Titanium phosphide particle-reinforced al-si matrix composite material and method for manufacturing the same

Abstract

The application belongs to the field of metal matrix composites, and particularly relates to a titanium phosphide particle reinforced Al-Si matrix composite material and a preparation method thereof. The application comprises the following steps: step (1): weighing raw materials: weighing aluminum phosphorus intermediate alloy, industrial pure aluminum, industrial pure silicon and sponge titanium according to proportions; step (2): melting: placing the weighed industrial pure aluminum, industrial pure silicon and sponge titanium into a water-cooled copper crucible of a vacuum arc furnace, heating to 850-1150 DEG C to melt, obtaining an aluminum alloy ingot; placing the obtained aluminum alloy ingot and the aluminum phosphorus intermediate alloy in the same water-cooled copper crucible, melting to obtain the titanium phosphide particle reinforced Al-Si matrix composite material. The application forms micro / nano dual-scale reinforcement through the titanium phosphide particle reinforced Al-Si matrix composite material, TiP particles generated and nano AlP particles formed by evolution of the TiP, so that the strength, toughness and wear resistance of the Al-Si matrix composite material at high temperature are improved.

Description

Technical Field

[0001] This invention belongs to the field of metal matrix composites, specifically relating to a titanium phosphide particle-reinforced Al-Si matrix composite and its preparation method. Background Technology

[0002] Cast Al-Si alloys are widely used in the manufacture of key engine components such as cylinders and pistons due to their low density, good thermal conductivity, high specific strength, good corrosion resistance, and excellent casting properties. However, with increasing demands for lightweight, energy-saving, and environmentally friendly automobiles, engines are developing towards higher power outputs. As a result, core components such as pistons need to withstand greater mechanical, thermal, and frictional loads. Therefore, higher requirements are placed on the high-temperature mechanical properties of the materials.

[0003] Particle-reinforced Al-Si matrix composites are currently the most widely studied and applied metal matrix composites. Common particle-reinforced Al-Si matrix composites are usually prepared by external addition methods, but the interfacial bonding ability between the reinforcing particles and the aluminum matrix is ​​poor, making it difficult to give full play to the advantages of the reinforcing particles, and it is difficult to control their stability in large-scale production. The above-mentioned shortcomings can be overcome by using the in-situ synthesis method in aluminum alloy melt.

[0004] In their article "Effect of trace bismuth on the solidification structure of hypereutectic Al–22Sialloys," published in *Materials Today Communications*, 2024, 38, YFWang et al. reported that with increasing silicon content, the size of primary silicon in the alloy microstructure gradually increases, severely disrupting the aluminum matrix and reducing the alloy's strength and toughness. Under external forces, stress concentration and microcracks appear at the sharp corners of the primary silicon phase, significantly reducing the alloy's strength and toughness, limiting the use of hypereutectic Al-Si alloys, and deteriorating the alloy's overall mechanical properties. Therefore, refining the primary Si phase in Al-Si alloys is of great significance.

[0005] Currently, there are numerous reports on particle-reinforced Al-Si matrix composites both domestically and internationally. For example, Dongxin Mao et al. published "Strength-ductility balance strategy in SiC reinforced aluminum matrix composites via deformation-driven metallurgy" in the *Journal of Alloys and Compounds*, 2022, 891, reporting an aluminum Al-Si matrix composite with a diameter of 16 mm and a height of 1 mm produced using deformation-driven metallurgy (DDM). The prepared SiC / AMCs exhibit a uniform microstructure and good material properties; however, the preparation time is long and the interfacial bonding between SiC particles and the aluminum matrix is ​​poor. Micron-sized particles can significantly improve the strength, hardness, and wear resistance of aluminum-silicon matrix composites, but their ductility and toughness decrease significantly. Nanoparticles, on the other hand, can maintain good ductility and toughness while improving strength, but due to their large specific surface energy, they are prone to agglomeration. Summary of the Invention

[0006] The purpose of this invention is to provide a titanium phosphide particle-reinforced Al-Si based composite material and its preparation method.

[0007] The technical solution to achieve the objective of this invention is: a method for preparing titanium phosphide particle-reinforced Al-Si based composite material, comprising the following steps:

[0008] Step (1): Weigh the raw materials: Weigh aluminum-phosphorus master alloy, industrial pure aluminum, industrial pure silicon and sponge titanium according to the proportion;

[0009] Step (2): Smelting: Weigh out industrial pure aluminum, industrial pure silicon and sponge titanium and place them into a water-cooled copper crucible in a vacuum electric arc furnace and heat them to 850-1150℃ to melt them and obtain aluminum alloy ingots; place the obtained aluminum alloy ingots and aluminum-phosphorus intermediate alloys in the same water-cooled copper crucible and smelt them to obtain titanium phosphide particle-reinforced Al-Si based composite materials.

