CN109112368A - One kind casting hypoeutectic Al-Mg containing Sc2Si alloy and its production method - Google Patents

Abstract

The present invention provides one kind to cast hypoeutectic Al-Mg containing Sc₂Si alloy and its production method are made of the substance of following mass percent: 2.53% ~ 7.26% Mg；1.47% ~ 4.24% Si；0.15% ~ 0.35% Sc；Surplus is Al；Wherein Mg and Si forms 4.0% ~ 11.5% Mg under as cast condition₂Si phase；The present invention is on the basis of rationally designing casting alloy ingredient, by rare earth Sc to eutectic Mg in alloy₂The metamorphism of Si phase and refining effect to Primary α-Al Phase, eutectic Mg₂Si is changed into tiny threadiness by coarse Chinese character shape, primary α-Al is changed into globular crystal by dendrite, mechanical property especially plasticity is largely increased, 21.41% and 86.11% is respectively increased in the wax-anti dispersant of alloy, Sc is as alterant, it is used as fining agent again simultaneously, it is rotten, refinement is combined into one, not only simplify smelting technology, it in turn avoids different elements and makees mutual " poisoning " between alterant and fining agent, catabolism, thinning effect, it is used by the structural member that the casting that the alloy is poured can be used as Novel lightweight material in field of traffic such as automobiles.

Description

One kind casting hypoeutectic Al-Mg containing Sc2Si alloy and its production method

Technical field

The invention belongs to technical field of aluminum alloy technology, in particular to a kind of to cast hypoeutectic Al-Mg containing Sc₂Si alloy and its life Production method.

Background technique

In traditional Al-Si-Mg alloy, Mg₂Si is to be heat-treated disperse educt by solid gas coupling as the second phase Reinforced Al-matrix body.In recent years, Mg is directly precipitated from molten aluminum₂Si phase and the Al-Mg formed₂Si alloy is by domestic and foreign scholars Extensive concern.Such alloy is compared with traditional Al-Si-Mg alloy, amount containing Mg and Mg₂Si phase volume fraction is higher, has The excellent performances such as higher specific stiffness, specific strength and wearability, the Novel lightweight material as fields such as space flight and aviation and automobiles Material has wider application prospect.However, the Mg being precipitated under as cast condition₂Si compares coarse, nascent Mg₂Si is in coarse, with holes Dendritic crystalline, and eutectic Mg₂Si is then in coarse Chinese character shape, netted, rodlike and sheet, seriously isolates Al matrix, leads to stress It concentrates, forms formation of crack, deteriorate the mechanical property of alloy.In addition, for the Al-Mg of hypoeutectic ingredient₂Si alloy, tissue in Primary α-Al it is microcosmic upper crystalline in coarse branch, macroscopically to be in the form of a column crystalline substance, lead to alloy mechanical property and feeding, anti- The decline of the casting characters such as fragility.

Rotten and micronization processes are refinement Mg₂Si phase and Primary α-Al Phase, the mechanical property especially plasticity for improving alloy Effective ways, and have many advantages, such as easy to operate, at low cost, significant effect.Up to now, people are to hypereutectic Al-Mg₂Si Alloy, that is, in-situ authigenic Mg₂The processes such as the Metamorphism treatment of Si/Al composite material have conducted extensive research, and to hypoeutectic Al-Mg₂The research of Si alloy is rarely reported.With hypereutectic Al-Mg₂Si alloy is compared, hypoeutectic Al-Mg₂The plasticity of Si alloy and Toughness is more preferable, has more excellent comprehensive mechanical property, it is contemplated that have wider application.On condition that coarse Chinese character Shape, netted and sheet eutectic Mg₂It Si phase and is effectively refined.Primary α-Al dendrite is refined simultaneously, makes alloy mechanical property Energy and casting character are further improved.

Application No. is 201810037556.6 patents of invention to disclose a kind of hypoeutectic Al-Mg₂Si alloy rotten and Thinning method, with Bi and Zr respectively to Mg₂Si content is the hypoeutectic Al-Mg of 4 ~ 12.5wt.%₂Eutectic Mg in Si alloy₂Si Mutually and Primary α-Al Phase carries out rotten and micronization processes, significant effect, greatly improves the mechanical property of alloy.

