Black sandblasted anodize is a surface treatment process that combines the texturing effect of sandblasting with the protective and decorative benefits of anodizing, resulting in a durable, matte black finish on aluminum parts. Sandblasting roughens the surface, while anodizing creates a porous aluminum oxide layer that can be dyed black, enhancing both aesthetics and corrosion resistance. This process is favored for its ability to mask imperfections, provide a tactile feel, and offer a uniform, visually appealing finish. 

Sandblasting:

Involves propelling abrasive material (like sand) at high pressure against the aluminum surface to create a textured, matte appearance. 

This roughened surface improves adhesion for subsequent anodizing and dyeing. 

Can mask extrusion defects like bands, rifling, and flames, reducing scrap during manufacturing according to NECE Anodizzazione. 

Anodizing:

A process where the aluminum part is immersed in an electrolytic solution and an electric current is passed through it. 

This forms a durable, protective oxide layer on the surface. 

The oxide layer is porous, allowing for the absorption of dye. 

Black Dyeing:

The anodized aluminum is then immersed in a black dye solution (organic, inorganic, or electrolytic).

The dye penetrates the pores of the oxide layer, imparting a black color. 

Benefits:

Aesthetics: Provides a uniform, matte black finish, enhancing the appearance of the product. 

Corrosion Resistance: Anodizing significantly improves the aluminum's resistance to corrosion. 

Wear Resistance: The anodized layer is hard and wear-resistant, making it suitable for mechanical parts. 

Adhesion: The textured surface from sandblasting enhances the adhesion of coatings or adhesives. 

Masking: Hides surface imperfections from the extrusion process. 

Applications:

Aerospace components, Building components, Consumer goods, Mechanical parts, Signage, Architectural embellishments, and Automotive parts.