Analysis of melt ejection during long pulsed laser drilling
Zhang Ting-Zhong1, Jia Zhi-Chao1, Cui Hai-Chao2, Zhu De-Hua3, Ni Xiao-Wu1, Lu Jian1, †, 
Shadowgraphs and emitted light images for material removal (vapour jet and melt ejection) at moments of 235 μs ((a), (e)), 470 μs ((b), (f)), 704 μs ((c), (g)) and 939 μs ((d), (h)) for 304 SS ((a)–(d)) and aluminum ((e)–(f)) under a laser power density of 5.71 MW/cm2 irradiation and laser pulse width of 1 ms. The red arrows indicate the melt ejection.
