Method for brazing carbon ceramic friction material parts and metal back plate with Ti-Fe brazing sheet and brazed parts

Abstract

The present invention proposes a method and a brazing part for brazing a carbon-ceramic friction material part and a metal backing plate with a Ti-Fe brazing sheet, the method comprising the following steps: obtaining a Ti-Fe brazing sheet, a carbon-ceramic friction material part and a metal backing plate, wherein the carbon-ceramic friction material part comprises carbon fiber, a carbon matrix and a SiC matrix, and the metal backing plate comprises an Fe element; pre-treating the surface to be welded of the carbon-ceramic friction material part and the surface to be welded of the metal backing plate; placing the Ti-Fe brazing sheet between the pre-treated surface to be welded of the carbon-ceramic friction material part and the surface to be welded of the metal backing plate to obtain an assembly part; placing the assembly part in a vacuum brazing furnace, evacuating the vacuum, then starting a heating program, and then cooling to room temperature to obtain a brazed part. The connection strength, high temperature resistance and long-term service reliability of the sandwich structure brazing parts manufactured by the present invention are all more excellent.

Description

Technical Field

[0001] The invention relates to the technical field of composite structure brazing, and in particular to a method for brazing a carbon ceramic friction material part and a metal back plate with a Ti-Fe brazing sheet, and a brazed part. Background Art

[0002] With the development of modern aerospace and rail transportation, the demand for high-performance vehicles such as high-speed trains and airplanes is increasing. These vehicles require efficient and reliable braking systems during high-speed operation to ensure the safety of passengers and the performance of the vehicle. In high-speed braking systems, the carbon-ceramic friction material / metal backing plate sandwich structure is a crucial component. The carbon-ceramic friction material generates braking force through friction with the brake disc or brake drum, and its performance directly affects the braking effect and the safety of the system. The metal backing plate provides the necessary structural support and heat conduction path to ensure that the carbon-ceramic friction material does not deform or fail under high temperature conditions. The carbon-ceramic friction material currently used is usually made of C f They are made of C / C-SiC composites or C / C-SiC composites, and they need to be firmly bonded to a metal backing plate (carbon steel, gray cast iron or stainless steel) to ensure that they do not separate or fall off under high temperature, high pressure and high frequency use conditions.

[0003] The existing manufacturing method is mainly based on adhesive connection. Although the adhesive connection method performs well in some applications, it has many shortcomings under the harsh conditions of high-speed braking systems, such as insufficient connection strength, poor high temperature resistance, and easy aging during long-term service. Summary of the invention

[0004] In order to solve the technical problems of insufficient connection strength, poor high temperature resistance and easy aging in long-term service of the carbon-ceramic friction material / metal back plate manufactured by the above-mentioned adhesive, the purpose of the present invention is to provide a method for brazing a carbon-ceramic friction material and a metal back plate with a Ti-Fe brazing sheet and a brazed part, and the technical scheme adopted is as follows:

[0005] In a first aspect, an embodiment of the present invention provides a method for brazing a carbon-ceramic friction material part and a metal back plate with a Ti-Fe brazing sheet, the method comprising the following steps:

[0006] Obtaining a Ti-Fe brazing sheet, a carbon-ceramic friction material piece and a metal back plate, wherein the carbon-ceramic friction material piece comprises carbon fiber, a carbon matrix and a SiC matrix, and the metal back plate comprises an Fe element;

[0007] Pre-treating the surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal back plate;

[0008] Placing the Ti-Fe brazing sheet between the pre-treated surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal back plate to obtain an assembly;

[0009] The assembly is placed in a vacuum brazing furnace, evacuated, and then a heating program is started, followed by cooling to room temperature to obtain a brazed part.

[0010] In some possible embodiments, the step of obtaining the Ti-Fe solder sheet includes:

[0011] Put high-purity titanium blocks and high-purity iron blocks as samples into a water-cooled crucible of an arc melting furnace, evacuate the furnace, and then introduce argon gas. Load current for arc melting. Each melting time is 2 to 4 minutes. The samples need to be fully turned over during the melting process.

[0012] The sample is smelted 6 to 10 times to obtain a Ti-Fe alloy ingot;

[0013] The Ti—Fe alloy ingot is cut into Ti—Fe brazing filler metal sheets.

[0014] In some possible embodiments, the thickness of the Ti—Fe solder sheet ranges from 0.1 mm to 0.4 mm.

[0015] In some possible embodiments, the atomic percentage of Ti in the Ti-Fe solder sheet is 62% to 76%, and the remainder is Fe.

[0016] In some possible embodiments, the current set during the smelting process ranges from 200A to 240A.

[0017] In some possible embodiments, the step of pretreating the surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal back plate comprises:

[0018] Grinding the surface to be welded of the carbon ceramic friction material piece and the surface to be welded of the metal back plate with 400#, 800# and 1200# SiC sandpaper in sequence;

[0019] The polished carbon-ceramic friction material piece and the metal back plate are then placed in anhydrous ethanol for ultrasonic cleaning for 10 to 20 minutes to remove tiny particles and polishing residues on the surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal back plate polished with sandpaper.

