CN118048543A - Titanium phosphide particle reinforced Al-Si based composite material and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of metal matrix composite materials, and particularly relates to a titanium phosphide particle reinforced Al-Si matrix composite material and a preparation method thereof. The method comprises the following steps: step (1): weighing the raw materials: weighing an aluminum-phosphorus intermediate alloy, industrial pure aluminum, industrial pure silicon and titanium sponge according to a proportion; step (2): smelting: placing the weighed industrial pure aluminum, industrial pure silicon and titanium sponge into a water-cooled copper crucible of a vacuum arc furnace, heating to 850-1150 ℃ and melting to obtain an aluminum alloy cast ingot; and placing the obtained aluminum alloy cast ingot and aluminum phosphorus intermediate alloy in the same water-cooled copper crucible, and smelting to obtain the titanium phosphide particle reinforced Al-Si-based composite material. According to the invention, the titanium phosphide particles are used for reinforcing the Al-Si based composite material, the original generated TiP particles and the nano AlP particles formed by the evolution of the TiP form micro-nano double-scale reinforcement, so that the strength, toughness and wear resistance of the Al-Si based composite material at high temperature are improved.

Description

Titanium phosphide particle reinforced Al-Si based composite material and preparation method thereof

Technical Field

The invention belongs to the field of metal-based composite materials, and in particular relates to a titanium phosphide particle reinforced Al-Si-based composite material and a preparation method thereof.

Background technique

Cast Al-Si alloys are widely used in the manufacture of key engine parts such as cylinders and pistons due to their low density, good thermal conductivity, high specific strength, good corrosion resistance and excellent casting performance. However, as people's requirements for lightweight, energy-saving and environmental protection of automobiles become higher and higher, engines are developing in the direction of higher power, and pistons as core parts need to withstand greater mechanical loads, thermal loads and friction loads. Therefore, higher requirements are placed on the high-temperature mechanical properties of materials.

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

In the article “Effect of trace bismuth on the solidification structure of hypereutectic Al–22Sialloys” published in Materials Today Communications 2024, 38., Y.F.Wang et al. reported that with the increase of silicon content, the size of primary silicon in the alloy structure gradually increases, seriously splitting the aluminum matrix and reducing the strength and toughness of the alloy. Under the action of external force, stress concentration and microcracks appear at the sharp corners of the primary silicon phase, which greatly reduces the strength and toughness of the alloy, limits the use of hypereutectic Al-Si alloys, and deteriorates the comprehensive mechanical properties of the alloy. Therefore, the refinement of the primary Si phase in Al-Si alloys is of great significance.

At present, there have been many reports on particle-reinforced Al-Si based composites at home and abroad. For example, Dongxin Mao et al. published "Strength-ductility balance strategy in SiC reinforced aluminum matrix composites via deformation-driven metallurgy" in Journal of Alloys and Compounds 2022 891, reporting an aluminum Al-Si based composite material with a diameter of 16 mm and a height of 1 mm produced by deformation-driven metallurgy (DDM) process. The prepared SiC/AMCs has a uniform microstructure and good material properties, but the preparation time is long and the interface bonding effect between SiC particles and aluminum matrix is not good. Micronized particles can significantly improve the strength, hardness and wear resistance of aluminum-silicon based composites, but the plasticity and toughness are greatly reduced; while nanoparticles can maintain good plasticity and toughness while improving strength, but due to the large specific surface energy of nanoparticles, they are easy to agglomerate.

Summary of the invention

The purpose of the present invention is to provide a titanium phosphide particle reinforced Al-Si based composite material and a preparation method thereof.

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

Step (1): weighing raw materials: weighing aluminum-phosphorus master alloy, industrial pure aluminum, industrial pure silicon and sponge titanium according to proportion;

Step (2): Smelting: weighing industrial pure aluminum, industrial pure silicon and sponge titanium into a water-cooled copper crucible of a vacuum arc furnace, heating to 850-1150° C. to melt and obtain an aluminum alloy ingot; placing the obtained aluminum alloy ingot and aluminum-phosphorus master alloy in the same water-cooled copper crucible, and smelting to obtain a titanium phosphide particle reinforced Al-Si based composite material.