[0010] Furthermore, the proportion of raw materials in step (1) is specifically defined as a percentage by mass as follows:

[0011] Industrial pure aluminum 7.9–75.0%, aluminum-phosphorus master alloy 5.0–82.0%, industrial pure silicon 1.0–21.0%, sponge titanium 0.1–15.0%.

[0012] Furthermore, step (2) specifically involves:

[0013] Step (21): Place industrial pure aluminum, industrial pure silicon, and sponge titanium into the water-cooled copper crucible of the vacuum arc melting furnace from bottom to top;

[0014] Step (22): Evacuate to 3×10 -5 Pa, then argon protective gas is introduced to 5 × 10 2 Pa, then turn on the DC current switch for melting, melt for 1-2 minutes under a current of 130A, and then melt for 1 minute under a current of 180-190A to obtain the ingot;

[0015] Step (23): Repeat the smelting process of the ingot obtained in step (22) 3 to 5 times to obtain an aluminum alloy ingot with uniform structure;

[0016] Step (24): Place the aluminum alloy ingot obtained in step (23) and the aluminum-phosphorus master alloy in the same water-cooled crucible; evacuate to 3×10 -5 Pa, then argon protective gas is introduced to 5 × 10 2 Pa, turn on the DC current switch for melting, melt the aluminum alloy ingot and aluminum-phosphorus master alloy. When melting, first melt under a current of 130A for 1 to 2 minutes, then melt under a current of 180 to 190A for 1 to 2 minutes. Repeat the melting process 3 to 5 times to obtain titanium phosphide particle-reinforced Al-Si based composite material.

[0017] Furthermore, prior to step (22), sponge titanium is placed in another water-cooled copper crucible in the vacuum arc melting furnace to absorb oxygen in the vacuum chamber by melting the sponge titanium.

[0018] A titanium phosphide particle-reinforced Al-Si based composite material is prepared using the method described above.

[0019] Furthermore, this includes TiP particles generated in situ and dispersed in the Al-Si matrix, as well as nanoscale AlP particles.

[0020] Furthermore, the TiP particle size is 0.2–10 μm.

[0021] Compared with the prior art, the significant advantages of this invention are:

[0022] (1) This invention uses a new type of reinforcing phase titanium phosphide particles to reinforce Al-Si based composite materials. Some of the TiP generated in situ undergoes solid-phase evolution to form nanoscale AlP particles, which serve as heterogeneous nucleation substrates for the primary Si phase, refining the coarse Si phase and further enhancing the comprehensive mechanical properties of Al-Si based composite materials. Micron-sized TiP can significantly improve the strength, hardness, and wear resistance of aluminum-silicon based composite materials, but the plasticity and toughness decrease significantly. Nanoscale AlP particles can maintain good plasticity and toughness while improving strength, but due to the large specific surface energy of nanoscale AlP particles, they are prone to agglomeration. After TiP particles are added to the matrix, a large number of nanoscale and submicron-sized AlP nucleation particles will be formed in a short time. This micro-nano hybrid particle reinforced Al-Si composite material can give full play to the advantages of micron and nanoparticles.

[0023] (2) This preparation method is more energy-saving and environmentally friendly, and has a high utilization rate of raw materials. The size and content of the reinforcing phase TiP particles can be controlled by changing the phosphorus content in the aluminum-phosphorus master alloy and the reaction time.

[0024] (3) The micro / nano-scale titanium phosphide particles synthesized in situ in the composite material prepared by the present invention have excellent thermal stability and good interfacial bonding with the aluminum matrix; the reinforcing phase particles are uniformly distributed in the aluminum matrix without obvious agglomeration, and the composite material exhibits good high-temperature mechanical properties. Attached Figure Description

[0025] Figure 1 This is a SEM image of TiP particles synthesized in situ from aluminum alloy in Example 1.

[0026] Figure 2 for Figure 1 EDS image of TiP particles in the image. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings.

[0028] This invention discloses a titanium phosphide particle-reinforced Al-Si matrix composite material and its in-situ preparation method. By generating micro / nano-scale TiP particles in-situ in Al-Si alloy melt, a portion of the in-situ generated TiP phase will re-evolve into nano-AlP particles, which serve as heterogeneous nucleation substrates for the primary Si phase to improve the strength, toughness, and wear resistance of Al-Si alloy at high temperatures.

