An integrated method for preparing and forming Ti / Al3Ti layered composite curved surface components

Abstract

The present invention discloses a Ti / Al3Ti layered composite curved surface component preparation and forming integrated method, comprising the following steps: cleaning and pre-treating the raw materials Ti foil and Al foil; stacking the pre-treated Ti foil and Al foil in a unit of "Ti-Al-...-Ti", with the outermost layer being Ti foil; placing the stacked sample as a whole in a vacuum hot pressing furnace for hot pressing and diffusion to prepare a Ti / Al layered composite material; placing the prepared Ti / Al layered composite material in a curved surface component hot pressing mold, forming and continuing the hot pressing reaction to completely consume the Al layer reaction, generating an Al3Ti layer in the middle, and obtaining a curved surface component with a Ti / Al3Ti multilayer structure. The present invention avoids the problem of cracks caused by deformation of brittle intermetallic compounds, and does not require multiple reactions or the addition of other equipment and processes, greatly simplifying the process flow.

Description

Technical Field

[0001] The present invention relates to the technical field of forming intermetallic compound composite curved surface components, and in particular to an integrated method for preparing and forming a Ti / Al3Ti layered composite curved surface component. Background Art

[0002] As the performance of key components of aviation and aerospace engines continues to improve, the requirements for high-temperature structural materials are also increasing. Researching and preparing new composite materials to make up for the inability of a single component material to meet actual engineering needs has become a hot topic in the field of aerospace engineering. Currently, the high-temperature materials used in aircraft are mainly titanium alloys and nickel-based high-temperature alloys. Although titanium alloys have high specific strength, they have poor resistance to high-temperature oxidation and are prone to oxidation, resulting in structural damage. They are not suitable for use as high-temperature components with high operating temperatures. Although nickel-based high-temperature alloys can be used at temperatures up to 1200°C, their high density limits their application in the aerospace field.

[0003] Titanium-aluminum intermetallic compounds (TiAl) are considered promising lightweight, high-temperature structural materials for aerospace applications, as their operating temperatures are comparable to those of nickel-based superalloys, yet their density is only half that of nickel-based superalloys. Therefore, TiAl intermetallic compounds are ideal alternatives to titanium and nickel-based superalloys for manufacturing high-temperature aerospace components, and have been a research hotspot in materials science in recent years.

[0004] Among them, Al3Ti has attracted much attention due to its lowest density, highest specific strength, and best high-temperature oxidation resistance. However, due to Al3Ti's inherent brittleness, it remains difficult to manufacture parts with complex shapes through conventional plastic forming. The titanium alloy in Ti / Al3Ti layered composites possesses excellent plasticity and toughness, which can improve the material's resistance to crack propagation while leveraging Al3Ti's advantages of lightweight, high strength, and corrosion resistance. However, currently disclosed patents primarily focus on the preparation of Ti / Al3Ti layered composites and do not address the technology for forming and preparing their components.

[0005] Invention application publication number CN112439804 A proposes a method for preparing a Ti-Al intermetallic compound laminated composite plate. This method first subjects the Ti / Al laminated plate to a non-vacuum heat treatment in a resistance furnace and then forges it. The final product is a Ti-Al intermetallic compound laminated composite plate. The method does not involve a forming method for curved surface components.

[0006] Invention application publication number CN 112091049A proposes a method for fabricating intermetallic compound curved, thin-walled components using a metal foil wrapped around a core mold. This method involves bulging a preform, followed by reaction synthesis and densification of the bulged component, ultimately yielding a Ni-NiAl or Ti-TiAl composite structure with a special-shaped, curved, thin-walled component. This method requires a bulging mold, followed by diffusion synthesis and densification under high temperature and high pressure, and finally, subsequent processing. This method is complex and can result in severe defects such as holes and cracks in the final component.

[0007] Publication No. CN 113151701A discloses a method for fabricating large-scale curved, thin-walled metal aluminide components. This method involves hot pressing and laminating to form a laminated composite plate. The final result is an in-situ primary diffusion reaction and secondary reaction to produce the curved, thin-walled metal aluminide component. Due to the high-temperature and high-pressure in-situ reaction, intermetallic compounds (TiAl and NiAl) are formed. These compounds are susceptible to brittle fracture during subsequent rolling, forming internal cracks and deteriorating performance. Summary of the Invention

[0008] Purpose of the invention: In order to overcome the shortcomings of the background technology, the present invention discloses a method for integrating the preparation and forming of Ti / Al3Ti layered composite curved surface components. The method adopts a preparation method combining forming and reaction, and obtains Ti / Al3Ti layered composite material curved surface components through the integration of forming and reaction, which effectively solves the difficulties in actual preparation.

