ALUMINUM ALLOY MATERIAL, AND PREPARATION METHOD THEREFOR AND USE THEREOF

Description

CROSS-REFERENCE TO THE RELATED APPLICATION

The present application claims priority to Chinese patent application No. 202211398488.9, filed on Nov. 9, 2022 before the China National Intellectual Property Administration, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates to the aluminum alloy technology, in particular to an aluminum alloy material and a preparation method therefor, and an application of the aluminum alloy material.

BACKGROUND

Driving induction motors are evolving towards high integration, high voltage, and high power density. Higher performance requirements are placed on materials of the rotor due to the continuous increase in rotational speed. Aluminum alloys, with their high specific strength, low cost, and high recyclability, are gradually replacing copper alloys to become the main material of automotive motor rotors. To meet performance requirements, aluminum alloys need to possess both high strength and high electrical conductivity.

To obtain cast aluminum alloy materials with high strength and high conductivity, alloying is required for improvement. US20210332461A1 discloses a cast aluminum rotor material suitable for high-pressure casting, which contains 4-6% Ni, 0.2-0.8% Fe, and 0.01-0.1% Ti. This aluminum rotor material is primarily added with Ni to form the NiAl₃ eutectic phase so as to enhance the castability of the alloy. CN 113981278A discloses a cast aluminum alloy with high conductivity, thermotolerance, and pressure resistance and a preparation method therefor. This aluminum alloy contains 1.8-3.8% Ni, 0.25-0.30% Fe, 0.006-0.15% Zr, 0.0015-0.025% Cr, and 0.001-0.02% V, which achieves high strength and high conductivity by combining the NiAl₃ eutectic phase with trace elements Fe, Zr, Cr, and V to form fine and dispersed intermetallic compounds that are stable at high temperatures. US20220090234A1 discloses an aluminum alloy rotor material manufactured through high-vacuum die-casting process, containing 1.5-6.5% Ni, 0.1-1.5% Si, 0.1-3% Mg, Fe<0.2%, Mn<0.65%, Ti<0.12%, V<0.15%, Zr<0.15%, Mo<0.15%, Cr<0.01, and Sr<0.02. This improves performance by combining the NiAl₃ eutectic phase with heat treatment strengthening of Mg₂Si.

In all of the above technologies, the alloy element Ni is added and adjusted to form the NiAl₃ eutectic phase, thereby enhancing the casting properties while minimizing the impact on electrical conductivity. Moreover, the yield strength is improved by adding trace elements Fe, Zr, Cr, V to form intermetallic compounds or by heat treatment strengthening of Mg₂Si. All these technologies face the issue of excessive content of nickel and insufficient content of iron, leading to high material costs. However, the strength and electrical conductivity of the aluminum alloy material may be affected if the contents of nickel and iron are changed.

Therefore, there is a need to develop an aluminum alloy material with high strength and high conductivity while reducing costs.

SUMMARY

The object of this disclosure is to provide an aluminum alloy material, a preparation method therefor, and an application thereof.

In view of the above, the following technical solutions are adopted in this disclosure.

A first aspect of this disclosure provides an aluminum alloy material. The as-cast microstructure of the aluminum alloy material further includes an eutectic phase NiAl₃, a primary solidification phase FeNiAl₉, and a primary solidification phase Fe₄Al₁₃ in addition to the aluminum matrix.

In some embodiments of this disclosure, the mass content of the eutectic phase NiAl₃ is 0.2% to 2.2%, the mass content of the primary solidification phase FeNiAl₉ is 0.1% to 1.1%, and the mass content of the primary solidification phase Fe₄Al₁₃ is 1% to 6%. The size of α-Al grains in the aluminum alloy material is below 100 μm.

The mass content of the eutectic phase NiAl₃ is 0.2% to 2.2% (e.g., 0.2%, 0.5%, 0.8%, 1%, 1.1%, 1.4%, 1.5%, 1.7%, 2%, or 2.2%, etc.).

The mass content of the primary solidification phase FeNiAl₉ is 0.1% to 1.1% (e.g., 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, or 1.1%, etc.).

