阅读说明：本技术 碳纳米管增强镁合金制备方法 (Preparation method of carbon nano tube reinforced magnesium alloy ) 是由 王金娥 董明 于 2019-11-07 设计创作，主要内容包括：一种碳纳米管增强镁合金制备方法,属于纳米材料技术领域。该碳纳米管增强镁合金制备方法包括以下步骤：S1,将碳纳米管制备成大孔径大孔隙率的碳纳米管纸,高温蒸发单质镁在碳纳米管纸表面生成均匀纳米镁晶层；S2,在惰性气体氛围中,将包覆有纳米镁晶层的碳纳米管纸直接加入到镁或镁合金半熔融体中,加压搅拌糅合使之均匀,通过半固态铸造法得到碳纳米管增强镁合金复合材料。本发明采用的方法简单、易操作,适合进行产业化铸造生产。(A preparation method of carbon nano tube reinforced magnesium alloy belongs to the technical field of nano materials. The preparation method of the carbon nano tube reinforced magnesium alloy comprises the following steps: s1, preparing the carbon nano tube into carbon nano tube paper with large aperture and porosity, and evaporating elemental magnesium at high temperature to generate a uniform nano magnesium crystal layer on the surface of the carbon nano tube paper; s2, directly adding the carbon nanotube paper coated with the nano magnesium crystal layer into the magnesium or magnesium alloy semi-molten mass in an inert gas atmosphere, pressurizing, stirring and mixing uniformly, and obtaining the carbon nanotube reinforced magnesium alloy composite material by a semi-solid casting method. The method adopted by the invention is simple and easy to operate, and is suitable for industrial casting production.)

1. The preparation method of the carbon nanotube reinforced magnesium alloy is characterized by comprising the following steps of:

s1, preparing the carbon nanotube into carbon nanotube paper with large aperture and large porosity, and evaporating the elemental magnesium at high temperature or sputtering the elemental magnesium in a cold state to generate a uniform nano magnesium crystal layer on the surface of the carbon nanotube paper;

s2, directly adding the carbon nanotube paper coated with the nano magnesium crystal layer into the magnesium or magnesium alloy semi-molten mass in an inert gas atmosphere, pressurizing, stirring and mixing uniformly, and obtaining the carbon nanotube reinforced magnesium alloy composite material by a semi-solid casting method.

2. The method for preparing a carbon nanotube-reinforced magnesium alloy according to claim 1, wherein the semi-molten mass is obtained by heating magnesium or a magnesium alloy to 420 to 660 ℃.

3. The method for preparing the carbon nanotube reinforced magnesium alloy as set forth in claim 1, wherein the method for preparing the carbon nanotube paper comprises the steps of:

s11, mixing the carbon nano tube, the surfactant and the mixed solution of deionized water and alcohol, and performing ultrasonic treatment to uniformly disperse the mixture to obtain carbon nano tube slurry;

s12, uniformly coating the carbon nanotube slurry prepared in the step S11 on the surface of the rough copper foil, and drying at 70-80 ℃;

and S13, tearing off the carbon nanotube film dried in the step S12 and rolling the carbon nanotube film into a carbon nanotube paper roll to obtain the carbon nanotube paper with large aperture and large porosity.

Technical Field

The invention relates to a technology in the field of nano materials, in particular to a preparation method of a carbon nano tube reinforced magnesium alloy.

Background

Carbon Nanotubes (CNTs) are a class of novel carbon materials, hollow seamless tubular nanostructures made of single or multiple layers of graphite sheets that are crimped. The average Young modulus of the multi-wall carbon nano-tube is about 1.8 multiplied by 1012Pa, which is 100 times of that of steel, the bending strength can reach 14.2GPa, the existing strain energy can reach 100KeV, the super-strong mechanical property is shown, and the density is only 1/6 of the steel. The calculation finds that the carbon nano tube can release stress through the pentagon and heptagon pairs when stressed, shows good self-lubricating performance, and shows good prospect for the application of the self-lubricating performance of the carbon nano tube. In addition, the carbon nano tube also has the characteristics of excellent optics, field emission, strong acid and strong alkali resistance, high temperature oxidation resistance and the like. Thus, carbon nanotubes are one of the ideal candidates for reinforcing composite materials.

