阅读说明：本技术 一种制备低热膨胀率铝合金复合材料的方法及其应用 (Method for preparing low-thermal-expansion-rate aluminum alloy composite material and application thereof ) 是由 孙军鹏 于 2020-06-09 设计创作，主要内容包括：一种低热膨胀率铝合金复合材料的制备方法,所述制备方法包括以下步骤：S1:将石墨蠕虫或纳米碳粉体与有机溶剂装入密闭水冷压力反应釜中进行混合、分散,制得纳米碳浆料；S2：在密闭热水压力反应釜中,将步骤S1得到的纳米碳浆料中加入有机硅树脂,搅拌混合均匀,制得纳米碳复合浆料；S3：将纳米碳复合浆料在真空状态下干燥、烧结,制得纳米碳复合粉；S4：以铝粉、碳化硅粉、硅粉、镁粉、纳米碳复合粉为原料粉体,分散于无水乙醇溶液中,混合并球磨成为片状,制得铝箔浆料；S5：将铝箔浆料过滤,回收溶剂,真空干燥,制得低热膨胀率铝合金复合材料。本发明提出的一种低热膨胀率的铝合金复合材料的制备方法,工艺简单,生产效率高,适合工业化生产。(A preparation method of a low-thermal-expansion-rate aluminum alloy composite material comprises the following steps: s1, putting the graphite worms or the nano-carbon powder and the organic solvent into a closed water-cooling pressure reaction kettle for mixing and dispersing to prepare nano-carbon slurry; s2: adding organic silicon resin into the nano-carbon slurry obtained in the step S1 in a closed hot water pressure reaction kettle, and uniformly stirring and mixing to obtain nano-carbon composite slurry; s3: drying and sintering the nano-carbon composite slurry in a vacuum state to prepare nano-carbon composite powder; s4: taking aluminum powder, silicon carbide powder, silicon powder, magnesium powder and nano-carbon composite powder as raw material powder, dispersing the raw material powder in an absolute ethyl alcohol solution, mixing and ball-milling the raw material powder into sheets to prepare aluminum foil slurry; s5: and filtering the aluminum foil slurry, recovering the solvent, and drying in vacuum to obtain the low-thermal-expansion-rate aluminum alloy composite material. The preparation method of the aluminum alloy composite material with low thermal expansion rate, provided by the invention, has the advantages of simple process and high production efficiency, and is suitable for industrial production.)

1. A method of making a low thermal expansion aluminum alloy composite, comprising the steps of:

s1, putting the graphite worms or the nano-carbon powder and the organic solvent into a closed water-cooling pressure reaction kettle for mixing and dispersing to prepare nano-carbon slurry;

s2: adding organic silicon resin into the nano-carbon slurry obtained in the step S1 in a closed hot water pressure reaction kettle, and uniformly stirring and mixing to obtain nano-carbon composite slurry;

s3: drying and sintering the nano-carbon composite slurry in a vacuum state to prepare nano-carbon composite powder;

s4: taking aluminum powder, silicon carbide powder, silicon powder, magnesium powder and nano-carbon composite powder as raw material powder, dispersing the raw material powder in an absolute ethyl alcohol solution, mixing and ball-milling the raw material powder into sheets to prepare aluminum foil slurry;

s5: and filtering the aluminum foil slurry, recovering the solvent, and drying in vacuum to obtain the low-thermal-expansion-rate aluminum alloy composite material.

2. The method of claim 1, wherein the graphite worms of step S1 have a specific surface area greater than 40m²(ii)/g; the graphite worms are obtained by heating expandable graphite to 400-1100 ℃ and expanding; the expandable graphite has a multiple expansion of greater than 200; the shear speed of mixing and dispersing is more than or equal to 9000 revolutions per second.

3. The method for preparing the aluminum alloy composite material with the low thermal expansion rate as claimed in claim 1, wherein the mass ratio of the graphite worms or the nano carbon powder to the organic solvent in the step S1 is (1-25): 100, respectively; the organic solvent is prepared from methyl isobutyl ketone, dimethyl methanol and triethanolamine according to the mass ratio of (2-40): (5-60): (4-30).

4. The method for preparing the low thermal expansion aluminum alloy composite material as claimed in claim 1, wherein the average particle size of the nanocarbon slurry in the step S1 is less than 40 μm.

