CN104862538B - A kind of carbon dust Modified Cast aluminium alloy and preparation method thereof - Google Patents

Abstract

The invention discloses a kind of carbon dust Modified Cast aluminium alloy and preparation method thereof, the component of the carbon dust Modified Cast aluminium alloy is by weight percentage：Copper 4.0~6.5%, manganese 0.08~0.6%, silicon 2.8~4.0%, carbon dust 0.1~15%, surplus are aluminium and inevitable impurity.The present invention is modified by adding common carbon dust in aluminium alloy, has obtained a kind of new high performance aluminium materials, with excellent mechanical performance, its toughness and elongation percentage are greatly promoted than traditional aluminium alloy, with wide market development prospect.

Description

A kind of carbon dust Modified Cast aluminium alloy and preparation method thereof

Technical field

The present invention relates to a kind of aluminum alloy materials and preparation method thereof, particularly a kind of carbon dust Modified Cast aluminium alloy and its Preparation method.

Background technology

With the fast development in the fields such as automobile and Aero-Space, aluminium alloy castings（Especially large-scale, complicated casting） Requirement to product quality also more and more higher., can be according to product to material property need in order to lift the mechanical performance of aluminium alloy Added material and element formation new alloy material in aluminium alloy casting process are asked, different types of preparation method can be also used Such as evacuated die-casting process, ultrasonically treated technique, obtains high performance aluminium materials.At present, there is the carbon containing material of many scholar's research Enhancing research to aluminium alloy, but carbide fibre or particulate reinforced composite are substantially focused on, common carbon dust is closed to aluminium The enhancing research of gold has no report.

The content of the invention

The technical problems to be solved by the invention are to provide a kind of carbon dust Modified Cast aluminum alloy materials and the casting aluminium The preparation method of alloy, so as to explore the mechanism of action of the common carbon dust in cast aluminium alloy gold, expands common carbon dust in casting aluminium The application of alloy field.

In order to solve the above technical problems, the technical solution adopted by the present invention is：A kind of carbon dust Modified Cast aluminium alloy, its group Divide and be by weight percentage：Copper 4.0~6.5%, manganese 0.08~0.6%, silicon 2.8~4.0%, carbon dust 0.1~15%, surplus is Aluminium and inevitable impurity.

Above-mentioned carbon dust Modified Cast aluminium alloy, it is preferred that its component is by weight percentage：Copper 5.0~6.0%, manganese 0.3~0.4%, silicon 3.1~3.8%, carbon dust 2.0~2.2%, surplus are aluminium and inevitable impurity.

A kind of preparation method of carbon dust Modified Cast aluminium alloy, comprises the following steps：

（1）Dewater treatment is carried out to common carbon dust in an oven, temperature control is between 100~300 DEG C, and time control exists 2~4 hours, screening process then is carried out using the screen cloth of 200 mesh, is dried, evengranular carbon dust；

（2）Aluminium ingot is subjected to melting, smelting temperature is controlled at 700~800 DEG C, and intermediate alloy or gold are added while melting Category；Then molten aluminum liquid is cooled between 580~630 DEG C, carbon dust is added into aluminium alloy melt in the atmosphere of isolation air In, stir 15~20 minutes, aluminium alloy is removed the gred between being then warming up to 780~800 DEG C, degasification and stood, is then adopted With the casting die cast molding Jing Guo the pre-heat treatment, aluminium alloy castings is obtained；

（3）Aluminium alloy castings is subjected to solution treatment in the range of 500~540 DEG C of temperature, time control is small 8~18 When, use temperature to carry out Quench for 40~60 DEG C of cold water when coming out of the stove, transfer time is no more than 3 minutes；Afterwards 130~ Artificial aging is carried out in the range of 180 DEG C to handle 4~8 hours.

Above-mentioned carbon dust is modified novel casting aluminum alloy preparation method, it is preferred that step（2）Described in completely cut off air atmosphere Enclose and refer to filling nitrogen or vacuumize process.