Furthermore, the ratio of the raw materials in step (1) is specifically as follows in terms of mass percentage:

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%.

Furthermore, step (2) is specifically as follows:

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

Step (22): evacuate to 3×10 ^-5 Pa, then introduce argon protective gas to 5×10 ² Pa, then turn on the smelting DC current switch, smelt at 130A for 1 to 2 minutes, and then smelt at 180 to 190A for 1 minute to obtain an ingot;

Step (23): repeatedly turning over and melting the ingot obtained in step (22) for 3 to 5 times to obtain an aluminum alloy ingot with uniform structure;

Step (24): placing the aluminum alloy ingot obtained in step (23) and the aluminum-phosphorus master alloy in the same water-cooled crucible; evacuating to 3×10 ^-5 Pa, then introducing argon protective gas to 5×10 ² Pa, turning on the smelting DC current switch, and smelting the aluminum alloy ingot and the aluminum-phosphorus master alloy. During smelting, first smelt at 130A for 1 to 2 minutes, then smelt at 180 to 190A for 1 to 2 minutes, and repeat the inversion smelting 3 to 5 times to obtain a titanium phosphide particle reinforced Al-Si based composite material.

Furthermore, before step (22), sponge titanium is placed in another water-cooled copper crucible of the vacuum arc melting furnace, and oxygen in the vacuum chamber is absorbed by melting the sponge titanium.

A titanium phosphide particle reinforced Al-Si based composite material is prepared by the above method.

Furthermore, it includes TiP particles generated by in-situ reaction and dispersed in the Al-Si matrix, and nano-scale AlP particles.

Furthermore, the TiP particle size is 0.2-10 μm.

Compared with the prior art, the present invention has the following significant advantages:

(1) The present invention adopts a new reinforcing phase titanium phosphide particles to reinforce Al-Si based composite materials. A part of the TiP generated in situ will undergo solid phase evolution to form nano-scale AlP particles, which serve as a heterogeneous nucleation substrate for the primary Si phase, refine the coarse Si phase, and further enhance the comprehensive mechanical properties of the Al-Si based composite materials. The micron-level TiP can significantly improve the strength, hardness and wear resistance of the aluminum-silicon based composite materials, but the plasticity and toughness are greatly reduced; while the nano-AlP particles can maintain good plasticity and toughness while improving the strength, but due to the large specific surface energy of the nano-AlP particles, they are easy to agglomerate; after the TiP particles are added to the matrix, a large number of nano- 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 respective advantages of micron and nano particles.

(2) This preparation method is more energy-saving and environmentally friendly, with 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.

(3) The in-situ synthesized micro/nano-scale titanium phosphide particles 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 evenly distributed in the aluminum matrix without obvious agglomeration, and the composite material exhibits good high-temperature mechanical properties.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a SEM image of TiP particles synthesized in situ on aluminum alloy in Example 1.

FIG. 2 is an EDS image of the TiP particles in FIG. 1 .

Detailed ways

The present invention is further described in detail below in conjunction with the accompanying drawings.

The present invention discloses a titanium phosphide particle reinforced Al-Si based composite material and an in-situ preparation method thereof. Micro/nano-scale TiP particles are in-situ generated in an Al-Si alloy melt, wherein a part of the in-situ generated TiP phase re-evolves to form nano AlP particles, which serve as a heterogeneous nucleation substrate for a primary Si phase to improve the strength, toughness and wear resistance of the Al-Si alloy at high temperatures.