The mass content of the primary solidification phase Fe₄Al₁₃ is 1% to 6% (e.g., 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, or 6%, etc.), and the size of α-Al grains in the aluminum alloy material is below 100 μm (e.g., 100 μm, 95 μm, 90 μm, 85 μm, 80 μm, 75 μm, 70 μm, 65 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20 μm, or 10 μm, etc.).

This disclosure can further optimize the electrical conductivity and strength of the aluminum alloy material while reducing costs by reasonably regulating the contents of the eutectic phase NiAl₃, the primary solidification phases FeNiAl₉ and Fe₄Al₁₃, and refining the size of α-Al grains.

In some embodiments of this disclosure, the aluminum alloy material includes no secondary phases other than the eutectic phase NiAl₃, the primary solidification phases FeNiAl₉ and Fe₄Al₁₃.

It should be noted that all crystal phases other than the main Al phase in the aluminum alloy material are collectively referred to as “secondary phases”. In this disclosure, the presence of secondary phases other than the eutectic phase NiAl₃, the primary solidification phases FeNiAl₉ and Fe₄Al₁₃ may lead to enhanced impurity scattering or matrix fracture, thereby affecting the electrical conductivity, strength, and other properties of the aluminum alloy material.

In some embodiments of this disclosure, the aluminum alloy material includes components of the following mass percentages:

Ni: 0.5% to 1.5%, Fe: 0.8% to 2.5%, one or more of Ti, Nb, V, and Zr, with the total mass percentage of Ti, Nb, V, and Zr being greater than or equal to 0.02%, and the rest being Al.

The mass percentage of Ni can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, or 1.5%, etc.

The mass percentage of Fe can be 0.8%, 0.9%, 1%, 1.2%, 1.3%, 1.5%, 1.6%, 1.8%, 2%, 2.2%, 2.3%, or 2.5%, etc.

The total mass percentage of Ti, Nb, V, and Zr can be 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, or 0.15%, etc.

In some embodiments of this disclosure, the mass ratio of Ni to Fe in the aluminum alloy material is 0.2 to 1.5; for example, it can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, or 1.5, etc.

In some embodiments of this disclosure, the total mass percentage of Ti, Nb, V, and Zr is less than or equal to 0.15%; preferably, it is 0.02% to 0.07%.

In some embodiments of this disclosure, the mass percentage of Ti is less than or equal to 0.1%, for example, it can be 0.1%, 0.09%, 0.08%, 0.07%, 0.06%, 0.05%, 0.04%, 0.03%, 0.02%, 0.01%, 0.005%, or 0%, etc.

The mass percentage of Nb is less than or equal to 0.1%, for example, it can be 0.1%, 0.09%, 0.08%, 0.07%, 0.06%, 0.05%, 0.04%, 0.03%, 0.02%, 0.01%, 0.005%, or 0%, etc.

The mass percentage of V is less than or equal to 0.1%, for example, it can be 0.1%, 0.09%, 0.08%, 0.07%, 0.06%, 0.05%, 0.04%, 0.03%, 0.02%, 0.01%, 0.005%, or 0%, etc.

The mass percentage of Zr is less than or equal to 0.1%, for example, it can be 0.1%, 0.09%, 0.08%, 0.07%, 0.06%, 0.05%, 0.04%, 0.03%, 0.02%, 0.01%, 0.005%, or 0%, etc.

In some embodiments of this disclosure, the aluminum alloy material also contains B.

In some embodiments of this disclosure, the ratio of the mass B to the total mass of Ti, Nb, V, and Zr is less than or equal to 2 (e.g., 2, 1.8, 1.5, 1.2, 1, 0.8, 0.5, 0.3, 0.2, 0.1, or 0, etc.); preferably, it is less than or equal to 0.5.

In some embodiments of this disclosure, the mass percentage of B is less than or equal to 0.05%; for example, it can be 0.05%, 0.04%, 0.03%, 0.02%, 0.01%, 0.008%, 0.006%, 0.005%, 0.003%, 0.001%, or 0%, etc.