Foregoing carbon dust is modified novel casting aluminum alloy preparation method, it is preferred that step（2）Middle casting die need to carry out pre- It is heat-treated to 300 DEG C or so.

Foregoing carbon dust is modified novel casting aluminum alloy preparation method, it is preferred that step（2）In cast molding can adopt With sand casting, permanent mold casting or other forging types.

Application of the carbon dust in cast aluminium alloy gold is prepared.

Compared with prior art, the present invention is modified by adding common carbon dust in aluminium alloy, has obtained a kind of new High performance aluminium materials-carbon dust Modified Cast aluminium alloy, it has excellent mechanical performance, and toughness and elongation percentage compare conventional aluminum Alloy is greatly promoted, and elongation percentage can be lifted close to 3 times, widely used, with wide market development prospect.

For the performance of the checking present invention, applicant carried out experiment, its process and result are as follows：

1. experimentation

The processing of 1.1 carbon dusts

1. dewater treatment is carried out to common carbon dust in an oven, treatment temperature dries about 2~4 between 100~300 DEG C Hour；2. sieved using the screen cloth of 200 mesh.

1.2 aluminium alloys are prepared and melting

1. it is formulated：According to percentage by weight, from copper（Cu）4.0~6.5%, manganese（Mn）0.08~0.6%, silicon（Si） 2.8~4.0%, carbon dust（C）0.1~15%, surplus is aluminium（Al）And impurity, proportionally alloyage and coupon of casting.

2. preparation process：By aluminium ingot（Double zero aluminium）It is put into graphite crucible and carries out melting, smelting temperature is controlled 700~800 DEG C, intermediate alloy or metal are added while melting.Due to soaking into angle very little between carbon dust and aluminium alloy liquid, input aluminium is closed Carbon dust in golden liquid will be swum in molten aluminum liquid, enter in order that obtaining carbon dust in molten aluminum liquid system, molten aluminum liquid is dropped Between warm to 580~630 DEG C；Aluminium liquid will be in half curdled appearance at such a temperature, by electric stirring system to the state Aluminium alloy stir about after 20 minutes carbon dust will be stirred and be distributed in the aluminium liquid system of semisolid；It is warming up to 780 afterwards~ Aluminium alloy is removed the gred between 800 DEG C, degasification and stood, is prepared for casting.Stretching examination is made by GB/T228~2002 Rod, coupon metal gravity castable, casting die need to carry out being preheated to 300 DEG C or so.

1.3 heat treatment

Casting needs to carry out solid solution and Ageing Treatment to it after obtaining.Its handling process is：In the range of 500~540 DEG C Solution treatment is carried out, the time, at 8~18 hours, cold water is used when coming out of the stove（40~60 DEG C）Carry out Quench（Transfer time does not surpass Spend 3 minutes）；Ageing Treatment is carried out in the range of 130~180 DEG C afterwards 4~8 hours.

1.4 performance test

Treated coupon uses polishing machine after sand paper is polished（PG~1）Polishing.Coupon is entered using HF aqueous acids Electronics metallographic microscope is used after row corrosion（4XC~TV）Coupon metallographic structure is observed.Using the FEG of Quanta 400 Type Flied emission environmental scanning electron microscope（FEI）Surface topography after corrosion is observed, and uses energy dispersion X-ray Micro-zone analysis（EDAX）Constituent analysis is carried out to local particle.The electron spectroscopy analysis instrument of Thermo Scientific companies （XPS~ESCALAB 250Xi）Surface-element is scanned, and the combination energy band of carbon is analyzed to determine it in alloy In form.Use X-ray diffractometer（XRD~X'pert Pro）Analyze the phase composition of alloy.The material finished to heat treatment Using electronic type universal material testing machine（CBW~10T）Carry out Mechanics Performance Testing, pass through electronic extensometer（Beijing steel is ground Study carefully institute）Measure test specimen elongation percentage.Using KYKY~2800B type SEM（The Chinese Academy of Sciences）Test bar fracture is broken in observation Looks.

