High-strength aluminum alloy material and preparation process thereof

Abstract

The invention provides a high-strength aluminum alloy material and a preparation process thereof, and relates to the technical field of aluminum alloys. The high-strength aluminum alloy material consists of the following raw material components in percentage by weight: 3.0-4.6% of Co, 0.8-1.8% of Fe, 0.03-0.11% of Ti, less than or equal to 0.2% of other impurities, and the balance of aluminum. Preferably, the aluminum alloy contains an Al3ML12 phase with the weight percentage content of 20%-45% and an Al3MD022 phase with the weight percentage content of not more than 0.05%. The aluminum alloy material has high mechanical strength, the tensile strength can reach 500 MPa or above, and the yield strength can reach 450 MPa or above.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum alloys and relates to a high-strength aluminum alloy material and a preparation process thereof. Background Art

[0002] With the increasing requirements for lightweight materials in various industrial fields, replacing steel with aluminum has become an important trend in the development of the industry. Although aluminum alloy has the characteristics of low specific gravity, corrosion resistance, and good thermal conductivity, its mechanical properties are far behind those of steel. For example, the tensile strength of commonly used alloy steels is mostly above 550MPa, and the yield strength is also above 450MPa. Some high-strength steels can even reach above 1000MPa, while the commonly used aluminum alloy materials are difficult to reach this performance standard. Therefore, in some applications that require higher tensile strength, aluminum alloys cannot replace alloy steels.

[0003] Therefore, developing higher strength aluminum alloys has become a hot topic in the industry. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a high-strength aluminum alloy material and a preparation process thereof.

[0005] The technical solution of the present invention is as follows:

[0006] A high-strength aluminum alloy material is composed of the following raw material components by weight: 3.0-4.6% Co, 0.8-1.8% Fe, 0.03-0.11% Ti, the total amount of other impurities is less than or equal to 0.2%, and the balance is aluminum.

[0007] Preferably, the weight percentage of Co is 3.2-4.5%.

[0008] Preferably, the weight percentage of Fe is 1-1.6%.

[0009] Preferably, the weight percentage of Ti is 0.035-0.11%.

[0010] More preferably, the weight percentage of Ti is 0.037-0.1%.

[0011] Preferably, the weight percentage of the Ti does not exceed 2.8% of the sum of the weight percentages of the Co and the Fe.

[0012] Preferably, the aluminum alloy material contains Al3M_L12 phase.

[0013] More preferably, the weight percentage of the Al3M_L12 phase in the aluminum alloy material is 20-40%.

[0014] Preferably, the aluminum alloy material contains Al3M_D0 22 Phase, the Al3M_D0 22 The weight percentage of the phase in the aluminum alloy does not exceed 0.05%.

[0015] A method for preparing the high-strength aluminum alloy material according to any of the above technical solutions comprises the following steps:

[0016] Weigh and prepare the raw materials according to the raw material components of the aluminum alloy;

[0017] Adding pure aluminum ingots into a smelting furnace, heating to 740°C-760°C and melting, adding the remaining raw material components, and continuing smelting;

[0018] Refining the melt and removing scum from the surface of the melt;

[0019] The refined aluminum alloy melt is cast to obtain the aluminum alloy material.

[0020] The beneficial effects of the present invention are:

[0021] (1) The present invention uses three metal raw materials and aluminum metal to prepare aluminum alloy. By controlling the proportion of each metal raw material, the obtained aluminum alloy material has high mechanical strength. The tensile strength can reach more than 500 MPa, the yield strength can reach more than 450 MPa, and even the tensile strength and yield strength can reach more than 600 MPa.

[0022] (2) Further research has revealed that a certain proportion of Al3M_L12 phase is formed in the aluminum alloy material of the present invention, which helps to improve the mechanical strength of the aluminum alloy material, and the content of Al3M_D022 phase in the aluminum alloy material is relatively low, thus avoiding the influence on the mechanical strength. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further illustrated and described below through specific implementation methods.

[0024] In order to improve the mechanical strength of aluminum alloy materials, especially tensile strength and yield strength, on the one hand, the present invention provides a high-strength aluminum alloy material, which is composed of the following raw material components by 100% by weight: 3.0-4.6% Co, 0.8-1.8% Fe, 0.03-0.11% Ti, the total amount of other impurities is less than or equal to 0.2%, and the balance is aluminum.