[0020] In some possible embodiments, after the vacuum brazing furnace is evacuated, the vacuum degree in the furnace chamber is lower than 5.0×10 -3 Pa.

[0021] In some possible embodiments, the step of placing the assembly in a vacuum brazing furnace, evacuating the furnace, and then starting a heating process, followed by cooling to room temperature, to obtain a brazed part includes:

[0022] Starting from room temperature, the temperature is increased to 850°C to 950°C at a heating rate of 10°C / min to 20°C / min and kept at this temperature for 5min to 15min, so that the temperature in the vacuum brazing furnace is uniform;

[0023] Raise the temperature to 1100°C to 1220°C at a heating rate of 5°C / min to 10°C / min and keep the temperature for 5min to 30min;

[0024] The temperature is lowered to 250° C. to 350° C. at a cooling rate of 3° C. / min to 7° C. / min, and then cooled to room temperature along with the vacuum brazing furnace.

[0025] In some possible embodiments, the carbon ceramic friction material piece is composed of C f The metal back plate is made of C / C-SiC composite material and / or C / C-SiC composite material, and the material of the metal back plate is one of carbon steel, gray cast iron or stainless steel.

[0026] In a second aspect, an embodiment of the present invention provides a brazing part, which is prepared by the method as described above.

[0027] The present invention has the following beneficial effects:

[0028] In the manufacturing process of traditional sandwich structures, the connection between carbon-ceramic friction material parts and metal backing plates is usually the weak link of the entire structure. By using Ti-Fe brazing filler metal for brazing of carbon-ceramic friction material parts / metal backing plates sandwich structures, the long-term service reliability in the harsh service environment of high-speed braking systems can be effectively improved, and many shortcomings of traditional adhesive connection methods can be overcome. During brazing manufacturing, the Ti element in the liquid brazing filler metal reacts with the metal backing plate (mainly Fe element) and the carbon-ceramic friction material (mainly carbon fiber, carbon matrix and SiC matrix) to form an interface reaction layer to obtain a brazed part of the sandwich structure. Since the metal backing plate is generally made of a metal material mainly composed of Fe element, by adding Fe element to the brazing filler metal, the wettability of the liquid brazing filler metal on the carbon-ceramic friction material parts and the metal backing plate can be improved, and at the same time, the gradient transition of the thermophysical properties (thermal expansion coefficient, elastic modulus, Poisson's ratio, etc.) of the carbon-ceramic friction material parts / metal backing plate sandwich structure can be achieved, thereby reducing the thermal mismatch between the brazing filler metal and the carbon-ceramic friction material parts and the metal backing plate. Therefore, compared with the manufacturing method of traditional adhesives, the connection strength, high temperature resistance and long-term service reliability of the sandwich structure brazed parts manufactured using Ti-Fe brazing filler metal are all superior. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A flow chart of a method for brazing a carbon-ceramic friction material part and a metal back plate using a Ti-Fe brazing sheet is provided in accordance with an embodiment of the present invention.

[0031] Figure 2 yes Figure 1 Flow chart of the steps for obtaining Ti-Fe brazing sheet.

[0032] Figure 3 yes Figure 1 A flow chart of the steps of pretreating the surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal backing plate.

[0033] Figure 4 yes Figure 1 A flow chart of the steps of placing the assembly in a vacuum brazing furnace, evacuating the vacuum, and then starting the heating program, followed by cooling to room temperature to obtain a brazed part.

[0034] Figure 5 The figure is a schematic structural diagram of a brazing component provided by an embodiment of the present invention.

[0035] Figure 6 It is a scanning electron microscope photograph of the microstructure of the Ti-Fe solder sheet of the present invention.

[0036] Figure 7 This is an interface microstructure diagram of a sandwich structure manufactured by brazing according to Example 1 of the present invention.

[0037] Figure 8 This is a macroscopic photograph of the fracture of the sandwich structure manufactured by brazing according to Example 1 of the present invention after the shear strength test.

[0038] Fig. 9 It is a macroscopic photograph of a C / C-SiC composite material / 410B stainless steel sandwich structure brazed and manufactured using Ti-35Ni brazing filler metal, TiZrNiCu brazing filler metal, and pure Fe foil according to the experimental operation and brazing process in Example 1.

[0039] Fig.10 This is an interface microstructure diagram of a C / C-SiC composite material / 410B stainless steel sandwich structure brazed using pure Fe foil according to the experimental operation and brazing process in Example 1. DETAILED DESCRIPTION

[0040] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the method of brazing a carbon ceramic friction material part and a metal back plate with a Ti-Fe brazing sheet and a brazing part according to the present invention, its specific implementation method, structure, features and effects, in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

[0041] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0042] See also Figure 1 One embodiment of the present invention provides a method for brazing a carbon-ceramic friction material part and a metal back plate with a Ti-Fe brazing sheet, the method comprising the following steps:

[0043] S10, obtaining a Ti-Fe brazing sheet, a carbon-ceramic friction material piece and a metal back plate, wherein the carbon-ceramic friction material piece includes carbon fiber, a carbon matrix and a SiC matrix, and the metal back plate includes Fe element.