5. The method for preparing the aluminum alloy composite material with the low thermal expansion rate as claimed in claim 1, wherein the mass ratio of the nanocarbon slurry to the silicone resin in the step S2 is 100: (1-30); the organic silicon resin is prepared from tetraethoxysilane, absolute ethyl alcohol and dibutyl dilaurate according to the mass ratio of (1-40): (2-40): (3-30).

6. The method for preparing the aluminum alloy composite material with the low thermal expansion rate as claimed in claim 1, wherein in the step S3, the sintering temperature of the nano carbon composite slurry is 200-700 ℃ and the sintering time is 1-10H.

7. The method for preparing the aluminum alloy composite material with the low thermal expansion rate as claimed in claim 1, wherein in the step S4, the mass ratio of the aluminum powder, the silicon carbide powder, the silicon powder, the magnesium powder and the nano carbon composite powder to the absolute ethyl alcohol solution is (10-40): 100, respectively; the mass ratio of the aluminum powder, the silicon carbide powder, the silicon powder, the magnesium powder and the nano-carbon composite powder is 100: (1-40): (1-20): (1-25): (1-20); the diameter of the aluminum powder is 30-100 mu m.

8. The method for preparing the low-thermal-expansion-rate aluminum alloy composite material as claimed in claim 1, wherein in the step S4, the powder is compositely ball-milled into sheets by using a stirred ball mill; the grinding medium is zirconia beads, the diameter of the zirconia beads is 5-30 mm, the rotating speed of the stirring ball mill is 20-800 rpm, the stirring temperature is controlled at 20-35 ℃, and the stirring time is 1-40 h; the mass ratio of the aluminum powder, the silicon carbide powder, the silicon powder, the magnesium powder and the nano-carbon composite powder to the zirconia beads is (1-40): 100.

9. the method of claim 1, wherein the aluminum foil slurry of step S4 has a specific surface area greater than 5m²/g。

10. Use of a low thermal expansion aluminium alloy composite material obtained by a method according to any one of claims 1 to 9 in the field of casting.

Technical Field

The invention belongs to the technical field of aluminum alloy composite materials, and particularly relates to a method for preparing an aluminum alloy composite material with a low thermal expansion rate and application thereof.

Background

The aluminum alloy is a non-ferrous metal structural material which is most widely applied in industry, the cast aluminum alloy has good casting performance, can be made into parts with complex shapes, does not need huge additional equipment, has the advantages of saving metal, reducing cost and the like, and is widely applied in the industries of aviation, aerospace, automobiles, mechanical manufacturing, ships and the like.

The nano carbon has super high modulus, strength, electric conductivity, heat conduction and low thermal expansion, and is an ideal reinforcing phase of the aluminum alloy, about 1 percent of nano carbon is added to obviously improve the mechanical property of the aluminum alloy, and the improvement of the content of the nano carbon in the aluminum alloy is an optional way for realizing performance enhancement.

The metal powder can be used for preparing parts with complex shapes and various sizes by various methods, including casting, powder metallurgy, extrusion forming and the like, so that the nano carbon aluminum alloy powder raw material can be used as a production mode of the aluminum alloy parts.

Chinese patent literature discloses a preparation method of graphene composite aluminum alloy, and the publication number is CN108359831A, in the invention, graphene and aluminum alloy powder are ground in a ball mill, so that the wettability of graphene is improved, the graphene is quickly and uniformly distributed in a metal solution, the thermal conductivity of the obtained graphene aluminum alloy section is greatly improved, and the strength, the toughness and the like of the graphene composite aluminum alloy material are improved. However, the nanocarbon is easy to oxidize in the grinding process, and the generated oxide causes the microstructure of the aluminum alloy material to be not compact, thereby causing adverse effects on the performance of the aluminum alloy material.

Disclosure of Invention

The invention provides a method for quickly preparing an aluminum alloy composite material with low thermal expansion rate, which is simple in process and aims to overcome the problem that nano carbon is easy to oxidize in the preparation of the aluminum alloy composite material.