[0025] The aluminum alloy of the present invention is composed of aluminum and three metals: Co, Fe and Ti. Co mainly forms a dispersed second phase in the aluminum alloy, such as Al9M2 phase, to ensure the strength of the alloy; Fe mainly prevents die sticking during die casting and also helps to improve the strength of the material; a trace amount of Ti helps to refine the grain structure and further improve the strength of the material. The weight percentages of the three metals are controlled within a certain range, so that an aluminum alloy material with high mechanical strength and good die-casting performance can be obtained, the tensile strength can reach 500MPa or higher, the yield strength can reach 450MPa or higher, and even the tensile strength and yield strength can reach more than 600MPa.

[0026] In a preferred embodiment of the present invention, the weight percentage of Co is 3.2-4.5%. For example, the weight percentage of Co can be any value or any value between 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4.0%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, etc., without any particular limitation. More preferably, the weight percentage of Co can be 3.5-4.4%.

[0027] In a preferred embodiment of the present invention, the weight percentage of Fe is 1-1.6%. For example, the weight percentage of Fe can be any value among 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, etc. or any value in between, without special limitation. More preferably, the weight percentage of Fe can be 1.1-1.6%.

[0028] In a preferred embodiment of the present invention, the weight percentage of Ti is 0.035-0.11%. For example, the weight percentage of Ti can be any value or any value in between 0.035%, 0.04%, 0.045%, 0.05%, 0.055%, 0.06%, 0.065%, 0.07%, 0.075%, 0.08%, 0.085%, 0.09%, 0.095%, 0.1%, 0.105%, 0.11%, etc., without special restrictions. More preferably, the weight percentage of Ti is 0.037-0.1%.

[0029] In a preferred embodiment of the present invention, the weight percentage of Ti does not exceed 2.8% of the sum of the weight percentages of Co and Fe. In the present invention, the weight percentage of Ti cannot be too high, otherwise it will be detrimental to the improvement of the mechanical strength of the aluminum alloy. Specifically, the weight percentage of Ti is set to c, the weight percentage of Co is set to a, and the weight percentage of Fe is set to b. For example, the value of c / (a+b) can be 2.8%, 2.7%, 2.6%, 2.5%, 2.4%, 2.3%, 2.2%, 2.1%, 2.0%, 1.9%, 1.8%, 1.7%, 1.6%, 1.5%, 1.4%, 1.3%, 1.2%, 1.1%, 1.0%, 0.9%, 0.8%, 0.7%, etc., or any value therebetween, without special restrictions.

[0030] In a preferred embodiment of the present invention, the aluminum alloy material contains Al3M_L12 phase, and M is any one of Co, Fe, and Ti, or a combination of two or more thereof. Al3M phase is also called Al3M intermetallic compound, and Al3M_L12 phase is also called L12-type Al3M phase. Al3M phase is a precipitated phase of aluminum alloy. The cubic structure of Al3M_L12 phase has 5 independent slip systems, which can improve the plasticity of Al3M intermetallic compound to a certain extent. Moreover, Al3M_L12 phase is similar to Al structure, and the lattice parameter is very close to Al, which can obtain the effect of maximizing the strengthening effect of dispersed particles, and can reduce the interface energy between the matrix and the precipitated phase, thereby reducing the driving force of particle coarsening and achieving the effect of grain refinement. Therefore, the aluminum alloy material of the present invention contains a certain amount of Al3M_L12 phase, which has a positive effect on improving the mechanical strength of aluminum alloy, including tensile strength and yield strength.

[0031] In a more preferred embodiment of the present invention, the weight percentage of the Al3M_L12 phase in the aluminum alloy material is 20-40%. For example, the weight percentage of the Al3M_L12 phase in the aluminum alloy material can be 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, etc., or any value in between, without special restrictions.

[0032] In a preferred embodiment of the present invention, the aluminum alloy material contains Al3M_D0 22 Phase, Al3M_D0 22 The weight percentage of Al3M_D0 phase in the aluminum alloy does not exceed 0.05%. 22 Compared with aluminum alloy materials, the mechanical strength is unfavorable, but with the gradual increase of Ti weight percentage, Al3M_D0 22The weight percentage of the phase also gradually increases from 0, but Al3M_D0 22 The weight percentage of the phase is controlled within a certain range, which has a low impact on the mechanical strength of the aluminum alloy material. 22 The weight percentage of the phase in the aluminum alloy can be any value among 0, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, etc. or any value in between, without any special limitation.

