High precision feature detection in laser texturing

The present work seeks to develop a novel and systematic approach to quantifying the repeatability of textured surfaces, a relevant property for several technological fields. Specifically, aluminum alloy and stainless steel specimens were subject to nanosecond pulsed laser texturing to produce arrays of ablation craters in a typical configuration employed to improve wettability and tribological performance. Feature repeatability was firstly assessed in terms of crater volume and interfacial area, after which an additional parameter was developed based on the Pearson's Correlation Coefficient (PCC). Within the tested laser parameter range, the crater volume exhibited highest repeatability in the high energy dose regime on aluminum alloy specimens, while the crater volume was more repeatable in the low energy dose regime on stainless steel specimens. This difference was attributed to the development of an oxide ring surrounding the craters on stainless steel at high energy dose. This outcome was confirmed through analysis of the point-to-point repeatability, where process repeatability was determined for different portions of the ablation craters.