Efficiency of laser ablation is a very important parameter in engraving. In our case it is defined as the ratio between the energy that is theoretically needed for vaporizing a volume of material and the energy of the light radiated by the excitation laser. We used a nanosecond (12-240 ns) Yb fiber laser with a wavelength of 1060 nm. The used materials in our experiment were stainless steel and aluminium. With the use of different parameter combinations like frequency, pulse shape, peak and average power we obtained different material ablation depths. From the acquired data we calculated and analyzed the laser ablation efficiency of the engraving process. We then examined out how the efficiency changes with different conditions and focused on the optimum parameters, that give us the best results. The efficiency we then further increased with optimization of additional parameters, such as scanning speed, number of scans, spacing of scanning lines and scanning strategies.
|
