阅读说明：本技术 一种高强度高韧性铝合金及其制备方法 (High-strength and high-toughness aluminum alloy and preparation method thereof ) 是由 金义泉 于 2019-09-27 设计创作，主要内容包括：本发明公开了一种高强度高韧性铝合金及其制备方法,合金的组成成分按重量百分比包括：Mg：1.3-2.06％、Zn：6.18-7.1％、Cu：1.05-2％、RE：0.07-0.16％、Fe：0.08-0.15％、Si：0.11-0.23％、Zr：0.04-0.12％、Ti：0.01-0.23％、Cr：0.01-0.03％、Mn：0.1-0.24％、B：0.07-0.14％、Li：0.11-0.27％、Ag：0.28-0.42％、余量为Al；RE为Yb、Sc、Er、Y、Ce、La中的一种或多种的混合物。本发明提出的高强度高韧性铝合金的制备方法过程简单,得到的铝合金强度高,韧性和耐腐蚀性好。(The invention discloses a high-strength high-toughness aluminum alloy and a preparation method thereof, wherein the alloy comprises the following components in percentage by weight: mg: 1.3-2.06%, Zn: 6.18-7.1%, Cu: 1.05-2%, RE: 0.07-0.16%, Fe: 0.08-0.15%, Si: 0.11 to 0.23%, Zr: 0.04-0.12%, Ti: 0.01-0.23%, Cr: 0.01-0.03%, Mn: 0.1-0.24%, B: 0.07-0.14%, Li: 0.11-0.27%, Ag: 0.28-0.42 percent of Al; RE is one or a mixture of Yb, Sc, Er, Y, Ce and La. The preparation method of the high-strength high-toughness aluminum alloy provided by the invention is simple in process, and the obtained aluminum alloy is high in strength, good in toughness and corrosion resistance.)

1. The high-strength high-toughness aluminum alloy is characterized by comprising the following components in percentage by weight: mg: 1.3-2.06%, Zn: 6.18-7.1%, Cu: 1.05-2%, RE: 0.07-0.16%, Fe: 0.08-0.15%, Si: 0.11 to 0.23%, Zr: 0.04-0.12%, Ti: 0.01-0.23%, Cr: 0.01-0.03%, Mn: 0.1-0.24%, B: 0.07-0.14%, Li: 0.11-0.27%, Ag: 0.28-0.42 percent of Al; wherein RE is one or a mixture of more of Yb, Sc, Er, Y, Ce and La.

2. The high strength, high toughness aluminum alloy of claim 1 wherein the weight percent of Si, Mg, Fe, B satisfies the relationship: si + Mg is more than or equal to 1.65 percent and less than or equal to 2.17 percent, and (Fe +3 xB + Mg)/Si is more than or equal to 11 and less than or equal to 14.2.

3. The high strength, high toughness aluminum alloy of claim 1 wherein the weight percentages of Zr, RE, Ti satisfy the following relationship: zr + RE is more than or equal to 0.16 percent and less than or equal to 0.2 percent, and Zr + RE is more than or equal to 1.6 multiplied by Ti.

4. The high strength, high toughness aluminum alloy of claim 1 wherein the weight percent of Mg, Cu, Mn, Cr satisfies the relationship: mg + Cu + Mn + Cr is more than or equal to 3.23 percent and less than or equal to 3.63 percent.

5. The high strength, high toughness aluminum alloy according to any one of claims 1 to 4 wherein the weight percentages of Mg, Ag satisfy the following relationship: Mg/Ag is 4.2-5.3.

6. A method for producing a high-strength high-toughness aluminum alloy as defined in any one of claims 1 to 5, comprising the steps of:

s1, weighing a magnesium ingot, a zinc ingot, an aluminum-copper intermediate alloy, an Al-RE intermediate alloy, an aluminum-iron intermediate alloy, metallic silicon, an aluminum-zirconium intermediate alloy, an aluminum-titanium intermediate alloy, an aluminum-chromium intermediate alloy, a manganese ingot, an aluminum-boron intermediate alloy, an aluminum-lithium intermediate alloy, an aluminum ingot and pure silver according to the proportion; adding metal silicon, aluminum ingots, magnesium ingots, zinc ingots and manganese ingots into a smelting furnace, smelting at the temperature of 750-770 ℃ for 25-55min, adding the rest raw materials, smelting, refining, and casting to obtain aluminum alloy ingots;

s2, homogenizing the aluminum alloy ingot, then preserving heat at the temperature of 430-450 ℃ for 180min, carrying out hot rolling and annealing, then carrying out cold rolling, then carrying out cryogenic deformation treatment, carrying out water quenching after solution treatment, and then carrying out aging treatment to obtain the high-strength high-toughness aluminum alloy.

7. The method as claimed in claim 6, wherein the homogenization treatment is performed at S2 for 16-22h and at 450-480 ℃.

