prepared reaches 76 MPa.

[0114] Embodiment 13

[0115] The embodiment 13 is different from the specific embodiment 1 in that the Ti-Si eutectic solder ribbon is brazed in step (3) and heated to a welding temperature of 1330 °C and kept for 20 min. The other steps are the same as those in the specific embodiment 1. The ribbon solder after the casting in the embodiment 13 can be folded over 150° without breaking, and the interface bonding effect of the joint after the brazing connection is good, and the shear strength of the silicon carbide ceramic connecting piece joint prepared reaches 74 MPa.

[0116] Embodiment 14

[0117] The embodiment 14 is different from the specific embodiment 1 in that the Ti-Si eutectic solder ribbon is brazed in step (3) and heated to a welding temperature of 1330 °C and kept for 10 min. The other steps are the same as those in the specific embodiment 1. The ribbon solder after the casting in the embodiment 14 can be folded over 150° without breaking, and the interface bonding effect of the joint after the brazing connection is good, and the shear strength of the silicon carbide ceramic connecting piece joint prepared reaches 76 MPa.

[0118] Embodiment 15

[0119] The difference between this embodiment 15 and the specific embodiment 1 is that: in step (3), the Ti-Si eutectic ribbon solder is brazed and connected: it is heated to a welding temperature of 1315℃, and kept for 30 min, and the others are the same as the specific embodiment 1. The ribbon solder after the tape casting in this embodiment 15 can be folded more than 150° without breaking, and the interface bonding effect of the joint after brazing and connecting is good, and the shear strength of the prepared silicon carbide ceramic connecting piece joint reaches 69 MPa.

[0120] Embodiment 16

[0121] The difference between this embodiment 16 and the specific embodiment 1 is that: in step (3), the Ti-Si eutectic ribbon solder is brazed and connected: it is heated to a welding temperature of 1315℃, and kept for 20 min, and the others are the same as the specific embodiment 1. The ribbon solder after the tape casting in this embodiment 16 can be folded more than 150° without breaking, and the interface bonding effect of the joint after brazing and connecting is good, and the shear strength of the prepared silicon carbide ceramic connecting piece joint reaches 71 MPa.

[0122] Embodiment 17

[0123] The difference between this embodiment 17 and the specific embodiment 1 is that: in step (3), the Ti-Si eutectic ribbon solder is brazed and connected: it is heated to a welding temperature of 1315℃, and kept for 10 min, and the others are the same as the specific embodiment 1. The ribbon solder after the tape casting in this embodiment 17 can be folded more than 150° without breaking, and the interface bonding effect of the joint after brazing and connecting is good, and the shear strength of the prepared silicon carbide ceramic connecting piece joint reaches 65 MPa.

[0124] Embodiment 18

[0125] The difference between this embodiment 18 and the specific embodiment 1 is that: in step (3), the Ti-Si eutectic ribbon solder is brazed and connected: it is heated to a welding temperature of 1300℃, and kept for 30 min, and the others are the same as the specific embodiment 1. The ribbon solder after the tape casting in this embodiment 18 can be folded more than 150° without breaking, and the interface bonding effect of the joint after brazing and connecting is good, and the shear strength of the prepared silicon carbide ceramic connecting piece joint reaches 68 MPa.

[0126] Embodiment 19

[0127] The embodiment 19 is different from the specific embodiment 1 in that: in step (3), the Ti-Si eutectic ribbon solder is brazed and connected: it is heated to a welding temperature of 1300°C, and is kept for 20 min, and the others are the same as those in the specific embodiment 1. The ribbon solder after the tape casting in the embodiment 19 can be folded by more than 150° without being broken, and the interface bonding effect of the joint after the brazing and connection is good, and the shear strength of the prepared silicon carbide ceramic connecting piece joint reaches 70 MPa.

[0128] Embodiment 20

[0129] The embodiment 20 is different from the specific embodiment 1 in that: in step (3), the Ti-Si eutectic ribbon solder is brazed and connected: it is heated to a welding temperature of 1300°C, and is kept for 10 min, and the others are the same as those in the specific embodiment 1. The ribbon solder after the tape casting in the embodiment 20 can be folded by more than 150° without being broken, and the interface bonding effect of the joint after the brazing and connection is good, and the shear strength of the prepared silicon carbide ceramic connecting piece joint reaches 65 MPa.

