CN104962841A - Interface design and preparation method of carbon nanotube metal matrix composite material - Google Patents

Abstract

The invention provides an interface design and a preparation method of a carbon nanotube metal matrix composite material. The interface design adopts nanoparticles to locally modify the defects on the surfaces of carbon nanotubes to block the interface reaction of the defects, and good interface combination is realized through an appropriate interface reaction of the structure complete positions of the surfaces of the carbon nanotubes and a metal matrix. The method comprises the following steps: locally activating the surfaces of the carbon nanotubes, and preparing a dispersion liquid; mixing the carbon nanotube dispersion liquid with nanometer sol, uniformly stirring, carrying out ultrasonic treatment, filtering, and drying to obtain the nanoparticle locally modified carbon nanotubes; and uniformly dispersing the modified carbon nanotubes in the metal matrix, and densifying to obtain the composite material. A discontinuous locally-modified material film is formed on the surfaces of the carbon nanotubes, and the introduced nanometer modification particles have a low volume content, do not agglomerate, have no influences on the densification of the composite material, and can effectively regulate the interface reaction in order to fully perform the enhanced potential of the carbon nanotubes.

Description

A kind of INTERFACE DESIGN of carbon nanotube metal based composite materials and preparation method

Technical field

The present invention relates to metal-base composites technical field, particularly, relate to a kind of INTERFACE DESIGN and preparation method of carbon nano-tube reinforced metal-matrix composite material.

Background technology

Composite is that metallic substance realizes one of effective way of high performance and functionalization.Carbon nanotube (CNT) is as one dimension tubular nanometer material, lightweight, has extremely excellent mechanics and heat-conductivity conducting performance, is the desirable high-strength light performance enhancement body of metal-base composites.Therefore, by metal and alloy compounds such as CNT and aluminium, copper, magnesium, titaniums, be expected to obtain high-strength light of new generation and the metal-base composites having functional performance concurrently, have broad application prospects in space flight, traffic, electronics and military field.

But up to now, still gap is larger for the reinforced effects that carbon nanotube embodies in metal-base composites and theory expectation, wherein most important reason is just to there is a surface reaction regulation and control difficult problem between carbon nanotube and metallic matrix, is difficult to the strengthening effect giving full play to carbon nanotube.On the one hand, chemical reaction does not occur completely between carbon nanotube and the metal such as copper, magnesium, interface compatibility is poor, and interface bond strength is low; On the other hand, be easy between carbon nanotube and the metal such as aluminium, titanium chemical reaction occurs, many times even carbon nanotube approach exhaustion all generated Al ₄c ₃, the carbide such as TiC., namely there is not the surface reaction of surface reaction or many degree in above two kinds of situations, all will the enhancing benefit of infringement carbon nanotube completely: weak interface combines cannot effective transmitted load, and excessively surface reaction makes carbon nanotube damage to aggravate, be easy to fracture failure.Therefore, how under the prerequisite of few consumption/damage carbon nanotube, regulation and control surface reaction obtains desirable interface bond strength, becomes the key issue that carbon nanotube metal based composite materials further develops.