Up to now there is not yet have single-element while refining hypoeutectic Al-Mg₂Eutectic Mg in Si alloy₂Si phase and The report of Primary α-Al Phase.Alterant is added simultaneously in the alloy and fining agent is also easy to produce mutual " poisoning " effect.Study table Bright, the B class fining agent such as Al-3B, Al -3Ti -4B has preferable refinement effect to the hypoeutectic cast aluminium-silicon alloy of silicon content > 4% Fruit, but B is easily reacted with alterant element Sr, generates SrB₆, Sr and B is consumed, sees Li J G, Zhang B Q, Wang L, et al. Combined effect and its mechanism of Al–3wt.%Ti–4wt.%B and Al–10wt.%Sr master alloy on microstructures of Al–Si–Cu alloy. Materials Science and Engineering A, 2002, 328(1):169–176.For Al-Mg₂Si alloy, due to wherein containing higher Mg amount, Refining Elements are easier to form non-raw nuclear compound with Mg and alterant element etc., weaken rotten and thinning effect or cause casting flaw Generation.

Rare earth Sc has been successfully applied for the primary α-of aluminium alloy as aluminium alloy most effectively one of grain refiner Davydov V G, Rostova T D, Zakharov V V, et al. Scientific is shown in the refinement of Al dendrite principles of making an alloying addition of scandium to aluminium alloys. Materials Science and Engineering A 2000, 280(1):30-36.And the refining effect of Sc be better than it is other The grain refiners such as common T i, B, Zr and V, are shown in Bai Zhenhai, effect material of the Luo Bing brightness scandium in aluminium and aluminium alloy Expect Leader, 2003,17 (7): 6-9.In the alloys such as related Sc refinement Al-Si, Al-Mg, Al-Cu and Al-Zn disclosed in the country The patent of Primary α-Al Phase have 201610340618.1,201510119205.6,201510854938.4, 201510619328.6 201410298108.3,201410512017.5,201410244926.5,201410235134.1, 201410208158.8 and 200810143170.X etc..For the casting Al-Si class alloy containing common reciever, recent Xu's et al. Studies have shown that between adding the secondary dendrite that suitable Sc not only reduces α-Al in hypoeutectic Al -7Si-0.6Mg alloy F357 Away from, and the size of eutectic Si is substantially reduced, and sees Xu C, Xiao W L, Hanada S, et al. The effect of scandium addition on microstructure and mechanical properties of Al–Si–Mg alloy: A multi-refinement modifier. Materials Characterization, 2015, 110 (12):160-169.Huang Ji et al. adds suitable Sc in A356 alloy and the shape of eutectic Si is made needle-shaped to become compacted from coarse Worm shape and dotted is shown in yellow Ji, and Cheng Hefa, Du Chengxin wait influence Special Processes of Metal Castings of the Sc to A356 alloy structure and performance And non-ferrous alloy, 2015,35 (12): 1318-1321.However, up to now there is not yet related cast hypoeutectic Al-containing Sc Mg₂Any report of Si alloy.

Summary of the invention

It is of the existing technology the purpose of the present invention is overcoming the problems, such as, a kind of rotten, thinning effect is provided and more preferably contains Sc Cast hypoeutectic Al-Mg₂Si alloy and its production method.

The present invention casts hypoeutectic Al-Mg containing Sc₂Si alloy is made of according to mass percent following substances:

The content that the content that the content of Mg is 2.53% ~ 7.26%, Si is 1.47% ~ 4.24%, Sc is 0.15% ~ 0.35%, and surplus is Al, wherein Mg and Si forms Mg under as cast condition₂Si phase.

The Al-Mg₂Si alloy is hypoeutectic ingredient, wherein Mg₂The mass percent of Si phase is 4.0% ~ 11.5%, surplus For Al.

The present invention casts hypoeutectic Al-Mg containing Sc₂Si alloy makes according to the following steps:

(1) according to the Mg of different quality percentage₂Si weighs fine aluminium, Al-Si intermediate alloy, Al-Mg intermediate alloy and Al-Sc Intermediate alloy, as production alloy cast ingot or the raw material of casting；

(2) it is put into the graphite crucible of resistance furnace, adds after being cleaned and dried fine aluminium, Al-Si intermediate alloy etc. that step (1) prepares For heat to 720 DEG C, heat preservation until completely melted, is cooled to 700 DEG C, and Al-Mg intermediate alloy is added in melt, until fusing, Stand 5min；

(3) melt for obtaining the carbon trichloride for accounting for melt quality 0.2% with 300 DEG C of preheating of graphite bell jar indentation step (2) In, it is stirred 2 ~ 4 minutes at a temperature of 740 DEG C, removes the dross of bath surface, the melt after being refined；

(4) Al-Sc intermediate alloy is added under conditions of temperature is 720 DEG C ~ 780 DEG C to the melt that step (3) obtains, is contained The melt of Sc；

(5) melt for obtaining the carbon trichloride for accounting for melt quality 0.3% with 300 DEG C of preheating of graphite bell jar indentation step (4) In, it is stirred 3 ~ 5 minutes at a temperature of 740 DEG C, removes the dross of bath surface, the melt after being refined；

(6) in the case where temperature is 720 DEG C ~ 760 DEG C, the melt cast that step (5) is obtained is in the cast iron preheated through 200 DEG C ~ 250 DEG C In mold, alloy casting blank or casting are obtained.

