화학공학소재연구정보센터
Journal of Materials Science, Vol.53, No.5, 3836-3845, 2018
Effect of topology and material properties on the imprint quality of the femtosecond-laser-induced surface structures
Femtosecond laser surface processing (FLSP) is a technique that can be used to modify surfaces imparting many desirable properties, such as an improved wettability, heat transfer, and drag reduction. The morphology of the FLSP surface along with surface chemistry is critical factors that strongly influences the wetting behavior of surfaces produced. Reproducing the FLSP original surface over a large area in an economic manner is a challenge. In this paper, imprinting the FLSP surface on oxygen-free copper is investigated. Based on the topology of an FLSP titanium surface, a model has been established to investigate the topology of the mounds, which is defined by the roughness and period between the self-organized structures. This topology affects the imprint quality indicated by the plastic deformation in the blank and is defined as the target material specimen. Both oxygen-free copper and stainless steel 304 were used as blank target material in this study and represent both soft and hard material specimens. The stress-displacement relationship was used to determine the sensitivity of imprint parameters. The imprint model was verified by comparing an equivalent imprint model with nanoindentation experimental results. The model results showed that the die's morphology, in particular the die roughness-to-period ratio (referring to the peak-to-valley height and the peak-to-peak distance), had greater influence than the blank material itself.