Iron powder, especially reduced iron powder, in friction materials is mainly to adjust friction performance, provide a stable friction coefficient, reduce braking noise, and increase the durability and wear resistance of the material. 

Here we list the advantage of iron powder in friction materials:

1. Adjusting friction performance: The addition of iron powder can make the friction coefficient of friction materials more stable, especially under high-speed friction conditions, iron powder can provide a more stable friction factor and reduce the fluctuation of friction factor caused by speed changes.

2. Reduce braking noise: The porous structure of iron powder helps to reduce the braking noise of friction materials during use and provide a quieter braking experience.

3. Increase durability: Iron powder is added to metal as a filler, which can provide additional durability and wear resistance, help transfer heat, and extend the service life of friction materials.

In summary, the application of iron powder in friction materials can not only improve the overall performance of the material, but also improve the use experience, so it is widely used in friction materials such as brake pads and brake drums.