Investigation on efficiency and quality for ultrashort pulsed laser ablation of nickel-based single crystal alloy DD6

The high processing efficiency and quality are constant pursuits for modern manufacturing industry. This paper investigated the ablation efficiency and quality of ultrashort pulsed laser ablation of DD6 single crystal alloy based on experiments and theoretical analysis. The experimental results showed that the ablation rate increases with the increase of laser fluence and with the decrease of scanning speed and scanning width, while the ablation efficiency decreases with the increase of laser fluence. A relatively flat and low melted zone ablation surface could be obtained by employing a low laser fluence and high scanning speed. The influence of laser parameters on the ablation diameter, equivalent energy density, and heat accumulation effect was analyzed based on the theory of laser ablation and heat conduction. The theoretical analysis revealed the material removal transforms from plasma or vaporization removal to melt ejection with the pulse energy increases and the scanning speed decreases, which can explain the formation mechanism of surface morphology very well. In addition, the scanning strategy of high efficiency and quality was proposed based on the theoretical analysis and experimental results.