On mechanism of explosive boiling in nanosecond regime


ÇELEN S.

APPLIED PHYSICS B-LASERS AND OPTICS, cilt.122, 2016 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 122 Konu: 6
  • Basım Tarihi: 2016
  • Doi Numarası: 10.1007/s00340-016-6444-6
  • Dergi Adı: APPLIED PHYSICS B-LASERS AND OPTICS

Özet

Today laser-based machining is used to manufacture vital parts for biomedical, aviation and aerospace industries. The aim of the paper is to report theoretical, numerical and experimental investigations of explosive boiling under nanosecond pulsed ytterbium fiber laser irradiation. Experiments were performed in an effective peak power density range between 1397 and 1450 MW/cm(2) on pure titanium specimens. The threshold laser fluence for phase explosion, the pressure and temperature at the target surface and the velocity of the expulsed material were reported. A narrow transition zone was realized between the normal vaporization and phase explosion fields. The proof of heterogeneous boiling was given with detailed micrographs. A novel thermal model was proposed for laser-induced splashing at high fluences. Packaging factor and scattering arc radius terms were proposed to state the level of the melt ejection process. Results of the present investigation explain the explosive boiling during highpower laser interaction with metal.