In some embodiments of this disclosure, the total mass percentage of Mn, Cr, and Si in the aluminum alloy material is less than or equal to 0.25%; for example, it can be 0.25%, 0.23%, 0.22%, 0.2%, 0.18%, 0.16%, 0.15%, 0.13%, 0.12%, 0.1%, 0.08%, 0.05%, 0.02%, or 0%, etc.

In some embodiments of this disclosure, the mass percentage of Mn in the aluminum alloy material is less than or equal to 0.1%, for example, it can be 0.1%, 0.09%, 0.08%, 0.07%, 0.06%, 0.05%, 0.04%, 0.03%, 0.02%, 0.01%, 0.005%, or 0%, etc.

The mass percentage of Cr is less than or equal to 0.05%, for example, it can be 0.05%, 0.04%, 0.03%, 0.02%, 0.01%, 0.008%, 0.005%, 0.002%, or 0%, etc.

The mass percentage of Si is less than or equal to 0.1%, for example, it can be 0.1%, 0.09%, 0.08%, 0.07%, 0.06%, 0.05%, 0.04%, 0.03%, 0.02%, 0.01%, 0.005%, or 0%, etc.

In some embodiments of this disclosure, the ratio of the total mass of Mn and Cr to the mass of Si in the aluminum alloy material is less than or equal to 0.5; for example, it can be 0.5, 0.4, 0.3, 0.2, 0.1, 0.05, or 0, etc.

In the aluminum alloy material of this disclosure, the content of impurities other than Mn, Cr, and Si is less than or equal to 0.1 wt %.

A second aspect of this disclosure provides a method for preparing the aluminum alloy material described in the first aspect. The method includes steps of:

• • (1) obtaining first aluminum alloy fusion liquid by mixing, according to proportions of respective elements in the aluminum alloy material, raw materials containing respective elements, and melting the raw materials;
  • (2) obtaining second aluminum alloy fusion liquid by refining, degassing, and removing slag from the first aluminum alloy fusion liquid;
  • (3) Keeping the second aluminum alloy fusion liquid at a constant temperature, and then obtaining the aluminum alloy material by casting the second aluminum alloy fusion liquid.

In some embodiments of this disclosure, the temperature for the melting is 680° C. to 800° C. (e.g., 680° C., 690° C., 700° C., 710° C., 720° C., 730° C., 740° C., 750° C., 760° C., 770° C., 780° C., 790° C., or 800° C., etc.), and the duration for the melting is 120 to 180 minutes (e.g., 120 minutes, 130 minutes, 140 minutes, 150 minutes, 160 minutes, 170 minutes, or 180 minutes, etc.).

In some embodiments of this disclosure, the temperature for the refining is 680 to 800° C. (e.g., 680° C., 690° C., 700° C., 710° C., 720° C., 730° C., 740° C., 750° C., 760° C., 770° C., 780° C., 790° C., or 800° C., etc.), and the duration for the refining is 15 to 30 minutes (e.g., 15 minutes, 18 minutes, 20 minutes, 22 minutes, 25 minutes, 28 minutes, or 30 minutes, etc.).

In some embodiments of this disclosure, the second aluminum alloy fusion liquid is kept at the temperature 680° C. to 800° C. (e.g., 680° C., 690° C., 700° C., 710° C., 720° C., 730° C., 740° C., 750° C., 760° C., 770° C., 780° C., 790° C., or 800° C., etc.), for 30 to 120 minutes (e.g., 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes, 80 minutes, 90 minutes, 100 minutes, 110 minutes, or 120 minutes, etc.).

In some embodiments of this disclosure, the casting is low-pressure casting, differential-pressure casting, squeeze casting, or high-pressure casting.

A third aspect of this disclosure provides an application of the aluminum alloy material described in the first aspect. The aluminum alloy material is used to manufacture automotive components.

In some embodiments, the automotive components are motor rotors, conductors, or inverters.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating phase compositions and phase relationships in Al-rich corner of Al-xFe-yNi system for an aluminum alloy material under non-equilibrium solidification conditions.