[0130] Embodiment 21

[0131] The embodiment 21 is different from the specific embodiment 1 in that: the amount of the binder is controlled to be 2.5 wt%, and the others are the same as those in the specific embodiment 1. The ribbon solder after the tape casting in the embodiment 21 can be folded by more than 150° without being broken, and the interface bonding effect of the joint after the brazing and connection is good, and the shear strength of the prepared silicon carbide ceramic connecting piece joint reaches 69 MPa.

[0132] Embodiment 22

[0133] The embodiment 22 is different from the specific embodiment 1 in that: the amount of the binder is controlled to be 5.5 wt%, and the others are the same as those in the specific embodiment 1. The ribbon solder after the tape casting in the embodiment 22 can be folded by more than 150° without being broken, and the interface bonding effect of the joint after the brazing and connection is good, and the shear strength of the prepared silicon carbide ceramic connecting piece joint reaches 63 MPa.

[0134] Embodiment 23

[0135] The embodiment 23 is different from the specific embodiment 1 in that: the amount of the plasticizer is controlled to be 1.3 wt%, and the others are the same as those in the specific embodiment 1. The ribbon solder after the tape casting in the embodiment 23 can be folded by more than 150° without being broken, and the interface bonding effect of the joint after the brazing and connection is good, and the shear strength of the prepared silicon carbide ceramic connecting piece joint reaches 65 MPa.

[0136] Embodiment 24

[0137] The embodiment 24 is different from the specific embodiment 1 in that the amount of the plasticizer is controlled to be 6wt%, and other conditions are the same as those in the specific embodiment 1. The tape-shaped solder in the embodiment 24 can be folded by more than 150° without being broken, and the interface bonding effect of the joint after brazing is good, and the shear strength of the prepared silicon carbide ceramic connector joint reaches 68MPa.

[0138] Comparative example 1

[0139] The comparative example 1 is different from the specific embodiment 1 in that the solder used is Ti-Si eutectic powder, and no binder, dispersant, plasticizer and other components are added, and other operation steps are the same as those in the specific embodiment 1. In the comparative example 1, all Ti-Si eutectic powder is used, and the interface of the silicon carbide ceramic connection after brazing is incomplete, and there are a large number of defects in the connection layer, which further leads to that the joint of the connector does not achieve the connection effect.

[0140] Comparative example 2

[0141] The comparative example 2 is different from the specific embodiment 1 in that the solder used is a slurry of Ti-Si eutectic powder mixed with the binder castor oil phosphate, and the mass ratio is 8.0:2.0, and other conditions are the same as those in the specific embodiment 1. In the comparative example 2, the solder is in the form of slurry, and the preparation of the tape-shaped solder of Ti-Si eutectic in the embodiment 1 does not exist, and the interface bonding effect of the joint after brazing has defects and is discontinuous, and there are a large number of defects in the connection layer, which further leads to that the prepared silicon carbide ceramic connector joint does not achieve the connection effect.

[0142] Comparative example 3

[0143] The comparative example 3 is different from the specific embodiment 1 in that the solder used is a slurry of Ti-Si eutectic powder mixed with the binder castor oil phosphate, and the mass ratio is 8.0:2.0, and the solder in the comparative example 3 is in the form of slurry, and the preparation of the tape-shaped solder of Ti-Si eutectic in the embodiment 1 does not exist, and the brazing connection in step (3) is that the welding temperature is raised to 1330°C, and the holding time is 20min, and other conditions are the same as those in the specific embodiment 1. The interface bonding effect of the joint after brazing in the comparative example 3 has defects and is discontinuous, and there are a large number of defects in the connection layer, which further leads to that the prepared silicon carbide ceramic connector joint does not achieve the connection effect.