Research shows, existing compound preparation process inevitably introduces a large amount of defect on the surface of carbon nanotube and end, and fault location is carbon nanotube/preferential place occurred of metal interface reaction.Therefore, carrying out modification to the defect of carbon nano tube surface is improve interface cohesion, the most effective approach of regulation and control surface reaction.Find existing literature search, carrying out surface coated treatment to carbon nanotube is the technical way reaching above target.Document 1 " Aluminum matrix composites reinforced by molybdenum-coatedcarbon nanotubes " (plating molybdenum carbon nanotube enhanced aluminium-based composite material) (International Journal of Minerals, Metallurgy, and Materials, 2011,18 (6): 695-702.) adopting metal organic chemical vapor deposition (MOCVD) evenly to apply one deck continuous print thickness in carbon nano tube surface is the metal molybdenum of 20-30nm, and the plating molybdenum carbon nanotube aluminum matrix composite that used discharge plasma sintering to prepare.Due to the introducing of excessive coating, cause the density of matrix material to reduce, final relative density only has 95%.In addition, metallorganics that this technique uses is highly toxic substance, easily causes environmental pollution.Document 2 " Coating of carbon nanotubeswith tungsten by physicalvapor deposition " (physical vapor deposition plates tungsten in carbon nano tube surface) (Solidstate communications, 2000,115 (1): 51-55.) adopting physical vapor deposition to deposit one deck continuous print thickness in carbon nano tube surface is the tungsten of 10-20nm.The physical vapor deposition device that this technique uses is complicated, and the introducing of continuous film causes carbon nanotube can not directly contact with metallic matrix, is unfavorable for that carbon nanotube strengthens the performance of benefit.Document 3 " Coating carbon nanotubes with iron oxide using methanol – thermal reaction " (the hot method of alcohol plates ferric oxide in carbon nano tube surface) (Materials Letters, 2007,61 (3): 697-700.) the hot method of alcohol is adopted to introduce the ferric oxide of needle-like in carbon nano tube surface, parcel carbon nanotube, but there is a large amount of reunions in its local, is unfavorable for the performance of densification process and reinforcement benefit.

Visible, aforesaid method all tends to top coat to regulate and control into continuous film distribution, and does not does not regulate and control the form of carbon nano tube surface coating and content, lacks the Fine design to interface structure and Effective Regulation thus, brings following weak point:

(1) specific surface area due to carbon nanotube is large, when forming continuous film, introduce the volume content of modifier considerably beyond carbon nanotube self, change the composition of composite system;

(2) modifier is that continuous film distribution can contact with the direct of metallic matrix by obstruct carbon nanotube completely, also can produce modifier time serious to reunite, affect the combination of carbon nanotube and metallic matrix, cause the density of matrix material to reduce, the enhancing benefit of carbon nanotube can not get effective performance;

(3) aforesaid method is unfriendly to environment, simultaneously complex process, is difficult to control.

Summary of the invention

For defect of the prior art, the invention provides a kind of INTERFACE DESIGN and preparation method of carbon nanotube metal based composite materials, only introduce a small amount of nanoparticle and local modification is carried out to carbon nano tube surface defect, the densification of matrix material can not be affected, but energy Effective Regulation surface reaction, makes carbon nanotube can give full play to it and strengthens potentiality.

For achieving the above object, the present invention is by the following technical solutions:

A kind of Interface Design of carbon nanotube metal based composite materials, the method abandons existing thinking top coat being regulated and controled into when modifying carbon nano tube surface defect continuous film distribution, but adopt nanoparticle to carry out local modification to carbon nano tube surface fault location dexterously, hinder fault location generation surface reaction, and obtain good interface cohesion by the surface reaction of appropriateness between carbon nano tube surface structural integrity place and metallic matrix.

The present invention forms discontinuous, partial modification thing film at carbon nano tube surface fault location, hinder this place that surface reaction occurs, and the structural integrity place of carbon nano tube surface is directly contacted with metallic matrix, the surface reaction making this place that appropriateness occur by process control obtains good interface cohesion.

The nanoparticle content that INTERFACE DESIGN of the present invention is introduced is very low, as shown in table 1, and compared with general continuous film modification, the nanoparticle content that INTERFACE DESIGN of the present invention is introduced is low more than 10 times.Therefore, interface cohesion and the densification of carbon nanotube metal based composite materials can not be affected; The surface imperfection of Nanoparticle Modified carbon nanotube, effectively can stop the surface reaction between carbon nanotube and metallic matrix, the carbon nanotube metal based composite materials excellent performance obtained.

Preferably, described nanoparticle is metal oxide or metal complex or silicon-dioxide, does not such as react with carbon nanotube and the metal oxide little with the spread coefficient of carbon nanotube.Selection metal oxide or complex compound (also can change into metal oxide after pyroprocessing) are the consistency because of ensureing itself and matrix on the one hand, in addition on the one hand because the spread coefficient of carbon nanotube in metal oxide is very little, and generally not easily react, therefore, it is possible to effectively hinder the generation of surface reaction.

