In situ measurement of oxide film growth on aluminium samples by holographic interferometry

In the present investigation, holographic interferometry was utilized for the first time to monitor the thickness of oxide film growth on aluminium samples during the initial stage of oxidation processes in aqueous solution without any physical contact. The oxidation process of the aluminium samples was cart icd out chemically in different sulphuric acid concentrations (0.5-3.125%;, H2SO4) at room temperature. Also, a method of holographic interferometry was used to measure the thickness of oxide film on the aluminium samples in aqueous solutions. Along with the holographic measurement, a mathematical model was derived in order to correlate the electrical resistance of the aluminium samples in solutions to the thickness of the oxide Rim on the aluminium samples which were formed due to chemical oxidation. The thickness of the oxide film on the aluminium samples was measured by the real-time holographic interferometry. Consequently, holographic interferometry is found to be very useful for surface finish industries especially for monitoring the early stage of oxidation processes of metals, in which the thickness of the oxide film as well as the electrical resistance of the aluminium samples can be determined in situ. (C) 2001 Elsevier Science Ltd. Ail rights reserved.