CN105562869B - One kind uses the solder brazing Ti of BNi 22The method of AlC ceramics and metallic nickel or nickel alloy - Google Patents

Abstract

The invention discloses a method for brazing Ti ₂ AlC ceramics and metal nickel or nickel alloys by using BNi‑2 solder, and relates to a method for brazing Ti ₂ AlC ceramics and metal nickel or nickel alloys. _The invention aims to solve the technical problems that the current Ti2AlC ceramics are easy to decompose in the brazing process and the reliability of the welded structural parts is poor when they are in service. The present invention: 1. preparing brazing samples; 2. brazing. _The advantages of the present invention: the present invention improves the reliability of brazing Ti2AlC ceramics and metal nickel or nickel alloy welding structural parts when in service, and at the same time, the use of nickel-based high-temperature solder is beneficial to improve the high-temperature mechanical properties and oxidation resistance of joints, so that The welded structure is expected to be used in high temperature fields. The invention is applied in the field of welding.

Description

A kind of method using BNi-2 solder to braze Ti2AlC ceramics and metal nickel or nickel alloy

technical field

_The invention relates to a method for brazing Ti2AlC ceramics and metal nickel or nickel alloy.

Background technique

Materials are one of the three pillars of the development of modern society, and their rapid development and transformation are an important driving force for the progress of science and technology. At the same time, the progress of human society and science and technology has also continuously put forward new requirements for materials. Traditional steel materials and non-ferrous metal materials have been unable to meet new service conditions and performance requirements, especially in the rapidly developing aerospace field. The demand for high-strength and high-temperature-resistant materials is becoming stronger and stronger. In recent years, a new type of ternary carbide or nitride ceramics has become the focus of many material science researchers. In 1963, Jeitschko and others first synthesized a class of ternary compounds with the chemical formula M ₂ AX and determined their crystal structures. In 2000, Barsoum et al. systematically described this type of compound and defined it as the MAX phase: a class of thermodynamically stable ternary carbides or nitrides with a nano-layered structure. This type of ceramics combines many properties of metals and ceramics, narrows the gap between metals and ceramics, and overcomes the respective limitations of metal and ceramic materials.

Compared with traditional superalloys, MAX phase ceramics, especially Al-containing MAX phases, have unique advantages as high-temperature structural materials. Taking the typical 211 phase Ti ₂ AlC as an example, its melting point is as high as 1600°C, and its structural stability can be maintained up to 1400°C under vacuum conditions. Compared with typical superalloys, the density of Ti ₂ AlC ceramics is 4.1g/cm ³ , which is only half that of nickel-based superalloys; its thermal conductivity is 46W·m ^-1 ·K ^-1 four times. In addition, Ti ₂ AlC ceramics also have excellent high-temperature mechanical properties. The high-temperature compression test results show that the ceramics can still maintain the elastic modulus at room temperature above 1200 ° C, and its compressive strength reaches 170 MPa. The thermal shock test results show that when ΔT=1300K, the matrix still maintains 75% of its strength. At the same time, the presence of Al atoms endows ceramics with excellent oxidation resistance and atmospheric corrosion resistance. The experimental results show that the oxidation weight gain of Ti ₂ AlC between 1000-1300°C is proportional to the reciprocal of the cube root of the oxidation time, and the oxidation rate is only 1.1×10 ^-10 kg ³ ·m ^-6 ·s at 1200°C ^-1 . At the same time, the α-Al ₂ O ₃ oxide film formed by oxidation and Ti ₂ AlC have similar thermal expansion coefficients, so the residual stress between the Ti ₂ AlC matrix and the oxide film is small, and its cycle oxidation resistance is also very good. Finally, although cracks are usually fatal to other ceramic materials, Ti ₂ AlC ceramics not only have a certain damage tolerance at room temperature, but also have self-healing cracks at high temperatures due to the volume increase effect caused by oxidation reactions. ability. It can be seen that Ti ₂ AlC ceramics are expected to become a new generation of high-temperature structural materials, which are applied to high-temperature components of aero-engines, gas nozzles, heating bodies with frequent alternating thermal cycles, and cladding materials for atomic energy reactors.