Preferably, the particle diameter of described nanoparticle is 1-50nm, and better, the particle diameter of described nanoparticle is 1-10nm.The particle diameter of nanoparticle is more little is more easily adsorbed on carbon nano tube surface fault location, and the content simultaneously introduced is also lower, and particle diameter is excessive easily causes nanoparticle self reunion to produce sedimentation, does not have modification.

Preferably, described carbon nanotube diameter is 5-100nm, and better, the diameter of described carbon nanotube is 10-50nm.The diameter of carbon nanotube is excessive is unfavorable for that it disperses, and the too small surface activation process of diameter can cause very large damage to its stuctures and properties, therefore selects the carbon nanotube of diameter 10-50nm.

According to a second aspect of the present invention, provide a kind of preparation method of carbon nanotube metal based composite materials, the method, on the basis of above-mentioned INTERFACE DESIGN, comprises the steps:

Step one, the process of carbon nano tube surface local activation, prepares carbon nano tube dispersion liquid or adopts the carbon nano tube dispersion liquid prepared in advance;

Step 2, prepares modifier Nano sol or adopts the modifier Nano sol prepared in advance, and being mixed with Nano sol by carbon nano tube dispersion liquid, stirring, then carry out supersound process, filtration drying, obtains the carbon nanotube that nanoparticle local is modified;

Step 3, is distributed to the even carbon nanotube that nanoparticle local is modified among metallic matrix, then obtains carbon nanotube metal based composite materials through densification.

Preferably, described metallic matrix is Aluminum-aluminum alloy.

Preferably, the massfraction of the carbon nanotube in described matrix material is 0.5 ~ 10%, and better, the massfraction of described carbon nanotube is 1 ~ 5%.

Preferably, described preparation method carries out activation treatment by acid solution to carbon nano tube surface, makes carbon nano tube surface defect become active site.

Preferably, described in stir, can mechanical stirring be adopted.

Preferably, described modifier Nano sol, modifier is metal oxide or metal complex or silicon-dioxide.

Preferably, in described step 2, after being mixed with Nano sol by carbon nanotube, add anion surfactant (SDS, SDBS etc.), suppress carbon nanotube reunion each other, make nanoparticle uniform adsorption on the active site of carbon nanotube.

Principle of the present invention: described INTERFACE DESIGN is from regulation and control surface reaction and the angle improving interface cohesion, although the introducing of continuous film can suppress surface reaction, but because the specific surface area of carbon nanotube is large, the introducing of high volume content continuous film and additional interfaces will inevitably be caused, the densification of matrix material is reduced, hinders the combination of carbon nanotube and metallic matrix; The nanoparticle content that Nanoparticle Modified is introduced is very low, can not affect the densification of matrix material.Meanwhile, the modification energy Effective Regulation surface reaction of nanoparticle.

Due to carbon nano tube surface and end inevitably existing defects, described preparation method carries out activation treatment by acid solution to carbon nano tube surface, makes carbon nano tube surface defect become active site.Because fault location has high surface energy, become the preferential attachment point of nanoparticle.After carbon nanotube is mixed with Nano sol, be aided with mechanical stirring and ultrasonic, the metastable state of Nano sol is destroyed, the anion surfactant (SDS, SDBS etc.) added can suppress carbon nanotube reunion each other, makes nanoparticle uniform adsorption on the active site of carbon nanotube.Nanoparticle preferentially in the attachment of carbon nano tube surface fault location, obtains the carbon nanotube of Nanoparticle Modified.Again by the carbon nanotube dispersed of Nanoparticle Modified in metallic matrix, obtain the carbon nanotube metal based composite materials of Nanoparticle Modified.

Modify for existing continuous film, the introduction volume of modifier can be passed through formula (1) relative to the volume fraction of carbon nanotube and calculate:

$\mathrm{\α}=\frac{2\mathrm{\πr}\×L\×\mathrm{\Δr}}{\mathrm{\π}{r}^2\×L}=2\frac{\mathrm{\Δr}}{r}---\left(1\right)$

Wherein, r is carbon nanotube radius, and L is length of carbon nanotube, and Δ r is the thickness of continuous film, and α is the volume fraction of continuous film relative to carbon nanotube.

