Identification of elements present in aluminum alloy beads
Goal:
Identify elements present in alloy beads using LIBS.
Method:
LIBS
Introduction:
Elemental analysis of alloy beads composed primarily of aluminum (80% Al) and iron (20% Fe) was carried out with LIBS to provide an elemental profile for the sample. Detection of contaminants present in the samples in addition to the major components was desired.
Hardware Used:
LIBS2000+ broadband, high-resolution spectrometer
50 mJ Big Sky Nd:YAG laser
LIBS sampling chamber with 125 mm focal length lens
Measurement Mode:
LIBS
Experimental Conditions:
The alloy beads were pressed onto a piece of double-sided, photo-mounting tape attached to a microscope slide. A total of 10 single shot spectra were acquired at different locations on the slide. An average spectrum was generated from the single shot spectra. The elements present in the average spectrum were identified with the OOILIBS Elemental Identification module.
Results:
The average spectrum (n=10) for the aluminum alloy beads is shown in Figure 1. The elements identified for the average spectrum are shown in Table 1 with the number of elemental lines identified per lines in the Elemental Identification library shown in Table 2. As shown in Table 2, 3 out of 9 Al lines were detected with all 15 of the Fe lines included in the LIBS Elemental Identification library detected with LIBS.
Other elements detected included potassium (P), gold (Au), iodine (I), lead (Pb), tin (Sn), calcium (Ca), magnesium (Mg), cadmium (Cd), phosphorus (P), chromium (Cr) and barium (Ba). In addition to the lines detected (see Table 1 for a complete list), numerous other emission lines were not identified by the library. The identity of these lines could be determined with a resource like the MIT Wavelength Tables. The identity and concentration of the elements present in the alloy beads (as determined by an alternative analytical method) was not provided with the samples for comparison.
