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신동식(D. S. Shin),이제훈(J. H. Lee),서정(J. Suh),노지환(J. H. Noh),정용운(Y. W. Chung),김재구(J. G. Kim) 한국정밀공학회 2006 한국정밀공학회 학술발표대회 논문집 Vol.2006 No.5월
In case of ultrashort laser ablation of metals, the transfer of energy from the electronic system causing strong absorption of laser light to the lattice needs relaxation times of the order of some picoseconds. Under the above theoretical background, nickel was ablated using femtosecond, picosecond and nanosecond laser. As a result, nickel ablation by picosecond laser and femtosecond laser, which are called ultrashort laser, has similar machinability because of relaxation time of metals, whereas nanosecond Nd:YAG laser has lower absorption, higher thermalization effect in comparison with ultrashort laser.
신동식(D. S. Shin),이제훈(J. H. Lee),서정(J. Suh),노지환(J. W. Noh),정용운(Y. W. Chung),김재구(J. G. Kim) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6
In contrast to dielectric materials, metals are characterized by a high density of quasi-free electrons causing strong absorption of laser light from the beginning of the ultrashort laser pulse without the need of nonlinear absorption effects like multiphoton absorption. The transfer of energy from the electronic system causing strong absorption of laser light to the lattice needs relaxation times of the order of some picoseconds. Under the above theoretical background, nickel was chiefly ablated using femtosecond, picosecond and nanosecond laser. As a result, nickel ablation by picosecond laser and femtosecond laser, which are called ultrashort laser, has similar machinability because of relaxation time of metals, whereas nanosecond Nd:YAG laser has lower absorption, higher thermalization effect in comparison with ultrashort laser.