For Nanoparticle Modified, the introduction volume of modifier can be passed through formula (2) relative to the volume fraction of carbon nanotube and calculate:

$\mathrm{\β}=\frac{\frac{2\mathrm{\πr}\×L\×c\%}{\mathrm{\π\Δ}{r}^2}\×\frac{4}{3}\mathrm{\π\Δ}{r}^3}{\mathrm{\π}{r}^2\×L}=\frac{8\mathrm{\Δr}}{3r}c\%---\left(2\right)$

Wherein, r is carbon nanotube radius, and L is length of carbon nanotube, and Δ r is the radius of nanoparticle, and c% is carbon nano tube surface defect density, and β is the volume fraction of nanoparticle relative to carbon nanotube.

Take diameter as 30nm, surface imperfection concentration be 5% carbon nanotube be example, i.e. r=15nm, c%=5%.Can calculate according to formula (1) (2), for continuous film and the nanoparticle of different thickness, the introduction volume of modifier is as shown in table 1 relative to the volume fraction of carbon nanotube.

Table 1 modifier introduction volume and modifier scaling relation

Δr/nm	2	5	10	15	20
						α	27％	67％	133％	200％	267％
β	2％	5％	9％	14％	18％

As can be seen from Table 1, for continuous film, because nanoparticle is only modified carbon nano tube surface fault location, the introduction volume of nanoparticle is little, can not affect the densification process of matrix material.Nanoparticle can and carbon nanotube between form good combination, select the nanoparticle good with metallic matrix wettability simultaneously, the interface cohesion of carbon nanotube and metallic matrix can be improved.On the other hand, nanoparticle, for the modification of carbon nano tube surface defect, makes nanoparticle as the barrier layer of Elements Diffusion and surface reaction, can slow down surface reaction, ensures the integrity of carbon nanotube.Therefore, compared with not carrying out the carbon nanotube metal based composite materials of nanoparticle point modification, adopt Nanoparticle Modified to slow down surface reaction, improve interface cohesion, improve the over-all properties of carbon nanotube metal based composite materials.

Compared with prior art, the present invention has following beneficial effect:

(1) interface cohesion and the densification of carbon nanotube metal based composite materials can be improved;

(2) can modify the surface imperfection of carbon nanotube, improve the enhancing benefit of carbon nanotube;

(3) surface reaction of energy Effective Regulation carbon nanotube and metallic matrix;

(4) technique is simple, and environmental friendliness, is conducive to further genralrlization.

Accompanying drawing explanation

By reading the detailed description done non-limiting example with reference to the following drawings, other features, objects and advantages of the present invention will become more obvious:

Fig. 1 is INTERFACE DESIGN schematic diagram of the present invention;

Fig. 2 is the carbon nano-tube modified transmission electron microscope microgram of aluminum oxide of preparation in the embodiment of the present invention 1.

Fig. 3 is the transmission electron microscope microgram of the Wolfram oxide modified carbon nanotube of preparation in the embodiment of the present invention 2.

Embodiment

Below in conjunction with specific embodiment, the present invention is described in detail.Following examples will contribute to those skilled in the art and understand the present invention further, but not limit the present invention in any form.It should be pointed out that to those skilled in the art, without departing from the inventive concept of the premise, some distortion and improvement can also be made.These all belong to protection scope of the present invention.

As shown in Figure 1, the invention provides a kind of INTERFACE DESIGN and preparation method of carbon nanotube metal based composite materials, the method adopts Nano sol to carry out surface modification to carbon nanotube, among the carbon nanotube dispersed of Nanoparticle Modified to metallic matrix, obtain the carbon nanotube metal based composite materials of Nanoparticle Modified.

In following examples 1-5 and comparing embodiment 1-3:

The diameter of carbon nanotube is 30-50nm, and length is 10-20 μm, and matrix is purity 99.9% pure aluminium powder or 5083 alloy powders, and the massfraction of carbon nanotube is 1.0%.Also the carbon nanotube of other diameters and length, massfraction can be adopted in other embodiments.

