ALUMINUM ALLOY FOR CASTING MOTOR ROTOR IN NEW ENERGY VEHICLE AND PREPARATION METHOD THEREFOR

Abstract

The present application belongs to the technical field of new energy vehicle motors, and discloses an aluminum alloy for casting a motor rotor in a new energy vehicle and a preparation method thereof. The aluminum alloy includes 0.05 wt %-0.06 wt % titanium, 0.04 wt %-0.06 wt % boron, 0.15 wt %-0.5 wt % silicon, 0.01 wt %-0.08 wt % iron, 0.5 wt %-0.7 wt % copper, 0.3 wt %-0.5 wt % magnesium, 0.01 wt %-0.2 wt % zinc, 0.02 wt %-0.12 wt % manganese, and the balance of aluminum. By adding new elements and adjusting the ratio of the elements, the strength of the cast aluminum alloy is enhanced, and meanwhile, the excellent electricity conductivity can also be kept.

Claims

1. An aluminum alloy for casting a motor rotor in a new energy vehicle, comprising 0.05 wt %-0.06 wt % titanium, 0.04 wt %-0.06 wt % boron, 0.15 wt %-0.5 wt % silicon, 0.01 wt %-0.08 wt % iron, 0.5 wt %-0.7 wt % copper, 0.3 wt %-0.5 wt % magnesium, 0.01 wt %-0.2 wt % zinc, 0.02 wt %-0.12 wt % manganese, and the balance of aluminum.

2. The aluminum alloy for casting the motor rotor according to claim 1, wherein tensile strength of the aluminum alloy is in a range from 80 MPa to 95 Mpa.

3. The aluminum alloy for casting the motor rotor according to claim 2, wherein tensile strength of the aluminum alloy is in a range from 85 MPa to 95 Mpa.

4. The aluminum alloy for casting the motor rotor according to claim 1, wherein yield strength of the aluminum alloy is in a range from 60 MPa to 80 Mpa.

5. The aluminum alloy for casting the motor rotor according to claim 1, wherein elongation of the aluminum alloy is in a range from 45% to 55%.

6. The aluminum alloy for casting the motor rotor according to claim 1, wherein electricity conductivity of the aluminum alloy is in a range from 30 MS/m to 33 MS/m.

7. The aluminum alloy for casting the motor rotor according to claim 1, composed of 0.05 wt %-0.06 wt % titanium, 0.04 wt %-0.06 wt % boron, 0.15 wt %-0.5 wt % silicon, 0.01 wt %-0.08 wt % iron, 0.5 wt %-0.7 wt % copper, 0.3 wt %-0.5 wt % magnesium, 0.01 wt %-0.2 wt % zinc, 0.02 wt %-0.12 wt % manganese, and the balance of aluminum.

8. The aluminum alloy for casting the motor rotor according to claim 7, wherein the aluminum is high purity aluminum, and the high purity aluminum is pure aluminum with purity greater than 99.8%.

9. A preparation method of an aluminum alloy for casting a motor rotor, wherein the method uses each elemental constituent in claim 1 and comprises the following steps: (1) melting an aluminum ingot, adding each elemental constituent, and performing even stirring; and (2) preheating a rotor cavity, and performing centrifugal casting to prepare the aluminum alloy for casting the motor rotor.

10. The preparation method according to claim 9, wherein a temperature in step (1) is in a range from 700 C. to 760 C., and a preheating temperature in step (2) is in a range from 680 C. to 720 C.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The present application is detailed below in conjunction with embodiments, but the present application is not limited to these embodiments.

[0022] Unless otherwise specified, raw materials in embodiments of the present application are purchased commercially, a preparation method adopts existing centrifugal casting and melting processes, and other undisclosed parameters such as a stirring rate are parameters used in the prior art.

Embodiment 1: Preparation of Aluminum Alloy 1 #

[0023] The composition of an aluminum alloy 1 # is: 0.05 wt % titanium, 0.05 wt % boron, 0.2 wt % silicon, 0.05 wt % iron, 0.6 wt % copper, 0.4 wt % magnesium, 0.1 wt % zinc, 0.08 wt % manganese, and the balance of high purity aluminum, and the high purity aluminum is pure aluminum with purity greater than 99.8%.

[0024] A preparation method is: (1) an aluminum ingot is melted at 720 C., each elemental constituent is added, and even stirring is performed; and (2) a rotor cavity is preheated to 700 C., and a conventional centrifugal casting process is adopted to prepare the aluminum alloy 1 # for casting a motor rotor.

Embodiment 2: Preparation of Aluminum Alloy 2 #

[0025] The composition of an aluminum alloy 2 # is: 0.05 wt % titanium, 0.04 wt % boron, 0.15 wt % silicon, 0.01 wt % iron, 0.5 wt % copper, 0.3 wt % magnesium, 0.05 wt % zinc, 0.02 wt % manganese, and the balance of high purity aluminum, and the high purity aluminum is pure aluminum with purity greater than 99.8%.

[0026] A preparation method is: (1) an aluminum ingot is melted at 700 C., each elemental constituent is added, and even stirring is performed; and (2) a rotor cavity is preheated to 680 C., and a conventional centrifugal casting process is adopted to prepare the aluminum alloy 2 # for casting the motor rotor.