2. result

2.1 microstructure morphology

2.1.1 metallographic structure

Fig. 1, Fig. 2 are the metallographic structure figure for being not added with carbon dust and adding carbon dust aluminium alloy respectively, it can be seen that both groups Knitting form has larger difference.Fig. 1 metallographic structure is larger, in dendritic distribution, there is bulk band, and part crystal boundary is imperfect, increases Strong thing is distributed along crystal boundary.Fig. 2 metallographic shows that its crystal grain is tiny, based on circular or ellipse, its big portion on matrix Divide and be uniformly distributed, certain wire distribution is partly presented.There is local atrament to reunite from the surface after its corrosion, portion Point aggregate is larger, and compares around aggregate the crystal grain for being dispersed with circle of concentration.

2.1.2 surface topography and Elemental redistribution

Electronic microscope photos, electron spectroscopy analysis and X-ray diffraction analysis are scanned to the alloy after surface corrosion.Fig. 3 It is the pattern for being not added with carbon dust, can finds out that alloy structure is more thick from figure, and locally lies in bulk ribbon tissue.It is right The power spectrum analysis of components of C points in Fig. 3（EDAX）Display essential element be copper, silicon and aluminium, as shown in Figure 4.These elements are constituted Compound can play invigoration effect to alloy.Fig. 5 is tissue topography's figure after addition carbon dust.It can be seen that addition carbon from figure The alloy structure of powder more uniform exquisiteness as being shown its metallographic, and its precipitate is based on circular or oval material.To Fig. 5 In D points and E point analysis contain 7.82% respectively（Wt%）With 9.84%（Wt%）Phosphorus content, such as Fig. 6, shown in Fig. 7, others are main First to have silicon, manganese and a small amount of copper.

Alloy surface is scanned by XPS.From its combination can from the point of view of alloy its essential element have Cu, O, C, Si, Al. Carbon, which contains four energy band peaks, mainly the combination energy between carbon~metal, carbon~carbon and carbon~oxygen, to be shown to the tunable band-gap of carbon Peak value.There is the compound and carbon simple substance of carbon and metal in this explanation alloy.In order to show the concrete form of carbon in alloy, to table Face carries out XRD tests, as shown in Figure 8.XRD results, which are shown, contains Al, Si and SiC in alloy, this explanation is formed in the alloy Carborundum.

2.2 mechanics property analysis

Table 1 shows the tensile strength and elongation percentage whether carbon dust add.As can be seen that strong after addition carbon dust from table Degree, which has no, to be decreased obviously, but its elongation percentage obtains very big lifting.Fig. 9 is stress~strain curve of material stretching.Relatively In common material, the elastic stage of carbon containing aluminium alloy can terminate relatively early and the plastic stage occurs in advance, and material yield point declines（About 100MPa）.With plastic deformation aggravation, occur in that and the different phenomenon of common material：It is not bright in stress after strain 2% It is aobvious it is increased in the case of strain increase suddenly, then there is the of short duration stress~strain mutation for being similar to elasticity；In this mutation Material has recovered plastic deformation again afterwards, occurs similar elasticity mutation after certain strain afterwards；So continue repeatedly, directly Broken completely to material；It can be seen that the mutation cycle is shorter in the plasticity incipient stage from Fig. 9（0.5% dependent variable）, with modeling Property deformation deepen, its occur elasticity mutation cycle also progressively extending（Later stage reaches 1.2% dependent variable）, after plastic deformation Phase even occurs in that the unexpected decline of internal stress（Similar to the fracture of material, F points in such as Fig. 9）, continue to hold afterwards again Continuous plastic strain, until fracture completely.Carbonaceous material displacement, which is can see, from Figure 10 stretching displacements occurs in that several displacements Constant platform, with being continuously increased for stretching, its platform is also corresponding elongated.