DETAILED DESCRIPTION

The technical solutions of this disclosure are further illustrated below in combination with accompanying drawings and specific embodiments. Those skilled in the art should understand that the specific embodiments are merely provided to aid in understanding this disclosure and should not be construed as specific limitations on this disclosure.

Examples 1 to 11 and Comparative Examples 1 to 5

Examples 1 to 11 and Comparative Examples 1 to 5 each provide an aluminum alloy material prepared by the following method.

(1) Raw materials of industrial pure aluminum, and Al—Ni alloy, Al—Fe alloy, Al—Ti alloy, Al—Nb alloy, Al—V alloy, Al—Zr alloy, and/or Al—B alloy are added to a melting furnace according to proportions of various elements in the aluminum alloy material, and melted at 740° C. for 120 minutes to obtain first aluminum alloy fusion liquid;

(2) The first aluminum alloy fusion liquid is added with 0.5 wt % of refining agent, and refined at 740° C. for 15 minutes; degassing is carried out with high-purity argon gas; after standing for 15 minutes, slag is removed to obtain second aluminum alloy fusion liquid.

(3) The second aluminum alloy fusion liquid is kept at 740° C. for 30 minutes; the aluminum alloy material is obtained by low-pressure casting (at pressure of 0.01 MPa, holding for 120 s), differential pressure casting (pressure difference between upper and lower cavities is 0.1 MPa, holding for 80 s), squeeze casting (at pressure of 15 MPa, holding for 25 s), or high-pressure casting (slow pressure-fast pressure conversion point 240 mm, injection speed 3 m/s, pressure 35 MPa, holding for 20 s). Casting parameters are as follows: the mold is pre-sprayed with release agent and preheated to 180° C.; the casting temperature is controlled at 720° C., and the demolding temperature is 370° C.

Contents of various elements in the aluminum alloy materials provided by Examples 1 to 11 and Comparative Examples 1 to 5 and casting methods are shown in Table 1 below.

TABLE 1
Element Content (wt %) and Casting Methods

											Casting
Category	Ni	Fe	Mn	Cr	Si	Ti	Nb	V	Zr	B	Method

Example 1	0.8	2.0	0.02	0.01	0.1	0.5	0	0	0	0	Differential
											Pressure
Example 2	1.1	1.9	0.03	0.02	0.1	0.03	0.02	0	0	0.007	Low
											Pressure
Example 3	1.3	1.5	0.02	0.01	0.06	0	0.02	0	0	0.004	Squeeze
											Casting
Example 4	1.5	1.1	0.01	0.02	0.07	0	0	0.04	0	0.008	High
											Pressure
Example 5	0.7	2.1	0.03	0	0.07	0	0	0	0.02	0	High
											Pressure
Example 6	1.4	1	0.02	0.01	0.06	0.02	0	0	0.02	0	Squeeze
											Casting
Example 7	0.5	2.5	0	0.02	0.05	0.03	0	0	0	0.006	High
											Pressure
Example 8	1.5	1	0.02	0.01	0.07	0.03	0	0	0	0.008	High
											Pressure
Example 9	1.2	1.3	0.02	0.01	0.09	0.03	0	0	0	0.006	High
											Pressure
Example 10	1.4	1.6	0.02	0	0.09	0.05	0.05	0.05	0	0.01	High
											Pressure
Example 11	1.3	1	0.02	0.01	0.07	0	0	0.02	0	0.04	High
											Pressure
Comparative	0.3	2.5	0	0.02	0.05	0.03	0	0	0	0.006	High
Example 1											Pressure
Comparative	1.5	0.3	0.02	0.01	0.07	0.03	0	0	0	0.008	High
Example 2											Pressure
Comparative	1.2	1.3	0.2	0.25	0.8	0.03	0	0	0	0.006	High
Example 3											Pressure
Comparative	1.4	1.6	0.02	0	0.09	0.15	0.15	0.04	0	0.01	High
Example 4											Pressure
Comparative	1.3	1	0.02	0.01	0.07	0	0	0.02	0	0.06	High
Example 5											Pressure

The ratios of various elements and microstructure information of the aluminum alloy materials provided in Examples 1 to 11 and Comparative Examples 1 to 5 are shown in Table 2 below.