In order to verify the relation between modifier introduction volume and carbon nano tube surface defect, adopting nitric acid and sulfuric acid (volume ratio 3:1) to carry out surperficial acidification to carbon nanotube, having regulated and controled the defect density of carbon nano tube surface by controlling acidificatoin time.Carbon nano tube surface carboxyl-content is measured to characterize carbon nano tube surface defect density by X-ray photoelectron spectroscopic analysis instrument.Also other acid solution can be adopted in other embodiments to carry out activation treatment to carbon nano tube surface, as long as can realize by activation treatment, make carbon nano tube surface defect become active site.

In addition, adopt weight-loss method to determine the modifier content of carbon nano tube surface introducing, test result shows that the content that modifier is introduced increases along with the increase of carbon nano tube surface defect content.Finally, adopt powder metallurgical technique, prepared carbon nanotube aluminum matrix composite through overmulling powder, pressed compact, sintering.And by the surface reaction degree of sample in electrochemical reaction and each embodiment of gas Chromatographic Determination, result is as shown in table 2.The final performance of the sample of the preparation that what table 3 provided is in each embodiment.

The surface reaction degree of material in each embodiment of table 2

The final performance of material in each embodiment of table 3

The present invention is elaborated by following embodiment:

Embodiment 1

Adopt nitric acid and sulfuric acid (volume ratio 3:1) to carry out surperficial acidification 5h to carbon nanotube, and prepare carbon nano tube dispersion liquid, the concentration of this dispersion liquid is 0.5 ~ 4g/200mL; Certainly also can be other concentration ranges in other embodiments;

Preparation of nano alumina sol (mol ratio Al:H ₂o=1:100, controls the introduction volume of modifier by the amount regulating and controlling to add colloidal sol), carbon nano tube dispersion liquid is dropwise joined in nano alumina sol, and magnetic agitation 30min, carry out supersound process 2h afterwards, filtration drying, obtain the carbon nanotube powder that nano aluminium oxide is modified.

Then with purity be 99.9% fine aluminium powder mix, pressed compact, 570 DEG C of sintering 2 hours, the carbon nanotube aluminum matrix composite density that the nano aluminium oxide of preparation is modified is 99.3%, and yield strength is 298MPa, and tensile strength is 415MPa, and unit elongation is 9.9%.Be 8.0% by electrochemical reaction and its surface reaction degree of gas Chromatographic Determination.

As shown in Figure 2, the transmission electron microscope microgram that the aluminum oxide for preparation in embodiment 1 is carbon nano-tube modified, aluminum oxide nanoparticle is evenly attached to carbon nano tube surface discretely, carries out local modify carbon nanotube.

Embodiment 2

Adopt nitric acid and sulfuric acid (volume ratio 3:1) to carry out surperficial acidification 8h to carbon nanotube, and prepare carbon nano tube dispersion liquid.

Preparation of nano alumina sol, dropwise joins carbon nano tube dispersion liquid in nano alumina sol, and magnetic agitation 30min, carry out supersound process 2h afterwards, filtration drying, obtain the carbon nanotube powder that nano aluminium oxide is modified.

Then with purity be 99.9% fine aluminium powder mix, pressed compact, 570 DEG C of sintering 2 hours, the carbon nanotube aluminum matrix composite density that the nano aluminium oxide of preparation is modified is 99.1%, and yield strength is 320MPa, and tensile strength is 440MPa, and unit elongation is 7.0%.Be 9.0% by electrochemical reaction and its surface reaction degree of gas Chromatographic Determination.

As shown in Figure 3, be the transmission electron microscope microgram of the Wolfram oxide modified carbon nanotube of preparation in embodiment 2, tungsten oxide nanoparticles is evenly attached to carbon nano tube surface discretely, carries out local modify carbon nanotube.

Embodiment 3

Adopt nitric acid and sulfuric acid (volume ratio 3:1) to carry out surperficial acidification 5h to carbon nanotube, and prepare carbon nano tube dispersion liquid.