[0044] Among them, the carbon ceramic friction material is composed of C f The metal back plate is made of C / C-SiC composite material and / or C / C-SiC composite material, and the material of the metal back plate is one of carbon steel, gray cast iron or stainless steel.

[0045] The thickness of the Ti-Fe solder sheet ranges from 0.1 mm to 0.4 mm.

[0046] The atomic percentage of Ti in the Ti-Fe brazing filler sheet is 62% to 76%, and the rest is Fe. Thus, according to the Ti-Fe binary alloy phase diagram, at the selected Ti / Fe ratio, the melting point of the Ti-Fe alloy is lower than 1220°C, and lower than the melting point of metal backing materials such as carbon steel (about 1425°C), gray cast iron (about 1250°C) and stainless steel (about 1370 to 1450°C), thereby avoiding the melting of the metal backing due to excessively high temperature during the brazing manufacturing process.

[0047] See also Figure 2 The step of obtaining the Ti-Fe solder sheet comprises:

[0048] S11, high-purity titanium blocks and high-purity iron blocks are placed as samples in a water-cooled crucible of an arc melting furnace, vacuumed and then introduced with argon gas, current is loaded for arc melting, each melting time is 2 to 4 minutes, and the samples need to be fully turned over during the melting process.

[0049] In this way, it can be ensured that the raw materials are fully melted, and the problems of oxidation and material burning caused by long smelting time can be avoided.

[0050] S12, smelting the sample 6 to 10 times to obtain a Ti-Fe alloy ingot.

[0051] In this way, the composition of the solder can be ensured to be uniform. The current value range set during the smelting process is 200A to 240A.

[0052] S13, cutting the Ti-Fe alloy ingot into Ti-Fe brazing filler sheets.

[0053] Specifically, the Ti-Fe alloy ingot is cut into 0.5mm-0.7mm thick Ti-Fe brazing sheet by wire cutting, and then the surface is polished to remove oxide scale and oil stains, and then further polished to thin it to 0.1mm-0.4mm, so as to avoid the problem of insufficient metallurgical reaction and performance degradation caused by too thin or too thick brazing sheet, thereby obtaining Ti-Fe brazing sheet of required thickness.

[0054] S20, pre-treating the surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal back plate.

[0055] See also Figure 3 The step of pre-treating the surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal backing plate comprises:

[0056] S21, grinding the to-be-welded surface of the carbon-ceramic friction material part and the to-be-welded surface of the metal back plate with 400#, 800# and 1200# SiC sandpapers in sequence;

[0057] S22, placing the polished carbon-ceramic friction material piece and the metal back plate in anhydrous ethanol for ultrasonic cleaning for 10 minutes to 20 minutes to remove tiny particles and polishing residues on the surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal back plate polished by sandpaper.

[0058] S30, placing a Ti-Fe brazing sheet between the pre-treated surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal back plate to obtain an assembly.

[0059] S40, placing the assembly in a vacuum brazing furnace, evacuating the furnace, and then starting a heating program, followed by cooling to room temperature, thereby obtaining a brazed part.

[0060] Among them, after the vacuum brazing furnace is evacuated, the vacuum degree in the furnace chamber is less than 5.0×10 -3 Pa.

[0061] Specifically, see Figure 4The steps of placing the assembly in a vacuum brazing furnace, evacuating the vacuum, and then starting a heating process, followed by cooling to room temperature, thereby obtaining a brazed part include:

[0062] S41, starting from room temperature, the temperature is increased to 850°C to 950°C at a heating rate of 10°C / min to 20°C / min and kept at this temperature for 5min to 15min, so as to make the temperature in the vacuum brazing furnace uniform.

[0063] S42, heating to 1100°C-1220°C at a heating rate of 5°C / min-10°C / min and keeping the temperature for 5min-30min.

[0064] S43, cooling to 250°C to 350°C at a cooling rate of 3°C / min to 7°C / min, and then cooling to room temperature in a vacuum brazing furnace.

[0065] See also Figure 5 An embodiment of the present invention provides a brazing component 100, including a carbon-ceramic friction material component 10, a metal backing plate 20 and a Ti-Fe brazing sheet 30, wherein the Ti-Fe brazing sheet 30 is connected between the carbon-ceramic friction material component 10 and the metal backing plate 20.

[0066] The present invention has the following beneficial effects:

[0067] In the manufacturing process of traditional sandwich structures, the connection between carbon-ceramic friction material parts and metal backing plates is usually the weak link of the entire structure. By using Ti-Fe brazing filler metal for brazing of carbon-ceramic friction material parts / metal backing plate sandwich structures, the long-term service reliability in the harsh service environment of high-speed braking systems can be effectively improved, and many shortcomings of traditional adhesive connection methods can be overcome. During brazing manufacturing, the Ti element in the liquid brazing filler metal reacts with the metal backing plate (mainly Fe element) and the carbon-ceramic friction material (mainly carbon fiber, carbon matrix and SiC matrix) to form an interface reaction layer to obtain a brazed part of the sandwich structure. Since the metal backing plate is generally made of a metal material mainly composed of Fe element, by adding Fe element to the brazing filler metal, the gradient transition of the thermophysical properties (thermal expansion coefficient, elastic modulus, Poisson's ratio, etc.) of the carbon-ceramic friction material parts / metal backing plate sandwich structure can be achieved, thereby improving the wettability of the liquid brazing filler metal on the metal backing plate and reducing the thermal mismatch between the brazing filler metal and the carbon-ceramic friction material parts and the metal backing plate. Therefore, compared with the manufacturing method of traditional adhesives, the connection strength, high temperature resistance and long-term service reliability of the sandwich structure brazed parts manufactured using Ti-Fe brazing filler metal are all superior.

