CN110218913A - A kind of aluminum matrix composite and preparation method thereof with excellent high deformability - Google Patents

Abstract

The invention belongs to aluminum matrix composite technical fields, disclose a kind of aluminum matrix composite and preparation method thereof with excellent high deformability.The composite material is prepared by volume fraction for 2%~20% enhancing particle and 80%~98% aluminium alloy；The enhancing particle is nano-amorphous diphase particles；The enhancing particle is Ti-Cu-Zr system alloy.The invention also discloses the preparation methods of composite material.Nano-amorphous diphase particles reinforced aluminum matrix composites room temperature intensity prepared by the present invention is high, specific strength is high, high temperature deformation ability is excellent, has extraordinary application prospect.

Description

An aluminum-based composite material with excellent high-temperature deformation ability and its preparation method

technical field

The invention belongs to the technical field of aluminum-based composite materials, and in particular relates to a nanocrystalline amorphous dual-phase particle-reinforced aluminum-based composite material with excellent high-temperature deformability and a preparation method thereof.

Background technique

Particle-reinforced aluminum matrix composites have excellent properties such as high specific strength, high wear resistance, and good dimensional stability, and have broad application prospects in aerospace, automotive, military, and electronics fields. Ceramic particles with high strength, high elastic modulus and high wear resistance such as Al ₂ O ₃ , SiC and B ₄ C are the most common reinforcement particles. However, the high density of ceramic particles, high hardness, high brittleness, easy agglomeration, and easy chemical reaction with the matrix to form a brittle interface lead to serious deterioration of the thermal processing performance of aluminum matrix composites, which greatly limits the engineering application of aluminum matrix composites. . Small high temperature deformation resistance can save labor and energy in product processing, lower equipment processing capacity requirements and easy to form integral parts with complex shapes, and can avoid the problem of difficult welding of aluminum matrix composite materials. Therefore, how to improve the high-temperature deformation ability of aluminum matrix composites is the key to promote the large-scale application of aluminum matrix composites.

Contents of the invention

In order to solve the technical problem of difficult thermal processing of aluminum matrix composite materials while improving the strength of aluminum matrix composite materials, the purpose of the present invention is to provide a nanocrystalline amorphous dual-phase particle reinforced aluminum matrix composite material with excellent high temperature deformation ability and its Preparation.

The purpose of the present invention is achieved by the following technical solutions:

A nanocrystalline amorphous dual-phase particle-reinforced aluminum-based composite material with excellent high-temperature deformability is prepared from reinforced particles with a volume fraction of 2% to 20% and aluminum alloys with a volume fraction of 80% to 98%.

The reinforcing particles are nanocrystalline amorphous dual-phase particles.

The aluminum alloy is preferably one or more of 7xxx series aluminum alloys and/or 2xxx series aluminum alloys.

The reinforcing particles are preferably Ti-Cu-Zr alloys, whose microstructure is 10-90vol.% nanocrystalline phase and 10-90vol.% amorphous phase; wherein, when the amorphous phase is 50vol.% or above , the composite material has better high temperature deformation ability. The diameter of the nanocrystals in the reinforced particles is 2-15nm, and the particle size of the reinforced particles is <20μm.

Preferably, the reinforcing particle composition is Ti ₄₅ Cu ₄₅ Zr ₅ Ni ₅ ; the nanocrystalline amorphous dual-phase particles are prepared by ball milling, specifically: the corresponding stoichiometric ratio of Ti ₄₅ Cu ₄₅ Zr ₅ Ni ₅ is weighed Each pure metal powder is mechanically alloyed on a planetary ball mill to prepare nanocrystalline amorphous dual-phase particles (by sieving and filtering to obtain a powder below 20 μm). Preferably, the powder mixing time is 5 hours, the ball-to-material ratio is 15:1, the ball milling speed is 200rpm, and the ball milling time is 5h to 100h. The amorphous phase in the nanocrystalline amorphous dual-phase particles increases with the ball milling time, and the nanocrystalline phase Decreases with increasing milling time.