TABLE 2
Element Ratios and Microstructural Information

					B/				Size
				Ti +	(Ti +				of α-
				Nb +	Nb +				Al
		Mn + Cr +	(Mn + Cr)/	V +	V +	NiAl3	FeNiAl9	Fe4Al13	Grain
Category	Ni/Fe	Si	Si	Zr	Zr)	(wt %)	(wt %)	(wt %)	(μm)

Example 1	0.4	0.13	0.30	0.05	0	0.76	0.38	5.3	85
Example 2	0.58	0.15	0.50	0.05	0.14	1.2	0.6	5.1	75
Example 3	0.87	0.09	0.50	0.02	0.2	1.63	0.82	4.32	50
Example 4	1.36	0.1	0.43	0.04	0.2	2.16	1.08	3	35
Example 5	0.33	0.1	0.43	0.02	0	0.62	0.31	5.42	32
Example 6	1.4	0.09	0.50	0.04	0	2.02	1.01	2.7	60
Example 7	0.2	0.07	0.40	0.03	0.2	0.28	0.15	5.95	25
Example 8	1.5	0.1	0.43	0.03	0.27	1.74	0.93	2.14	22
Example 9	0.92	0.12	0.33	0.03	0.2	1.31	0.68	3.42	27
Example 10	0.88	0.11	0.22	0.15	0.07	1.65	0.84	4.46	15
Example 11	1.3	0.1	0.43	0.02	2	1.42	0.79	2.14	35
Comparative	0.12	0.07	0.40	0.03	0.2	0.15	0.07	6.02	40
Example 1
Comparative	5	0.1	0.43	0.03	0.27	2.12	0.88	0.57	65
Example 2
Comparative	0.92	1.25	0.56	0.03	0.2	1.30	0.69	3.40	55
Example 3
Comparative	0.88	0.11	0.22	0.34	0.03	1.43	0.87	3.43	20
Example 4
Comparative	1.3	0.1	0.43	0.02	3	1.43	0.76	2.17	110
Example 5

The testing methods for contents of Mn, Cr, and Si are as follows: elemental analysis is performed by measuring with an inductively coupled plasma optical emission spectrometer, and the analysis error is 3% to 5%. Powder is taken from different regions of the alloy sample, mixed evenly, and then 1 g of the powder is analyzed. Each batch of samples is tested independently twice, and an average value is calculated.

The testing methods for the contents of NiAl₃, FeNiAl₉, and Fe₄Al₁₃ are as follows: powder diffraction is conducted on powdered alloy samples using an X-ray diffractometer. The testing conditions are: Cu target Kα ray; 2θ angle range of 10° to 90°; scanning step size of 0.02°; and scanning speed of 0.33°/s. The test results are refined using Topas (Total Pattern Solution).

The testing method for size of α-Al grains is as follows: polarized light photographs of the metallographic samples are obtained through an optical microscope, and grain size statistics are performed using the intercept method (ASTM standard E112-10).

Performance Testing:

The electrical conductivity, yield strength, tensile strength, elongation at room temperature, and high-temperature resistance of the aluminum alloy materials provided by Examples 1 to 11 and Comparative Examples 1 to 5 are tested as follows:

• • The electrical conductivity is tested according to GB/T 12966-2022 (The Methods for Determining Aluminium and Aluminium Alloys Conductivity Using Eddy Current);
  • The yield strength at room temperature is tested according to GB/T 228.1-2021 (Metallic Materials-Tensile Testing-Part 1, Method of Test at Room Temperature);
  • The tensile strength at room temperature is tested according to GB/T 228.1-2021 (Metallic Materials-Tensile Testing-Part 1, Method of Test at Room Temperature);
  • The Elongation at room temperature is tested according to GB/T 228.1-2021 (Metallic Materials-Tensile Testing-Part 1, Method of Test at Room Temperature).

The High-Temperature Resistance: the aluminum alloy material is kept at 180° C. for 100 hours, and the yield strength thereof is tested to calculate a strength attenuation rate.

The results of the above tests are shown in Table 3 below.

