Alternative black coatings prepared on aluminium alloy 1050

Abstract

The present study investigated the preparation and characterisation of alternative black anodic films on aluminium alloy 1050 using three different inorganic colouring processes. The colouring process was performed via the standard chemical reaction and two alternative mechanisms, i.e. electrochemical reaction or a combination of electrochemical and chemical reactions. Black anodic films with high thermo-optical properties (αs ≥ 0.90 and εn ≥ 0.90) were successfully obtained using all three processes. Differences in chemical content and location of the Co-based pigments in the coatings were highlighted and explained according to the colouring reaction mechanisms.