The advantages of technical solution of the present invention, is mainly reflected in:

(1) using rare earth Sc as alterant and fining agent, can effectively go bad hypoeutectic Al-Mg₂Eutectic in Si alloy Mg₂Si phase, while also there is significant refining effect to the Primary α-Al Phase in the alloy；Sc is to eutectic Mg₂The rotten work of Si phase With with it in eutectic Mg₂The enrichment in the growth interface forward position of Si is related, and solubility of the Sc element in α-Al is very low, solidifies Cheng Zhong, with the reduction of temperature, the α-Al of crystallization mutually becomes more and more, the Sc element of enriched in remaining liquid phase；Together When a kind of Sc or surface active element, easily adsorbing and assembling the eutectic Mg being formerly precipitated₂The growth interface forward position of Si phase, Eutectic Mg is constantly blocked in eutectic growth₂The original twin step of Si, and a large amount of new re-entrant angle twins are constantly inspired, make eutectic Mg₂Si Branching Ratio is unmetamorphosed to want much more frequent；In this way, eutectic Mg₂The mode of Si limited and thick sheet development by rotten preceding branch The sharp fibrous growth for becoming a large amount of frequently branches, final eutectic Mg₂The pattern and size of Si have the change of matter；Sc is simultaneously It is to generate Al because Sc is in conjunction with the Al in alloy melt that Primary α-Al Phase can be refined as fining agent₃Sc phase.Al₃Sc phase with The lattice constant of Primary α-Al Phase is close, and mismatch between the two is only 1.5%.Theoretical according to heterogeneous forming core, mismatch is got over Small, the interatomic binding force of the two is stronger, easier in its substrate forming core.Therefore, Al₃Sc can be used as the heterogeneous of primary α-Al Forming core core, to refine Primary α-Al Phase.

(2) Sc is to different content Mg₂Hypoeutectic Al-the Mg of Si₂Si alloy all has excellent rotten, thinning effect, expands The big application range of such alloy.

(3) Sc is not only used as alterant, but also is used as fining agent, and rotten, refinement is combined into one, and not only simplifies smelter Skill in turn avoids mutual " poisoning " between different alterants and fining agent, catabolism, thinning effect.

(4) casting hypoeutectic Al-Mg rotten through Sc, after refinement₂Si alloy mechanical property especially plasticity obtains substantially It improves, is used on the vehicles such as automobile by the structural member that the casting that the alloy is poured can be used as Novel lightweight material.

Detailed description of the invention

Fig. 1 is the low power metallographic microstructure of 0.25%Sc refinement, modified alloy；

Fig. 2 is the high power metallographic microstructure of 0.25%Sc refinement, modified alloy；

Fig. 3 be do not refine, the low power metallographic microstructure of modified alloy；

Fig. 4 be do not refine, the high power metallographic microstructure of modified alloy.

Specific embodiment

The present invention is for containing Mg₂Hypoeutectic Al-Si-Mg the alloy or Al-Mg-Si alloy of Si phase are applicable in, including Situations such as various alloy elements, additional and interior raw reinforced phase are added, be intended merely to below the present invention it is detailed for example, but The invention is not limited to following implementation, various modifications and replacement under all core of the invention technical conditions belong to Within the scope of the present invention.

Al-Mg of the present invention₂Mg in Si alloy₂The ingredient of Si is limited to 4.0% ~ 11.5%, is hypoeutectic ingredient, has excellent Good comprehensive mechanical property works as Mg to meet the use needs of the field of traffic cast structure part such as automobile₂When Si < 4.0%, Mg₂Si phasor is low, and alloy strength is too low；Work as Mg₂When Si > 11.5%, Mg₂Si phasor is high, and alloy plasticity is too low.Mg simultaneously₂Si phase Amount exceeds 4.0% ~ 11.5% range, and Sc is to Mg₂The modification effect of Si phase is unobvious；Mg₂Si in 4.0% ~ 11.5% range, with Mg₂The increase of Si amount, alloy strength, hardness increase, and plasticity, toughness reduce；It, can be according to workpiece mechanical property in practical application It is required that reasonably selecting Mg₂The quantity of Si phase, so that it is determined that final alloying component.

