7055-TiC aluminum-based composite material and preparation method thereof

Abstract

The invention discloses a 7055-TiC aluminum-based composite material and a preparation method thereof. The preparation method comprises the following steps: taking 7055 aluminum alloy powder and TiC particles as raw materials; 7055 aluminum alloy is used as a matrix, and TiC is used as a reinforcing phase; 7055 aluminum alloy powder and TiC particles are subjected to ball milling and mixing; packaging the composite material powder in a graphite mold; and the 7055-TiC composite material is obtained by adopting a spark plasma sintering process. The composite material obtained by the method provided by the invention has relatively high density and relatively good corrosion resistance, the preparation process is simple, the efficiency is high, and the production cost is low.

Description

Technical Field

[0001] This invention discloses a 7055-TiC aluminum-based composite material and its preparation method, which relates to the field of powder metallurgy aluminum-based composite material technology. Background Technology

[0002] Against the backdrop of the global aerospace industry's evolution towards higher speeds, lighter weights, and longer lifespans, the requirements for strength, fracture toughness, and corrosion resistance in aerospace structural materials are becoming increasingly stringent. Currently, while traditional aluminum alloys are widely used in aerospace structural components due to their low density and ease of machining, their insufficient synergy between strength, fracture toughness, and corrosion resistance is becoming increasingly apparent in the extreme service environments faced by next-generation aircraft. This makes it difficult to meet the integrated requirements of "high strength-low density-high reliability" for key components such as fuselage frames, engine blades, and landing gear. In this context, developing high-performance, low-density aluminum-based composite materials has become an effective way to meet the demands for high strength and high corrosion resistance.

[0003] Aluminum-based composites use aluminum and aluminum alloys as the matrix, and their performance is improved by introducing reinforcing phases. They retain the good processability and thermal and electrical conductivity of the aluminum matrix, while significantly enhancing key properties such as strength, wear resistance, and corrosion resistance through the regulation of the reinforcing phases. Currently, commonly used reinforcing phases in aluminum-based composites include particulate phases such as silicon carbide, alumina, and boron carbide; one-dimensional reinforcements such as silicon carbide whiskers; and fibrous phases such as carbon fibers. Different morphologies and compositions of reinforcing phases can endow aluminum-based composites with different superior properties, enabling performance customization. These characteristics make aluminum-based composites a core candidate material for replacing traditional structural materials and driving the upgrade of aerospace equipment.

[0004] TiC is a face-centered cubic carbide with a similar lattice constant and crystal structure to Al, exhibiting good compatibility with Al. Therefore, TiC is an ideal reinforcement for preparing aluminum-based composites. Researchers have proposed that the addition of TiC can not only improve mechanical properties but also induce the formation of a continuous and dense passivation layer on the material surface, enhancing the material's corrosion resistance.

[0005] To obtain high-performance aluminum-based composite materials, the choice of preparation process is paramount. Traditional preparation techniques are prone to problems such as reinforcing phase agglomeration, intense interfacial reactions, coarse grains, and insufficient density, exhibiting significant limitations. Spark plasma sintering (SPCS), as a novel rapid sintering technology, achieves rapid heating through Joule heating and electromigration effects generated by pulsed current, combined with high pressure to promote interparticle densification, enabling material preparation at relatively low sintering temperatures and in short time. This technology not only effectively suppresses grain growth and interfacial reactions but also precisely controls the material's density, the uniformity of reinforcing phase distribution, and the interfacial bonding state, providing core technological support for the preparation of high-performance aluminum-based composite materials. Currently, SPCS technology has demonstrated unique advantages in the preparation of titanium-based and ceramic-based composite materials. Summary of the Invention

[0006] The present invention aims to provide a high-density, high-corrosion-resistant 7055-TiC aluminum-based composite material and its preparation method. Using TiC particles as a reinforcing phase induces the formation of a uniform and dense passivation film on the material surface, effectively improving the corrosion resistance of the aluminum-based composite material. Simultaneously, the use of spark plasma sintering technology enables rapid material densification, improving preparation efficiency.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] This invention provides a 7055-TiC aluminum-based composite material, wherein the raw materials of the composite material include 7055 aluminum alloy powder and TiC powder particles; in the raw materials of the composite material, the mass fraction of TiC is 2~6%, and the balance is 7055 aluminum alloy powder.

[0009] Preferably, the 7055 aluminum alloy powder used in the composite material raw material has an average particle size of 20 μm.

[0010] Preferably, the mass fraction of TiC in the composite material raw material is 4%.

[0011] Preferably, the TiC powder used in the composite material raw material has an average particle size of 1~2 μm.

[0012] This invention also provides a method for preparing 7055-TiC aluminum-based composite materials, comprising the following steps:

[0013] Step 1: Mix 7055 aluminum alloy powder with TiC powder particles using a ball milling method;

[0014] Step 2: Encapsulate the obtained composite material powder in a graphite mold;

[0015] Step 3: A dense and corrosion-resistant 7055-TiC aluminum-based composite material is obtained by using a spark plasma sintering process.