The magnesium-based composite material has good wear-resistant thermal property and good heat-conducting property. Low density, easy processing and easy recovery, and has very good application prospect in the fields of aerospace, electronic industry and the like. Although the research and development work of carbon nanotube reinforced magnesium-based composite materials at home and abroad has achieved some results, the reinforcing effect of the carbon nanotubes on the composite materials is not as expected due to the problems of dispersion and wettability of the carbon nanotubes in matrix tissues and the like.

The present invention has been made to solve the above-mentioned problems occurring in the prior art.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a preparation method of a carbon nano tube reinforced magnesium alloy, which adopts a semi-solid casting process and is suitable for industrial production.

The invention comprises the following steps:

s1, preparing the carbon nanotube into carbon nanotube paper with large aperture and large porosity, and evaporating the elemental magnesium at high temperature or sputtering the elemental magnesium in a cold state to generate a uniform nano magnesium crystal layer on the surface of the carbon nanotube paper;

s2, directly adding the carbon nanotube paper coated with the nano magnesium crystal layer into the magnesium or magnesium alloy semi-molten mass in an inert gas atmosphere, pressurizing, stirring and mixing uniformly, and obtaining the carbon nanotube reinforced magnesium alloy composite material by a semi-solid casting method.

Preferably, the carbon nanotube is at least one of a single-walled carbon nanotube and a multi-walled carbon nanotube, the diameter is 20-180 nm, and the length is 10-20 μm.

Preferably, the thickness of the carbon nanotube paper is 350-450 μm.

Preferably, the preparation method of the carbon nanotube paper comprises the following steps:

s11, mixing the carbon nano tube, the surfactant and the mixed solution of deionized water and alcohol, and performing ultrasonic treatment to uniformly disperse the mixture to obtain carbon nano tube slurry;

s12, uniformly coating the carbon nanotube slurry prepared in the step S11 on the surface of the rough copper foil, and drying at 70-80 ℃;

and S13, tearing off the carbon nanotube film dried in the step S12 and rolling the carbon nanotube film into a carbon nanotube paper roll to obtain the carbon nanotube paper with large aperture and large porosity.

Preferably, the surfactant is a nonionic surfactant, including but not limited to PEG, PVP, PVA.

Preferably, the ratio of the deionized water to the alcohol is 1: 1-2, and during operation, the CNT is soaked by the alcohol and then the deionized water is added.

Preferably, the semi-molten mass is obtained by heating magnesium or magnesium alloy to 420-660 ℃.

Preferably, the preparation method of the carbon nanotube paper comprises the following steps:

s11, mixing the carbon nano tube, the surfactant and the mixed solution of deionized water and alcohol, and uniformly dispersing by means of ultrasound, sanding, stirring and the like to obtain carbon nano tube slurry;

s12, uniformly coating the obtained carbon nanotube slurry on the surface of the raw copper foil, and drying at 70-80 ℃;

and S13, tearing off the dried carbon nanotube film and rolling into a carbon nanotube paper roll to obtain the carbon nanotube paper.

Technical effects

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

1) a nano magnesium crystal layer is formed on the surface of the carbon nano tube, so that the effective combination of the carbon nano tube and magnesium or magnesium alloy is ensured, the structural integrity of the carbon nano tube is ensured, and the reinforcing effect is obvious;

2) the mechanical fusion method of mixing by pressure stirring is adopted, the uniform distribution of the carbon nano tubes in the magnesium or magnesium alloy is realized, the product has the advantages of the magnesium or magnesium alloy and the carbon nano tube material, the preparation method is simple and easy to operate, high-efficiency and environment-friendly, and the method is suitable for industrial casting production.

Drawings

FIG. 1 is an SEM photograph of carbon nanotube paper coated with nano-magnesium crystal layer prepared in example 1;

fig. 2 is an EDS composition analysis chart of the carbon nanotube paper coated with a nano magnesium crystal layer prepared in example 1.

Detailed Description

The invention is described in detail below with reference to the drawings and the detailed description.