The preparation method of the above-mentioned nanocrystalline amorphous dual-phase particle-reinforced aluminum-based composite material with excellent high-temperature deformability comprises the following steps:

(1) Powder mixing: ball mill the reinforcing particles with a volume fraction of 2% to 20% and the aluminum alloy powder of 80% to 98% to obtain composite material powder; the time of ball milling is 10-30h;

(2) Composite material powder-coated hot extrusion: the composite material powder obtained in step (1) is subjected to hot extrusion to obtain a nanocrystalline amorphous dual-phase particle-reinforced aluminum matrix composite material. The hot extrusion refers to putting the powder into an extrusion sleeve and putting it into a preheated mold of a hot extrusion equipment for extrusion. Hot extrusion conditions: extrusion temperature is 300°C-550°C, heating rate is 30°C-150°C/min, extrusion time is 1min-20min, extrusion pressure is 50-200MPa.

The principle of the present invention: the reinforcing body of the present invention is a nanocrystalline amorphous dual-phase particle, which has the advantages of high strength and good wettability, and improves the room temperature strength of the composite material; at the same time, the amorphous phase is used in the supercooled liquid phase interval The characteristics of low viscosity improve the high-temperature deformation ability of the composite material, so that the nanocrystalline amorphous dual-phase particle-reinforced aluminum matrix composite material has excellent high-temperature deformation ability; Time and temperature during hot extrusion are regulated.

The preparation method of the present invention and the resulting composite material have the following advantages and beneficial effects:

(1) The nanocrystalline amorphous dual-phase particles used in the present invention can not only improve the room temperature strength of the composite material, but also improve the high-temperature deformation capacity of the composite material, which is beneficial to thermal processing and temperature deformation, and breaks through the high-temperature deformation of traditional aluminum-based composite materials difficult bottleneck.

(2) The nanocrystalline amorphous dual-phase particles used in the present invention itself contain a nanocrystalline phase, so they are compatible with the nanocrystallization behavior of the amorphous phase.

(3) The nanocrystalline amorphous dual-phase particle-reinforced aluminum-based composite material prepared by the present invention has high room temperature strength, high specific strength, and excellent high-temperature deformation ability, and basically meets the application requirements as a lightweight structural material. , military industry and other fields have a wide range of promotion and application prospects.

Description of drawings

Fig. 1 is the scanning electron micrograph of the nanocrystalline amorphous dual-phase particle reinforced aluminum-based composite material prepared in Example 1; a and b respectively represent different magnification figures;

Figure 2 is a comparison of the true stress-true strain curves of the nanocrystalline amorphous dual-phase particle-reinforced aluminum matrix composite material prepared in Examples 1 and 2 and pure 7075 aluminum alloy when compressed at 250°C; 7075Al+2% reinforcement corresponds to the implementation Example 1, 7075Al+6% reinforcement corresponds to Example 2, 7075Al corresponds to pure 7075 aluminum alloy;

Figure 3 is a comparison of the true stress-true strain curves of the nanocrystalline amorphous dual-phase particle-reinforced aluminum matrix composite material prepared in Examples 1 and 2 and pure 7075 aluminum alloy when compressed at 400°C; 7075Al+2% reinforcement corresponds to the implementation Example 1, 7075Al+6% reinforcement corresponds to Example 2, 7075Al corresponds to pure 7075 aluminum alloy;

Figure 4 is a comparison of the true stress-true strain curves of the nanocrystalline amorphous dual-phase particle-reinforced aluminum matrix composite prepared in Examples 1 and 2 and pure 7075 aluminum alloy when compressed at 450°C; 7075Al+2% reinforcement corresponds to the implementation Example 1, 7075Al+6% reinforcement corresponds to Example 2, 7075Al corresponds to pure 7075 aluminum alloy.

