Effect of Coatings on the Mechanical Properties and Fatigue Life of 6061 Aluminum Alloys

• Published in: Transactions of the Indian Institute of Metals Vol. 74; no. 9; pp. 2135 - 2147
• Main Authors: Chanyathunyaroj, Kittisak, Samit, Witthaya, Poonthananiwatkul, Chaweewan, Phetchcrai, Sompob
• Format: Journal Article
• Language: English
• Published: New Delhi Springer India 01.09.2021; Springer Nature B.V
• Subjects: Alloys; Aluminum alloys; Aluminum base alloys; Anodizing; Chemistry and Materials Science; Coated electrodes; Coating effects; Corrosion and Coatings; Crack initiation; Crack propagation; Electrodeposition; Elongation; Extrusion coating; Fatigue failure; Fatigue life; Fatigue limit; Fracture mechanics; Materials Science; Mechanical properties; Metal fatigue; Metallic Materials; Nucleation; Original Article; Pickling; Powder coating; Tensile strength; Tribology; Fatigue life; Electrodeposition; 6061 aluminum alloy; Anodization; Powder
• ISSN: 0972-2815; 0975-1645
• DOI: 10.1007/s12666-021-02296-5

This study investigated the effects of 3 coating processes, anodizing, electrodeposition, and powder, on the mechanical properties and fatigue life of 6061 aluminum alloys. The coatings were applied at an aluminum extrusion industrial company. All coatings were found to increase the tensile strength and elongation. The anodized coating, prepared via a pickling process, produced a surface vulnerable to pitting attack, which led to fatigue crack nucleation throughout the surface and decreased the fatigue life of the anodized specimens. The powder coating, with a thickness of 100 µm, slightly increased the tensile strength and elongation but did not change the fatigue life of the 6061 aluminum alloy. The electrodeposited coating after anodization recovered the fatigue life so that it was equivalent to that of an uncoated 6061 aluminum alloy. Although the specimens treated by electrodeposition inherited nucleation sites from the prior anodizing process, the electrodeposition increased the endurance limit of the anodized 6061 aluminum alloy from approximately 39% to 50% of the yield tensile strength.