Sputtering of aluminium alloys in the grimm glow lamp for emission spectrochemical analysis

Abstract

The effects of surface roughness, grain size and target thickness on the cathodic sputtering and emission intensities of spectral lines in the Grimm glow lamp have been investigated for samples of aluminium alloys. The intensities of the alloying elements changed with discharge time because the θ phase (Al2Cu) and β phase (Si) are sputtered selectively. The selective sputtering of the θ phase in an Al-8% Cu alloy can be decreased and the intensities can be made constant during discharge by polishing the target surface with coarse sand paper before discharge. When a fine-grained Al-4.9% Cu-7.2% Si alloy sample was used as a target, the intensities remained nearly constant during discharge. The sample preparation for obtaining fine-grained samples involves casting the melt in a metal mould. The thickness of disk samples influences not only the sample temperature but the current, sputtering and intensities. Special attention should be paid to the thickness for the determination of copper in aluminium alloys. © 1978.