Detailed ways

The present invention will be further described in detail below in conjunction with the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

The composition of the nanocrystalline amorphous dual-phase particles in the examples is Ti ₄₅ Cu ₄₅ Zr ₅ Ni ₅ ; the nanocrystalline amorphous dual-phase particles are prepared by ball milling, specifically: according to the stoichiometric ratio of Ti ₄₅ Cu ₄₅ Zr ₅ Ni ₅ The corresponding pure metal powders are weighed out, mechanically alloyed on a planetary ball mill, sieved and filtered to obtain powders below 20 μm, and nanocrystalline amorphous dual-phase particles are prepared. Preferably, the powder mixing time is 5 hours, the ball-to-material ratio is 15:1, the ball milling speed is 200rpm, and the ball milling time is 5h to 100h. The amorphous phase in the nanocrystalline amorphous dual-phase particles increases with the ball milling time, and the nanocrystalline phase Decreases with increasing milling time.

Example 1

(1) Powder mixing: put 2% reinforced particles and 98% aluminum alloy powder (7075 aluminum alloy) into a ball mill jar, and ball mill on a ball mill for 20 hours (the ball milling speed is 200rpm) to obtain a composite material powder;

(2) Composite material powder-coated hot extrusion: put the composite material powder obtained in step (1) into the extrusion sleeve, and put it into the preheated mold of the hot extrusion equipment, the extrusion temperature is 350 °C, and the heating rate is 100 °C/min, the extrusion time is ~5min, and the extrusion pressure is ~100MPa to obtain a bulk nanocrystalline amorphous dual-phase particle-reinforced aluminum matrix composite material. Wherein, the reinforcing particles contain about 20vol.% nanocrystalline phase and about 80vol.% amorphous phase. FIG. 1 is a scanning electron microscope image of the nanocrystalline amorphous dual-phase particle-reinforced aluminum-based composite material prepared in Example 1.

After testing, in the process of compression deformation at room temperature, when the strain rate is 1×10 ^-3 s ^-1 , the yield strength and compressive strength of the composite material are 520MPa and 596MPa, respectively, compared with 480MPa of pure 7075Al aluminum alloy under the same conditions and 553MPa, increased by 40MPa and 43MPa respectively. During high temperature compression deformation, when the strain rate is 1×10 ^-3 s ^-1 and the thermal compression temperature is 250°C, 400°C and 450°C, the deformation resistance of the composite is 257MPa, 54MPa and 36MPa, respectively, compared with pure 272MPa, 62MPa and 43MPa of 7075Al aluminum alloy, the deformation resistance is reduced by 5.5%, 13.0% and 16.3%, respectively. The true stress-true strain curves obtained by high temperature compression of the composite material in this embodiment are shown in Figures 2, 3 and 4.

Example 2

(1) Powder mixing: put the reinforced particles with a volume fraction of 6% and the aluminum alloy powder of 94% into a ball mill jar, and ball mill on a ball mill for 20 hours (the ball milling speed is 200rpm) to obtain a composite material powder;

(2) Composite material powder-coated hot extrusion: put the composite material powder obtained in step (1) into the extrusion sleeve, and put it into the preheated mold of the hot extrusion equipment, the extrusion temperature is 350 °C, and the heating rate is 100 °C/min, the extrusion time is ~5min, and the extrusion pressure is ~100MPa to obtain a bulk nanocrystalline amorphous dual-phase particle-reinforced aluminum matrix composite material. Wherein, the reinforcing particles contain about 25vol.% nanocrystalline phase and about 75vol.% amorphous phase.

After testing, in the process of compression deformation at room temperature, when the strain rate is 1×10 ^-3 s ^-1 , the yield strength and compressive strength of the composite material are 557MPa and 618MPa respectively, which are higher than those of pure 7075Al aluminum alloy under the same conditions. 77MPa and 65MPa. During high temperature compression deformation, when the strain rate is 1×10 ^-3 s ^-1 , and the thermal compression temperature is 250°C, 400°C and 450°C, the deformation resistance of the composite is 214MPa, 38MPa and 30MPa, respectively. The deformation resistance of 7075Al aluminum alloy decreased by 21.3%, 38.7% and 30.2%, respectively. The true stress-true strain curves obtained by high temperature compression of the composite material in this embodiment are shown in Figures 2, 3 and 4.

