Surface morphology and fracture strength analysis of nanosecond ablated alumina

Although the research on laser ablation advances steadily, mainly on ultra-short pulses (in the order of pico- and femtoseconds), research on the low-cost and low-power-consuming nanosecond regime (>100 ns) is relatively scarce. This process is still difficult to predict, due to the many simultaneous and interacting physical processes that take place in a relatively short time. This study provides an experimental analysis for a ytterbium pulsed fibre-laser on Al2O3, by evaluating surface morphology and fracture strength for two sets of parameters. A very well-defined difference in removal rate and resulting surface topographies was observed, suggesting a threshold point between distinct ablation mechanisms. Laser machining also caused a clear increase on the Weibull modulus, while reducing the characteristic stress. (C) 2015 The Ceramic Society of Japan. All rights reserved.