Investigation of the Effect of Anodizing Dyes Using Purple Cabbage and Dragon Fruit Peel on Aluminum 6061 alloy

Abstract

Anodizing on aluminum 6061 was carried out to improve the mechanical properties and aesthetic value of the specimen surface. Anodizing produces a thin, porous oxide layer resulting in hard surface properties and corrosion resistance. The pores resulting from the anodizing process can be used to provide various colors when filled with dyes. Coloring in the anodizing process can be done with chemical dyes or natural dyes. Anodizing using chemical solutions produces waste that can be harmful to the environment. To overcome this pollution problem, a natural dye solution is used using dyes from purple cabbage and dragon fruit peel so that it is expected to minimize the impact of environmental pollution. The purpose of this study was to investigate the effect of using natural dyes produced from purple cabbage and dragon fruit peel on anodizing aluminum 6061. The investigation is carried out through visual color testing, coating thickness testing, micro-structure testing, and micro Vickers hardness testing. From these results, it was found that the variation in the concentration of the dye solution did not affect the thickness of the resulting oxide layer. The oxide layer and pore size are influenced by temperature, electric current, voltage, solution concentration, and immersion time in the electrolyte solution during the anodizing process. So the factors that greatly influence the diffusion quality of the dye solution are the correct pore size and thickness of the oxide layer so that the dye can adhere perfectly to the surface of the specimen.