TABLE 3
		Yield	Tensile
		strength at	Strength at		Yield strength
	Electrical	room	Room	Elongation at	attenuation rate/%
	conductivity/%	temperature/	Temperature/	Room	after holding at
Category	IACS	MPa	MPa	Temperature/%	180° C. for 100 hours

Example 1	51	80	165	13	3
Example 2	50	82	170	11	4
Example 3	50	89	180	12	6
Example 4	52	78	160	11	4
Example 5	49	85	172	13	3
Example 6	51	78	166	12	6
Example 7	48	84	170	13	5
Example 8	52	75	160	11	4
Example 9	50	80	165	12	5
Example 10	49	85	172	13	3
Example 11	50	86	170	10	8
Comparative	46	86	175	11	6
Example 1
Comparative	53	70	150	14	5
Example 2
Comparative	44	95	200	6	8
Example 3
Comparative	49	65	150	8	7
Example 4
Comparative	47	70	152	8	8
Example 5

As can be seen from the performance data of the above examples, for the aluminum alloy materials provided by this disclosure, the electrical conductivity is greater than or equal to 48% IACS (International Annealed Copper Standard), the yield strength at room temperature is greater than or equal to 75 MPa, the tensile strength at room temperature is greater than or equal to 160 MPa, and the elongation at room temperature is greater than or equal to 10%. Additionally, the attenuation rate of the yield strength of the aluminum alloy materials after being kept at 180° C. for 100 hours is less than or equal to 10%. The Ni/Fe ratio is low. The aluminum alloy materials provided by this disclosure have advantages of high strength, high conductivity, and low cost. Moreover, the aluminum alloy materials provided by this disclosure have good fluidity, and can be cast using low-pressure, differential-pressure, squeeze, or high-pressure casting methods.

Compared with Example 7, the content of Ni in Comparative Example 1 is too low, and the Ni/Fe ratio is too low, resulting in the contents of the eutectic phase NiAl₃ and the primary solidification phase FeNiAl₉ being too low. This leads to a decrease in the electrical conductivity of the aluminum alloy material.

Compared with Example 8, the content of Fe in Comparative Example 2 is too low, and the Ni/Fe ratio is too high, resulting in the content of the primary solidification phase Fe₄Al₁₃ being too low. This leads to a decrease in the yield strength and tensile strength of the aluminum alloy material.

Compared with Example 9, the individual contents, total content of Mn, Cr, and Si, as well as the mass ratio of (Mn+Cr)/Si in Comparative Example 3 are all too high. This leads to the formation of secondary phases that are rich in Mn, Cr, and Si elements, other than the eutectic phase NiAl₃, the primary solidification phases FeNiAl₉ and Fe₄Al₁₃ in the aluminum alloy material. As a result, the electrical conductivity and elongation of the aluminum alloy material decrease.

Compared with Example 10, the total content of Ti, Nb, V, and Zr in Comparative Example 4 is too high. This leads to the formation of secondary phases that are rich in Ti, Nb, V, and Zr elements, other than the eutectic phase NiAl₃, the primary solidification phases FeNiAl₉ and Fe₄Al₁₃ in the aluminum alloy material. As a result, the strength and elongation of the aluminum alloy material decrease.

Compared with Example 11, the mass ratio of B/(Ti+Nb+V+Zr) in Comparative Example 5 is too high. This leads to the formation of secondary phases that are rich in B elements, other than the eutectic phase NiAl₃ and the primary solidification phase FeNiAl₉ in the aluminum alloy material. Moreover, the size of α-Al grains is larger. As a result, in the electrical conductivity, strength, and elongation of the aluminum alloy material decrease.

Calphad thermodynamic calculations were respectively carried out on the phase compositions and phase relationships of the aluminum alloy materials provided in this disclosure, as well as those of Rio Tinto (US20220090234A1), Tesla (US20210332461A1), and Shenzhen Xinshen (CN 113981278A) in the Al-xFe-yNi system (0≤x/y≤7) rich in the Al corner under non-equilibrium solidification conditions. The results are shown in FIG. 1.