The addition of the carbon of table 1 influences on material mechanical performance

Note：A~not carbon containing aluminium alloy；The carbon containing aluminium alloys of B

2.3 fracture apperance

Figure 11, Figure 12 are the fracture apperance for breaking coupon for not adding carbon dust and addition carbon dust respectively, be can be seen that from figure Fractograph fine homogeneous containing carbon dust, the presence for having substantial amounts of transcrystalline dimple, shows obvious ductile rupture.Conversely, Not plus carbon dust material its there is more gully lines, and its dimple size is more thick.Region A amplifications to adding carbon dust After obtain Figure 13.Tension failure regional center is can see in the presence of a large hole from Figure 13 central areas, around hole There is smooth lines along tension failure direction（Region B）, also containing certain miniature small holes in smooth lines.

3. discuss

（1）From the point of view of XPS and XRD test surfaces, carbon has been added in aluminum alloy system.In test result also Containing O, this is probably caused by being oxidized in atmosphere in casting process or sample.XPS detected the different knots of carbon Closing can band peak value.Control can band, it is C~metal and C~C energy band that wherein C1s Scan A and B is corresponding respectively, and C1s Scan C and D are then the energy bands that carbon is combined with oxygen, and this is mainly caused by oxidation effect.Therefore, carbon in the alloy will be with carbide And carbon simple substance is present.Contain SiC particulate in XRD test surfaces materials, this explanation carbon can be with alloy member in casting process Element forms related compound.This is probably due to being enabled in molten condition addition carbon dust in casting alloy system situ Generate SiC particulate.These generated in-situ SiC particulates, which can not only more carefully serve as forming core in crystallization process and be desirable to it, to be turned into Strengthen particle.XRD does not measure carbon simple substance, this be probably due to carbon simple substance content very little.

（2）Addition carbon dust causes aluminium alloy elongation percentage to be substantially improved（Close to 3 times）.From the point of view of microstructure, carbon dust adds Plus alloy structure it is finer and smoother, hardening constituent point is uniform, based on circular or oval hardening constituent.This is probably lighter due to adding Carbon atom and generated in-situ SiC particulate can serve as the effective crystal grain thinning of forming core in melt process of setting, form circle The tissue of shape or ellipse.The content of carbon is higher and is not fully absorbed, and will locally reunite in alloy system.What these were reunited Carbon may be present in aluminum alloy system with the compound of graphite form or similar graphite form under high temperature action.By carbon or The mode of the integral slipping of graphite resists external forces, can be obviously improved material elongation percentage.It is carbon containing from the point of view of fracture apperance Fracture apperance shows significant ductile rupture feature.Phosphorus-containing alloy has larger hole, and forms in the stretching direction The smooth platform of stratiform.This is probably the reunion due to carbon, and carbon is weakened with material adhesion, under a stretching force small hole Formed, extended, polymerize, ultimately form big hole, and the presence of carbon simple substance can be in hole expansion process to Grain Boundary Sliding The effect of lubrication is served, so enables to whole crystal boundary to be slid in longer path, enhances the plasticity of material, significantly Improve the toughness of material.But, for intensity, being not added with carbon alloy then has more preferable intensity.This is probably By the ribbon hardening constituent that copper, manganese are formed hinders dislocation motion so that cause it to have in drawing process higher Intensity；But it is due to that the bulk strip hardening constituent to be formed serves the effect of isolating to material structure, the same base of hardening constituent in stretching Body tissue adhesion is smaller, causes it to go out grain boundary fracture, and toughness of material declines.