[0009] Technical solution: The integrated method for preparing and forming a Ti / Al3Ti layered composite curved surface component disclosed in the present invention comprises the following steps:

[0010] S1, cleaning and pre-treating the raw materials Ti foil and Al foil;

[0011] S2. stacking the pretreated Ti foil and Al foil in the order of "Ti-Al-...-Ti" as a unit, with the outermost layer being the Ti foil;

[0012] S3, placing the stacked samples in a vacuum hot pressing furnace for hot pressing and diffusion to prepare a Ti / Al layered composite material;

[0013] S4. Place the prepared Ti / Al layered composite material into a hot pressing mold for a curved component, shape it, and continue the hot pressing reaction to consume the Al layer completely, generate an Al3Ti layer in the middle, and obtain a curved component with a Ti / Al3Ti multilayer structure.

[0014] S1 includes cleaning the foils with acetone and alcohol in sequence, and then performing acid washing on the Ti foil and alkali washing and acid washing on the Al foil.

[0015] Furthermore, the Ti foil and Al foil selected in S2 are pure Ti and pure Al, with a thickness of 0.1-0.2 mm, and the number of stacked layers is greater than or equal to five.

[0016] Furthermore, the S3 process parameters are as follows: -3 Pa, the temperature was raised to 500°C in 60 minutes under the initial pressure of 3 MPa and kept at that temperature for 30 minutes; then the temperature was raised to 550°C and the pressure was raised to 7 MPa and kept at that temperature for 180 minutes to ensure the mutual diffusion of Ti and Al atoms; then the temperature was lowered to 500°C within 30 minutes and kept at that temperature for 30 minutes, while the pressure was lowered to 3 MPa, and finally the heating was stopped and the furnace was cooled.

[0017] Furthermore, the S4 process parameters are as follows: -3 The temperature was raised to 350°C for 50 minutes under a vacuum degree of less than Pa, and then pressurized. The downward speed of the pressure head was controlled at 10 mm / h. After keeping warm for 30 minutes, the temperature was raised to 650°C. The pressure head was continued to be moved. A pressure of 25 MPa was applied and the temperature was kept warm for 480 minutes. After that, the heating was stopped and the furnace was cooled.

[0018] Furthermore, the mold surface of the vacuum hot pressing furnace is evenly sprayed with boron nitride solder resist.

[0019] Beneficial effects: Compared with the prior art, the advantages of the present invention are:

[0020] 1. To address the difficulty in forming composite materials containing intermetallic compounds, the Ti / Al layered composite material is formed first, and the Al3Ti intermetallic compound is generated later. After the Ti / Al layered composite material is formed into a component, an in-situ reaction is continued in the mold to obtain a Ti / Al3Ti layered composite curved surface component, thereby cleverly avoiding the problem of brittle intermetallic compounds deforming and cracking. The forming and reaction are integrated, and a set of molds and a single process can directly obtain formed components containing intermetallic compounds. There is no need for multiple reactions or the addition of other equipment and processes, which greatly simplifies the process flow. It provides a new method for high-temperature resistant, lightweight, high-strength, and complex-shaped parts in engineering fields such as aviation, aerospace, and weaponry, and solves the problem of difficult forming of composite sheets containing intermetallic compounds.

[0021] 2. Ti / Al3Ti layered composite curved surface components of different thicknesses can be generated by controlling the relative thickness of the titanium layer and the aluminum layer, the hot pressing temperature and time; Ti / Al3Ti layered composite curved surface components of different sizes and types can be obtained by changing the mold size and shape;

[0022] 3. The preparation cost is low, the preparation process is pollution-free, the production efficiency is high, and it has important engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a process flow chart of the present invention;

[0024] Figure 2 The Ti / Al layered composite material prepared in Example 1 of the present invention;

[0025] Figure 3 This is an assembly diagram of the Ti / Al layered composite material in Example 1 of the present invention in a hot pressing mold for a spherical part;

[0026] Figure 4 This is a diagram of a hot pressing mold for a spherical part in Example 1 of the present invention;

[0027] Figure 5 The curved surface component of the Ti / Al3Ti multilayer structure prepared in Example 1 of the present invention;

[0028] Figure 6 for Figure 5 Microstructure diagram of the curved surface component. Figure 6 (a) corresponds to 1 place, Figure 6 (b) corresponds to 2 places, Figure 6 (c) corresponds to 3 places. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0030] Example 1

[0031] like Figure 1 As shown, a method for integrating the preparation and forming of a Ti / Al3Ti layered composite curved surface component comprises the following steps:

[0032] S1. Cleaning and pre-treating raw materials Ti foil (pure Ti) and Al foil (pure Al) with a thickness of 0.1 mm, including cleaning the foils with acetone and alcohol in sequence, and then pickling the Ti foil and alkali washing and pickling the Al foil.