The preparation method comprises the following steps:

Step (1): weighing raw materials: weighing aluminum-phosphorus master alloy, industrial pure aluminum, industrial pure silicon and sponge titanium according to proportion;

The proportion of raw materials is specifically as follows in mass percentage:

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): Smelting: weighing industrial pure aluminum, industrial pure silicon and sponge titanium into a water-cooled copper crucible of a vacuum arc furnace, heating to 850-1150° C. to melt and obtain an ingot; placing the obtained ingot and a certain amount of aluminum-phosphorus master alloy in the same water-cooled copper crucible, and smelting to obtain a titanium phosphide particle reinforced Al-Si based composite material.

Step (21): placing weighed industrial pure aluminum, industrial pure silicon, and sponge titanium into a water-cooled copper crucible of a vacuum arc melting furnace from bottom to top;

Step (22): evacuate to 3×10 ^-5 Pa, then introduce argon protective gas to 5×10 ² Pa, then turn on the smelting DC current switch, smelt at 130A for 1-2 minutes, and then smelt at 180-190A for 1 minute to obtain an ingot.

Step (23): Repeat the ingot obtained in step (22) by flipping and smelting for 3 to 5 times to obtain an aluminum alloy ingot with uniform structure.

Step (24): placing the aluminum alloy ingot obtained in step (23) and the aluminum-phosphorus master alloy in the same water-cooled crucible; evacuating to 3×10 ^-5 Pa, then introducing argon protective gas to 5×10 ² Pa, turning on the smelting DC current switch, smelting the aluminum alloy ingot and the aluminum-phosphorus master alloy, first smelting at 130A for 1 to 2 minutes, then smelting at 180 to 190A for 1 to 2 minutes, repeating the flipping smelting 3 to 5 times, to obtain a high-strength and heat-resistant titanium phosphide particle reinforced Al-Si based composite material.

Step (22) Before melting industrial pure aluminum, industrial pure silicon, sponge titanium and aluminum-phosphorus master alloy, 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.

Example 1

Step (1): weighing raw materials: preparing 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;

Step (2): Smelting: weighing industrial pure aluminum, industrial pure silicon and sponge titanium into a water-cooled copper crucible of a vacuum arc furnace, heating to 850-1150° C. to melt and obtain an ingot; placing the obtained ingot and a certain amount of aluminum-phosphorus master alloy in the same water-cooled copper crucible, and smelting to obtain a titanium phosphide particle reinforced Al-Si based composite material.

Step (21): placing weighed industrial pure aluminum, industrial pure silicon, and industrial sponge titanium into a water-cooled copper crucible of a vacuum arc melting furnace from bottom to top;

Step (22): evacuate to 3×10 ^-5 Pa, then introduce argon protective gas to 5×10 ² Pa, then turn on the smelting DC current switch, smelt at 130A for 2 minutes, and then smelt at 180A for 1 minute to obtain an ingot.

Step (23): Repeat the ingot obtained in step (22) by flipping and smelting for 4 times to obtain an aluminum alloy ingot with uniform structure.

Step (24): placing the aluminum alloy ingot obtained in step (23) and the aluminum-phosphorus master alloy in the same water-cooled crucible; evacuating to 3×10 ^-5 Pa, then introducing argon protective gas to 5×10 ² Pa, turning on the smelting DC current switch, smelting the aluminum alloy ingot and the aluminum-phosphorus master alloy, first smelting at 130A for 2 minutes, then smelting at 180A for 2 minutes, repeating the flip smelting 5 times, and obtaining a titanium phosphide particle reinforced Al-Si based composite material. The specific composition is Al-5.54Si-2.55TiP, and the average size of TiP is 3 to 4 μm.

FIG1 is a SEM image of Example 1, wherein the TiP particles are block or plate-like structures with a particle size of 3 to 4 μm, and the AlP particles are hexagonal with a particle size of 0.4 to 0.6 μm; FIG2 is an EDS image of the corresponding particles.

