Dependence of the Surface Morphology and Micromechanical and Sclerometric Properties of Al2O3 Layers on the Parameters of Anodizing Aluminum Alloy

Abstract

The article presents the dependence of the morphology as well as micromechanical and sclerometric properties of Al2O3 layers on the parameters of anodizing of aluminum alloys. The oxide layers were produced on the EN AW-5251 aluminum alloy by means of a direct current anodizing in a three-component electrolyte. The input variables (current density and electrolyte temperature) were selected based on the overall design of the experiment. The current density was 1, 2, 3 A/dm2, and the electrolyte temperature was 283, 293, 303 K. The surface morphology was examined using a scanning electron microscope (SEM), and then the microscopic images were analyzed using a graphics program. The micromechanical and sclerometric properties were examined by determining the HIT hardness and three critical loads: Lc1 (critical load at which the first damage of the tested layers occurred-Hertz tensile cracks inside the crack), Lc2 (critical load at which the first cohesive damage of the layers occurred) and Lc3 (load at which the layers were completely damaged). Sclerometric tests with the use of scratch tests were supplemented with pictures from a scanning microscope, showing the scratches. The produced layers are characterized by a hardness above 3 GPa and a porosity of 4.9–10.3%. Such a range of porosity of the produced layers allows their wide application, both for sliding associations with polymers and for their modification.

Study on the Influence of Surface Treatment Process on the Corrosion Resistance of Aluminum Alloy Profile Coating

“…In addition, comparative studies between different surface treatment processes are rarely seen. In this work, the corrosion resistance of powder coatings and anodized films on the surfaces of aluminum alloy building profiles was studied [20][21][22][23][24][25][26][27][28]. Through the coupling analysis of microscopic observation and electrochemical fitting, scanning electron microscopy (SEM) and electrochemical analysis were used to investigate the corrosion behavior and corrosion resistance of the sand texture film layer, the flat powder film layer, the hard anodized, and the ordinary anodized heat-sealed hole aluminum alloy profiles in weakly corrosive electrolytes.…”

Influence of Research Factors and Al2O3 Layer Production Parameters on Tribological and Microstructural Properties

“…Anodic Al 2 O 3 layers on aluminum and its alloys are often used for protection against wear and corrosion [17][18][19][20]. The optimal layer for sliding cooperation should ensure good adhesion to the substrate, appropriate hardness, and good tribological properties.…”