[0033] S2. Stack the pretreated Ti foil and Al foil in nine layers according to the order of "Ti-Al-Ti-Al-Ti-Al-Ti-Al-Ti", with the outermost layer being Ti foil.

[0034] S3, placing the stacked samples in a vacuum hot pressing furnace for hot pressing and diffusion to prepare a Ti / Al layered composite material; Figure 2 As shown, the surface of the obtained Ti / Al layered composite material is smooth, each layer is metallurgically bonded and does not contain any intermetallic compounds.

[0035] The specific process parameters are: below 10 -3Pa, the temperature was raised to 500°C in 60 minutes under the initial pressure of 3 MPa and kept at that temperature for 30 minutes; then the temperature was raised to 550°C and the pressure was raised to 7 MPa and kept at that temperature for 180 minutes to ensure the mutual diffusion of Ti and Al atoms; then the temperature was lowered to 500°C within 30 minutes and kept at that temperature for 30 minutes, while the pressure was lowered to 3 MPa, and finally the heating was stopped and the furnace was cooled.

[0036] S4. Spray boron nitride solder resist evenly on the mold surface of vacuum hot pressing furnace, such as Figure 3 and Figure 4 As shown, the spherical hot pressing mold is an integrated preparation mold, including a spherical punch and a spherical die, which are respectively connected to the upper and lower pressure heads of the hot pressing equipment. The prepared Ti / Al layered composite material is placed in the spherical hot pressing mold for forming reaction. The integrated mold assembly is performed, forming and continuously hot pressing reaction, the Al layer is completely consumed by reaction, and an Al3Ti layer is generated in the middle to obtain a curved surface component of a Ti / Al3Ti multilayer structure, as shown in FIG. Figure 5 shown.

[0037] The specific process parameters are: below 10 -3 The temperature was raised to 350°C for 50 minutes under a vacuum degree of less than Pa, and then pressurized. The downward speed of the pressure head was controlled at 10 mm / h. After keeping warm for 30 minutes, the temperature was raised to 650°C. The pressure head was continued to be moved. A pressure of 25 MPa was applied and the temperature was kept warm for 480 minutes. After that, the heating was stopped and the furnace was cooled.

[0038] like Figure 6 As shown in the figure, the microstructure of three parts of the spherical component was observed and analyzed, and no Al was left, only multilayer Ti and Al3Ti.

[0039] Example 2

[0040] A method for integrating the preparation and forming of a Ti / Al3Ti layered composite curved surface component comprises the following steps:

[0041] S1. Cleaning and pre-treating raw materials Ti foil (pure Ti) and Al foil (pure Al) with a thickness of 0.15 mm, including cleaning the foils with acetone and alcohol in sequence, and then pickling the Ti foil and alkali washing and pickling the Al foil.

[0042] S2. Stack the pretreated Ti foil and Al foil in seven layers according to the order of "Ti-Al-Ti-Al-Ti Al-Ti" as a unit, with the outermost layer being Ti foil.

[0043] S3, placing the stacked samples in a vacuum hot pressing furnace for hot pressing and diffusion to prepare Ti / Al layered composite materials; the specific process parameters are: -3Pa, the temperature was raised to 500°C in 60 minutes under the initial pressure of 3 MPa and kept at that temperature for 30 minutes; then the temperature was raised to 550°C and the pressure was raised to 7 MPa and kept at that temperature for 180 minutes to ensure the mutual diffusion of Ti and Al atoms; then the temperature was lowered to 500°C within 30 minutes and kept at that temperature for 30 minutes, while the pressure was lowered to 3 MPa, and finally the heating was stopped and the furnace was cooled.

[0044] S4, put the prepared Ti / Al layered composite material into a cylindrical hot pressing mold, shape it and continue the hot pressing reaction, consume the Al layer completely, generate Al3Ti layer in the middle, and obtain a curved surface component of Ti / Al3Ti multilayer structure. The specific process parameters are: -3 The temperature was raised to 350°C for 50 minutes under a vacuum degree of less than Pa, and then pressurized. The downward speed of the pressure head was controlled at 10 mm / h. After keeping warm for 30 minutes, the temperature was raised to 650°C. The pressure head was continued to be moved. A pressure of 25 MPa was applied and the temperature was kept warm for 480 minutes. After that, the heating was stopped and the furnace was cooled.