As can be seen from FIG. 1, the existing aluminum alloys mainly consist of the aluminum matrix (Fcc), NiAl₃, and FeNiAl₉ in their respective Ni and Fe composition ranges. In contrast, the aluminum alloy provided by this disclosure mainly consists of the aluminum matrix (Fcc), NiAl₃, FeNiAl₉, and Fe₄Al₁₃ in the disclosed Ni and Fe composition ranges. The differences in phase compositions lead to differences in the properties of the alloy.

This disclosure has found through research that under the condition of a low Ni/Fe ratio, in addition to the NiAl₃ phase and the FeNiAl₉ phase, the Fe₄Al₁₃ phase will also be formed in the aluminum alloy. The Fe₄Al₁₃ phase has good thermal stability, which helps to suppress the slip of defects such as high-temperature dislocations, stabilize the performance of the aluminum alloy material, and improve its strength. Meanwhile, the appearance of the Fe₄Al₁₃ phase also indicates that the Ni/Fe ratio in the aluminum alloy material is low, which further shows that the addition amount of nickel is small and the content of iron element is high. This is beneficial to reducing the cost. Therefore, through the coordination of the NiAl₃ phase, the FeNiAl₉ phase and the Fe₄Al₁₃ phase, the obtained aluminum alloy material has the advantages of high strength, high conductivity and low cost simultaneously.

The eutectic phase NiAl₃ helps to improve the fluidity of the aluminum alloy material, making it easier to cast. The content of NiAl₃ is positively correlated with the addition amount of Ni. An increase in the content of NiAl₃ implies an increase in the content of Ni, which means higher costs. A high content of the primary solidification phases FeNiAl₉ and Fe₄Al₁₃ can effectively inhibit the dissolution loss of Fe in the mold. Moreover, an increase in the content of FeNiAl₉ and Fe₄Al₁₃ indicates an increase in the content of Fe, which allows the aluminum alloy provided by this disclosure to use waste aluminum with a high iron content as the raw material. This helps to reduce the cost. Moreover, the good thermal stability of FeNiAl₉ and Fe₄Al₁₃ helps to inhibit the slip of defects such as high-temperature dislocations, stabilizing the material's performance. Therefore, FeNiAl₉ and Fe₄Al₁₃ help to enhance the strength of the aluminum alloy material, but excessive content thereof can fracture the matrix and reduce the material's elongation. Refining the α-Al grains helps to improve the material's strength and elongation.

This disclosure can further optimize the electrical conductivity and strength of the aluminum alloy material while reducing costs by reasonably regulating the contents of the eutectic phase NiAl₃, the primary solidification phases FeNiAl₉ and Fe₄Al₁₃, and refining the size of α-Al grains.

Through research, this disclosure has found that under the Ni/Fe ratio conditions of this disclosure, in addition to the NiAl₃ and FeNiAl₉ phases, the Fe₄Al₁₃ phase is also formed. The Fe₄Al₁₃ phase has good thermal stability, which helps to inhibit the slip of defects such as high-temperature dislocations, stabilizing the performance of the aluminum alloy material and enhancing its strength.

On one hand, this disclosure reduces the content of Ni and increases the content of Fe to lower the Ni/Fe ratio, and regulates the contents of the eutectic phase NiAl₃, the primary solidification phases FeNiAl₉ and Fe₄Al₁₃. On the other hand, the grain is regulated to refine elements (Ti, V, Nb, Zr, and B) and refine the size of α-Al grains. This allows the disclosure to further optimize the electrical conductivity and strength of the aluminum alloy material while reducing costs.