（3）Influence of the carbon with other elements formation compound to toughness.Tension test shows carbonaceous material with pulling force Increase is not complete plastic deformation, and periodic elastic stress~strain occurs after starting plastic deformation occur.Grind Study carefully and show, then material can not be equably plastically deformed under external force when there is rigid ceramic SiC particulate, composite wood Material is internal to have that serious deformation is uneven, and now elastic deformation only occurs for SiC ceramic particle, and alloy matrix aluminum can be carried out greatly The plastic deformation of amount.The addition of carbon dust generates SiC in alloy system, and these SiC generate above-mentioned effect with aluminium alloy: SiC produces elastic deformation in Tensile, and alloy matrix aluminum proceeds plastic deformation after the completion of elastic deformation, and alloy is utilized Extraneous stress is offset in interim SiC elastic deformation.This goes out the progressively sliding of material in macro manifestations, can be clear from fracture Sliding platforms at different levels are found out clearly.Due to SiC content and limited strength, with the continuous aggravation of stretching, elastic stage constantly drops Low, material shows plasticity enhancing.It is probably to be formed because SiC slides and separated with alloy matrix aluminum in the close fracture of material The pseudo- fracture of F points in Fig. 9, so far SiC and aluminium alloy completely disengage from, finally under action of pulling stress, material is broken completely. As plasticity strengthens, SiC declines with alloy combination degree, and the cycle of its elasticity mutation also can progressively extend, and the cycle is more at most Show that the stretching displacement of material is bigger, also indicate that toughness is better.

4. conclusion

1）Carbon dust, which is added in cast aluminium alloy gold, to be existed with carbon simple substance and carbon compound form, and this two classes material can There is larger lifting to the toughness of aluminium alloy.

2）The carbon dust addition of certain particle size can effectively lift the elongation percentage of material（Elongation percentage is lifted close to 3 times）, still Its intensity has to be hoisted；

3）The SiC that the addition of carbon is generated enables to occur plastic strain in drawing process to replace hair with elastic strain Raw, as plastic deformation is aggravated, the cycle of elasticity mutation can be progressively elongated, and these mutation cycles reflect material to a certain extent Toughness.

Brief description of the drawings

Fig. 1 is the metallographic structure figure for the aluminium alloy for being not added with carbon dust；

Fig. 2 is the metallographic structure figure for the aluminium alloy for adding carbon dust；

Fig. 3 is the aluminum alloy surface shape appearance figure for being not added with carbon dust；

Fig. 4 is the power spectrum analysis of components figure of C points in Fig. 3；

Fig. 5 is the aluminum alloy surface shape appearance figure for adding carbon dust；

Fig. 6 is the power spectrum analysis of components figure of D points in Fig. 5；

Fig. 7 is the power spectrum analysis of components figure of E points in Fig. 5；

Fig. 8 is the XRD analysis figure of alloy surface；

Fig. 9 is stress~strain curve of material stretching；

Figure 10 is material displacement curve；

Figure 11 is the fracture apperance figure for breaking coupon for not adding carbon dust；

Figure 12 is the fracture apperance figure for breaking coupon for adding carbon dust;

Figure 13 is a-quadrant enlarged drawing in Figure 12.

With reference to embodiment, the present invention is further illustrated.

Embodiment

Embodiment 1.Carbon dust Modified Cast aluminium alloy, component is by weight percentage：Copper 5.5%, manganese 0.5%, silicon 3.5%, Carbon dust 2.1%, surplus is aluminium and inevitable impurity.

During preparation, according to following steps：

（1）Dewater treatment is carried out to common carbon dust in an oven, temperature control is at 200 DEG C or so, and time control is small 3 When, screening process then is carried out using the screen cloth of 200 mesh, is dried, evengranular carbon dust；

（2）By aluminium ingot（Double zero aluminium）Melting is carried out, smelting temperature is controlled at 750 DEG C or so, added while melting middle Alloy or metal；It is sufficiently stirred for and is fully contacted, it is necessary to which molten aluminum liquid is cooled into 600 DEG C of left sides with alloy in order that obtains carbon dust The right side, makes alloy be in carbon dust at half curdled appearance, too high or too low temperature and can not fully be soaked into aluminium liquid；Then it is empty in isolation In the atmosphere of gas（Using filling nitrogen or vacuumize process）Carbon dust is added in aluminium alloy melt, stirred 15 minutes, is mixed, so After be warming up to 780 DEG C or so aluminium alloy removed the gred, degasification and stood, poured afterwards using the casting die Jing Guo the pre-heat treatment Type casting moulding, obtains aluminium alloy castings, casting die need to be preheated to 300 DEG C or so, using sand casting or permanent mold casting；

（3）By aluminium alloy castings in 520 DEG C or so progress solution treatment of temperature, time control was at 10 hours, when coming out of the stove Temperature is used to carry out Quench for 50 DEG C or so of cold water, transfer time is no more than 3 minutes；Carried out afterwards at 150 DEG C or so artificial Ageing Treatment 6 hours, further to lift the mechanical performance of casting.

