Semi-quantitative chemical analysis of hard coatings by Raman micro-spectroscopy: the aluminium chromium nitride system as an example.
A new method for chemical analyses of nitride-based hard coatings is presented. Raman band shifts in the spectra of Al(x)Cr(1-x)N coatings, deposited by physical vapour deposition from Al(x)Cr(1-x) targets with x (T,Al) = 0, 0.25, 0.50, 0.70 and 0.85, are calibrated using compositional data of the coatings derived by elastic recoil detection analysis (ERDA) and electron probe micro-analysis (EPMA). Inserting the composition-dependent Raman shift of a combinatorial acoustic-optic lattice mode into an empirically derived equation allows the determination of Al/Cr ratios of the coating with an accuracy of about +/-2%. Spot, line and area analyses of coated cemented carbide and cold work steel samples by using a computer-controlled, motorized x,y-stage are demonstrated and the most important errors influencing precision and accuracy are discussed. Figure Raman map of a coated cold-work steel sample.
Kaindl
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R
Institute of Mineralogy and Petrography, University Innsbruck, Innrain 52, 6020 Innsbruck, Austria. reinhard.kaindl@uibk.ac.at
Sartory
B
B
Neidhardt
J
J
Franz
R
R
Reiter
A
A
Polcik
P
P
Tessadri
R
R
Mitterer
C
C