Polishing: Removes surface imperfections and improves finish by mechanical or chemical methods, often used for components such as surgical instruments and implants that require a smooth surface.

Coating: A protective metal or non-metal coating is formed on the surface of parts by electroplating or chemical coating to improve corrosion resistance, wear resistance and biocompatibility.

Oxidation: Expose the metal surface to an oxidant to form an oxide film, which increases the corrosion resistance and hardness of the material. It is commonly used in the surface treatment of titanium alloys and aluminum alloys.

Sand blasting: spray particles at high speed to make tiny dents on the surface, increase surface roughness and adhesion, and are often used to increase coating adhesion and enhance appearance.