Spectroscopic investigation of laser produced plasma of carbon nanotube reinforced AlMg5 metal matrix nanocomposites

摘要

Laser produced plasma of carbon nanotube reinforced AlMg5 metal matrix nanocomposites (AlMg5-CNT) is investigated by optical emission spectroscopy which dominantly consists of neutral aluminum (Al I) and magnesium (Mg I) atomic species. The blue-green (B-2 Sigma - X-2 Sigma) band system of AlO and green ((1)Sigma - (1)Sigma) system of MgO are observed in the optical emission spectra of AlMg5-CNT plasma recorded without Ar shielding gas due to oxidation of Al I and Mg I species in air. The AlO blue-green (B-2 Sigma - X-2 Sigma) band system is also observed with Ar shielding gas in the optical emission spectra of plasma of AlMg5-CNT having oxidized grain boundaries which is irradiated by one or more laser pulses prior to plasma creation. The oxidation of grain boundaries in AlMg5-CNT is found to be nullified as the concentration of CNT reinforcement increases. Furthermore, the intensity ratio (I-MgI/I-AlI) of Mg I to Al I emission is found to be more for pristine AlMg5-CNT than that for AlMg5-CNT which is shot by one laser pulse prior to plasma creation, indicating more depletion of magnesium relative to aluminum.