[0068] The technical solution of the present application is not limited to the specific implementation modes given below, but also includes any combination of the specific implementation modes.

[0069] Example 1

[0070] The method of brazing a carbon-ceramic friction material piece and a metal back plate with a Ti-Fe brazing sheet in this embodiment comprises the following steps:

[0071] A high-purity titanium block and a high-purity iron block with a preset weight are placed as samples in a water-cooled crucible of an arc melting furnace, and then evacuated and argon gas is introduced. A current is loaded for arc melting. The current set during the melting process is 220A, and the melting time is 3 minutes each time. The samples need to be fully turned over during the melting process.

[0072] The sample was melted 8 times to obtain a Ti-Fe alloy ingot;

[0073] The Ti-Fe alloy ingot is cut into 0.6 mm thick Ti-Fe brazing sheet by wire cutting, and then the surface is polished to remove oxide scale and oil stains, and then further polished to thin to 0.3 mm to obtain the Ti-Fe brazing sheet of required thickness, wherein the atomic percentage of Ti in the Ti-Fe brazing sheet is 70% and the rest is Fe;

[0074] The surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal back plate are polished in sequence with 400#, 800# and 1200# SiC sandpapers, wherein the carbon-ceramic friction material piece is a C / C-SiC composite material, and the metal back plate is 410B stainless steel;

[0075] The polished carbon ceramic friction material and metal back plate were then placed in anhydrous ethanol for ultrasonic cleaning for 10 minutes, taken out and blown dry;

[0076] placing a Ti-Fe brazing sheet between the pre-treated surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal backing plate to obtain an assembly;

[0077] Place the assembly in a vacuum brazing furnace and evacuate the furnace until the vacuum degree in the furnace chamber is less than 5.0×10 -3 Pa, and then start the heating program, specifically, first start from room temperature to 900 ° C at a heating rate of 10 ° C / min and keep it for 10 min, then increase the temperature to the brazing temperature of 1140 ° C at a heating rate of 5 ° C / min and keep it for 15 min, finally cool down to 300 ° C at a cooling rate of 5 ° C / min, and then cool to room temperature to obtain a brazed part.

[0078] In this embodiment, the microstructure of the Ti-Fe alloy obtained by arc melting is as follows: Figure 6 As shown in Figure 1, the alloy is mainly composed of a eutectic structure consisting of a Ti-based solid solution and a TiFe compound. Figure 7As shown in the figure, the brazing connection between the carbon ceramic friction material and the metal back plate is achieved by using Ti-Fe brazing sheet, and there are no obvious metallurgical defects such as cracks and holes at the interface. In this embodiment, the brazing area of ​​the brazed part is 5mm*5mm. The shear strength test of the brazed part shows that the shear strength of the brazed part is 40.8MPa, and the fracture position is the C / C-SiC composite material / Ti-Fe brazing sheet interface reaction layer. The fracture macroscopic photo is shown in Figure 8 shown.

[0079] Comparative Example 1

[0080] The method for brazing a carbon-ceramic friction material part and a metal back plate with a Ti-Ni brazing sheet in this comparative example comprises the following steps:

[0081] A high-purity titanium block and a high-purity nickel block of preset weight are placed as samples in a water-cooled crucible of an arc melting furnace, and then evacuated and argon gas is introduced. A current is loaded for arc melting. The current set during the melting process is 220A, and the melting time is 3 minutes each time. The samples need to be fully turned over during the melting process.

[0082] The sample was melted 8 times to obtain a Ti-Ni alloy ingot;

[0083] The Ti-Ni alloy ingot is cut into 0.6 mm thick Ti-Ni brazing sheet by wire cutting, and then the surface is polished to remove oxide scale and oil stains, and then further polished to thin to 0.3 mm to obtain the Ti-Ni brazing sheet of the required thickness, wherein the atomic percentage of Ni in the Ti-Ni brazing sheet is 35% and the rest is Ti;

[0084] The surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal back plate are polished in sequence with 400#, 800# and 1200# SiC sandpapers, wherein the carbon-ceramic friction material piece is a C / C-SiC composite material, and the metal back plate is 410B stainless steel;

[0085] The polished carbon ceramic friction material and metal back plate were placed in anhydrous ethanol for ultrasonic cleaning for 10 minutes, taken out and blown dry;

[0086] Placing a Ti-Ni brazing sheet between the pre-treated surface to be welded of the carbon ceramic friction material piece and the surface to be welded of the metal backing plate to obtain an assembly;

[0087] Place the assembly in a vacuum brazing furnace and evacuate the furnace until the vacuum degree in the furnace chamber is less than 5.0×10 -3Pa, and then start the heating program, specifically, first start from room temperature to 900 °C at a heating rate of 10 °C / min and keep it for 10 min, then heat up to the brazing temperature of 1140 °C at a heating rate of 5 °C / min and keep it for 15 min, finally cool to 300 °C at a cooling rate of 5 °C / min, and then cool to room temperature.