Embodiment 2.Carbon dust Modified Cast aluminium alloy, component is by weight percentage：Copper 4.0%, manganese 0.08%, silicon 2.8%th, carbon dust 0.1%, surplus is aluminium and inevitable impurity.

During preparation, according to following steps：

（1）Dewater treatment is carried out to common carbon dust in an oven, temperature control is at 100 DEG C or so, and time control is small 4 When, screening process then is carried out using the screen cloth of 200 mesh, is dried, evengranular carbon dust；

（2）By aluminium ingot（Double zero aluminium）Melting is carried out, smelting temperature is controlled at 700 DEG C or so, added while melting middle Alloy or metal；It is sufficiently stirred for and is fully contacted, it is necessary to which molten aluminum liquid is cooled into 580 DEG C of left sides with alloy in order that obtains carbon dust The right side, makes alloy be in carbon dust at half curdled appearance, too high or too low temperature and can not fully be soaked into aluminium liquid；Then it is empty in isolation In the atmosphere of gas（Using filling nitrogen or vacuumize process）Carbon dust is added in aluminium alloy melt, stirred 15 minutes, is mixed, so After be warming up to 780 DEG C or so aluminium alloy removed the gred, degasification and stood, poured afterwards using the casting die Jing Guo the pre-heat treatment Type casting moulding, obtains aluminium alloy castings, casting die need to be preheated to 300 DEG C or so, using sand casting or permanent mold casting；

（3）By aluminium alloy castings in 500 DEG C or so progress solution treatment of temperature, time control was adopted at 8 hours when coming out of the stove Quench is carried out for 40 DEG C or so of cold water with temperature, transfer time is no more than 3 minutes；Afterwards when carrying out artificial for 130 DEG C or so Effect processing 4 hours, further to lift the mechanical performance of casting.

Embodiment 3.Carbon dust Modified Cast aluminium alloy, component is by weight percentage：Copper 6.5%, manganese 0.6%, silicon 4.0%, Carbon dust 10%, surplus is aluminium and inevitable impurity.

During preparation, according to following steps：

（1）Dewater treatment is carried out to common carbon dust in an oven, temperature control is at 300 DEG C or so, and time control is small 2 When, screening process then is carried out using the screen cloth of 200 mesh, is dried, evengranular carbon dust；

（2）Aluminium ingot is subjected to melting, smelting temperature is controlled at 800 DEG C or so, and intermediate alloy or gold are added while melting Category；In order that carbon dust is sufficiently stirred for alloy and fully contacted, it is necessary to molten aluminum liquid is cooled into 630 DEG C or so, make alloy In half curdled appearance, carbon dust can not fully soak into aluminium liquid at too high or too low temperature；Then in the atmosphere of isolation air In（Using filling nitrogen or vacuumize process）Carbon dust is added in aluminium alloy melt, stirs 20 minutes, is then warming up to 800 DEG C Left and right is removed the gred to aluminium alloy, degasification and stood, then using the casting die cast molding Jing Guo the pre-heat treatment, acquisition aluminium Alloy-steel casting, casting die need to be preheated to 300 DEG C or so, using sand casting or permanent mold casting；

（3）By aluminium alloy castings in 540 DEG C or so progress solution treatment of temperature, time control was at 18 hours, when coming out of the stove Temperature is used to carry out Quench for 60 DEG C or so of cold water, transfer time is no more than 3 minutes, carried out afterwards at 180 DEG C or so artificial Ageing Treatment 8 hours.

Embodiment 4.Carbon dust Modified Cast aluminium alloy, component is by weight percentage：Copper 5.0%, manganese 0.3%, silicon 3.1%, Carbon dust 2.0%, surplus is aluminium and inevitable impurity.

