NEWS

I. Surface treatment determines a product's "visual appeal" and "lifespan."

Aluminum alloys are easy to machine and offer a wide range of surface treatment options, making them widely used in sectors such as consumer electronics and automotive manufacturing.

Aluminum alloy workpieces fresh off the CNC machine often retain tool marks, burrs, and minor scratches. Grinding, polishing, and brushing—three essential surface preparation processes—are the key steps to resolving these issues. II. Grinding—The foundational step for removing burrs and leveling the surface.

Grinding is the first surface treatment step following CNC machining. Its primary functions are to: remove burrs and flash left by cutting; eliminate tool marks and localized surface irregularities; and provide a smooth, level base for subsequent polishing or brushing. Grinding is categorized into coarse grinding (for rapid material removal) and fine grinding (to eliminate coarse marks); common tools include belt sanders and grinding heads.

Polishing—An Advanced Process for Transforming Matte Finishes into Mirror-Like Surfaces

Polishing reduces surface roughness through mechanical friction or chemical methods to achieve a smooth, glossy finish. It is primarily categorized into three types: mechanical polishing (using polishing wheels and abrasives, suitable for most aluminum parts), chemical polishing (dissolving the surface layer with chemical agents to achieve uniform luster), and electropolishing (an electrochemical process yielding a finish approaching that of a stainless steel mirror). Polished aluminum parts can achieve surface roughness values ​​as low as Ra < 0.1 μm, making them suitable for applications such as medical devices, optical instruments, and high-end digital device casings.

Brushed Finish—A Decorative Process Creating Fine Metal Texture

Brushing is a manufacturing process in which lines are repeatedly abraded onto the surface of an aluminum sheet using sandpaper. Common types include: straight-line brushing (parallel lines, offering a clean, streamlined look), random-pattern brushing (irregular textures with strong visual depth), and swirl brushing (circular patterns, ideal for round components). This finish effectively conceals minor scratches and creates a distinctive matte metallic texture that conveys both style and a high-tech aesthetic. It is commonly found on laptop casings, mobile phone panels, and home appliance control panels.

How do you choose between the three main processes?

For a smooth, burr-free finish → Grinding

For a glossy, mirror-like finish → Polishing

For a textured, linear finish → Brushed finish

For a comprehensive effect → A combination of grinding, polishing, brushing, and anodizing

VI. Conclusion

Grinding, polishing, and brushing each serve different purposes and are often used in combination during actual production. The choice of process depends on the product's functional positioning and aesthetic requirements.