Embodiment 1

Al-8Mg₂0.25%Sc is added in Si alloy, according to the quality hundred of 91.75%Al, 5.06%Mg, 2.94%Si and 0.25%Sc Divide ratio, weighs among aluminium ingot, 215.06gAl-40Mg intermediate alloy block, 249.90gAl-Si that 1150.04g purity is 99.96% Alloy block and 85.00gAl-Sc intermediate alloy block, as the raw material of production alloy cast ingot, ingredient gross mass is 1700g；It prepares The cleaned drying of various raw material after, 1150.04g aluminium ingot and 249.90g Al-Si intermediate alloy block are put into resistance first In the graphite crucible of furnace, 720 DEG C are heated to, heat preservation until completely melted, is cooled to 700 DEG C, among 215.06g Al-Mg Alloy block is added in melt, until fusing, stands 5min；The carbon trichloride stone for preheating 300 DEG C of melt quality 0.2% will be accounted for In black bell jar indentation melt, is stirred 3 minutes at a temperature of 740 DEG C, remove the dross of bath surface；At 740 DEG C by 85.00g Al-Sc intermediate alloy block is added in melt；After fusing, the carbon trichloride graphite for preheating 300 DEG C of melt quality 0.3% will be accounted for Bell jar is pressed into melt, is stirred 4 minutes at a temperature of 740 DEG C, is removed the dross of bath surface；In the case where temperature is 740 DEG C, will melt Body is cast in the cast iron die preheated through 230 DEG C, obtains alloy cast ingot.

Through Mechanics Performance Testing, the tensile strength 312.84MPa of alloy, elongation 12.06%, as shown in table 1.Through gold Phase software is analyzed, and the average largest dimension of Primary α-Al Phase is 17.6 μm in alloy structure, eutectic Mg₂The average maximum ruler of Si phase Very little is 2.4 μm, as shown in table 2.

Comparative example 1

Prepare Al-8Mg₂It is pure to weigh 1235.04g according to the mass percent of 92.0%Al, 5.06%Mg and 2.94%Si for Si alloy Aluminium ingot, 215.06gAl-40Mg intermediate alloy block and the 249.90gAl-Si intermediate alloy block that degree is 99.96% are closed as production The raw material of golden ingot casting, ingredient gross mass are 1700g；After the cleaned drying of various raw material prepared, first by 1235.04g Aluminium ingot and 249.90g Al-Si intermediate alloy block are put into the graphite crucible of resistance furnace, are heated to 720 DEG C, heat preservation, to complete After fusing, 700 DEG C are cooled to, 215.06g Al-Mg intermediate alloy block is added in melt, until fusing, stands 5min；It will account for In the carbon trichloride of the melt quality 0.3% graphite bell jar indentation melt for preheating 300 DEG C, stirred 2 minutes at a temperature of 740 DEG C, Remove the dross of bath surface；In the case where temperature is 740 DEG C, by melt cast in the cast iron die preheated through 230 DEG C, closed Golden ingot casting.

Through Mechanics Performance Testing, the tensile strength 257.68MPa of alloy, elongation 6.48%, as shown in table 1.Through metallographic Software is analyzed, and the average largest dimension of Primary α-Al Phase is 81.3 μm in alloy structure, eutectic Mg₂The average largest dimension of Si phase It is 14.7 μm, as shown in table 2.

Embodiment 1 and 1 ingot casting of comparative example are sampled, cutting, polishing and polishing, then is seen under an optical microscope after corroding Examine alloy microscopic structure, Fig. 3 and Fig. 4 do not refine respectively, the modified alloy i.e. low power of comparative example 1 and high power microscopic structure, Fig. 1 It is respectively 0.25%Sc refinement, the modified alloy i.e. low power of embodiment 1 and high power microscopic structure with Fig. 2, as seen from the figure, not The Primary α-Al Phase added in Sc alloy is coarse dendrite, sees Fig. 3, Mg₂Si phase is coarse Chinese character, lath-shaped, sees figure 4；Primary α-Al Phase after addition 0.25%Sc in alloy is changed into tiny spherical by coarse branch is crystalline, sees Fig. 1, Mg₂Si Mutually become threadiness and minimal amount of tiny strip, see Fig. 2, the addition of Sc so that alloy microscopic structure be improved significantly, power It learns performance to greatly improve, the tensile strength and elongation of alloy are increased to by the 257.68MPa and 6.48% that are not added with Sc respectively to be added The 312.84MPa and 12.06% for adding 0.25%Sc, is shown in Table 1,21.41% and 86.11% is respectively increased.

