Ablation mechanism study on metallic materials with a 10ps laser under high fluence

Laser Beam MicroMachining (LBMM) – A review

“…The model can predict the shape of crater for both single pulse as well as multi-pulse. The variation in ablation rate at high laser fluence in several metallic materials having wide variation in the values of electron coupling constant has been explained by Cheng et al [176]. Simulation was done using a predictive model based on critical-point phase separation (CPPS) theory.…”

Effects of laser operating parameters on metals micromachining with ultrafast lasers

“…For instance, ultrafast laser ablation of dielectrics is mainly attributed to Coulomb explosion [8], and Coulomb explosion may happen even for metals under ultra-intense laser irradiation during the laser pulse [9]. For metals, mechanisms such as phase explosion, critical point phase separation, spallation and fragmentation have been supported by both experimental observation and molecular dynamics simulation [7,[10][11][12][13][14]. While studies of ultrafast laser ablation mechanisms are essential, this work demonstrates that some key laser operating parameters, i.e., laser repetition rate, pulse overlap and number of overscan are also important for efficient, precision machining which is crucial for industrial transfer [15].…”

Laser Beam Machining, Laser Beam Hybrid Machining, and Micro-channels Applications and Fabrication Techniques

“…The ablation rate under these modes varies for different materials. To explain this variation, in a study of [32] the researchers employed single shot laser pulses of 10 picosecond having 1064 nm wavelength and fluence range of 2-25 J/cm 2 on aluminum, Ti6Al4V and gold. The mechanism behind this variation was reported as the electron heat capacity and electron-phonon coupling time.…”