[0016] Preferably, in step 1, a planetary ball mill is used for ball milling, with a ball-to-material ratio of 5:2, a rotation speed of 200 rpm, and a milling time of 3 hours.

[0017] Preferably, in step 2, the graphite mold is a hollow cylindrical mold with an outer diameter of 50 mm, an inner diameter of 15.2 mm, and a height of 40 mm.

[0018] Preferably, in step 2, a 0.05 mm graphite paper pad is used on the inner wall of the mold when encapsulating the powder to facilitate demolding.

[0019] Preferably, in step 3, the sintering temperature is 500~550℃, the radial pressure is 50 MPa, the heating rate is 50 ℃ / min, and the holding time is 10 min.

[0020] This invention utilizes the above-described preparation method to obtain a 7055 aluminum-based composite material with uniform TiC distribution. By rationally selecting the amount of TiC added, TiC is uniformly distributed on the matrix, preventing TiC agglomeration and thus avoiding increased defect density. Simultaneously, the addition of TiC promotes the formation of a uniform and dense passivation film on the composite material surface, enhancing its corrosion resistance. Using appropriate sintering temperature and holding time during the sintering process inhibits grain growth and interfacial reactions, enabling effective control over the microstructure of the composite material. Applying appropriate pressure during sintering promotes the filling of internal voids in the composite material, increasing its density.

[0021] Compared with the prior art, the advantages of the present invention are as follows:

[0022] (1) In the 7055-TiC aluminum-based composite material prepared by the present invention, TiC is uniformly dispersed, has high density, and no S-phase Al2CuMg is generated.

[0023] (2) The 7055-TiC aluminum-based composite material prepared by this invention has good corrosion resistance. Compared with 7055 aluminum alloy, this composite material has a lower corrosion current density and a shallower corrosion depth.

[0024] (3) The preparation method of the present invention has a wide range of applications, a simple preparation process, high preparation efficiency, and reliable process. It overcomes the problems of grain coarsening and low density in the preparation process of aluminum-based composite materials, and can achieve precise control of the microstructure of composite materials. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the experimental procedure of the present invention;

[0026] Figure 2 The XRD pattern of Example 2;

[0027] Figure 3 Scanning electron microscope images of 7055-TiC aluminum matrix composites: (a) Example 1, (b) Example 2, (c) Example 3. Detailed Implementation

[0028] The present invention will be further illustrated below with reference to embodiments. These embodiments are for illustrative purposes only and are not intended to limit the invention in any way.

[0029] Example 1: This example is a 7055-TiC aluminum-based composite material with a TiC mass fraction of 2%, and the preparation method is as follows:

[0030] Step 1: Mix 7055 aluminum alloy powder with TiC powder particles using a ball milling method.

[0031] Weigh 19.6 g of 7055 aluminum alloy powder and 0.4 g of TiC powder particles, and place them in a ball mill jar with a ball-to-powder ratio of 5:2. Use a planetary ball mill at a speed of 200 rpm for 3 hours.

[0032] Step 2: Encapsulate the obtained composite material powder in a graphite mold:

[0033] The obtained composite material powder was encapsulated in a hollow cylindrical graphite mold with an outer diameter of 50 mm, an inner diameter of 15.2 mm, and a height of 40 mm. 0.05 mm graphite paper was used as a pad on the inner wall of the mold to facilitate demolding.

[0034] Step 3: A dense and corrosion-resistant 7055-TiC aluminum-based composite material was obtained using a spark plasma sintering process.

[0035] The sintering temperature was set at 500 ℃, the sintering pressure at 50 MPa, and the heating rate at 50 ℃ / min. At 500 ℃, the temperature was held at 50 MPa for 10 min. After holding, the furnace was cooled to room temperature, removed, and demolded to obtain the 7055-TiC aluminum-based composite material.

[0036] Scanning electron microscope images of the material's microstructure are shown below. Figure 3 (a).

[0037] The aluminum-based composite material prepared in this embodiment exhibits good corrosion resistance, with a corrosion current density of 1.948 × 10⁻⁶ in 0.1 M NaCl solution. -6 A / cm 2 .

[0038] Example 2: This example is a 7055-TiC aluminum-based composite material with a TiC mass fraction of 4%, and the preparation method is as follows:

[0039] Step 1: Mix 7055 aluminum alloy powder with TiC powder particles using a ball milling method.

[0040] Weigh 19.2 g of 7055 aluminum alloy powder and 0.8 g of TiC powder particles, and place them in a ball mill jar with a ball-to-powder ratio of 5:2. Use a planetary ball mill at a speed of 200 rpm for 3 hours.

[0041] Step 2: Encapsulate the obtained composite material powder in a graphite mold:

[0042] The obtained composite material powder was encapsulated in a hollow cylindrical graphite mold with an outer diameter of 50 mm, an inner diameter of 15.2 mm, and a height of 40 mm. 0.05 mm graphite paper was used as a pad on the inner wall of the mold to facilitate demolding.

[0043] Step 3: A dense and corrosion-resistant 7055-TiC aluminum-based composite material was obtained using a spark plasma sintering process.