Embodiment 2

Al-8Mg₂0.15%Sc is added in Si alloy, according to the quality hundred of 91.85%Al, 5.06%Mg, 2.94%Si and 0.15%Sc Divide ratio, weighs among aluminium ingot, 215.06gAl-40Mg intermediate alloy block, 249.90gAl-Si that 1184.04g purity is 99.96% Alloy block and 51.00gAl-Sc intermediate alloy block, as the raw material of production alloy cast ingot, ingredient gross mass is 1700g；It prepares The cleaned drying of various raw material after, 1184.04g aluminium ingot and 249.90g Al-Si intermediate alloy block are put into resistance first In the graphite crucible of furnace, 720 DEG C are heated to, heat preservation until completely melted, is cooled to 700 DEG C, among 215.06g Al-Mg Alloy block is added in melt, until fusing, stands 5min；The carbon trichloride stone for preheating 300 DEG C of melt quality 0.2% will be accounted for In black bell jar indentation melt, is stirred 4 minutes at a temperature of 740 DEG C, remove the dross of bath surface；At 720 DEG C by 51.00g Al-Sc intermediate alloy block is added in melt；After fusing, the carbon trichloride graphite for preheating 300 DEG C of melt quality 0.3% will be accounted for Bell jar is pressed into melt, is stirred 5 minutes at a temperature of 740 DEG C, is removed the dross of bath surface；In the case where temperature is 720 DEG C, will melt Body is cast in the cast iron die preheated through 250 DEG C, obtains alloy cast ingot.

Through Mechanics Performance Testing, the tensile strength 303.75MPa of alloy, elongation 11.49%, as shown in table 1.Through gold Phase software is analyzed, and the average largest dimension of Primary α-Al Phase is 29.3 μm in alloy structure, eutectic Mg₂The average maximum ruler of Si phase Very little is 3.6 μm, as shown in table 2.

Comparative example 2

Al-8Mg₂0.05%Sc is added in Si alloy, according to the quality hundred of 91.95%Al, 5.06%Mg, 2.94%Si and 0.05%Sc Divide ratio, weighs among aluminium ingot, 215.06gAl-40Mg intermediate alloy block, 249.90gAl-Si that 1218.04g purity is 99.96% Alloy block and 17.00gAl-Sc intermediate alloy block, as the raw material of production alloy cast ingot, ingredient gross mass is 1700g；It prepares The cleaned drying of various raw material after, 1218.04g aluminium ingot and 249.90g Al-Si intermediate alloy block are put into resistance first In the graphite crucible of furnace, 720 DEG C are heated to, heat preservation until completely melted, is cooled to 700 DEG C, among 215.06g Al-Mg Alloy block is added in melt, until fusing, stands 5min；The carbon trichloride stone for preheating 300 DEG C of melt quality 0.2% will be accounted for In black bell jar indentation melt, is stirred 3 minutes at a temperature of 740 DEG C, remove the dross of bath surface.At 720 DEG C by 17.00g Al-Sc intermediate alloy block is added in melt；After fusing, the carbon trichloride graphite for preheating 300 DEG C of melt quality 0.3% will be accounted for Bell jar is pressed into melt, is stirred 3 minutes at a temperature of 740 DEG C, is removed the dross of bath surface；In the case where temperature is 720 DEG C, will melt Body is cast in the cast iron die preheated through 250 DEG C, obtains alloy cast ingot.

Through Mechanics Performance Testing, the tensile strength 281.53MPa of alloy, elongation 8.61%, as shown in table 1.Through metallographic Software is analyzed, and the average largest dimension of Primary α-Al Phase is 46.5 μm in alloy structure, eutectic Mg₂The average largest dimension of Si phase It is 8.2 μm, as shown in table 2.

Embodiment 3

Al-8Mg₂0.35%Sc is added in Si alloy, according to the quality hundred of 91.65%Al, 5.06%Mg, 2.94%Si and 0.35%Sc Divide ratio, weighs among aluminium ingot, 215.06gAl-40Mg intermediate alloy block, 249.90gAl-Si that 1116.04g purity is 99.96% Alloy block and 119.00gAl-Sc intermediate alloy block, as the raw material of production alloy cast ingot, ingredient gross mass is 1700g；Match After the good cleaned drying of various raw material, 1116.04g aluminium ingot and 249.90g Al-Si intermediate alloy block are put into electricity first In the graphite crucible for hindering furnace, 720 DEG C are heated to, heat preservation until completely melted, is cooled to 700 DEG C, will be in 215.06g Al-Mg Between alloy block be added melt in, until fusing, stand 5min；The carbon trichloride of melt quality 0.2% will be accounted for 300 DEG C of preheating Graphite bell jar is pressed into melt, is stirred 4 minutes at a temperature of 740 DEG C, is removed the dross of bath surface；At 780 DEG C by 119.00g Al-Sc intermediate alloy block is added in melt；After fusing, the carbon trichloride graphite for preheating 300 DEG C of melt quality 0.3% will be accounted for Bell jar is pressed into melt, is stirred 3 minutes at a temperature of 740 DEG C, is removed the dross of bath surface；In the case where temperature is 760 DEG C, will melt Body is cast in the cast iron die preheated through 200 DEG C, obtains alloy cast ingot.

