Accession Number:

ADA270101

Title:

Characterization of Vapor Plume Species and Deposition Residues Resulting from Pulsed Laser Ablation of a Graphite/Epoxy Composite

Descriptive Note:

Final rept. Jun 1992-Jan 1993

Corporate Author:

PHILLIPS LAB KIRTLAND AFB NM

Report Date:

1993-08-01

Pagination or Media Count:

28.0

Abstract:

A modified time-of-flight mass spectrometer TOFMS fitted with a special collection stage for carbon-coated transmission electron microscope specimen grids is used to monitor laser-pulse ablation products from graphite epoxy composite targets. Scanning electron microscopy observations show ablation damage to consist of matrix pyrolysis, fiber fracture, and spallation of fragments which include elemental hydrogen, carbon epoxide, and acetylene groups. Transmission electron microscope examination of specimen grids showed a variety of crystals and polycrystalline hexagonal graphites having a wide range of shapes including spheres and faceted polyhedra and platelets, textured flake structures, and microrosettes. These observations lend some credibility to a model for laser-shock and pyrolysis effects which creates molecular plume fragments and deposition fragments of hexagonal graphite.... Graphiteepoxy composite, Laser ablation. Laser shock, Time-of-Flight Mass Spectrometry TOFMS , Vapor blow-off, Transmission Electron Microscopy TEM

Subject Categories:

  • Physical Chemistry
  • Lasers and Masers
  • Laminates and Composite Materials
  • Nuclear Physics and Elementary Particle Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE