Cast aluminum alloy and preparation method thereof, motor rotor and automobile

The invention provides a cast aluminum alloy and a preparation method thereof, a motor rotor and an automobile, and belongs to the technical field of cast aluminum alloys. The cast aluminum alloy is prepared from the following components in percentage by weight: 0.5 to 2 percent of Fe, 0.1 to 1 percent of Ni, 0.1 to 0.5 percent of Mg and the balance of Al and inevitable impurities, wherein the total mass of the cast aluminum alloy is 100 percent. The cast aluminum alloy has excellent conductivity and good yield strength and tensile strength, and the production cost is relatively low. 本发明提供了一种铸造铝合金及其制备方法、电机转子和汽车，属于铸造铝合金技术领域。以所述铸造铝合金的总质量为100wt.％计，所述铸造铝合金包括以下组分：Fe 0.5-2wt.％，Ni 0.1-1wt.％，Mg 0.1-0.5wt.％，余量为Al和不可避免的杂质。所述铸造铝合金兼具优异的电导率和良好的屈服强度、抗拉强度，且生产成本也相对较低。