During preparation, according to following steps：

（1）Dewater treatment is carried out to common carbon dust in an oven, temperature control is at 200 DEG C or so, and time control is small 3 When, screening process then is carried out using the screen cloth of 200 mesh, is dried, evengranular carbon dust；

（2）Aluminium ingot is subjected to melting, smelting temperature is controlled at 800 DEG C or so, and intermediate alloy or gold are added while melting Category；In order that carbon dust is sufficiently stirred for alloy and fully contacted, it is necessary to molten aluminum liquid is cooled into 600 DEG C or so, make alloy In half curdled appearance, carbon dust can not fully soak into aluminium liquid at too high or too low temperature；Then in the atmosphere of isolation air In（Using filling nitrogen or vacuumize process）Carbon dust is added in aluminium alloy melt, stirs 18 minutes, is then warming up to 790 DEG C Left and right is removed the gred to aluminium alloy, degasification and stood, afterwards using the casting die cast molding Jing Guo the pre-heat treatment, acquisition aluminium Alloy-steel casting, casting die need to be preheated to 300 DEG C or so, can use sand casting or permanent mold casting；

（3）By aluminium alloy castings in 520 DEG C or so progress solution treatment of temperature, time control was at 12 hours, when coming out of the stove Temperature is used to carry out Quench for 50 DEG C or so of cold water, transfer time is no more than 3 minutes；Carried out afterwards at 160 DEG C or so artificial Ageing Treatment 6 hours.

Claims (5)

1. a kind of preparation method of carbon dust Modified Cast aluminium alloy, it is characterised in that：Described carbon dust Modified Cast aluminium alloy, its It is formulated and is：By weight percentage, from copper 4.0~6.5%, manganese 0.08~0.6%, silicon 2.8~4.0%, carbon dust 0.1~ 15%, surplus is aluminium and inevitable impurity；Preparation method comprises the following steps：

(1) dewater treatment is carried out to common carbon dust in an oven, temperature control is between 100~300 DEG C, and time control is 2~4 Hour, screening process then is carried out using the screen cloth of 200 mesh, is dried, evengranular carbon dust；

(2) aluminium ingot is subjected to melting, smelting temperature is controlled at 700~800 DEG C, and intermediate alloy is added while melting；Then will Molten aluminum liquid is cooled between 580~630 DEG C, is added carbon dust in aluminium alloy melt in the atmosphere of isolation air, stirring 15 ~20 minutes, aluminium alloy is removed the gred between being then warming up to 780~800 DEG C, degasification and stood, then using by preheating The casting die cast molding of processing, obtains aluminium alloy castings；

(3) aluminium alloy castings is subjected to solution treatment in the range of 500~540 DEG C of temperature, time control at 8~18 hours, Temperature is used to carry out Quench for 40~60 DEG C of cold water when coming out of the stove, transfer time is no more than 3 minutes；Afterwards in 130~180 DEG C of models Interior progress artificial aging is enclosed to handle 4~8 hours.

2. the preparation method of carbon dust Modified Cast aluminium alloy according to claim 1, it is characterised in that：Institute in step (2) The atmosphere for stating isolation air refers to filling nitrogen or vacuumize process.

3. the preparation method of carbon dust Modified Cast aluminium alloy according to claim 1, it is characterised in that：Step is poured in (2) Casting mould need to carry out the pre-heat treatment to 300 DEG C.

4. the preparation method of carbon dust Modified Cast aluminium alloy according to claim 1, it is characterised in that：In step (2) Cast molding is to use sand casting or permanent mold casting.

5. the preparation method of carbon dust Modified Cast aluminium alloy according to claim 1, it is characterised in that：Described carbon dust changes Property cast aluminium alloy gold, its be formulated：By weight percentage, from copper 5.0~6.0%, manganese 0.3~0.4%, silicon 3.1~3.8%, Carbon dust 2.0~2.2%, surplus is aluminium and inevitable impurity.