Influence of surface pre-treatments on the high-cycle fatigue behavior of Ti-6Al-4V - From anodizing to laser-assisted techniques

In the aerospace industry, adhesive bonding of materials is the key to advanced light-weight design. Therefore, new surface preparation methods such as anodizing and laser pre-treatment are intensely studied. Surface preparation has an impact on the resulting mechanical properties of the bonded metallic components. In order to shed light on the process-property-failure relationships, the effects of different surface treatments on the high-cycle fatigue behavior of titanium specimens were investigated. The results of the current work reveal that mainly three aspects have to be considered: defects being present in the treated surfaces and residual stresses as well as grain refinement in case of laser-treatment. Clearly, surface treatment parameters have to account for both bond durability and fatigue properties. Laser treatment using medium energy density and TiO2-Nanotube anodizing showed best overall performance.