[0088] In the comparative example, Fig. 9 As shown in the figure, the carbon-ceramic friction material part and the metal back plate cannot be connected by using Ti-Ni brazing filler metal. It can be seen that this is caused by the large difference in thermal expansion coefficient between 410B stainless steel and C / C-SiC composite material and Ti-Ni brazing filler metal, and the excessive Ti-Ni brittle compounds contained in the Ti-Ni brazing filler metal.

[0089] Comparative Example 2

[0090] The method of brazing a carbon ceramic friction material part and a metal back plate with a TiZrNiCu brazing sheet in this comparative example comprises the following steps:

[0091] High-purity titanium blocks, zirconium blocks, nickel blocks and copper blocks of preset weights are placed as samples in a water-cooled crucible of an arc melting furnace, evacuated and then introduced with argon gas, and current is loaded for arc melting. The current set for the melting process is 220A, and the melting time for each time is 3 minutes. The samples need to be fully turned over during the melting process;

[0092] The sample was melted 8 times to obtain a TiZrNiCu alloy ingot;

[0093] The TiZrNiCu alloy ingot is cut into 0.6 mm thick TiZrNiCu solder sheets by wire cutting, and then the surface is polished to remove oxide scale and oil stains, and then the surface is further polished to be thinned to 0.3 mm to obtain a TiZrNiCu solder sheet of the required thickness, wherein the mass percentage of Zr in the TiZrNiCu solder sheet is 38.65%, the mass percentage of Ni is 10.1%, the mass percentage of Cu is 15.7%, and the rest is Ti;

[0094] The surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal back plate are polished in sequence with 400#, 800# and 1200# SiC sandpapers, wherein the carbon-ceramic friction material piece is a C / C-SiC composite material, and the metal back plate is 410B stainless steel;

[0095] The polished carbon ceramic friction material and metal back plate were placed in anhydrous ethanol for ultrasonic cleaning for 10 minutes, taken out and blown dry;

[0096] Placing a TiZrNiCu brazing sheet between the pre-treated surface to be welded of the carbon ceramic friction material piece and the surface to be welded of the metal backing plate to obtain an assembly;

[0097] Place the assembly in a vacuum brazing furnace and evacuate the furnace until the vacuum degree in the furnace chamber is less than 5.0×10 -3 Pa, and then start the heating program, specifically, first start from room temperature to 600 ° C at a heating rate of 10 ° C / min and keep it for 10 min, then increase the temperature to the brazing temperature of 1050 ° C at a heating rate of 5 ° C / min and keep it for 10 min, finally cool down to 300 ° C at a cooling rate of 5 ° C / min, and then cool to room temperature.

[0098] In this comparative example, Fig. 9 As shown, similar to Comparative Example 1, the carbon-ceramic friction material part and the metal back plate cannot be connected using the TiZrNiCu solder. This is because the thermal expansion coefficients of the 410B stainless steel and C / C-SiC composite material are too different from those of the TiZrNiCu solder.

[0099] Comparative Example 3

[0100] The method for brazing the carbon ceramic friction material piece and the metal back plate with the pure Fe foil in this comparative example comprises the following steps:

[0101] The surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal back plate are polished in sequence with 400#, 800# and 1200# SiC sandpapers, wherein the carbon-ceramic friction material piece is a C / C-SiC composite material, and the metal back plate is 410B stainless steel;

[0102] The polished carbon ceramic friction material and metal back plate were placed in anhydrous ethanol for ultrasonic cleaning for 10 minutes, taken out and blown dry;

[0103] Placing a 0.05 mm thick pure Fe foil between the pre-treated carbon ceramic friction material surface to be welded and the metal backing plate surface to be welded to obtain an assembly;

[0104] Place the assembly in a vacuum brazing furnace and evacuate the furnace until the vacuum degree in the furnace chamber is less than 5.0×10 -3 Pa, and then start the heating program, specifically, first start from room temperature to 900 ° C at a heating rate of 10 ° C / min and keep it for 10 min, then increase the temperature to the brazing temperature of 1160 ° C at a heating rate of 5 ° C / min and keep it for 10 min, finally cool down to 300 ° C at a cooling rate of 5 ° C / min, and then cool to room temperature.

[0105] In this comparative example, Fig. 9 and Fig.10 As shown in the figure, although the connection can be achieved when pure Fe foil is used, the 410B stainless steel base material has a serious dissolution phenomenon, and there is an obvious transition reaction between the pure Fe foil and the C / C-SiC composite material, which is not suitable for the brazing of the carbon-ceramic friction material / metal back plate sandwich structure in the high-speed braking system.