In this disclosure, Ti, V, Nb, Zr, and B are elements having refined grain, which help to improve the cleanliness of the melt, reduce the hydrogen absorption tendency, improve the fluidity, and refine α-Al grains, ultimately enhancing the material's strength and elongation. By controlling the total content of Ti, Nb, V, and Zr to be greater than or equal to 0.02%, and the ratio of the mass of B to the total mass of Ti, Nb, V, and Zr to be less than or equal to 2, it helps to fully refine α-Al grains and improve the performance of the aluminum alloy material. However, if the mass percentage of Ti is greater than 0.1%, or the mass percentage of Nb is greater than 0.1%, or the mass percentage of V is greater than 0.1%, or the mass percentage of Zr is greater than 0.1%, or the mass percentage of B is greater than 0.05%, or the total mass percentage of Ti, Nb, V, and Zr is greater than 0.15%, or the ratio of the mass of B to the total mass of Ti, Nb, V, and Zr is greater than 2, it is easy to induce the formation of secondary phases containing Ti, Nb, V, Zr, and/or B, which can reduce the strength and electrical conductivity of the material. Therefore, in this disclosure, the contents of Ti, V, Nb, Zr, and B preferably meet the contents or ratio requirements described in this disclosure, and preferably simultaneously meets the requirements of the total mass percentage of Ti, Nb, V, and Zr being 0.02% to 0.15%, the mass percentage of Ti being less than or equal to 0.1%, the mass percentage of Nb being less than or equal to 0.1%, the mass percentage of V being less than or equal to 0.1%, the mass percentage of Zr being less than or equal to 0.1%, the mass percentage of B being less than or equal to 0.05%, and the ratio of the mass of B to the total mass of Ti, Nb, V, and Zr being less than or equal to 2.

It should be noted that Mn, Cr, and Si are impurities in this disclosure, and the lower their contents are, the better. However, these elements are often inevitably contained in existing aluminum materials. If the mass percentage of Mn is greater than 0.1%, or the mass percentage of Cr is greater than 0.05%, or the mass percentage of Si is greater than 0.1%, or the total mass percentage of Mn, Cr, and Si is greater than 0.25%, or the ratio of the total mass of Mn and Cr to the mass of Si is greater than 0.5, it is easy to form secondary phases other than the eutectic phase NiAl₃, the primary solidification phases FeNiAl₉ and Fe₄Al₁₃, which can affect the electrical conductivity, strength, and other properties of the aluminum alloy material. Therefore, in this disclosure, when the aluminum alloy material contains Mn, Cr, and Si, their contents must meet the contents or ratio requirements described in this disclosure, and preferably simultaneously meet the requirements of the total mass percentage of Mn, Cr, and Si being less than or equal to 0.25%, the mass percentage of Mn being less than or equal to 0.1%, the mass percentage of Cr being less than or equal to 0.05%, the mass percentage of Si being less than or equal to 0.1%, and the ratio of the total mass of Mn and Cr to the mass of Si being less than or equal to 0.5.

Since the aluminum alloy material provided by this disclosure has a relatively high content of iron, the raw materials of each element, especially the aluminum material, can either be electrolytic aluminum with a low iron content or waste aluminum with a high iron content. Moreover, the aluminum alloy material prepared using the latter as the raw material not only has a lower cost, but also maintains or even exceeds the performance of that prepared using the former.

Through the coordination of the NiAl₃ phase, the FeNiAl₉ phase and the Fe₄Al₁₃ phase, the aluminum alloy material obtained in the disclosure has the advantages of high strength, high electrical conductivity and low cost simultaneously.

Additionally, the aluminum alloy material obtained through further optimization has an electrical conductivity that is greater than or equal to 48% IACS, a yield strength thereof at room temperature is greater than or equal to 75 MPa, a tensile strength thereof at room temperature is greater than or equal to 160 MPa, an elongation thereof at room temperature is greater than or equal to 10%, and an attenuation rate of the yield strength after being kept at 180° C. for 100 hours is less than or equal to 10%. Moreover, the aluminum alloy material has the advantages of high strength, good electrical conductivity and low cost simultaneously, and also has good fluidity. It can be prepared by means of low-pressure, differential-pressure, squeeze, or high-pressure casting methods, and is suitable for manufacturing automotive parts such as motor rotors, wires, and inverters.

The above description is merely a specific implementation of this disclosure, enabling those skilled in the art to understand or implement the disclosure. Various modifications to these examples will be apparent to those skilled in the art, and the general principles defined herein can be realized in other examples without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not limited to the specific examples described herein but should conform to the broadest scope consistent with the principles and novel features disclosed herein.