8. The method for preparing the high-strength high-toughness aluminum alloy as recited in claim 6, wherein in S2, the hot rolling temperature is 400-420 ℃, and the total deformation is 75-85%; the total deformation of the cold rolling is 45-55%; the temperature of the solution treatment is 500-515 ℃, and the time is 100-120 min.

9. The method of claim 6, wherein in S2, the temperature of the cryogenic deformation treatment is-185 ℃ to-135 ℃, the holding time is 8-12min, and the deformation amount of the cryogenic deformation treatment is 35-65%.

10. The method for preparing the high-strength high-toughness aluminum alloy according to any one of claims 6 to 9, wherein in S2, the aging treatment comprises the following specific processes: the material is stretched unidirectionally at room temperature with the deformation amount of 5-7 percent, then is preserved in ice water for 20-30min, then is preserved for 5-9h at the temperature of 95-105 ℃, is preserved for 3-8h at the temperature of 115-150 ℃, and is preserved for 3-8h at the temperature of 145-150 ℃ and is cooled in air.

Technical Field

The invention relates to the technical field of aluminum materials, in particular to a high-strength high-toughness aluminum alloy and a preparation method thereof.

Background

The aluminum alloy has high specific strength, good corrosion resistance, easy forming, good electrical and thermal conductivity and other excellent characteristics, and is widely applied to replace steel materials at present. The Al-Zn-Mg-Cu aluminum alloy is a heat-treatable strengthened aluminum alloy, is one of the most important light structural materials in the fields of aerospace, ships, bridges, pipelines, vehicles and the like, and is widely applied at present. With the development of science and technology, the requirements on the strength, toughness and corrosion resistance of the aluminum alloy are increasingly improved, the strength of the existing Al-Zn-Mg-Cu series aluminum alloy is often reduced while the existing Al-Zn-Mg-Cu series aluminum alloy obtains good toughness and corrosion resistance, so that the aluminum alloy product fails in the service process, and the application of the aluminum alloy product is limited; it is one of the important issues in the field of aluminum alloy research to improve the toughness and corrosion resistance of materials while maintaining high strength of aluminum alloys.

Disclosure of Invention

In order to solve the technical problems in the background art, the invention provides the high-strength high-toughness aluminum alloy and the preparation method thereof.

The invention provides a high-strength high-toughness aluminum alloy which comprises the following components in percentage by weight: mg: 1.3-2.06%, Zn: 6.18-7.1%, Cu: 1.05-2%, RE: 0.07-0.16%, Fe: 0.08-0.15%, Si: 0.11 to 0.23%, Zr: 0.04-0.12%, Ti: 0.01-0.23%, Cr: 0.01-0.03%, Mn: 0.1-0.24%, B: 0.07-0.14%, Li: 0.11-0.27%, Ag: 0.28-0.42 percent of Al; wherein RE is one or a mixture of more of Yb, Sc, Er, Y, Ce and La.

Preferably, the weight percentages of Si, Mg, Fe, B satisfy the following relation: si + Mg is more than or equal to 1.65 percent and less than or equal to 2.17 percent, and (Fe +3 xB + Mg)/Si is more than or equal to 11 and less than or equal to 14.2.

Preferably, the weight percentages of Zr, RE and Ti satisfy the following relation: zr + RE is more than or equal to 0.16 percent and less than or equal to 0.2 percent, and Zr + RE is more than or equal to 1.6 multiplied by Ti.

Preferably, the weight percentages of Mg, Cu, Mn, Cr satisfy the following relationship: mg + Cu + Mn + Cr is more than or equal to 3.23 percent and less than or equal to 3.63 percent.

Preferably, the weight percentages of Mg and Ag satisfy the following relationship: Mg/Ag is 4.2-5.3.

The invention also provides a preparation method of the high-strength high-toughness aluminum alloy, which comprises the following steps:

s1, weighing a magnesium ingot, a zinc ingot, an aluminum-copper intermediate alloy, an Al-RE intermediate alloy, an aluminum-iron intermediate alloy, metallic silicon, an aluminum-zirconium intermediate alloy, an aluminum-titanium intermediate alloy, an aluminum-chromium intermediate alloy, a manganese ingot, an aluminum-boron intermediate alloy, an aluminum-lithium intermediate alloy, an aluminum ingot and pure silver according to the proportion; adding metal silicon, aluminum ingots, magnesium ingots, zinc ingots and manganese ingots into a smelting furnace, smelting at the temperature of 750-770 ℃ for 25-55min, adding the rest raw materials, smelting, refining, and casting to obtain aluminum alloy ingots;

s2, homogenizing the aluminum alloy ingot, then preserving heat at the temperature of 430-450 ℃ for 180min, carrying out hot rolling and annealing, then carrying out cold rolling, then carrying out cryogenic deformation treatment, carrying out water quenching after solution treatment, and then carrying out aging treatment to obtain the high-strength high-toughness aluminum alloy.

Preferably, in S2, the temperature of the homogenization treatment is 450-480 ℃ and the time is 16-22 h.