Through Mechanics Performance Testing, the tensile strength 308.23MPa of alloy, elongation 12.01%, as shown in table 1.Through gold Phase software is analyzed, and the average largest dimension of Primary α-Al Phase is 24.8 μm in alloy structure, eutectic Mg₂The average maximum ruler of Si phase Very little is 3.1 μm, as shown in table 2.

Comparative example 3

Al-8Mg₂0.45%Sc is added in Si alloy；According to the quality hundred of 91.55%Al, 5.06%Mg, 2.94%Si and 0.45%Sc Divide ratio, weighs among aluminium ingot, 215.06gAl-40Mg intermediate alloy block, 249.90gAl-Si that 1082.04g purity is 99.96% Alloy block and 153.00gAl-Sc intermediate alloy block, as the raw material of production alloy cast ingot, ingredient gross mass is 1700g；Match After the good cleaned drying of various raw material, 1082.04g aluminium ingot and 249.90g Al-Si intermediate alloy block are put into electricity first In the graphite crucible for hindering furnace, 720 DEG C are heated to, heat preservation until completely melted, is cooled to 700 DEG C, will be in 215.06g Al-Mg Between alloy block be added melt in, until fusing, stand 5min；The carbon trichloride of melt quality 0.2% will be accounted for 300 DEG C of preheating Graphite bell jar is pressed into melt, is stirred 4 minutes at a temperature of 740 DEG C, is removed the dross of bath surface.At 780 DEG C by 153.00g Al-Sc intermediate alloy block is added in melt；After fusing, the carbon trichloride graphite for preheating 300 DEG C of melt quality 0.3% will be accounted for Bell jar is pressed into melt, is stirred 4 minutes at a temperature of 740 DEG C, is removed the dross of bath surface；In the case where temperature is 760 DEG C, will melt Body is cast in the cast iron die preheated through 200 DEG C, obtains alloy cast ingot.

Through Mechanics Performance Testing, the tensile strength 292.80MPa of alloy, elongation 7.94%, as shown in table 1.Through metallographic Software is analyzed, and the average largest dimension of Primary α-Al Phase is 38.4 μm in alloy structure, eutectic Mg₂The average largest dimension of Si phase It is 4.8 μm, as shown in table 2.

Embodiment 4

Al-4Mg₂0.25%Sc is added in Si alloy, according to the quality hundred of 95.75%Al, 2.53%Mg, 1.47%Si and 0.25%Sc Divide ratio, weighs among aluminium ingot, 107.53gAl-40Mg intermediate alloy block, 124.95gAl-Si that 1382.52g purity is 99.96% Alloy block and 85.00gAl-Sc intermediate alloy block, as the raw material of production alloy cast ingot, ingredient gross mass is 1700g；It prepares The cleaned drying of various raw material after, 1382.52g aluminium ingot and 124.95g Al-Si intermediate alloy block are put into resistance first In the graphite crucible of furnace, 720 DEG C are heated to, heat preservation until completely melted, is cooled to 700 DEG C, among 107.53g Al-Mg Alloy block is added in melt, until fusing, stands 5min；The carbon trichloride stone for preheating 300 DEG C of melt quality 0.2% will be accounted for In black bell jar indentation melt, is stirred 2 minutes at a temperature of 740 DEG C, remove the dross of bath surface；At 750 DEG C by 85.00g Al-Sc intermediate alloy block is added in melt；After fusing, the carbon trichloride graphite for preheating 300 DEG C of melt quality 0.3% will be accounted for Bell jar is pressed into melt, is stirred 4 minutes at a temperature of 740 DEG C, is removed the dross of bath surface；In the case where temperature is 750 DEG C, will melt Body is cast in the cast iron die preheated through 240 DEG C, obtains alloy cast ingot.