[0029] The preparation method includes the following steps:

[0030] Step (1): Weigh the raw materials: Weigh aluminum-phosphorus master alloy, industrial pure aluminum, industrial pure silicon and sponge titanium according to the proportion;

[0031] The specific proportions of the raw materials, expressed as a percentage by mass, are as follows:

[0032] Industrial pure aluminum 7.9–75.0%, aluminum-phosphorus master alloy 5.0–82.0%, industrial pure silicon 1.0–21.0%, sponge titanium 0.1–15.0%.

[0033] Step (2): Smelting: Weigh out industrial pure aluminum, industrial pure silicon and sponge titanium and place them into a water-cooled copper crucible in a vacuum electric arc furnace and heat them to 850-1150℃ to melt them and obtain an ingot; place the obtained ingot and a certain amount of aluminum-phosphorus intermediate alloy in the same water-cooled copper crucible and smelt them to obtain titanium phosphide particle-reinforced Al-Si based composite material.

[0034] Step (21): Weigh out the industrial pure aluminum, industrial pure silicon, and sponge titanium and place them from bottom to top into the water-cooled copper crucible of the vacuum arc melting furnace;

[0035] Step (22): Evacuate to 3×10 -5 Pa, then argon protective gas is introduced to 5 × 10 2 Pa, then turn on the DC current switch for melting, melt for 1-2 minutes under a current of 130A, and then melt for 1 minute under a current of 180-190A to obtain the ingot.

[0036] Step (23): Repeat the smelting process of the ingot obtained in step (22) 3 to 5 times to obtain an aluminum alloy ingot with uniform structure.

[0037] Step (24): Place the aluminum alloy ingot obtained in step (23) and the aluminum-phosphorus master alloy in the same water-cooled crucible; evacuate to 3×10 -5 Pa, then argon protective gas is introduced to 5 × 10 2 Pa, turn on the DC current switch for melting, melt aluminum alloy ingots and aluminum-phosphorus master alloy. When melting, first melt under a current of 130A for 1-2 minutes, then melt under a current of 180-190A for 1-2 minutes, repeat the melting process 3-5 times to obtain high-strength heat-resistant titanium phosphide particle-reinforced Al-Si based composite material.

[0038] Step (22) Before smelting industrial pure aluminum, industrial pure silicon, sponge titanium and aluminum-phosphorus master alloy, sponge titanium is placed in another water-cooled copper crucible in a vacuum arc melting furnace to absorb oxygen in the vacuum chamber by smelting sponge titanium.

[0039] Example 1

[0040] Step (1): Weigh the raw materials: Prepare the required raw materials according to the following mass percentages: 72.91% industrial pure aluminum, 20% Al-5P master alloy, 1.55% sponge titanium, and 5.54% industrial pure silicon;

[0041] Step (2): Smelting: Weigh out industrial pure aluminum, industrial pure silicon and sponge titanium and place them into a water-cooled copper crucible in a vacuum electric arc furnace and heat them to 850-1150℃ to melt them and obtain an ingot; place the obtained ingot and a certain amount of aluminum-phosphorus intermediate alloy in the same water-cooled copper crucible and smelt them to obtain titanium phosphide particle-reinforced Al-Si based composite material.

[0042] Step (21): Weigh out the industrial pure aluminum, industrial pure silicon and industrial sponge titanium and place them from bottom to top into the water-cooled copper crucible of the vacuum arc melting furnace;

[0043] Step (22): Evacuate to 3×10 -5 Pa, then argon protective gas is introduced to 5 × 10 2 Pa, then turn on the DC current switch for melting, melt for 2 minutes under 130A current conditions, and then melt for 1 minute under 180A current conditions to obtain the ingot.

[0044] Step (23): Repeat the smelting process of the ingot obtained in step (22) 4 times to obtain an aluminum alloy ingot with uniform structure.

[0045] Step (24): Place the aluminum alloy ingot obtained in step (23) and the aluminum-phosphorus master alloy in the same water-cooled crucible; evacuate to 3×10 -5 Pa, then argon protective gas is introduced to 5 × 10 2 At Pa, the DC current switch for melting was turned on to melt the aluminum alloy ingot and the aluminum-phosphorus master alloy. Melting was first carried out at 130A for 2 minutes, then at 180A for 2 minutes, and this process was repeated 5 times by flipping the ingot to obtain a titanium phosphide particle-reinforced Al-Si based composite material. Its specific composition is Al-5.54Si-2.55TiP, with an average TiP size of 3–4 μm.

[0046] Figure 1 The image shown is a SEM image of Example 1, in which the TiP particles have a blocky or plate-like structure with a particle size of 3-4 μm, and the AlP particles are hexagonal with a particle size of 0.4-0.6 μm. Figure 2 This is the EDS diagram of the corresponding particles.