[0044] The sintering temperature was set at 500 ℃, the sintering pressure at 50 MPa, and the heating rate at 50 ℃ / min. At 500 ℃, the temperature was held at 50 MPa for 10 min. After holding, the furnace was cooled to room temperature, removed, and demolded to obtain the 7055-TiC aluminum-based composite material.

[0045] Scanning electron microscope images of the material's microstructure are shown below. Figure 3 (b)

[0046] The aluminum-based composite material prepared in this embodiment exhibits good corrosion resistance, with a corrosion current density of 1.787 × 10⁻⁶ in 0.1 M NaCl solution. -6 A / cm 2 .

[0047] Example 3: This example is a 7055-TiC aluminum-based composite material with a TiC mass fraction of 4%, and the preparation method is as follows:

[0048] Step 1: Mix 7055 aluminum alloy powder with TiC powder particles using a ball milling method.

[0049] Weigh 19.2 g of 7055 aluminum alloy powder and 0.8 g of TiC powder particles, and place them in a ball mill jar with a ball-to-powder ratio of 5:2. Use a planetary ball mill at a speed of 200 rpm for 3 hours.

[0050] Step 2: Encapsulate the obtained composite material powder in a graphite mold:

[0051] The obtained composite material powder was encapsulated in a hollow cylindrical graphite mold with an outer diameter of 50 mm, an inner diameter of 15.2 mm, and a height of 40 mm. 0.05 mm graphite paper was used as a pad on the inner wall of the mold to facilitate demolding.

[0052] Step 3: A dense and corrosion-resistant 7055-TiC aluminum-based composite material was obtained using a spark plasma sintering process.

[0053] The sintering temperature was set at 550 ℃, the sintering pressure at 50 MPa, and the heating rate at 50 ℃ / min. When the temperature reached 500 ℃, it was held at 50 MPa for 10 min. After the holding period, the furnace was cooled to room temperature and removed from the mold to obtain 7055-TiC aluminum-based composite material.

[0054] Scanning electron microscope images of the material's microstructure are shown below. Figure 3 (c)

[0055] The aluminum-based composite material prepared in this embodiment exhibits good corrosion resistance, with a corrosion current density of 1.882 × 10⁻⁶ in 0.1 M NaCl solution. -6 A / cm 2 .

[0056] Comparative Example 1: The method of this comparative example is basically the same as that of Example 1, except that TiC powder particles are not added in this comparative example.

[0057] The resulting 7055 aluminum alloy matrix material exhibits poor corrosion resistance, with a corrosion current density of 10.955*10. -6 A / cm 2 The value is significantly greater than that in the above embodiments. This is because the introduction of TiC promotes the formation of a dense and uniform passivation film on the material surface, while the absence of TiC particles reduces the protective properties of the passivation film on the material surface.

[0058] Comparative Example 2: The method of this comparative example is basically the same as that of Example 2, except that the sintering temperature is set to 400 °C in this comparative example.

[0059] The resulting 7055-TiC aluminum-based composite material exhibited poor corrosion resistance, with a corrosion current density of 26.010 × 10⁻⁶. -6 A / cm 2 The temperature is significantly higher than in the above embodiments. This is because the sintering temperature is set too low, resulting in insufficient densification of the material during sintering, which increases the number of voids and defects in the material and reduces its corrosion resistance.

[0060] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A 7055-TiC aluminum-based composite material and its preparation method, characterized in that, The raw materials of the composite material include 7055 aluminum alloy powder and TiC powder particles; in the raw materials of the composite material, the mass fraction of TiC is 2~6%, and the balance is 7055 aluminum alloy powder; The preparation method of the 7055-TiC aluminum-based composite material includes the following steps: Step 1: Mix 7055 aluminum alloy powder with TiC powder particles using a ball milling method; Step 2: Encapsulate the obtained composite material powder in a graphite mold; Step 3: A dense and corrosion-resistant 7055-TiC aluminum-based composite material is obtained by using a spark plasma sintering process.

2. The preparation method according to claim 1, characterized in that, The 7055 aluminum alloy powder used in the composite material has an average particle size of 20 μm.

3. The preparation method according to claim 1, characterized in that, The TiC powder used in the composite material raw material has an average particle size of 1~2 μm.

4. The preparation method according to claim 1, characterized in that, In step 1, a planetary ball mill is used for ball milling, with a ball-to-material ratio of 5:2, a rotation speed of 200 rpm, and a milling time of 3 hours.

5. The preparation method according to claim 1, characterized in that, In step 2, the graphite mold is a hollow cylindrical mold with an outer diameter of 50 mm, an inner diameter of 15.2 mm, and a height of 40 mm.

6. The preparation method according to claim 1, characterized in that, In step 2, 0.05 mm graphite paper is used to line the inner wall of the mold when encapsulating the powder to facilitate demolding.

7. The preparation method according to claim 1, characterized in that, In step 3, the sintering temperature is 500~550℃, the radial pressure is 50 MPa, the heating rate is 50 ℃ / min, and the holding time is 10 min.

Images