Example 2

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

Step (2): Smelting: weighing industrial pure aluminum, industrial pure silicon and sponge titanium into a water-cooled copper crucible of a vacuum arc furnace, heating to 850-1150° C. to melt and obtain an ingot; placing the obtained ingot and a certain amount of aluminum-phosphorus master alloy in the same water-cooled copper crucible, and smelting to obtain a titanium phosphide particle reinforced Al-Si based composite material.

Step (21): placing weighed industrial pure aluminum, industrial pure silicon, and industrial sponge titanium into a water-cooled copper crucible of a vacuum arc melting furnace from bottom to top;

Step (22): evacuate to 3×10 ^-5 Pa, then introduce argon protective gas to 5×10 ² Pa, then turn on the smelting DC current switch, smelt at 130A for 3 minutes, and then smelt at 190A for 2 minutes to obtain an ingot.

Step (23): Repeat the ingot obtained in step (22) by flipping and smelting for 4 times to obtain an aluminum alloy ingot with uniform structure.

Step (24): placing the aluminum alloy ingot obtained in step (23) and the aluminum-phosphorus master alloy in the same water-cooled crucible; evacuating to 3×10 ^-5 Pa, then introducing argon protective gas to 5×10 ² Pa, turning on the smelting DC current switch, smelting the aluminum alloy ingot and the aluminum-phosphorus master alloy, first smelting for 3 minutes under 130A current conditions, then smelting for 2 minutes under 190A current conditions, repeating the flip smelting 3 to 5 times, and obtaining a titanium phosphide particle reinforced Al-Si based composite material. The specific composition is Al-5.54Si-12.74TiP, and the average size of TiP is 0.2 to 4μm.

Example 3

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

Step (2): Smelting: weighing industrial pure aluminum, industrial pure silicon and sponge titanium into a water-cooled copper crucible of a vacuum arc furnace, heating to 850-1150° C. to melt and obtain an ingot; placing the obtained ingot and a certain amount of aluminum-phosphorus master alloy in the same water-cooled copper crucible, and smelting to obtain a titanium phosphide particle reinforced Al-Si based composite material.

Step (21): placing weighed industrial pure aluminum, industrial pure silicon, and industrial sponge titanium into a water-cooled copper crucible of a vacuum arc melting furnace from bottom to top;

Step (22): evacuate to 3×10 ^-5 Pa, then introduce argon protective gas to 5×10 ² Pa, then turn on the smelting DC current switch, smelt at 130A for 2 minutes, and then smelt at 190A for 1 minute to obtain an ingot.

Step (23): Repeat the flipping and smelting of the ingot obtained in step (22) for 4 times to obtain an aluminum alloy ingot with uniform structure.

Step (24): placing the aluminum alloy ingot obtained in step (23) and the aluminum-phosphorus master alloy in the same water-cooled crucible; evacuating to 3×10 ^-5 Pa, then introducing argon protective gas to 5×10 ² Pa, turning on the smelting DC current switch, smelting the aluminum alloy ingot and the aluminum-phosphorus master alloy, first smelting under 130A current conditions for 5 to 6 minutes, then smelting under 190A current conditions for 2 minutes, repeating the flip smelting 4 times, and obtaining a titanium phosphide particle reinforced Al-Si based composite material. The specific composition is Al-17.65Si-17.39TiP, and the average size of TiP is 0.6 to 8μm.

Example 4

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

Step (2): Smelting: weighing industrial pure aluminum, industrial pure silicon and sponge titanium into a water-cooled copper crucible of a vacuum arc furnace, heating to 850-1150° C. to melt and obtain an ingot; placing the obtained ingot and a certain amount of aluminum-phosphorus master alloy in the same water-cooled copper crucible, and smelting to obtain a titanium phosphide particle reinforced Al-Si based composite material.

Step (21): placing weighed industrial pure aluminum, industrial pure silicon, and industrial sponge titanium into a water-cooled copper crucible of a vacuum arc melting furnace from bottom to top;

Step (22): evacuate to 3×10 ^-5 Pa, then introduce argon protective gas to 5×10 ² Pa, then turn on the smelting DC current switch, smelt at 130A for 2 minutes, and then smelt at 190A for 1 minute to obtain an ingot.