Through Mechanics Performance Testing, the tensile strength 282.51MPa of alloy, elongation 19.64% is analyzed through metallographic software, The average largest dimension of Primary α-Al Phase is 13.7 μm in alloy structure, eutectic Mg₂The average largest dimension of Si phase is 2.6 μm.

Comparative example 4

Prepare Al-4Mg₂Si alloy weighs 1467.52g purity according to the mass percent of 96%Al, 2.53%Mg and 1.47%Si For 99.96% aluminium ingot, 107.53gAl-40Mg intermediate alloy block and 124.95gAl-Si intermediate alloy block, as production alloy The raw material of ingot casting, ingredient gross mass are 1700g；After the cleaned drying of various raw material prepared, first by 1467.52g aluminium Ingot and 124.95g Al-Si intermediate alloy block are put into the graphite crucible of resistance furnace, are heated to 720 DEG C, heat preservation, to completely molten After change, 700 DEG C are cooled to, 107.53g Al-Mg intermediate alloy block is added in melt, until fusing, stands 5min；It will account for molten In the carbon trichloride of the weight 0.2% graphite bell jar indentation melt for preheating 300 DEG C, stirs 4 minutes, remove at a temperature of 740 DEG C Remove the dross of bath surface；In the case where temperature is 750 DEG C, by melt cast in the cast iron die preheated through 240 DEG C, alloy is obtained Ingot casting.

Through Mechanics Performance Testing, the tensile strength 214.37MPa of alloy, elongation 11.85% is analyzed through metallographic software, The average largest dimension of Primary α-Al Phase is 76.9 μm in alloy structure, eutectic Mg₂The average largest dimension of Si phase is 13.3 μm.

Embodiment 5

Al-11.5Mg₂0.25%Sc is added in Si alloy, according to the quality of 88.25%Al, 7.26%Mg, 4.24%Si and 0.25%Sc Percentage weighs in aluminium ingot, 308.62gAl-40Mg intermediate alloy block, 360.28gAl-Si that 946.10g purity is 99.96% Between alloy block and 85.00gAl-Sc intermediate alloy block, as production alloy cast ingot raw material, ingredient gross mass be 1700g；Match After the good cleaned drying of various raw material, 946.10g aluminium ingot and 360.28g Al-Si intermediate alloy block are put into resistance first In the graphite crucible of furnace, 720 DEG C are heated to, heat preservation until completely melted, is cooled to 700 DEG C, among 308.62g Al-Mg Alloy block is added in melt, until fusing, stands 5min；The carbon trichloride stone for preheating 300 DEG C of melt quality 0.2% will be accounted for In black bell jar indentation melt, is stirred 4 minutes at a temperature of 740 DEG C, remove the dross of bath surface；At 750 DEG C by 85.00g Al-Sc intermediate alloy block is added in melt；After fusing, the carbon trichloride graphite for preheating 300 DEG C of melt quality 0.3% will be accounted for Bell jar is pressed into melt, is stirred 3 minutes at a temperature of 740 DEG C, is removed the dross of bath surface；In the case where temperature is 750 DEG C, will melt Body is cast in the cast iron die preheated through 240 DEG C, obtains alloy cast ingot.

Through Mechanics Performance Testing, the tensile strength 323.9MPa of alloy, elongation 10.73% is analyzed through metallographic software, The average largest dimension of Primary α-Al Phase is 16.1 μm in alloy structure, eutectic Mg₂The average largest dimension of Si phase is 3.5 μm.

Comparative example 5

Prepare Al-11.5Mg₂Si alloy is weighed according to the mass percent of 88.5%Al, 7.26%Mg and 4.24%Si Aluminium ingot, 308.62gAl-40Mg intermediate alloy block and the 360.28gAl-Si intermediate alloy block that 1031.10g purity is 99.96%, As the raw material of production alloy cast ingot, ingredient gross mass is 1700g；After the cleaned drying of various raw material prepared, first 1031.10g aluminium ingot and 360.28g Al-Si intermediate alloy block are put into the graphite crucible of resistance furnace, are heated to 720 DEG C, is protected Temperature is cooled to 700 DEG C until completely melted, and 308.62g Al-Mg intermediate alloy block is added in melt, until fusing, stands 5min；The carbon trichloride for the accounting for melt quality 0.2% graphite bell jar for preheating 300 DEG C is pressed into melt, at a temperature of 740 DEG C Stirring 3 minutes, removes the dross of bath surface；In the case where temperature is 750 DEG C, by melt cast in the pig mold preheated through 240 DEG C In tool, alloy cast ingot is obtained.