[0033] In the present invention, Al3M_L12 phase and Al3M_D0 22 The weight percentage of the phase can be calculated from the phase diagram.

[0034] On the other hand, the present invention provides a method for preparing the high-strength aluminum alloy material described in any one of the above technical solutions, which can adopt a conventional preparation process and can include the following steps:

[0035] According to the raw material components of the aluminum alloy, the raw materials are weighed and prepared; wherein the master alloy AlCo10 is used as the raw material of Co, the master alloy AlFe20 is used as the raw material of Fe, and the master alloy AlTi5 is used as the raw material of Ti;

[0036] Add pure aluminum ingots into the smelting furnace, heat to 740℃-760℃ and melt, add the remaining raw material components, and continue smelting;

[0037] The melt is subjected to refining treatments such as slag removal and hydrogen removal, and scum on the surface of the melt is removed to obtain a refined aluminum alloy melt;

[0038] The refined aluminum alloy melt is cast into a mold to obtain an aluminum alloy material.

[0039] The technical solution of the present invention is further described and illustrated according to various embodiments below. Unless otherwise specified, the parts described in the following embodiments are parts by weight.

[0040] Example 1

[0041] The composition and weight percentage of the prepared high-strength aluminum alloy are as follows: 4.2% Co, 1.3% Fe, 0.09% Ti, the total amount of other impurities does not exceed 0.1%, and the balance is Al.

[0042] preparing aluminum ingots, aluminum-cobalt alloys, aluminum-iron alloys, and aluminum-titanium alloys according to the above composition;

[0043] (1) adding an aluminum ingot into a smelting furnace and melting it at 750-760° C. to obtain aluminum liquid, adding aluminum-cobalt alloy, aluminum-iron alloy and aluminum-titanium alloy into the aluminum liquid for smelting, and maintaining the temperature at 750-760° C.;

[0044] (2) preparing a refining agent at 0.2 wt% of the total weight of the aluminum alloy melt, mixing it with nitrogen through a degasser, blowing it into the aluminum melt, and refining it at 740-750° C. for 10-15 min, leaving it to stand for more than 20 min, and then removing the slag on the surface of the melt;

[0045] (3) The refined melt is cooled to 700°C and finally cast into aluminum alloy ingots or transferred to a machine-side furnace for direct die-casting products.

[0046] Example 2

[0047] The difference between this embodiment and embodiment 1 is that in embodiment 1, the weight percentage of Co is adjusted from 4.2% to 3.0%, and the weight percentage of Al is increased accordingly. The remaining steps remain unchanged.

[0048] Example 3

[0049] The difference between this embodiment and embodiment 1 is that in embodiment 1, the weight percentage of Co is adjusted from 4.2% to 3.2%, and the weight percentage of Al is increased accordingly. The remaining steps remain unchanged.

[0050] Example 4

[0051] The difference between this embodiment and embodiment 1 is that in embodiment 1, the weight percentage of Co is adjusted from 4.2% to 4.5%, and the weight percentage of Al is reduced accordingly. The remaining steps remain unchanged.

[0052] Example 5

[0053] The difference between this embodiment and embodiment 1 is that in embodiment 1, the weight percentage of Fe is adjusted from 1.3% to 0.8%, and the weight percentage of Al is increased accordingly. The remaining steps remain unchanged.

[0054] Example 6

[0055] The difference between this embodiment and embodiment 1 is that in embodiment 1, the weight percentage of Fe is adjusted from 1.3% to 1.0%, and the weight percentage of Al is increased accordingly. The remaining steps remain unchanged.

[0056] Example 7

[0057] The difference between this embodiment and embodiment 1 is that in embodiment 1, the weight percentage of Fe is adjusted from 1.3% to 1.6%, and the weight percentage of Al is reduced accordingly. The remaining steps remain unchanged.

[0058] Example 8

[0059] The difference between this embodiment and embodiment 1 is that in embodiment 1, the weight percentage of Fe is adjusted from 1.3% to 1.8%, and the weight percentage of Al is reduced accordingly. The remaining steps remain unchanged.

[0060] Example 9

[0061] The difference between this embodiment and embodiment 1 is that in embodiment 1, the weight percentage of Ti is adjusted from 0.09% to 0.03%, and the weight percentage of Al is increased accordingly. The remaining steps remain unchanged.