[0144] Comparative example 4

[0145] The difference between the present comparative example 4 and the specific example 1 is that: the solder used is a slurry of Ti-Si eutectic powder mixed with the binder castor oil phosphate with a mass ratio of 8.0:2.0. In the present comparative example 4, the solder is in the form of a slurry, and the preparation of the Ti-Si eutectic strip-shaped solder in the specific example 1 does not exist. In step (3), the brazing connection is carried out by heating to a welding temperature of 1330°C and holding for 10 minutes, and the other steps are the same as in the specific example 1. In the present comparative example 4, the interface bonding effect of the joint after brazing connection is defective and discontinuous, and there are a large number of defects in the connection layer, which further leads to the fact that the silicon carbide ceramic connecting piece joint prepared does not achieve the connection effect.

[0146] Comparative example 5

[0147] The difference between the present comparative example 5 and the specific example 1 is that: the amount of binder added is controlled to be 0wt%. In the present comparative example 5, the preparation of the Ti-Si eutectic strip-shaped solder cannot be realized, and it cannot be completely formed during the preparation of the Ti-Si eutectic solder strip and presents a cracking phenomenon. In addition, the interface bonding effect of the joint after brazing connection is defective and discontinuous, there are a large number of defects in the connection layer, and a large area of TiSi2 is generated, which further leads to the fact that the silicon carbide ceramic connecting piece joint prepared does not achieve the connection effect.

[0148] Comparative example 6

[0149] The difference between the present comparative example 6 and the specific example 1 is that: the amount of plasticizer added is controlled to be 0wt%, and the other steps are the same as in the specific example 1. In the present comparative example 6, the preparation of the Ti-Si eutectic strip-shaped solder cannot be realized, and it cannot be completely formed during the preparation of the Ti-Si eutectic solder strip and presents a cracking phenomenon. In addition, the interface bonding effect of the joint after brazing connection is defective and discontinuous, there are a large number of defects in the connection layer, and a large area of TiSi2 is generated, which further leads to the fact that the silicon carbide ceramic connecting piece joint prepared does not achieve the connection effect.

[0150] Comparative example 7

[0151] The difference between the present comparative example 7 and the specific example 1 is that: the amount of binder added is controlled to be 7wt%, and the other steps are the same as in the specific example 1. In the present comparative example 7, the interface bonding effect of the joint after brazing connection has a small number of defects, which reduces the shear strength of the silicon carbide ceramic connecting piece joint prepared to 45MPa.

[0152] Comparative example 8

[0153] The difference between the present comparative example 8 and the specific example 1 is that: the amount of plasticizer added is controlled to be 8wt%, and the other steps are the same as in the specific example 1. In the present comparative example 8, the interface bonding effect of the joint after brazing connection has a small number of defects, which reduces the shear strength of the silicon carbide ceramic connecting piece joint prepared to 38MPa.

[0154] Table 9 is the Ti-Si eutectic ribbon solder composition of the examples and comparative examples and its welding parameters:

[0155]

[0156]

[0157] The above examples are possible embodiments of the present application, but the embodiments of the present application are not limited to the above examples, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application are equivalent replacement methods, and are included in the protection scope of the present application.

Claims

1. A method for welding ceramics using Ti-Si eutectic ribbon solder, characterized in that, The Ti-Si eutectic ribbon solder comprises Ti-Si eutectic powder, binder, dispersant, and plasticizer; the atomic ratio of Ti to Si in the Ti-Si eutectic powder is (16-30):(84-70); the mass ratio of dispersant to Ti-Si eutectic powder is (1.2-3.5):(50-60); the mass ratio of binder to Ti-Si eutectic powder is (2.5-5.5):(50-60); the mass ratio of plasticizer to Ti-Si eutectic powder is (1.3-6):(50-60); the ceramic is silicon carbide ceramic or silicon carbide ceramic-based composite material. The method for welding ceramics using Ti-Si eutectic ribbon solder includes: (1) After cutting the Ti-Si eutectic ribbon solder according to the shape of the welding surface, place it flat between the two ceramic end faces to be welded to form a sandwich structure base material; (2) The base material of the sandwich structure is fixed with a graphite mold and placed in a high-temperature brazing furnace to complete the vacuum brazing process, thereby achieving the connection of ceramics; the vacuum brazing process includes: vacuum degree ≤ 5×10 -3 The vacuum conditions are Pa, with a temperature of 1300–1330 °C and a duration of 10–30 minutes.