According to the isothermal cross-sectional phase diagram of the Ti-Al-C ternary system at 1300 °C, it can be seen that Ti ₂ AlC is in the ternary phase region with TiC _x and Ti-Al intermetallic compounds, while the single Ti ₂ AlC phase region is very narrow, As a result, there will always be impurities such as TiC _x in the final synthesized Ti ₂ AlC ceramics, so the current preparation methods are not suitable for the synthesis of bulk materials with large sizes and complex shapes. In order to overcome this bottleneck, realize the brazing of Ti ₂ AlC ceramics, especially the connection with nickel-based superalloys, and make Ti ₂ AlC-Ni composite components, which can greatly reduce the specific gravity of components, increase the service temperature, and improve corrosion resistance. , to better play the respective performance advantages of ceramics and metals. Up to now, there are relatively few domestic and foreign literature reports on brazing Ti ₂ AlC ceramics, and there is no related report on brazing Ti ₂ AlC ceramics using nickel-based high-temperature brazing filler metal. The current Ti ₂ AlC ceramics are easy to decompose during the brazing process, and the reliability of the welded structural parts is poor when they are in service.

Contents of the invention

The present invention aims to solve the technical problems that current Ti ₂ AlC ceramics are prone to decompose during the brazing process, and the reliability of welded structural parts is poor when they are in service, and provide a method of brazing Ti ₂ AlC ceramics and metals using BNi-2 Nickel or nickel alloy method.

A kind of use BNi- ₂ brazing filler metal of the present invention Ti AlC ceramics and the method for metal nickel or nickel alloy are to carry out according to the following steps:

1. Prepare brazing samples: prepare Ti ₂ AlC ceramic blocks by wire cutting method, and then use 100#, 320#, 600#, 1000# and 1500# water sandpaper to polish Ti ₂ AlC ceramics on the pre-grinder The surface to be welded of the block is mechanically polished with a diamond polishing agent with a particle size of 0.5 μm until there is no scratch on the surface to be welded of the Ti ₂ AlC ceramic block, and the Ti ₂ AlC ceramic base material is obtained;

Adopt the method for wire cutting to prepare metal Ni block or Ni alloy block, then use the metallographic sandpaper of 200#, 500#, 1000# and 2000# to polish the surface to be welded of metal Ni block or Ni alloy block, obtain Metal Ni base material or Ni alloy base material;

Put the Ti ₂ AlC ceramic base material and the metal Ni base material or Ni alloy base material into acetone for 10 minutes of ultrasonic cleaning, then put them into anhydrous ethanol for 10 minutes of ultrasonic cleaning, and then air-dry, use an organic binder to BNi-2 solder Adjust the powder to a paste, and then apply it evenly on the cleaned surface of the Ti ₂ AlC ceramic base material to be welded and the cleaned metal Ni base material or cleaned Ni alloy base material to be welded, and then use the solder layer as the middle The layer form is assembled into a sandwich structure to obtain the part to be welded; the mass ratio of the volume of the organic binder to the BNi-2 solder powder is 1mL:1.5g;

2. Brazing: Put the parts to be welded in step 1 in the mold, then put the mold in a vacuum heating furnace, apply a mechanical pressure of 5MPa to 10MPa to the parts to be welded, and then vacuumize, when the vacuum degree in the furnace When the vacuum degree in the furnace is 10 ^-3 Pa, and the vacuum degree in the furnace is 10 ^-3 Pa and the mechanical pressure of 5MPa ~ 10MPa is applied to the workpiece to be welded, the temperature in the furnace is raised from room temperature to 300°C, and the vacuum degree in the furnace 10 ^-3 Pa, apply a mechanical pressure of 5MPa~10MPa to the workpiece to be welded and keep it warm for 10min-30min at a furnace temperature of 300°C, the vacuum in the furnace is 10 ^-3 Pa and apply 5MPa~10MPa to the workpiece to be welded Under the condition of mechanical pressure, the temperature in the furnace is raised from 300 ° C to 1000 ° C ~ 1100 ° C, and the vacuum degree in the furnace is 10 ^{- 3} Pa, the mechanical pressure of 5 MPa ~ 10 MPa is applied to the weldment and the temperature in the furnace is 1000 Keep warm for ^15min -60min under the condition of ℃～1100℃, then reduce the temperature in the furnace from 1000 ℃ ~ 1100 ℃ cooled to 300 ℃, and then in the vacuum degree of the furnace is 10 ^-3 Pa and the mechanical pressure of 5 MPa ~ 10 MPa is applied to the workpiece to be welded and cooled to room temperature with the furnace, that is, the use of BNi-2 solder is completed. Brazing Ti ₂ AlC ceramics and metallic nickel or nickel alloys.