Preferably, in S2, the hot rolling temperature is 400-420 ℃, and the total deformation is 75-85%; the total deformation of the cold rolling is 45-55%; the temperature of the solution treatment is 500-515 ℃, and the time is 100-120 min.

Preferably, in S2, the temperature of the cryogenic deformation treatment is-185 ℃ to-135 ℃, the holding time is 8-12min, and the deformation amount of the cryogenic deformation treatment is 35-65%.

Preferably, in S2, the aging treatment includes: the material is stretched unidirectionally at room temperature with the deformation amount of 5-7 percent, then is preserved in ice water for 20-30min, then is preserved for 5-9h at the temperature of 95-105 ℃, is preserved for 3-8h at the temperature of 115-150 ℃, and is preserved for 3-8h at the temperature of 145-150 ℃ and is cooled in air.

The high-strength high-toughness aluminum alloy has the components of Mg, Zn, Cu, RE, Fe, Si, Zr, Ti, Cr, Mn, B, Li, Ag and Al which are specifically selected, the content of each component is adjusted, and meanwhile, the preparation method of the aluminum alloy is optimized, so that the obtained aluminum alloy has high strength, good toughness, excellent corrosion resistance and excellent heat resistance; specifically, Zr, RE and Ti are added, and the weight percentages of Zr, RE and Ti are controlled to satisfy the following relational expression: zr + RE is more than or equal to 0.16% and less than or equal to 0.2%, and 1.6 xTi is more than or equal to Zr + RE, Al with small size and uniform distribution is formed in the aluminum alloy₃(RE, Zr) and other disperse phases, and the subgrain formation, combination and growth caused by dislocation and subgrain boundary migration are effectively prevented, so that the substructure of the alloy is stabilized, recrystallization is inhibited, and the strength and toughness of the alloy are improved; mg and Ag are added and can generate strong interaction to form Ag-Mg atomic groups, and the weight percentage of Mg and Ag is controlled to meet the following relationIs represented by the following formula: Mg/Ag is 4.2-5.3, the composition of a strengthening phase in the alloy is adjusted, so that a heat-resistant precipitated phase can be precipitated, the formation of an S phase is controlled, and the heat resistance of the alloy is improved; si, Mg, Fe and B are added, the weight percentages of Si, Mg, Fe and B are controlled to satisfy the relation that Si + Mg is more than or equal to 1.65% and less than or equal to 2.17%, and (Fe +3 xB + Mg)/Si is more than or equal to 11 and less than or equal to 14.2, the four components play a synergistic effect, wherein Si can replace partial Al on aluminum crystal lattices, the vacancy concentration of an aluminum matrix is increased, the diffusion rate of Fe is increased, B is doped with Si, the number of effective carriers is increased, the conductivity of the alloy is improved, a second phase containing Fe and Si and an MgSi series intermetallic compound are formed and are finely dispersed in the matrix, the toughness and the strength of the aluminum alloy are improved, meanwhile, the generation of cracks can be reduced in the hot rolling process, and aging precipitates which improve the strength are formed in the aging process, so that the strength, the toughness and the conductivity of the obtained alloy are high; mg, Cu, Mn and Cr are added, and the weight percentage of the four components is controlled to satisfy the following relational expression: mg + Cu + Mn + Cr is more than or equal to 3.23% and less than or equal to 3.63%, the S phase in the system is adjusted, the recrystallization temperature of the alloy is improved, and the heat resistance of the alloy is further improved; in the preparation method of the aluminum alloy, the aluminum alloy ingot is subjected to homogenization treatment, the temperature and time of the homogenization treatment are controlled, the defects of component segregation, nonuniform structure and the like in the alloy are eliminated, and then the alloy is subjected to heat preservation at the temperature of 430-450 ℃ for 180min, so that the overall temperature of the alloy is uniform, and the generation of cracks in the subsequent hot rolling process can be reduced; the hot rolling and the cold rolling are carried out after the annealing, so that the coarse structure of the alloy is improved, and the performance of the alloy is improved; the deep cooling deformation treatment is carried out before the solid solution treatment, the technological parameters of the deep cooling deformation treatment are controlled, the crystal grains are continuously refined, the grain boundary density and the grain boundary precipitated phase distribution density are increased under the same volume, the effect of pinning dislocation is achieved, the sliding resistance of the dislocation at the grain boundary is greatly improved, and the strength of the alloy is obviously improved; water quenching after solution treatment for 100-120min at the temperature of 500-515 ℃ improves the supersaturation degree of the aluminum alloy and reduces coarse second-phase particles, then aging treatment is carried out to precipitate a large amount of fine dispersed strengthening phases and improve the strength of the aluminum alloy, and during the aging treatment, the aluminum alloy is preferably subjected to room temperatureThe material is subjected to unidirectional stretching, aging process parameters are controlled, grain refinement is facilitated, a strengthening phase with a larger strengthening effect is formed, fine isometric crystals are obtained, and the strength and the corrosion resistance of the alloy are improved.

Detailed Description

The technical solution of the present invention will be described in detail below with reference to specific examples.