[0106] Example 2

[0107] The method of brazing a carbon-ceramic friction material piece and a metal back plate with a Ti-Fe brazing sheet in this embodiment comprises the following steps:

[0108] A high-purity titanium block and a high-purity iron block with a preset weight are placed as samples in a water-cooled crucible of an arc melting furnace, and then evacuated and argon gas is introduced. A current is loaded for arc melting. The current set during the melting process is 240A, and the melting time is 4 minutes each time. The samples need to be fully turned over during the melting process.

[0109] The sample was melted 9 times to obtain a Ti-Fe alloy ingot;

[0110] The Ti-Fe alloy ingot is cut into 0.5 mm thick Ti-Fe brazing sheet by wire cutting, and then the surface is polished to remove oxide scale and oil stains, and then further polished to thin to 0.3 mm to obtain the Ti-Fe brazing sheet of required thickness, wherein the atomic percentage of Ti in the Ti-Fe brazing sheet is 67% and the rest is Fe;

[0111] Use 400#, 800# and 1200# SiC sandpaper to grind the surface to be welded of the carbon ceramic friction material and the surface to be welded of the metal back plate. f / SiC composite material, the metal back plate is 410B stainless steel;

[0112] The polished carbon ceramic friction material and metal back plate were then placed in anhydrous ethanol for ultrasonic cleaning for 10 minutes, taken out and blown dry;

[0113] placing a Ti-Fe brazing sheet between the pre-treated surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal backing plate to obtain an assembly;

[0114] Place the assembly in a vacuum brazing furnace and evacuate the furnace until the vacuum degree in the furnace chamber is less than 5.0×10 -3 Pa, and then start the heating program, specifically, first start from room temperature to 900 ° C at a heating rate of 10 ° C / min and keep it for 10 min, then heat it to the brazing temperature of 1160 ° C at a heating rate of 5 ° C / min and keep it for 15 min, finally cool it to 300 ° C at a cooling rate of 5 ° C / min, and then cool it to room temperature to obtain a brazed part.

[0115] In this embodiment, the brazing area of ​​the brazing piece is 5mm*5mm. The shear strength test of the brazing piece is carried out. The measurement results show that the shear strength of the brazing piece is 46.5MPa and the fracture position is C f / SiC composite material / Ti-Fe solder sheet interface reaction layer.

[0116] Example 3

[0117] The method of brazing a carbon-ceramic friction material piece and a metal back plate with a Ti-Fe brazing sheet in this embodiment comprises the following steps:

[0118] A high-purity titanium block and a high-purity iron block of preset weight are placed as samples in a water-cooled crucible of an arc melting furnace, and then evacuated and argon gas is introduced. A current is loaded for arc melting. The current set during the melting process is 200A, and the melting time is 2 minutes each time. The samples need to be fully turned over during the melting process.

[0119] The sample was melted 8 times to obtain a Ti-Fe alloy ingot;

[0120] The Ti-Fe alloy ingot is cut into 0.7 mm thick Ti-Fe brazing sheet by wire cutting, and then the surface is polished to remove oxide scale and oil stains, and then further polished to thin to 0.3 mm to obtain the Ti-Fe brazing sheet of required thickness, wherein the atomic percentage of Ti in the Ti-Fe brazing sheet is 70% and the rest is Fe;

[0121] The surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal backing plate are polished in sequence with 400#, 800# and 1200# SiC sandpapers, wherein the carbon-ceramic friction material piece is a C / C-SiC composite material and the metal backing plate is carbon steel;

[0122] The polished carbon ceramic friction material and metal back plate were then placed in anhydrous ethanol for ultrasonic cleaning for 20 minutes, taken out and blown dry;

[0123] placing a Ti-Fe brazing sheet between the pre-treated surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal backing plate to obtain an assembly;

[0124] Place the assembly in a vacuum brazing furnace and evacuate the furnace until the vacuum degree in the furnace chamber is less than 5.0×10 -3 Pa, and then start the heating program, specifically, first start from room temperature to 900 ° C at a heating rate of 10 ° C / min and keep it for 10 min, then increase the temperature to the brazing temperature of 1100 ° C at a heating rate of 5 ° C / min and keep it for 10 min, finally cool down to 300 ° C at a cooling rate of 5 ° C / min, and then cool to room temperature to obtain a brazed part.

[0125] In this embodiment, the brazing area of ​​the brazing part is 5mm*5mm. The shear strength test of the brazing part is carried out. The measurement results show that the shear strength of the brazing part is 38.2MPa, and the fracture position is the C / C-SiC composite material / Ti-Fe brazing sheet interface reaction layer.

[0126] Example 4

[0127] The method of brazing a carbon-ceramic friction material piece and a metal back plate with a Ti-Fe brazing sheet in this embodiment comprises the following steps:

[0128] A high-purity titanium block and a high-purity iron block with a preset weight are placed as samples in a water-cooled crucible of an arc melting furnace, and then evacuated and argon gas is introduced. A current is loaded for arc melting. The current set during the melting process is 210A, and the melting time is 3 minutes each time. The samples need to be fully turned over during the melting process.

