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The material selection for new energy vehicle gears should meet the requirements of high bending fatigue strength, high contact fatigue strength, high hardness, wear resistance, as well as good core strength and toughness, while also considering processing performance and economy. The specific details are as follows:

High bending fatigue strength and contact fatigue strength: New energy vehicle gears undergo significant alternating bending stress during operation, and are subjected to certain impact loads during shifting, starting, or uneven meshing. Therefore, materials need to have high bending fatigue strength and contact fatigue strength to prevent gear teeth from breaking due to fatigue.

High hardness and wear resistance: When the gear rotates, the tooth surface will bear significant contact pressure stress, as well as friction and wear. Therefore, the material needs to have sufficient hardness and wear resistance to avoid damage to the tooth surface.

Good core strength and toughness: During the operation of gears, the root of the teeth is subjected to significant alternating bending forces due to the transmission of torque. Therefore, the core of the material needs to have sufficient strength and toughness to prevent tooth fracture.

Good machining process performance: Gear materials should have good cutting and heat treatment properties to ensure that the gears meet design requirements during the machining process, reducing machining difficulty and costs.

Economy: On the premise of meeting the performance requirements, the total cost of parts should be minimized as much as possible. Therefore, when selecting materials, factors such as material price, processing cost, and service life need to be considered.