2. The method according to claim 1, characterized in that, The particle size of the Ti-Si eutectic powder is ≤25μm.

3. The method according to claim 2, characterized in that, The particle size of the Ti-Si eutectic powder is ≤15μm.

4. The method according to claim 1, characterized in that, The dispersant is at least one of castor oil phosphate, trioleic acid glycerol, phenylphosphine, and fish oil.

5. The method according to claim 1, characterized in that, The adhesive is at least one of polyvinyl butyral, polymethyl acrylate, polyvinyl alcohol, and polymethyl methacrylate.

6. The method according to claim 1, characterized in that, The plasticizer is at least one of dimethyl phthalate, xylene phosphate, polyethylene glycol, and titanate.

7. The method according to claim 1, characterized in that, The thickness of the Ti-Si eutectic ribbon solder is 0.05–0.3 mm; the Ti-Si eutectic ribbon solder can be folded more than 150° without breaking.

8. The method according to claim 1, characterized in that, The method for preparing the Ti-Si eutectic ribbon solder includes: (1) The Ti-Si eutectic powder, solvent, binder, dispersant and plasticizer are mixed to obtain a mixed slurry; (2) The mixed slurry is degassed under vacuum and cast to obtain the Ti-Si eutectic ribbon solder.

9. The method according to claim 8, characterized in that, The method for preparing the Ti-Si eutectic powder includes: mechanically mixing Ti powder particles and Si powder particles and placing them in a water-cooled copper crucible; melting them 5 to 7 times under vacuum conditions using a vacuum arc melting device; controlling the ingot to be rotated 180° after each melting; and finally cooling them naturally to room temperature to obtain a Ti-Si eutectic ingot. The Ti-Si eutectic ingot is placed in a vibratory mill and pulverized by vibration, and then sieved to obtain the Ti-Si eutectic powder.

10. The method according to claim 9, characterized in that, The purity of the Ti powder particles is ≥99.99%, and the purity of the Si powder particles is ≥99.999%.

11. The method according to claim 9, characterized in that, The vacuum degree in the vacuum arc melting equipment is ≤8×10 -3 Pa, current range 120~260 A.

12. The method according to claim 9, characterized in that, The coefficient of thermal expansion of the prepared Ti-Si eutectic ingot is 5.5 × 10⁻⁶. -6 ~6.14×10 -6 ℃ -1 .

13. The method according to claim 9, characterized in that, The sieving process involves passing the material through a 400-mesh sieve.

14. The method according to claim 8, characterized in that, The solid content of the mixed slurry is 50-60 wt%; The solvent is a binary azeotropic solvent; the binary azeotropic solvent is a methyl ethyl ketone / n-acetone binary azeotropic solvent or a n-propanol / butyl acetate binary azeotropic solvent.

15. The method according to claim 14, characterized in that, The mass ratio of methyl ethyl ketone to n-acetone in the binary azeotropic solvent of methyl ethyl ketone / n-acetone is (2-4):(6-8).

16. The method according to claim 14, characterized in that, The mass ratio of methyl ethyl ketone to n-acetone in the binary azeotropic solvent of methyl ethyl ketone / n-acetone is 3:

7.

17. The method according to claim 14, characterized in that, The mass ratio of n-propanol to butyl acetate in the binary azeotropic solvent is (10-17):(8-15).

18. The method according to claim 14, characterized in that, The mass ratio of n-propanol to butyl acetate in the binary azeotropic solvent is 13:

12.

19. The method according to claim 8, characterized in that, The vacuum degree of the vacuum degassing is ≤5×10⁻⁶. -1 Pa, time is 30-60 min; The parameters for the casting process include: the height of the scraper is 0.05mm to 0.3mm.

20. The method according to claim 1, characterized in that, The ceramic is atmospheric pressure sintered silicon carbide ceramic, reaction sintered silicon carbide ceramic, hot-pressed silicon carbide ceramic, or chemical vapor deposition silicon carbide ceramic.

21. The method according to claim 1, characterized in that, The vacuum brazing process includes: ≤5×10 -3 Under vacuum conditions of Pa, the temperature is increased to 650℃ at 5-10℃ / min and held for 30 min, then increased to 1300-1330℃ at 5-10℃ / min and held for 10-30 min, and finally cooled to 600℃ at 5℃ / min and cooled to room temperature in the furnace.

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