Preparation of nano Tungsten oxide 99.999 colloidal sol, dropwise joins carbon nano tube dispersion liquid in nanometer tungsten oxide colloidal sol, and magnetic agitation 30min, carry out supersound process 2h afterwards, filtration drying, obtain the carbon nanotube powder that nanometer tungsten oxide is modified.

Then with purity be 99.9% fine aluminium powder mix, pressed compact, 570 DEG C sintering 2 hours, the density of the carbon nanotube aluminum matrix composite of the nanometer tungsten oxide modification of preparation is 99.1%, yield strength is 295MPa, and tensile strength is 408MPa, and unit elongation is 8.5%.Be 7.5% by electrochemical reaction and its surface reaction degree of gas Chromatographic Determination.

Embodiment 4

Adopt nitric acid and sulfuric acid (volume ratio 3:1) to carry out surperficial acidification 8h to carbon nanotube, and prepare carbon nano tube dispersion liquid.Preparation of nano Tungsten oxide 99.999 colloidal sol, dropwise joins carbon nano tube dispersion liquid in nanometer tungsten oxide colloidal sol, and magnetic agitation 30min, carry out supersound process 2h afterwards, filtration drying, obtain the carbon nanotube powder that nanometer tungsten oxide is modified.Then with purity be 99.9% fine aluminium powder mix, pressed compact, the density of the carbon nanotube aluminum matrix composite of the nanometer tungsten oxide modification of 570 DEG C of sintering preparation in 2 hours is 98.5%, and yield strength is 310MPa, tensile strength is 430MPa, and unit elongation is 6.0%.Be 8.0% by electrochemical reaction and its surface reaction degree of gas Chromatographic Determination.

Embodiment 5

Adopt nitric acid and sulfuric acid (volume ratio 3:1) to carry out surperficial acidification 5h to carbon nanotube, and prepare carbon nano tube dispersion liquid.Preparation of nano alumina sol, dropwise joins carbon nano tube dispersion liquid in nano alumina sol, and magnetic agitation 30min, carry out supersound process 2h afterwards, filtration drying, obtain the carbon nanotube powder that nano aluminium oxide is modified.Then with purity be 99.9% 5083 powdered alloys mix, pressed compact, the carbon nanotube aluminum matrix composite density that the nano aluminium oxide of 570 DEG C of sintering preparation in 2 hours is modified is 99.1%, and yield strength is 345MPa, tensile strength is 455MPa, and unit elongation is 8.0%.Be 6.0% by electrochemical reaction and its surface reaction degree of gas Chromatographic Determination.

Comparing embodiment 1

Adopt strong acid to carry out surface activation process to carbon nanotube, after filtration, drying, obtain carbon nanotube powder.Then with purity be 99.9% fine aluminium powder mix, pressed compact, the densityes of carbon nanotube aluminum composite of 570 DEG C of sintering preparation in 2 hours are 99.5%, and yield strength is 247MPa, and tensile strength is 358MPa, and unit elongation is 12.1%.Be 25.0% by electrochemical reaction and its surface reaction degree of gas Chromatographic Determination.

Comparing embodiment 2

Adopt strong acid to carry out surface activation process to carbon nanotube, obtain carbon nanotube powder after filtration, drying, then adopt physical vapor deposition to be the pellumina of 10-20nm at carbon nano tube surface deposit thickness.Then with purity be 99.9% fine aluminium powder mix, pressed compact, the density of the carbon nanotube aluminum matrix composite of the continuous aluminium oxide modification of 570 DEG C of sintering preparation in 2 hours is 95.2%, and yield strength is 274MPa, tensile strength is 382MPa, and unit elongation is 3.5%.Be 5.8% by electrochemical reaction and its surface reaction degree of gas Chromatographic Determination.