Step (23): Repeat the ingot obtained in step (22) by flipping and smelting for 4 times to obtain an aluminum alloy ingot with uniform structure.

Step (24): placing the aluminum alloy ingot obtained in step (23) and the aluminum-phosphorus master alloy in the same water-cooled crucible; evacuating to 3×10 ^-5 Pa, then introducing argon protective gas to 5×10 ² Pa, turning on the smelting DC current switch, smelting the aluminum alloy ingot and the aluminum-phosphorus master alloy, first smelting for 6 minutes under 130A current conditions, then smelting for 5 minutes under 180-190A current conditions, repeating the flip smelting 4 times, and obtaining a titanium phosphide particle reinforced Al-Si based composite material. The specific composition is Al-17.65Si-12.74TiP, and the average size of TiP is 1-8μm.

Claims (7)

1. The preparation method of the titanium phosphide particle reinforced Al-Si based composite material is characterized by comprising the following steps of:

Step (1): weighing the raw materials: weighing an aluminum-phosphorus intermediate alloy, industrial pure aluminum, industrial pure silicon and titanium sponge according to a proportion;

Step (2): smelting: placing the weighed industrial pure aluminum, industrial pure silicon and titanium sponge into a water-cooled copper crucible of a vacuum arc furnace, heating to 850-1150 ℃ and melting to obtain an aluminum alloy cast ingot; and placing the obtained aluminum alloy cast ingot and aluminum phosphorus intermediate alloy in the same water-cooled copper crucible, and smelting to obtain the titanium phosphide particle reinforced Al-Si-based composite material.

2. The method according to claim 1, wherein the proportion of the raw materials in the step (1) is specifically as follows in mass percent:

7.9 to 75.0 percent of industrial pure aluminum, 5.0 to 82.0 percent of aluminum-phosphorus intermediate alloy, 1.0 to 21.0 percent of industrial pure silicon and 0.1 to 15.0 percent of titanium sponge.

3. The method according to claim 2, wherein step (2) is specifically:

step (21): placing industrial pure aluminum, industrial pure silicon and titanium sponge into a water-cooled copper crucible of a vacuum arc melting furnace from bottom to top;

Step (22): vacuumizing to 3X 10 ^-5 Pa, introducing argon shielding gas to 5X 10 ² Pa, then turning on a smelting direct current switch, smelting for 1-2 min under the current condition of 130A, and smelting for 1min under the current condition of 180-190A to obtain an ingot;

step (23): repeatedly overturning and smelting the cast ingot obtained in the step (22) for 3-5 times to obtain an aluminum alloy cast ingot with uniform structure;

step (24): placing the aluminum alloy cast ingot obtained in the step (23) and the aluminum-phosphorus intermediate alloy into the same water-cooling crucible; vacuumizing to 3X 10 ^-5 Pa, introducing argon shielding gas to 5X 10 ² Pa, opening a smelting direct current switch, smelting an aluminum alloy cast ingot and an aluminum-phosphorus intermediate alloy, firstly smelting for 1-2 min under the current condition of 130A, then smelting for 1-2 min under the current condition of 180-190A, and repeatedly overturning and smelting for 3-5 times to obtain the titanium phosphide particle reinforced Al-Si-based composite material.

4. A method according to claim 3, characterized in that, before step (22), titanium sponge is placed in another water-cooled copper crucible of the vacuum arc melting furnace, and oxygen in the vacuum chamber is absorbed by melting the titanium sponge.

5. A titanium phosphide particle-reinforced Al-Si-based composite material, characterized by being prepared by the method according to any one of claims 1 to 4.

6. The composite material of claim 5, comprising TiP particles generated by an in situ reaction and dispersed in an Al-Si matrix, and nano-scale AlP particles.

7. The composite material of claim 6, wherein the TiP particles have a size of 0.2 to 10 μm.