[0129] The sample was melted 10 times to obtain a Ti-Fe alloy ingot;

[0130] The Ti-Fe alloy ingot is cut into 0.6 mm thick Ti-Fe brazing sheet by wire cutting, and then the surface is polished to remove oxide scale and oil stains, and then further polished to thin to 0.1 mm to obtain the Ti-Fe brazing sheet of required thickness, in which the atomic percentage of Ti is 72% and the rest is Fe;

[0131] Use 400#, 800# and 1200# SiC sandpaper to grind the surface to be welded of the carbon ceramic friction material and the surface to be welded of the metal back plate. f / SiC composite material, the metal back plate is gray cast iron;

[0132] The polished carbon ceramic friction material and metal back plate were then placed in anhydrous ethanol for ultrasonic cleaning for 12 minutes, taken out and blown dry;

[0133] placing a Ti-Fe brazing sheet between the pre-treated surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal backing plate to obtain an assembly;

[0134] Place the assembly in a vacuum brazing furnace and evacuate the furnace until the vacuum degree in the furnace chamber is less than 5.0×10 -3 Pa, and then start the heating program, specifically, first start from room temperature to 900 ° C at a heating rate of 10 ° C / min and keep it for 10 min, then heat it to the brazing temperature of 1120 ° C at a heating rate of 5 ° C / min and keep it for 15 min, finally cool it to 300 ° C at a cooling rate of 5 ° C / min, and then cool it to room temperature to obtain a brazed part.

[0135] In this embodiment, the brazing area of ​​the brazing piece is 5mm*5mm. The shear strength test of the brazing piece is carried out. The measurement results show that the shear strength of the brazing piece is 36.7MPa and the fracture position is C f / SiC composite material / Ti-Fe solder sheet interface reaction layer.

[0136] Example 5

[0137] The method of brazing a carbon-ceramic friction material piece and a metal back plate with a Ti-Fe brazing sheet in this embodiment comprises the following steps:

[0138] A high-purity titanium block and a high-purity iron block with a preset weight are placed as samples in a water-cooled crucible of an arc melting furnace, and then evacuated and argon gas is introduced. A current is loaded for arc melting. The current set during the melting process is 220A, and the melting time is 3 minutes each time. The samples need to be fully turned over during the melting process.

[0139] The sample was melted six times to obtain a Ti-Fe alloy ingot;

[0140] The Ti-Fe alloy ingot is cut into 0.5 mm thick Ti-Fe brazing sheet by wire cutting, and then the surface is polished to remove oxide scale and oil stains, and then further polished to thin to 0.2 mm to obtain the Ti-Fe brazing sheet of required thickness, in which the atomic percentage of Ti is 73% and the rest is Fe;

[0141] The surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal back plate are polished in sequence with 400#, 800# and 1200# SiC sandpapers, wherein the carbon-ceramic friction material piece is a C / C-SiC composite material and the metal back plate is gray cast iron;

[0142] The polished carbon ceramic friction material and metal back plate were then placed in anhydrous ethanol for ultrasonic cleaning for 15 minutes, taken out and blown dry;

[0143] placing a Ti-Fe brazing sheet between the pre-treated surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal backing plate to obtain an assembly;

[0144] Place the assembly in a vacuum brazing furnace and evacuate the furnace until the vacuum degree in the furnace chamber is less than 5.0×10 -3 Pa, and then start the heating program, specifically, first start from room temperature to 900 ° C at a heating rate of 10 ° C / min and keep it for 10 min, then increase the temperature to the brazing temperature of 1120 ° C at a heating rate of 5 ° C / min and keep it for 30 min, finally cool down to 300 ° C at a cooling rate of 5 ° C / min, and then cool to room temperature to obtain a brazed part.

[0145] In this embodiment, the brazing area of ​​the brazing part is 5mm*5mm. The shear strength test of the brazing part is carried out. The measurement results show that the shear strength of the brazing part is 32.6MPa, and the fracture position is the C / C-SiC composite material / Ti-Fe brazing material interface reaction layer.

[0146] Example 6

[0147] The method of brazing a carbon-ceramic friction material piece and a metal back plate with a Ti-Fe brazing sheet in this embodiment comprises the following steps:

[0148] A high-purity titanium block and a high-purity iron block with a preset weight are placed as samples in a water-cooled crucible of an arc melting furnace, and then evacuated and argon gas is introduced. A current is loaded for arc melting. The current set during the melting process is 230A, and the melting time is 2 minutes each time. The samples need to be fully turned over during the melting process.

[0149] The sample was melted 8 times to obtain a Ti-Fe alloy ingot;

[0150] The Ti-Fe alloy ingot is cut into 0.6 mm thick Ti-Fe brazing sheet by wire cutting, and then the surface is polished to remove oxide scale and oil stains, and then further polished to thin to 0.4 mm to obtain the Ti-Fe brazing sheet of required thickness, wherein the atomic percentage of Ti in the Ti-Fe brazing sheet is 75% and the rest is Fe;

[0151] Use 400#, 800# and 1200# SiC sandpaper to grind the surface to be welded of the carbon ceramic friction material and the surface to be welded of the metal back plate. f / SiC composite material, the metal back plate is carbon steel;

[0152] The polished carbon ceramic friction material and metal back plate were then placed in anhydrous ethanol for ultrasonic cleaning for 18 minutes, taken out and blown dry;

[0153] placing a Ti-Fe brazing sheet between the pre-treated surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal backing plate to obtain an assembly;

[0154] Place the assembly in a vacuum brazing furnace and evacuate the furnace until the vacuum degree in the furnace chamber is less than 5.0×10 -3 Pa, and then start the heating program, specifically, first start from room temperature to 900 ° C at a heating rate of 10 ° C / min and keep it for 10 min, then increase the temperature to the brazing temperature of 1140 ° C at a heating rate of 5 ° C / min and keep it for 5 min, finally cool down to 300 ° C at a cooling rate of 5 ° C / min, and then cool to room temperature to obtain a brazed part.