Comparing embodiment 3

Adopt strong acid to carry out surface activation process to carbon nanotube, obtain carbon nanotube powder after filtration, drying, then adopt physical vapor deposition to be the oxidation tungsten film of 10-20nm at carbon nano tube surface deposit thickness.Then with purity be 99.9% fine aluminium powder mix, pressed compact, the density of the carbon nanotube aluminum matrix composite of the continuous oxidation tungsten modification of 570 DEG C of sintering preparation in 2 hours is 94.7%, and yield strength is 270MPa, tensile strength is 381MPa, and unit elongation is 3.1%.Be 6.2% by electrochemical reaction and its surface reaction degree of gas Chromatographic Determination.

Embodiment 6

Select diameter to be 10-20nm, length is the carbon nanotube of 5-10 μm, and matrix is 2024 Al alloy powders of 99.9% purity, and employing the inventive method preparation quality mark is the carbon nanotube aluminum matrix composite of 2.0%, and concrete technology is as follows:

Potassium permanganate solution is adopted to carry out acidification to carbon nano tube surface, prepare carbon nano tube dispersion liquid, preparation tin oxide sol, carbon nano tube dispersion liquid is dropwise joined in nano oxidized tin oxide sol, and magnetic agitation 30min, carry out supersound process 2h afterwards, filtration drying, obtain the carbon nanotube powder that nano tin dioxide is modified.Then with purity be 99.9% 2024 Al alloy powders mix, pressed compact, the density of the carbon nanotube aluminum matrix composite of the nano tin dioxide modification of 570 DEG C of sintering preparation in 2 hours is 97.5%, and yield strength is 410MPa, tensile strength is 590MPa, and unit elongation is 5.5%.Be 6.7% by electrochemical reaction and its surface reaction degree of gas Chromatographic Determination.

Embodiment 7

Select diameter to be 100-150nm, length is the carbon nanotube of 10-20 μm, and matrix is 6061 Al alloy powders of 99.9% purity, and employing the inventive method preparation quality mark is the carbon nanotube aluminum matrix composite of 3.0%, and concrete technology is as follows:

Adopt concentrated nitric acid to carry out surface to carbon nanotube and carry out acidification, prepare carbon nano tube dispersion liquid, preparing titanium dioxide colloidal sol, carbon nano tube dispersion liquid is dropwise joined in nano-oxide colloidal sol, and magnetic agitation 30min, carry out supersound process 2h afterwards, filtration drying, obtain the carbon nanotube powder that nano titanium oxide is modified.Then with purity be 99.9% 6061 Al alloy powders mix, pressed compact, the density of the carbon nanotube aluminum matrix composite of the nano titanium oxide modification of 570 DEG C of sintering preparation in 2 hours is 98.1%, and yield strength is 350MPa, tensile strength is 460MPa, and unit elongation is 5.1%.Be 7.2% by electrochemical reaction and its surface reaction degree of gas Chromatographic Determination.

Comparing embodiment is compared with the present invention, owing to not modifying carbon nano tube surface or adopting continuous film to modify, under same material component and preparation process condition, the density of material and mechanical property in comparing embodiment, the low 15-20% of intensity of the carbon nanotube aluminum matrix composite generally prepared than the present invention.Wherein, the carbon nano-tube modified aluminum matrix composite densification difficulty of continuous film, unit elongation significantly reduces; And Nanoparticle Modified carbon nanotube aluminum matrix composite, when unit elongation reduces very little, intensity is greatly improved.Can find by measuring its surface reaction degree, the CNT/Al surface reaction degree of not carrying out surface modification is 25.0%, and adopt Nanoparticle Modified and continuous film to modify CNT/Al surface reaction and be well controlled, level of response is 6 ~ 8%.In sum, INTERFACE DESIGN of the present invention and preparation method can improve interface cohesion, regulation and control surface reaction degree, and density and combination can not be affected, and the mechanical property of carbon nanotube metal based composite materials is largely increased.

Above specific embodiments of the invention are described.It is to be appreciated that the present invention is not limited to above-mentioned particular implementation, those skilled in the art can make various distortion or amendment within the scope of the claims, and this does not affect flesh and blood of the present invention.

Claims (14)

1. the Interface Design of a carbon nanotube metal based composite materials, it is characterized in that: adopt nanoparticle to carry out local to carbon nano tube surface fault location and modify, hinder fault location generation surface reaction, and obtain good interface cohesion by the surface reaction of appropriateness between carbon nano tube surface structural integrity place and metallic matrix.