Embodiment 3: Preparation of Aluminum Alloy 3 #

[0027] The composition of an aluminum alloy 3 # is: 0.06 wt % titanium, 0.06 wt % boron, 0.5 wt % silicon, 0.08 wt % iron, 0.7 wt % copper, 0.5 wt % magnesium, 0.2 wt % zinc, 0.12 wt % manganese, and the balance of high purity aluminum, and the high purity aluminum is pure aluminum with purity greater than 99.8%.

[0028] A preparation method is as follows: (1) an aluminum ingot is melted at 760 C., and each elemental constituent is added, and even stirring is performed; and (2) a rotor cavity is preheated to 720 C., and a conventional centrifugal casting process is adopted to prepare the aluminum alloy 3 # for casting the motor rotor.

Comparative Examples 1-6: Preparation of Aluminum Alloys 4 #-9 #

[0029] Preparation methods of aluminum alloys 4 #-9 # are the same as the preparation method of the aluminum alloy 1 #, and composition differences are shown in Table 1.

TABLE-US-00001 TABLE 1 Elementary composition (mass fraction wt %) of aluminum alloys 1#-9# Serial Elements Number Titanium Boron Silicon Iron Copper Magnesium Zinc Manganese Aluminum 1# 0.05 0.05 0.2 0.05 0.6 0.4 0.1 0.08 The 2# 0.05 0.04 0.15 0.01 0.5 0.3 0.05 0.02 balance 3# 0.06 0.06 0.5 0.08 0.7 0.5 0.2 0.12 is high 4# 0.01 0.01 0.06 0.1 0.005 0.004 0.005 0 purity 5# 0.05 0.05 0.2 0.05 0.6 0.4 0.1 0.01 aluminum 6# 0.05 0.05 0.2 0.05 0.6 0.4 0.1 0.15 7# 0.05 0.05 0.2 0.1 0.6 0.4 0.1 0.08 8# 0.05 0.05 0.2 0.05 0.6 0.1 0.1 0.08 9# 0.05 0.05 0.2 0.05 0.2 0.4 0.1 0.08

Embodiment 4: Property Characterization of Aluminum Alloys 1 #-9 #

[0030] Aluminum alloys 1 #-9 # for casting the motor rotor are sampled respectively on their respective end faces, an electricity conductivity sample size meets the requirements of GB/T12966-2008, and an electricity conductivity test is carried out. A mechanical property test sample size meets ASTM E8, tensile property analysis is carried out, and mechanical property and electricity conductivity test results are shown in Table 2.

TABLE-US-00002 TABLE 2 Mechanical property and electricity conductivity test results of motor rotor aluminum alloys 1#-9# Project Tensile Yield Electricity strength strength Elongation conductivity Group (MPa) (MPa) (%) (MS/m) Aluminum alloy 1# 95 80 55 33 Aluminum alloy 2# 85 68 46 32.7 Aluminum alloy 3# 90 70 50 32.8 Aluminum alloy 4# 63 35 37 34 Aluminum alloy 5# 65 40 37 28 Aluminum alloy 6# 66 42 47 30 Aluminum alloy 7# 63 43 34 26 Aluminum alloy 8# 61 40 45 31 Aluminum alloy 9# 60 37 42 28

[0031] The results show that the aluminum alloys 1 #-3 # for casting the motor rotor prepared by using the elemental constituents defined by the present application have excellent tensile strength and yield strength, the maximum tensile strength can reach 95 MPa, the maximum yield strength can reach 80 MPa, the requirement that the latest manufacturer's tensile strength is 70 MPa and above is fully met, meanwhile, by adding a limited ratio of manganese element, the elongation is also significantly improved, the electricity conductivity can still meet the needs of 30 MS/m and above, the electricity conductivity is excellent, ratios of copper and magnesium elements are also limited, and the tensile strength, yield strength and elongation are significantly improved finally by scarifying a small amount of electricity conductivity, which meets the higher need for strength of the manufacturer, and may also ensure the excellent electricity conductivity of the aluminum alloy.

[0032] The aluminum alloy 4 # is a formula in the prior art, and significantly differs from element types and ratios of the present application, the final results show that although the electricity conductivity of the aluminum alloy 4 # is excellent, the strength and other mechanical properties cannot meet the latest needs, and the tensile strength and the yield strength are both low. The content of manganese in the aluminum alloy 5 # is lower than the range limited by the present application, the final properties are far lower than those of the aluminum alloy 1 #, and it is specifically analyzed that the amount of manganese is too little and cannot eliminate the harmful effect of iron; and the content of manganese in the aluminum alloy 6 # is higher than the range limited by the present application, the final elongation and electricity conductivity are good, but the strength is not enough, it is analyzed that the amount of manganese is more, and more coarse brittle phases (Mn,Fe)Al.sub.6 are generated, which ultimately affects the strength.

[0033] The content of iron in the aluminum alloy 7 # exceeds the range limited by the present application, which ultimately indicates that its electricity conductivity is low, and the strength and other parameters are not up to standard; the content of magnesium in the aluminum alloy 8 # is lower than the range limited by the present application, which ultimately indicates that its strength is not enough, and far lower than that of the aluminum alloy 1 #; and the content of copper in the aluminum alloy 9 # is lower than the range limited by the present application, which ultimately indicates that its parameters are not as good as those of the aluminum alloy 1 #, and it is analyzed that the copper content cannot generate more precipitation strengthening phases.

[0034] The above are only embodiments of the present application, and the scope of protection of the present application is not limited by these specific embodiments, but is determined by the claims of the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the technical ideas and principles of the present application shall be included in the scope of protection of the present application.