[0155] In this embodiment, the brazing area of ​​the brazing piece is 5mm*5mm. The shear strength test of the brazing piece is carried out. The measurement results show that the shear strength of the brazing piece is 34.8MPa and the fracture position is C. f / SiC composite material / Ti-Fe solder interface reaction layer.

[0156] It should be noted that the sequence of the embodiments of the present invention described above is for description only and does not represent the advantages and disadvantages of the embodiments. The above describes specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0157] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0158] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for brazing a carbon ceramic friction material part and a metal back plate with a Ti-Fe brazing sheet, characterized in that: The method comprises the following steps: Obtaining a Ti-Fe brazing sheet, a carbon-ceramic friction material piece and a metal backing plate, wherein the carbon-ceramic friction material piece comprises carbon fiber, a carbon matrix and a SiC matrix, the metal backing plate comprises an Fe element, and the atomic percentage of Ti in the Ti-Fe brazing sheet is 62% to 76%, and the remainder is Fe; Pre-treating the surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal back plate; Placing the Ti-Fe brazing sheet between the pre-treated surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal back plate to obtain an assembly; The assembly is placed in a vacuum brazing furnace, evacuated, and then a heating program is started, followed by cooling to room temperature to obtain a brazed part.

2. The method for brazing a carbon-ceramic friction material part and a metal back plate with a Ti-Fe brazing sheet according to claim 1, characterized in that: The step of obtaining the Ti-Fe solder sheet comprises: Put high-purity titanium blocks and high-purity iron blocks as samples into a water-cooled crucible of an arc melting furnace, evacuate the furnace, and then introduce argon gas. Load current for arc melting. Each melting time is 2 to 4 minutes. The samples need to be fully turned over during the melting process. The sample is smelted 6 to 10 times to obtain a Ti-Fe alloy ingot; The Ti—Fe alloy ingot is cut into Ti—Fe brazing filler metal sheets.

3. The method for brazing a carbon-ceramic friction material part and a metal back plate with a Ti-Fe brazing sheet according to claim 2, characterized in that: The thickness of the Ti-Fe solder sheet ranges from 0.1 mm to 0.4 mm.

4. The method for brazing a carbon-ceramic friction material part and a metal back plate with a Ti-Fe brazing sheet according to claim 2, characterized in that: The current set during the smelting process ranges from 200A to 240A.

5. The method for brazing a carbon-ceramic friction material part and a metal back plate with a Ti-Fe brazing sheet according to claim 1, characterized in that: The step of pre-treating the surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal back plate comprises: Grinding the surface to be welded of the carbon ceramic friction material piece and the surface to be welded of the metal back plate with 400#, 800# and 1200# SiC sandpaper in sequence; The polished carbon-ceramic friction material piece and the metal back plate are then placed in anhydrous ethanol for ultrasonic cleaning for 10 to 20 minutes to remove tiny particles and polishing residues on the surface to be welded of the carbon-ceramic friction material piece and the surface to be welded of the metal back plate polished with sandpaper.

6. The method for brazing a carbon-ceramic friction material part and a metal back plate with a Ti-Fe brazing sheet according to claim 1, characterized in that: After the vacuum brazing furnace is evacuated, the vacuum degree in the furnace chamber is less than 5.0×10 -3 Pa.

7. The method for brazing a carbon-ceramic friction material part and a metal back plate with a Ti-Fe brazing sheet according to claim 1, characterized in that: The steps of placing the assembly in a vacuum brazing furnace, evacuating the vacuum, then starting a heating process, and then cooling to room temperature to obtain a brazed part include: Starting from room temperature, the temperature is increased to 850°C to 950°C at a heating rate of 10°C / min to 20°C / min and kept at this temperature for 5min to 15min, so that the temperature in the vacuum brazing furnace is uniform; Raise the temperature to 1100°C to 1220°C at a heating rate of 5°C / min to 10°C / min and keep the temperature for 5min to 30min; The temperature is lowered to 250° C. to 350° C. at a cooling rate of 3° C. / min to 7° C. / min, and then cooled to room temperature along with the vacuum brazing furnace.

8. The method for brazing a carbon-ceramic friction material part and a metal back plate with a Ti-Fe brazing sheet according to claim 1, characterized in that: The carbon ceramic friction material piece is made of C f The metal back plate is made of C / C-SiC composite material and / or C / C-SiC composite material, and the material of the metal back plate is one of carbon steel, gray cast iron or stainless steel.

9. A brazing part, characterized in that: The method is prepared by any one of claims 1 to 8.

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