Advantages of the present invention:

_The invention improves the reliability of brazing Ti2AlC ceramics and metal nickel or nickel alloy welded structural parts in service, and at the same time, the use of nickel-based high-temperature solder is beneficial to improve the high-temperature mechanical properties and oxidation resistance of the joints, making the welded structural parts promising Used in high temperature field.

(1) Compared with other brazing filler metals containing Cu, Al, Au and other alloying elements, Ni-based brazing filler metals have less influence on the stability of Ti ₂ AlC ceramics, and the components are more reliable when serving in high temperature environments;

(2) BNi-2 solder has good wettability on the surface of Ti ₂ AlC ceramics, and the brazed joint is dense without holes, cracks and other defects;

(3) The interaction zone formed during the brazing process helps to relieve residual stress, and no continuous intermetallic compound is formed in the joint, so the obtained welded joint has excellent performance.

Description of drawings

Fig. 1 is the sandwich structure schematic diagram of the assembly of step 1 of the present invention, A is Ti ₂ AlC ceramic base material, B is brazing filler metal layer, C is metal Ni or Ni alloy base material;

Figure 2 is the SEM image of the finished joint after brazing in Test 1. Area A is the Ti ₂ AlC ceramic base material, area B is the interaction area between the brazing material and the Ti ₂ AlC ceramic base material, area C is the weld, and area D is a metallic Ni base material.

detailed description

Embodiment 1: This embodiment is a method of using BNi- ₂ solder to braze Ti2AlC ceramics and metal nickel or nickel alloys, specifically according to the following steps:

1. Prepare brazing samples: prepare Ti ₂ AlC ceramic blocks by wire cutting method, and then use 100#, 320#, 600#, 1000# and 1500# water sandpaper to polish Ti ₂ AlC ceramics on the pre-grinder The surface to be welded of the block is mechanically polished with a diamond polishing agent with a particle size of 0.5 μm until there is no scratch on the surface to be welded of the Ti ₂ AlC ceramic block, and the Ti ₂ AlC ceramic base material is obtained;

Adopt the method for wire cutting to prepare metal Ni block or Ni alloy block, then use the metallographic sandpaper of 200#, 500#, 1000# and 2000# to polish the surface to be welded of metal Ni block or Ni alloy block, obtain Metal Ni base material or Ni alloy base material;

Put the Ti ₂ AlC ceramic base material and the metal Ni base material or Ni alloy base material into acetone for 10 minutes of ultrasonic cleaning, then put them into anhydrous ethanol for 10 minutes of ultrasonic cleaning, and then air-dry, use an organic binder to BNi-2 solder Adjust the powder to a paste, and then apply it evenly on the cleaned surface of the Ti ₂ AlC ceramic base material to be welded and the cleaned metal Ni base material or cleaned Ni alloy base material to be welded, and then use the solder layer as the middle The layer form is assembled into a sandwich structure to obtain the part to be welded; the mass ratio of the volume of the organic binder to the BNi-2 solder powder is 1mL:1.5g;

2. Brazing: Put the parts to be welded in step 1 in the mold, then put the mold in a vacuum heating furnace, apply a mechanical pressure of 5MPa to 10MPa to the parts to be welded, and then vacuumize, when the vacuum degree in the furnace When the vacuum degree in the furnace is 10 ^-3 Pa, and the vacuum degree in the furnace is 10 ^-3 Pa and the mechanical pressure of 5MPa ~ 10MPa is applied to the workpiece to be welded, the temperature in the furnace is raised from room temperature to 300°C, and the vacuum degree in the furnace 10 ^-3 Pa, apply a mechanical pressure of 5MPa~10MPa to the workpiece to be welded and keep it warm for 10min-30min at a furnace temperature of 300°C, the vacuum in the furnace is 10 ^-3 Pa and apply 5MPa~10MPa to the workpiece to be welded Under the condition of mechanical pressure, the temperature in the furnace is raised from 300 ° C to 1000 ° C ~ 1100 ° C, and the vacuum degree in the furnace is 10 ^{- 3} Pa, the mechanical pressure of 5 MPa ~ 10 MPa is applied to the weldment and the temperature in the furnace is 1000 Keep warm for ^15min -60min under the condition of ℃～1100℃, then reduce the temperature in the furnace from 1000 ℃ ~ 1100 ℃ cooled to 300 ℃, and then in the vacuum degree of the furnace is 10 ^-3 Pa and the mechanical pressure of 5 MPa ~ 10 MPa is applied to the workpiece to be welded and cooled to room temperature with the furnace, that is, the use of BNi-2 solder is completed. Brazing Ti ₂ AlC ceramics and metallic nickel or nickel alloys.