[0047] Example 2

[0048] Step (1): Weigh the raw materials: Prepare the required raw materials according to the following mass percentages: 36.72% industrial pure aluminum, 50% Al-10P master alloy, 7.74% sponge titanium, and 5.54% industrial pure silicon;

[0049] Step (2): Smelting: Weigh out industrial pure aluminum, industrial pure silicon and sponge titanium and place them into a water-cooled copper crucible in a vacuum electric arc furnace and heat them to 850-1150℃ to melt them and obtain an ingot; place the obtained ingot and a certain amount of aluminum-phosphorus intermediate alloy in the same water-cooled copper crucible and smelt them to obtain titanium phosphide particle-reinforced Al-Si based composite material.

[0050] Step (21): Weigh out the industrial pure aluminum, industrial pure silicon and industrial sponge titanium and place them from bottom to top into the water-cooled copper crucible of the vacuum arc melting furnace;

[0051] Step (22): Evacuate to 3×10 -5 Pa, then argon protective gas is introduced to 5 × 10 2 Pa, then turn on the DC current switch for melting, melt for 3 minutes under 130A current conditions, and then melt for 2 minutes under 190A current conditions to obtain the ingot.

[0052] Step (23): Repeat the smelting process of the ingot obtained in step (22) 4 times to obtain an aluminum alloy ingot with uniform structure.

[0053] Step (24): Place the aluminum alloy ingot obtained in step (23) and the aluminum-phosphorus master alloy in the same water-cooled crucible; evacuate to 3×10 -5 Pa, then argon protective gas is introduced to 5 × 10 2 At Pa, the DC current switch for melting is turned on to melt the aluminum alloy ingot and the aluminum-phosphorus master alloy. During melting, the ingot is first melted at 130A for 3 minutes, and then at 190A for 2 minutes. This melting process is repeated 3 to 5 times to obtain a titanium phosphide particle-reinforced Al-Si based composite material. Its specific composition is Al-5.54Si-12.74TiP, and the average size of TiP is 0.2 to 4 μm.

[0054] Example 3

[0055] Step (1): Weigh the raw materials: Prepare the required raw materials according to the following mass percentages: 19.96% industrial pure aluminum, 50% Al-10P master alloy, 12.39% sponge titanium, and 17.65% industrial pure silicon;

[0056] Step (2): Smelting: Weigh out industrial pure aluminum, industrial pure silicon and sponge titanium and place them into a water-cooled copper crucible in a vacuum electric arc furnace and heat them to 850-1150℃ to melt them and obtain an ingot; place the obtained ingot and a certain amount of aluminum-phosphorus intermediate alloy in the same water-cooled copper crucible and smelt them to obtain titanium phosphide particle-reinforced Al-Si based composite material.

[0057] Step (21): Weigh out the industrial pure aluminum, industrial pure silicon and industrial sponge titanium and place them from bottom to top into the water-cooled copper crucible of the vacuum arc melting furnace;

[0058] Step (22): Evacuate to 3×10 -5 Pa, then argon protective gas is introduced to 5 × 10 2 Pa, then turn on the DC current switch for melting, melt for 2 minutes under a current of 130A, and then melt for 1 minute under a current of 190A to obtain the ingot.

[0059] Step (23): Repeat the smelting process of the ingot obtained in step (22) 4 times to obtain an aluminum alloy ingot with uniform structure.

[0060] Step (24): Place the aluminum alloy ingot obtained in step (23) and the aluminum-phosphorus master alloy in the same water-cooled crucible; evacuate to 3×10 -5 Pa, then argon protective gas is introduced to 5 × 10 2 At Pa, the DC current switch for melting is turned on to melt the aluminum alloy ingot and the aluminum-phosphorus master alloy. During melting, the ingot is first melted at 130A for 5-6 minutes, and then at 190A for 2 minutes. This melting process is repeated 4 times by flipping the ingot to obtain a titanium phosphide particle-reinforced Al-Si based composite material. Its specific composition is Al-17.65Si-17.39TiP, and the average size of TiP is 0.6-8μm.

[0061] Example 4

[0062] Step (1): Weigh the raw materials: Prepare the required raw materials according to the following mass percentages: 24.61% industrial pure aluminum, 50% Al-10P master alloy, 7.74% sponge titanium, and 17.65% industrial pure silicon;

[0063] Step (2): Smelting: Weigh out industrial pure aluminum, industrial pure silicon and sponge titanium and place them into a water-cooled copper crucible in a vacuum electric arc furnace and heat them to 850-1150℃ to melt them and obtain an ingot; place the obtained ingot and a certain amount of aluminum-phosphorus intermediate alloy in the same water-cooled copper crucible and smelt them to obtain titanium phosphide particle-reinforced Al-Si based composite material.