[0045] Example 3

[0046] A method for integrating the preparation and forming of a Ti / Al3Ti layered composite curved surface component comprises the following steps:

[0047] S1. Cleaning and pre-treating raw materials Ti foil (pure Ti) and Al foil (pure Al) with a thickness of 0.2 mm, including cleaning the foils with acetone and alcohol in sequence, and then pickling the Ti foil and alkali washing and pickling the Al foil.

[0048] S2. Stack the pretreated Ti foil and Al foil in five layers in the order of "Ti-Al-Ti-Al-Ti" as a unit, with the outermost layer being Ti foil.

[0049] S3, placing the stacked samples in a vacuum hot pressing furnace for hot pressing and diffusion to prepare Ti / Al layered composite materials; the specific process parameters are: -3 Pa, the temperature was raised to 500°C in 60 minutes under the initial pressure of 3 MPa and kept at that temperature for 30 minutes; then the temperature was raised to 550°C and the pressure was raised to 7 MPa and kept at that temperature for 180 minutes to ensure the mutual diffusion of Ti and Al atoms; then the temperature was lowered to 500°C within 30 minutes and kept at that temperature for 30 minutes, while the pressure was lowered to 3 MPa, and finally the heating was stopped and the furnace was cooled.

[0050] S4, put the prepared Ti / Al layered composite material into a spherical hot pressing mold, shape it and continue the hot pressing reaction, consume the Al layer completely, generate Al3Ti layer in the middle, and obtain a curved surface component of Ti / Al3Ti multilayer structure. The specific process parameters are: -3The temperature was raised to 350°C for 50 minutes under a vacuum degree of less than Pa, and then pressurized. The downward speed of the pressure head was controlled to be 10 mm / h. After keeping warm for 30 minutes, the temperature was raised to 650°C. The pressure head was continued to be moved. A pressure of 25 MPa was applied and kept warm for 480 minutes. After that, the heating was stopped and the furnace was cooled.

Claims

1. A method for integrating the preparation and forming of a Ti / Al3Ti layered composite curved surface component, characterized in that: The following steps are involved: S1, cleaning and pre-treating the raw materials Ti foil and Al foil; S2. Stack the pretreated Ti foil and Al foil in the order of "Ti-Al-...-Ti" as a unit, with the outermost layer being the Ti foil; S3, placing the stacked samples in a vacuum hot pressing furnace for hot pressing and diffusion to prepare a Ti / Al layered composite material; S4, placing the prepared Ti / Al layered composite material into a hot pressing mold for a curved surface component, forming it and continuing the hot pressing reaction to completely consume the Al layer and generate an Al3Ti layer in the middle, thereby obtaining a curved surface component with a Ti / Al3Ti multilayer structure; Among them, the S3 process parameters are as follows: below 10 -3 Under a vacuum degree of less than 1.5 Pa, the temperature was raised to 500°C in 60 minutes at an initial pressure of 3 MPa and kept at that temperature for 30 minutes; then the temperature was raised to 550°C and the pressure was raised to 7 MPa and kept at that temperature for 180 minutes to ensure the mutual diffusion of Ti and Al atoms; then the temperature was lowered to 500°C within 30 minutes and kept at that temperature for 30 minutes, while the pressure was reduced to 3 MPa, and finally the heating was stopped and the furnace was cooled; The specific process parameters of S4 are: -3 The temperature was raised to 350°C for 50 minutes under a vacuum degree of less than Pa, and then pressurized. The downward speed of the pressure head was controlled at 10 mm / h. After keeping warm for 30 minutes, the temperature was raised to 650°C. The pressure head was continued to be moved. A pressure of 25 MPa was applied and the temperature was kept warm for 480 minutes. After that, the heating was stopped and the furnace was cooled.

2. The integrated method for preparing and forming a Ti / Al3Ti layered composite curved surface component according to claim 1, characterized in that: S1 includes cleaning the foils with acetone and alcohol in sequence, and then respectively performing acid washing on the Ti foil and alkali washing and acid washing on the Al foil.

3. The integrated method for preparing and forming a Ti / Al3Ti layered composite curved surface component according to claim 1, characterized in that: The Ti foil and Al foil selected in S2 are pure Ti and pure Al, with a thickness of 0.1-0.2 mm, and the number of stacked layers is greater than or equal to five.

4. The integrated method for preparing and forming a Ti / Al3Ti layered composite curved surface component according to claim 1, characterized in that: The mold surface of the vacuum hot pressing furnace is evenly sprayed with boron nitride solder resist.

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