Specific embodiment two: the difference between this embodiment and specific embodiment one is: the organic binder described in step one is formed by mixing hydroxyethyl cellulose and distilled water, and the mass ratio of hydroxyethyl cellulose and distilled water for 1:99. Others are the same as the first embodiment.

Specific embodiment three: the difference between this embodiment and specific embodiment one is: the BNi-2 solder powder described in step one is composed of: 3% Fe, 7% Cr, 4.5% Si, 3% B, the rest is Ni. Others are the same as the first embodiment.

Embodiment 4: The difference between this embodiment and Embodiment 1 or 2 is that the nickel alloy is GH648. Others are the same as the first embodiment.

Embodiment 5: The difference between this embodiment and Embodiments 1 to 3 is that the nickel alloy is Inconel600. Others are the same as the first embodiment.

Prove the beneficial effect of the present invention by following test:

Test 1: This test is a method of brazing Ti ₂ AlC ceramics and metal nickel or nickel alloys using BNi-2 filler metal, which is carried out according to the following steps:

1. Prepare brazing samples: prepare Ti ₂ AlC ceramic blocks by wire cutting method, and then use 100#, 320#, 600#, 1000# and 1500# water sandpaper to polish Ti ₂ AlC ceramics on the pre-grinder The surface to be welded of the block is mechanically polished with a diamond polishing agent with a particle size of 0.5 μm until there is no scratch on the surface to be welded of the Ti ₂ AlC ceramic block, and the Ti ₂ AlC ceramic base material is obtained;

Adopt the method for wire cutting to prepare metal Ni block, then use the metallographic sandpaper of 200#, 500#, 1000# and 2000# to polish the surface to be welded of metal Ni block, obtain metal Ni base material;

Put the Ti ₂ AlC ceramic base material and the metal Ni base material into acetone for 10 minutes, then ultrasonically clean them in absolute ethanol for 10 minutes, then air-dry, and use an organic binder to adjust the BNi-2 solder powder to a paste , and then spread evenly on the surface to be welded of the cleaned Ti ₂ AlC ceramic base material and the cleaned metal Ni base material or the cleaned Ni alloy base material to be welded, and then assembled into a sandwich with the brazing material layer as the middle layer structure, to obtain the workpiece to be welded; the mass ratio of the volume of the organic binder to the BNi-2 solder powder is 1mL:1.5g;

2. Brazing: Put the parts to be welded in step 1 in the mold, then place the mold in a vacuum heating furnace, apply a mechanical pressure of 10 MPa to the parts to be welded, and then vacuumize. When the vacuum in the furnace is 10 At ^-3 Pa, raise the temperature in the furnace from room temperature to 300°C under the condition that the vacuum degree in the furnace is 10 ^-3 Pa and the mechanical pressure of 10 MPa is applied to the workpiece to be welded, and the vacuum degree in the furnace is 10 ^-3 Pa, apply a mechanical pressure of 10MPa to the workpiece to be welded and keep the temperature in the furnace at 300°C for 30 minutes, and keep the temperature in the furnace at a vacuum of 10 ^-3 Pa and a mechanical pressure of 10MPa to the workpiece to be welded. Raise the temperature from 300°C to 1000°C, keep the vacuum in the furnace at 10 ^-3 Pa, apply a mechanical pressure of 10MPa to the workpiece to be welded, and keep the temperature in the furnace at 1000°C for 30 minutes, then keep the vacuum in the furnace at Cool the temperature in the furnace from 1000°C to 300°C at a rate of 5°C/min under the condition of 10 ^-3 Pa and a mechanical pressure of 10 MPa on the workpiece to be welded, and then the vacuum in the furnace is 10 ^-3 Pa and the weldment to be welded Under the condition of applying a mechanical pressure of 10MPa, the piece is cooled to room temperature with the furnace, that is, the brazing of Ti ₂ AlC ceramics and metal nickel with BNi-2 solder is completed. The organic binder described in step 1 is formed by mixing hydroxyethyl cellulose and distilled water, and the mass ratio of hydroxyethyl cellulose and distilled water is 1:99;