2. the preparation method of carbon nanotube metal based composite materials according to claim 1, is characterized in that: described carbon nanotube diameter is 5-100nm.

3. the preparation method of carbon nanotube metal based composite materials according to claim 2, is characterized in that: the diameter of described carbon nanotube is 10-50nm.

4. the preparation method of carbon nanotube metal based composite materials according to claim 1, is characterized in that: described nanoparticle is metal oxide or metal complex or silicon-dioxide.

5. the preparation method of carbon nanotube metal based composite materials according to claim 4, is characterized in that: the particle diameter of described nanoparticle is 1-50nm.

6. the preparation method of carbon nanotube metal based composite materials according to claim 5, is characterized in that: the particle diameter of described nanoparticle is 1-10nm.

7. the preparation method of the carbon nanotube metal based composite materials according to any one of claim 1-6, it is characterized in that: between described nanoparticle energy and carbon nanotube, form good combination, select the nanoparticle good with metallic matrix wettability simultaneously, the interface cohesion of carbon nanotube and metallic matrix can be improved; Nanoparticle, for the modification of carbon nano tube surface defect, makes nanoparticle as the barrier layer of Elements Diffusion and surface reaction, slows down surface reaction, ensure the integrity of carbon nanotube.

8., based on a preparation method for the carbon nanotube metal based composite materials of Interface Design described in any one of claim 1-7, it is characterized in that described preparation method comprises:

Step one, the process of carbon nano tube surface local activation, prepares carbon nano tube dispersion liquid or adopts the carbon nano tube dispersion liquid prepared in advance;

Step 2, prepares modifier Nano sol or adopts the modifier Nano sol prepared in advance, and being mixed with Nano sol by carbon nano tube dispersion liquid, stirring, then carry out supersound process, filtration drying, obtains the carbon nanotube that nanoparticle local is modified;

Step 3, is distributed to the even carbon nanotube that nanoparticle local is modified among metallic matrix, then obtains carbon nanotube metal based composite materials through densification.

9. the preparation method of carbon nanotube metal based composite materials according to claim 8, is characterized in that: described metallic matrix is Aluminum-aluminum alloy.

10. the preparation method of carbon nanotube metal based composite materials according to claim 8, is characterized in that: in described matrix material, the massfraction of carbon nanotube is 0.5 ~ 10%.

The preparation method of 11. carbon nanotube metal based composite materials according to claim 10, is characterized in that: the massfraction of described carbon nanotube is 1 ~ 5%.

The preparation method of 12. carbon nanotube metal based composite materials according to Claim 8 described in-11 any one, it is characterized in that: described preparation method carries out activation treatment by acid solution to carbon nano tube surface, carbon nano tube surface defect is made to become active site, fault location has high surface energy, becomes the preferential attachment point of nanoparticle.

The preparation method of 13. carbon nanotube metal based composite materials according to Claim 8 described in-11 any one, it is characterized in that: in described step 2, after carbon nanotube is mixed with Nano sol, add anion surfactant, suppress carbon nanotube reunion each other, make nanoparticle uniform adsorption on the active site of carbon nanotube.

The preparation method of 14. carbon nanotube metal based composite materials according to Claim 8 described in-11 any one, is characterized in that: described modifier Nano sol, wherein the introduction volume of modifier relative to the volume fraction of carbon nanotube by following formulae discovery:

$\mathrm{\β}=\frac{\frac{2\mathrm{\πr}\×L\×c\%}{\mathrm{\π\Δ}{r}^2}\×\frac{4}{3}\mathrm{\π}{\mathrm{\Δr}}^3}{{\mathrm{\πr}}^2\×L}=\frac{8\mathrm{\Δr}}{3r}\×c\%$

Wherein, r is carbon nanotube radius, and L is length of carbon nanotube, and Δ r is the radius of nanoparticle, and c% is carbon nano tube surface defect density, and β is the volume fraction of nanoparticle relative to carbon nanotube.