When selecting materials for gears in new energy vehicles, the following factors should be considered:

1. Strength and hardness: Gear materials need to have high strength and hardness to withstand high torque and high load transmission requirements, ensuring the wear resistance and service life of gears.

2. Fatigue resistance: Gears undergo periodic stress changes during high-speed rotation, so it is necessary for materials to have good fatigue resistance to prevent the occurrence of fatigue cracks.

3. Corrosion resistance: Gears may need to work in humid, salt spray, and other environments, so materials with good corrosion resistance are required to prevent corrosion damage.

4. Wear resistance: Gears will experience wear during meshing, so materials with good wear resistance are required to extend the service life of the gears.

5. Thermal conductivity: Gears generate heat during high-speed rotation, so materials with good thermal conductivity are needed to help dissipate heat and prevent overheating.

6. Machining performance: The manufacturing of gears requires precise machining processes, so materials with good machining performance, such as cutting performance, grinding performance, etc., are needed.

7. Cost: When selecting gear materials, cost factors also need to be considered to ensure that the product has market competitiveness.

8. Lightweight: In order to improve the energy efficiency and range of new energy vehicles, gear materials need to be as lightweight as possible to reduce the total weight of the vehicle.

9. Environmental friendliness: With the increasing demand for environmental protection, the selection of gear materials also needs to consider their environmental friendliness, such as reducing the emission of harmful substances.

10. Recyclability: In order to reduce the impact on the environment, choosing gear materials with good recyclability is also an important consideration factor.

By considering the above factors comprehensively, materials suitable for new energy vehicle gears can be selected to ensure their performance, reliability, and economy. With the continuous development of materials science and manufacturing technology, the material selection for new energy vehicle gears is also constantly advancing.