The BNi-2 solder powder in the first step is composed of 3% Fe, 7% Cr, 4.5% Si, 3% B, and the rest is Ni.

Test 2: The difference between this test and Test 1 is that the vacuum degree in the furnace is 10 ^-3 Pa, the mechanical pressure of 10 MPa is applied to the workpiece to be welded, and the temperature in the furnace is 1000 ° C for 15 minutes. Others are the same as Test 1. same.

Test 3: The difference between this test and Test 1 is that in step 2, the temperature in the furnace is raised from 300°C to 1050°C under the condition that the vacuum degree in the furnace is 10 ^-3 Pa and the mechanical pressure of 10 MPa is applied to the weldment, and The vacuum degree in the furnace is 10 ^-3 Pa, the mechanical pressure of 10 MPa is applied to the workpiece to be welded, and the temperature in the furnace is 1050 ° C for 30 minutes, and then the vacuum degree in the furnace is 10 ^-3 Pa and the workpiece to be welded is applied. Under the condition of a mechanical pressure of 10MPa, the temperature in the furnace was cooled from 1050°C to 300°C at a rate of 5°C/min, and the rest were the same as in Test 1.

Test 4: The difference between this test and test 3 is that in step 2, the vacuum degree in the furnace is 10 ^-3 Pa, the mechanical pressure of 10 MPa is applied to the workpiece to be welded, and the temperature in the furnace is 1050 ° C for 60 minutes. Others are the same as Trial three were the same.

Test 5: The difference between this test and Test 1 is that in Step 2, the temperature in the furnace is raised from 300°C to 1100°C under the condition that the vacuum degree in the furnace is 10 ^-3 Pa and the mechanical pressure of 10 MPa is applied to the workpiece to be welded. The vacuum degree in the furnace is 10 ^-3 Pa, the mechanical pressure of 10 MPa is applied to the workpiece to be welded, and the temperature in the furnace is 1100 ° C for 30 minutes, and then the vacuum degree in the furnace is 10 ^-3 Pa and the workpiece to be welded is applied. Under the condition of a mechanical pressure of 10MPa, the temperature in the furnace was cooled from 1100°C to 300°C at a rate of 5°C/min, and the rest were the same as in Test 1.

Table 1

Table 1 is the shear strength test data of the finished joint after brazing of tests ₁ to 5. As can be seen from the table, the Ti2AlC/Ni joint with excellent mechanical properties can be obtained by adopting the method of the present invention, and its maximum shear strength It is 203MPa, reaching 91% of the strength of the Ti ₂ AlC ceramic base material.

Figure 2 is the SEM image of the finished joint after brazing in Test 1. Area A is the Ti ₂ AlC ceramic base material, area B is the interaction area between the brazing material and the Ti ₂ AlC ceramic base material, area C is the weld, and area D is the metal Ni base material. It can be seen from the figure that the solder and Ti ₂ AlC ceramics have good wettability, and there are no holes and cracks in the joint obtained, and the brazing effect is good. At the same time, there is an interaction zone on the side of the Ti ₂ AlC ceramic base material close to the weld seam. Observing the morphology of the interaction zone, it can be found that this zone remains solid during the brazing process, that is, the formation of this zone is closely related to that of the brazing filler metal. Diffusion behavior of Ni element in Ti ₂ AlC ceramic base material. It can be concluded that the Ni element has little influence on the stability of Ti ₂ AlC ceramics, so the nickel-based high-temperature brazing material mainly composed of Ni will not cause violent decomposition of the ceramic when brazing Ti ₂ AlC ceramics, which is a very High-temperature solder suitable for brazing Ti ₂ AlC ceramics.

Claims (5)

1. a kind of use BNi-2 brazing filler metal Ti ₂ AlC ceramics and the method for metal nickel or nickel alloy, it is characterized in that use BNi-2 brazing filler Ti ₂ The method for AlC ceramics and metal nickel or nickel alloy is according to The following steps are performed: 1. Prepare brazing samples: prepare Ti ₂ AlC ceramic blocks by wire cutting method, and then use 100#, 320#, 600#, 1000# and 1500# water sandpaper to polish Ti ₂ AlC ceramics on the pre-grinder The surface to be welded of the block is mechanically polished with a diamond polishing agent with a particle size of 0.5 μm until there is no scratch on the surface to be welded of the Ti ₂ AlC ceramic block, and the Ti ₂ AlC ceramic base material is obtained; Adopt the method for wire cutting to prepare metal Ni block or Ni alloy block, then use the metallographic sandpaper of 200#, 500#, 1000# and 2000# to polish the surface to be welded of metal Ni block or Ni alloy block, obtain Metal Ni base material or Ni alloy base material; Put the Ti ₂ AlC ceramic base material and the metal Ni base material or Ni alloy base material into acetone for 10 minutes of ultrasonic cleaning, then put them into anhydrous ethanol for 10 minutes of ultrasonic cleaning, and then air-dry, use an organic binder to BNi-2 solder Adjust the powder to a paste, and then apply it evenly on the cleaned surface of the Ti ₂ AlC ceramic base material to be welded and the cleaned metal Ni base material or cleaned Ni alloy base material to be welded, and then use the solder layer as the middle The layer form is assembled into a sandwich structure to obtain the part to be welded; the mass ratio of the volume of the organic binder to the BNi-2 solder powder is 1mL:1.5g; 2. Brazing: Put the parts to be welded in step 1 in the mold, then put the mold in a vacuum heating furnace, apply a mechanical pressure of 5MPa to 10MPa to the parts to be welded, and then vacuumize, when the vacuum degree in the furnace When the vacuum degree in the furnace is 10 ^-3 Pa, and the vacuum degree in the furnace is 10 ^-3 Pa and the mechanical pressure of 5MPa ~ 10MPa is applied to the workpiece to be welded, the temperature in the furnace is raised from room temperature to 300°C, and the vacuum degree in the furnace 10 ^-3 Pa, apply a mechanical pressure of 5MPa~10MPa to the workpiece to be welded and keep it warm for 10min-30min at a furnace temperature of 300°C, the vacuum in the furnace is 10 ^-3 Pa and apply 5MPa~10MPa to the workpiece to be welded Under the condition of mechanical pressure, the temperature in the furnace is raised from 300 ° C to 1000 ° C ~ 1100 ° C, and the vacuum degree in the furnace is 10 ^{- 3} Pa, the mechanical pressure of 5 MPa ~ 10 MPa is applied to the weldment and the temperature in the furnace is 1000 Keep warm for ^15min -60min under the condition of ℃～1100℃, then reduce the temperature in the furnace from 1000 ℃ ~ 1100 ℃ cooled to 300 ℃, and then in the vacuum degree of the furnace is 10 ^-3 Pa and the mechanical pressure of 5 MPa ~ 10 MPa is applied to the workpiece to be welded and cooled to room temperature with the furnace, that is, the use of BNi-2 solder is completed. Brazing Ti ₂ AlC ceramics and metallic nickel or nickel alloys. 2. a kind of use BNi-2 brazing filler metal according to claim 1 The method for brazing Ti ₂ AlC ceramics and metal nickel or nickel alloy is characterized in that the organic binder described in step 1 is made of hydroxyethyl fiber The mass ratio of hydroxyethyl cellulose and distilled water is 1:99. 3. a kind of use BNi- ₂ solder brazing Ti according to claim 1 The method of AlC ceramics and metal nickel or nickel alloy is characterized in that the BNi-2 solder powder described in step 1 is grouped by mass fraction Become: 3% Fe, 7% Cr, 4.5% Si, 3% B, and the rest Ni. 4. A method for brazing Ti ₂ AlC ceramics and metallic nickel or nickel alloys using BNi-2 filler material according to claim 1, characterized in that said nickel alloy is GH648. 5. A method for brazing Ti ₂ AlC ceramics and metallic nickel or nickel alloys using BNi-2 solder according to claim 1, characterized in that the nickel alloy is Inconel600.