Through Mechanics Performance Testing, the tensile strength 264.08MPa of alloy, elongation 5.76% is analyzed through metallographic software, The average largest dimension of Primary α-Al Phase is 72.4 μm in alloy structure, eutectic Mg₂The average largest dimension of Si phase is 13.7 μm.

1 Al-8Mg of table₂The mechanical property of Si-xSc alloy

Alloy species	σb(MPa)	δ(%)	Remarks
				Al-8Mg2Si-0.25Sc	312.84	12.06	Embodiment 1
Al-8Mg2Si-0.15Sc	303.75	11.49	Embodiment 2
				Al-8Mg2Si-0.35Sc	308.23	12.01	Embodiment 3
Al-8Mg2Si	257.68	6.48	Comparative example 1
				Al-8Mg2Si-0.05Sc	281.53	8.61	Comparative example 2
Al-8Mg2Si-0.45Sc	292.80	7.94	Comparative example 3
				Al-4Mg2Si-0.25Sc	282.51	19.64	Embodiment 4
Al-4Mg2Si	214.37	11.85	Comparative example 4
				Al-11.5Mg2Si-0.25Sc	323.90	10.73	Embodiment 5
Al-11.5Mg2Si	264.08	5.76	Comparative example 5

2 Al-8Mg of table₂The phase size of Si-xSc alloy

Alloy species	Primary α-Al Phase full-size (μm)	Eutectic Mg2Si phase full-size (μm)	Remarks
				Al-8Mg2Si-0.25Sc	17.6	2.4	Embodiment 1
Al-8Mg2Si-0.15Sc	29.3	3.6	Embodiment 2
				Al-8Mg2Si-0.35Sc	24.8	3.1	Embodiment 3
Al-8Mg2Si	81.3	14.7	Comparative example 1
				Al-8Mg2Si-0.05Sc	46.5	8.2	Comparative example 2
Al-8Mg2Si-0.45Sc	38.4	4.8	Comparative example 3
				Al-4Mg2Si-0.25Sc	13.71	2.6	Embodiment 4
Al-4Mg2Si	76.9	13.3	Comparative example 4
				Al-11.5Mg2Si-0.25Sc	16.1	3.5	Embodiment 5
Al-11.5Mg2Si	72.4	13.7	Comparative example 5

Claims (3)

1. one kind casts hypoeutectic Al-Mg containing Sc₂Si alloy, it is characterised in that: component and mass percent in alloy are as follows: Mg's The content that the content that content is 2.53% ~ 7.26%, Si is 1.47% ~ 4.24%, Sc is 0.15% ~ 0.35%, surplus Al, wherein Mg Mg is formed under as cast condition with Si₂Si phase.

2. according to claim 1 cast hypoeutectic Al-Mg containing Sc₂Si alloy, it is characterised in that: the Al-Mg₂Si Alloy is hypoeutectic ingredient, wherein Mg₂The mass percent of Si phase is 4.0% ~ 11.5%, surplus Al.

3. a kind of claim 1 ~ 2 Sc that contains for preparing casts hypoeutectic Al-Mg₂The production method of Si alloy, which is characterized in that It makes according to the following steps:

(1) according to the Mg of different quality percentage₂Si is weighed in fine aluminium, Al-Si intermediate alloy, Al-Mg intermediate alloy and Al-Sc Between alloy, as production alloy cast ingot or casting raw material；

(2) it is put into the graphite crucible of resistance furnace, adds after being cleaned and dried fine aluminium, Al-Si intermediate alloy etc. that step (1) prepares For heat to 720 DEG C, heat preservation until completely melted, is cooled to 700 DEG C, and Al-Mg intermediate alloy is added in melt, until fusing, Stand 5min；

(3) melt for obtaining the carbon trichloride for accounting for melt quality 0.2% with 300 DEG C of preheating of graphite bell jar indentation step (2) In, it is stirred 2 ~ 4 minutes at a temperature of 740 DEG C, removes the dross of bath surface, the melt after being refined；

(4) Al-Sc intermediate alloy is added under conditions of temperature is 720 DEG C ~ 780 DEG C to the melt that step (3) obtains, is contained The melt of Sc；

(5) melt for obtaining the carbon trichloride for accounting for melt quality 0.3% with 300 DEG C of preheating of graphite bell jar indentation step (4) In, it is stirred 3 ~ 5 minutes at a temperature of 740 DEG C, removes the dross of bath surface, the melt after being refined；

(6) in the case where temperature is 720 DEG C ~ 760 DEG C, the melt cast that step (5) is obtained is in the cast iron preheated through 200 DEG C ~ 250 DEG C In mold, alloy casting blank or casting are obtained.