[0064] Step (21): Weigh out the industrial pure aluminum, industrial pure silicon and industrial sponge titanium and place them from bottom to top into the water-cooled copper crucible of the vacuum arc melting furnace;

[0065] Step (22): Evacuate to 3×10 -5 Pa, then argon protective gas is introduced to 5 × 10 2 Pa, then turn on the DC current switch for melting, melt for 2 minutes under a current of 130A, and then melt for 1 minute under a current of 190A to obtain the ingot.

[0066] Step (23): Repeat the smelting process of the ingot obtained in step (22) 4 times to obtain an aluminum alloy ingot with uniform structure.

[0067] Step (24): Place the aluminum alloy ingot obtained in step (23) and the aluminum-phosphorus master alloy in the same water-cooled crucible; evacuate to 3×10 -5 Pa, then argon protective gas is introduced to 5 × 10 2 At Pa, the DC current switch for melting was turned on to melt the aluminum alloy ingot and the aluminum-phosphorus master alloy. Melting was first carried out at 130A for 6 minutes, followed by melting at 180–190A for 5 minutes. This melting process was repeated four times by flipping the ingot to obtain a titanium phosphide particle-reinforced Al-Si based composite material. Its specific composition is Al-17.65Si-12.74TiP, with an average TiP size of 1–8 μm.

Claims

1. A method for preparing a titanium phosphide particle-reinforced Al-Si based composite material, characterized in that, Includes the following steps: Step (1): Weigh the raw materials: Weigh aluminum-phosphorus master alloy, industrial pure aluminum, industrial pure silicon and sponge titanium according to the proportion; Step (2): Smelting: Weigh the industrial pure aluminum, industrial pure silicon and sponge titanium into a water-cooled copper crucible of a vacuum electric arc furnace and heat it to 850-1150℃ to melt it and obtain an aluminum alloy ingot; place the obtained aluminum alloy ingot and aluminum-phosphorus master alloy in the same water-cooled copper crucible and smelt it to obtain titanium phosphide particle-reinforced Al-Si based composite material. The proportions of raw materials in step (1) are as follows, expressed as a percentage by mass: Industrial pure aluminum 7.9–75.0%, aluminum-phosphorus master alloy 5.0–82.0%, industrial pure silicon 1.0–21.0%, sponge titanium 0.1–15.0%; Step (2) specifically involves: Step (21): Place industrial pure aluminum, industrial pure silicon, and sponge titanium into the water-cooled copper crucible of the vacuum arc melting furnace from bottom to top; Step (22): Evacuate to 3×10 -5 Pa, then argon protective gas is introduced to 5 × 10 2 Pa, then turn on the DC current switch for melting, melt for 1-2 minutes under a current of 130A, and then melt for 1 minute under a current of 180-190A to obtain the ingot; Step (23): Repeat the smelting process of the ingot obtained in step (22) 3 to 5 times to obtain an aluminum alloy ingot with uniform structure; Step (24): Place the aluminum alloy ingot obtained in step (23) and the aluminum-phosphorus master alloy in the same water-cooled crucible; Vacuum up to 3×10 -5 Pa, then argon protective gas is introduced to 5 × 10 2 Pa, turn on the DC current switch for melting, melt the aluminum alloy ingot and aluminum-phosphorus master alloy. When melting, first melt under a current of 130A for 1 to 2 minutes, then melt under a current of 180 to 190A for 1 to 2 minutes. Repeat the melting process 3 to 5 times to obtain titanium phosphide particle-reinforced Al-Si based composite material.

2. The method for preparing titanium phosphide particle-reinforced Al-Si based composite material according to claim 1, characterized in that, Before step (22), sponge titanium is placed in another water-cooled copper crucible in the vacuum arc melting furnace to absorb oxygen in the vacuum chamber by melting the sponge titanium.

3. A titanium phosphide particle-reinforced Al-Si based composite material, characterized in that, The Al-Si based composite material is prepared using the method described in claim 1 or 2 for preparing titanium phosphide particle-reinforced composite materials.

4. The titanium phosphide particle-reinforced Al-Si based composite material according to claim 3, characterized in that, This includes TiP particles generated in situ and dispersed in the Al-Si matrix, as well as nanoscale AlP particles.

5. The titanium phosphide particle-reinforced Al-Si based composite material according to claim 4, characterized in that, The TiP particle size ranges from 0.2 to 10 μm.

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