Fast LIBS Identification of Aluminum Alloys

• Published in: Progress in physics (Rehoboth, N.M.) N.M.), 2007-04, Vol.2, p.87-92
• Main Author: Mohamed, Walid Tawfik Y
• Format: Article
• Language: English
• Subjects: Alloys; Aluminum; Emissions; Silica; Trace elements
• ISSN: 1555-5534; 1555-5615; 1833-1742

Laser-induced breakdown spectroscopy (LIBS) has been applied to analysis aluminum alloy targets. The plasma is generated by focusing a 300 mJ pulsed Nd: YAG laser on the target in air at atmospheric pressure. Such plasma emission spectrum was collected using a one-meter length wide band fused-silica optical fiber connected to a portable Echelle spectrometer with intensified CCD camera. Spectroscopic analysis of plasma evolution of laser produced plasmas has been characterized in terms of their spectra, electron density and electron temperature assuming the LTE and optically thin plasma conditions. The LIBS spectrum was optimized for high S/N ratio especially for trace elements. The electron temperature and density were determined using the emission intensity and stark broadening, respectively, of selected aluminum spectral lines. The values of these parameters were found to change with the aluminum alloy matrix, i.e. they could be used as a fingerprint character to distinguish between different aluminum alloy matrices using only one major element (aluminum) without needing to analysis the rest of elements in the matrix. Moreover, It was found that the values of T^sub e^ and N^sub e^ decrease with increasing the trace elements concentrations in the aluminum alloy samples. The obtained results indicate that it is possible to improve the exploitation of LIBS in the remote on-line industrial monitoring application, by following up only the values of T^sub e^ and N^sub e^ for aluminum in aluminum alloys as a marker for the correct alloying using an optical fiber probe. [PUBLICATION ABSTRACT]