Example 3

(1) Powder mixing: the nanocrystalline amorphous dual-phase particles with a volume fraction of 17% and the aluminum alloy powder of 83% are loaded into a ball mill jar, and ball milled on a ball mill for 20 hours (the ball milling speed is 200rpm) to obtain a composite material powder;

(2) Composite material powder-coated hot extrusion: put the composite material powder obtained in step (1) into the extrusion sleeve, and put it into the preheated mold of the hot extrusion equipment, the extrusion temperature is 350 °C, and the heating rate is 100 °C/min, the extrusion time is ~5min, and the extrusion pressure is ~100MPa to obtain a bulk nanocrystalline amorphous dual-phase particle-reinforced aluminum matrix composite material. Wherein, the reinforcing particles contain about 30vol.% nanocrystalline phase and about 70vol.% amorphous phase.

After testing, in the process of compression deformation at room temperature, when the strain rate is 1×10 ^-3 s ^-1 , the yield strength and compressive strength of the composite material are 902MPa and 953MPa respectively, which are higher than those of pure 7075Al aluminum alloy under the same conditions. 422MPa and 400MPa. In the process of high temperature compression deformation, when the strain rate is 1×10 ^-3 s ^-1 and the hot compression temperature is 250℃, 400℃ and 450℃, the deformation resistance of the composite material is 180MPa, 29MPa and 25MPa, respectively, compared with pure The deformation resistance of 7075Al aluminum alloy was reduced by 34%, 23% and 15%, respectively.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (7)

1. A nanocrystalline amorphous dual-phase particle-reinforced aluminum-based composite material with excellent high-temperature deformability, characterized in that: it is prepared from reinforced particles with a volume fraction of 2% to 20% and aluminum alloys of 80% to 98%. to make; The reinforcing particles are nanocrystalline amorphous dual-phase particles; The reinforcing particles are Ti-Cu-Zr alloys. 2. The nanocrystalline amorphous dual-phase particle-reinforced aluminum matrix composite material with excellent high-temperature deformability according to claim 1, characterized in that: the microstructure of the reinforced particles is 10-90vol.% of nanocrystalline phase and 10 -90vol.% amorphous phase, the diameter of nanocrystals is 2-15nm, and the particle size of reinforcing particles is <20μm. 3. The nanocrystalline amorphous dual-phase particle-reinforced aluminum matrix composite material with excellent high-temperature deformability according to claim 1, wherein the composition of the reinforcing particles is Ti ₄₅ Cu ₄₅ Zr ₅ Ni ₅ . 4. The method for preparing the nanocrystalline amorphous dual-phase particle-reinforced aluminum-based composite material with excellent high-temperature deformability according to any one of claims 1 to 3, characterized in that it comprises the following steps: (1) Powder mixing: ball mill the reinforcing particles with a volume fraction of 2% to 20% and the aluminum alloy powder of 80% to 98% to obtain composite material powder; (2) Composite material powder-coated hot extrusion: the composite material powder obtained in step (1) is subjected to hot extrusion to obtain a nanocrystalline amorphous dual-phase particle-reinforced aluminum matrix composite material. 5. The method for preparing the nanocrystalline amorphous dual-phase particle-reinforced aluminum matrix composite material with excellent high-temperature deformability according to claim 4, characterized in that: the ball milling time is 10-30 hours. 6. The preparation method of the nanocrystalline amorphous dual-phase particle-reinforced aluminum-based composite material with excellent high-temperature deformability according to claim 4, characterized in that: the hot extrusion conditions: the extrusion temperature is 300° C. to 550° C. ℃. 7. The method for preparing the nanocrystalline amorphous dual-phase particle-reinforced aluminum matrix composite material with excellent high-temperature deformability according to claim 4, characterized in that: the hot extrusion conditions further include: the heating rate is 30°C to 150°C/min, the extrusion time is 1min-20min, and the extrusion pressure is 50-200 MPa.