[0062] Example 10

[0063] The difference between this embodiment and embodiment 1 is that in embodiment 1, the weight percentage of Ti is adjusted from 0.09% to 0.037%, and the weight percentage of Al is increased accordingly. The remaining steps remain unchanged.

[0064] Embodiment 11

[0065] The difference between this embodiment and embodiment 1 is that in embodiment 1, the weight percentage of Ti is adjusted from 0.09% to 0.11%, and the weight percentage of Al is reduced accordingly. The remaining steps remain unchanged.

[0066] Examples 12-18

[0067] The difference between Examples 12-18 and Example 1 is that in Example 1, the weight percentages of Co, Fe and Ti are adjusted. The other steps remain unchanged, as shown in Table 1 below.

[0068] Comparative Example 1

[0069] The difference between this comparative example and Example 1 is that in Example 1, the weight percentage of Ti is adjusted from 0.09% to 0.12%, and the weight percentage of Al is reduced accordingly. The remaining steps remain unchanged.

[0070] Comparative Example 2

[0071] The difference between this comparative example and Example 1 is that in Example 1, the weight percentage of Ti is adjusted from 0.09% to 0.15%, and the weight percentage of Al is reduced accordingly. The remaining steps remain unchanged.

[0072] Composition of each embodiment and comparative example, Al3M_L12 phase and Al3M_D0 22 The weight percentages of the phases and the tensile strength and yield strength are shown in Table 1. a is the weight percentage of Co, b is the weight percentage of Fe, c is the weight percentage of Ti, d is the weight percentage of Al3M_L12 phase, e is the weight percentage of Al3M_D0 22 Phase weight percentage.

[0073] Table 1

[0074]

[0075]

[0076] It can be seen from the experimental data in Table 1 above that the aluminum alloy material of the present invention has relatively high mechanical strength, and the tensile strength and yield strength can basically reach above 500 MPa. Through formulation optimization, the tensile strength and yield strength can reach 600 MPa and above.

[0077] As described above, the basic principles, main features and advantages of the present invention are shown and described. Those skilled in the art should understand that the present invention is not limited by the above embodiments, which are only preferred embodiments of the present invention and cannot be used to limit the scope of the present invention. That is, equivalent changes and modifications made according to the scope of the present invention and the content of the specification should still be within the scope of the present invention. The scope of protection required by the present invention is defined by the attached claims and their equivalents.

Claims

1. A high-strength aluminum alloy material, characterized in that: The material is composed of the following raw material components according to 100% by weight: 3.0-4.6% Co, 0.8-1.8% Fe, 0.03-0.11% Ti, the total amount of other impurities is less than or equal to 0.2%, and the balance is aluminum.

2. The high-strength aluminum alloy material according to claim 1, characterized in that: The weight percentage of Co is 3.2-4.5%.

3. The high-strength aluminum alloy material according to claim 1, characterized in that: The weight percentage of Fe is 1-1.6%.

4. The high-strength aluminum alloy material according to claim 1, characterized in that: The weight percentage of Ti is 0.035-0.11%.

5. The high-strength aluminum alloy material according to claim 4, characterized in that: The weight percentage of Ti is 0.037-0.1%.

6. The high-strength aluminum alloy material according to claim 1, characterized in that: The weight percentage of the Ti does not exceed 2.8% of the sum of the weight percentages of the Co and the Fe.

7. The high-strength aluminum alloy material according to claim 1, characterized in that: The aluminum alloy material contains Al3M_L12 phase.

8. The high-strength aluminum alloy material according to claim 7, characterized in that: The weight percentage of the Al3M_L12 phase in the aluminum alloy material is 20-40%.

9. The high-strength aluminum alloy material according to claim 1, characterized in that: The aluminum alloy material contains Al3M_D0 22 Phase, the Al3M_D0 22 The weight percentage of the phase in the aluminum alloy does not exceed 0.05%.

10. A method for preparing the high-strength aluminum alloy material according to any one of claims 1 to 9, characterized in that: The following steps are involved: Weigh and prepare the raw materials according to the raw material components of the aluminum alloy; Adding pure aluminum ingots into a smelting furnace, heating to 740°C-760°C and melting, adding the remaining raw material components, and continuing smelting; Refining the melt and removing scum from the surface of the melt; The refined aluminum alloy melt is cast to obtain the aluminum alloy material.

Images