The specific solution provided by the invention comprises the following steps:

s1, putting the graphite worms or the nano-carbon powder and the organic solvent into a closed water-cooling pressure reaction kettle for mixing and dispersing to prepare nano-carbon slurry;

s2: adding organic silicon resin into the nano-carbon slurry obtained in the step S1 in a closed hot water pressure reaction kettle, and uniformly stirring and mixing to obtain nano-carbon composite slurry;

s3: drying and sintering the nano-carbon composite slurry in a vacuum state to prepare nano-carbon composite powder;

s4: taking aluminum powder, silicon carbide powder, silicon powder, magnesium powder and nano-carbon composite powder as raw material powder, dispersing the raw material powder in an absolute ethyl alcohol solution, mixing and ball-milling the raw material powder into sheets to prepare aluminum foil slurry;

s5: and filtering the aluminum foil slurry, recovering the solvent, and drying in vacuum to obtain the low-thermal-expansion-rate high-thermal-conductivity aluminum alloy composite material.

Further, the specific surface area of the graphite worms in the step S1 is more than 40m²(ii)/g; the graphite worms are obtained by heating expandable graphite to 400-1100 ℃ and expanding; the expandable graphite has a multiple expansion of greater than 200; the shear speed of mixing and dispersing is more than or equal to 9000 revolutions per second.

Further, the mass ratio of the graphite worms or the nano-carbon powder to the organic solvent in the step S1 is (1-25): 100, respectively; the organic solvent is prepared from methyl isobutyl ketone, dimethyl methanol and triethanolamine according to the mass ratio of (2-40): (5-60): (4-30).

Further, the average particle size of the nanocarbon slurry in the step S1 is less than 40 μm.

Further, the mass ratio of the nanocarbon slurry to the silicone resin in the step S2 is 100: (1-30); the organic silicon resin is prepared from tetraethoxysilane, absolute ethyl alcohol and dibutyl dilaurate according to the mass ratio of (1-40): (2-40): (3-30);

further, in the step S3, the sintering temperature of the nanocarbon composite slurry is 200 to 700 ℃ and the sintering time is 1H to 10H.

Further, in step S4, the mass ratio of the aluminum powder, the silicon carbide powder, the silicon powder, the magnesium powder and the nano-carbon composite powder raw material powder to the absolute ethyl alcohol solution is (10-40): 100, respectively; the mass ratio of the aluminum powder, the silicon carbide powder, the silicon powder, the magnesium powder and the nano-carbon composite powder is 100: (1-40): (1-20): (1-25): (1-20); the diameter of the aluminum powder is 30-100 mu m.

Further, in the step S4, a stirring ball mill is adopted to compound ball mill the powder into a sheet shape; the grinding medium is zirconia beads, the diameter of the zirconia beads is 5-30 mm, the rotating speed of the stirring ball mill is 20-800 rpm, the stirring temperature is controlled at 20-35 ℃, and the stirring time is 1-40 h; the mass ratio of the aluminum powder, the silicon carbide powder, the silicon powder, the magnesium powder and the nano-carbon composite powder to the zirconia beads is (1-40): 100.

further, the specific surface area of the aluminum foil slurry in the step S4 is more than 5m²/g。

Further, the application of the low-thermal expansion coefficient aluminum alloy composite material in the casting field.

Compared with the prior art, the invention has the following beneficial effects:

(1) due to the addition of the organic silicon resin, the nano carbon slurry is not easily oxidized, so that the nano carbon slurry is better compounded with aluminum powder, silicon carbide powder, silicon powder and magnesium powder in absolute ethyl alcohol, and the aluminum foil slurry with stable performance is more easily obtained;

(2) a pressure pump is not needed to provide a preparation environment, the preparation process is simple, the process is easy to control, the production efficiency is higher, and the industrial production is easy to realize;

(3) the low-thermal expansion rate aluminum alloy composite material prepared by the process has lower thermal expansion rate and higher thermal conductivity, can also be used for preparing parts with complex structural shapes by a metal casting method, and has wide application prospect.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

FIG. 1 is a flow chart of the production process of the low thermal expansion aluminum alloy composite material of the present invention.

FIG. 2 is a schematic structural diagram of an apparatus used in the method for preparing the low thermal expansion coefficient aluminum alloy composite material of the present invention.

Wherein: 1 is a first feed conduit; 2 is a second feed conduit; 3 is a third feeding pipeline; 4, a closed water-cooling pressure reaction kettle; 5 is a stirring driving motor; 6 is a vacuum pump; 7 is a first cooling water inlet; 8 is a second cooling water inlet; and 9 is a kettle bottom valve.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.