The ball mill plays a vital role in powder preparation, and its main functions include:

　　Grinding and mixing: The ball mill grinds and mixes the raw materials by high-speed friction and collision of the grinding balls in the rotating cylinder. This helps to crush the raw materials into the required particle size and ensure that the various components are evenly mixed to obtain high-quality powders.

　　Powder refinement: The ball mill can crush and refine the raw materials to achieve the required fineness and uniformity. By adjusting the operating parameters of the ball mill, such as ball milling time, ball-to-material ratio, speed, etc., the particle size and particle size of the powder can be controlled to meet the requirements of different application scenarios.

　　Surface activation: The ball mill can introduce certain surface defects and dislocations through high-speed grinding and collision of the raw materials, thereby increasing the surface activity of the raw materials. This helps to improve the reactivity and adsorption of the raw materials and promote subsequent chemical reactions and physical processes.

　　Preparation of composite materials: The ball mill can be used to prepare powders of various composite materials, such as metal-based composite materials, ceramic-based composite materials, etc. By putting raw material powders of different components into a ball mill for mixing and grinding, the uniform dispersion and mixing of composite materials can be achieved, providing a basis for subsequent molding and processing.

　　In general, ball mills play a key role in powder preparation. Through grinding, mixing, and refinement, they can process and handle raw materials, providing important technical support for the preparation and application of new materials.