Monte Carlo simulation and AES characterization of phase formation in Pt‐Al thin films

Abstract

AbstractConventional bulk‐ and thin‐film diffusion has been a topic of study for many years, and these studies have addressed various technical problems which are encountered whenever two dissimilar materials are joined together. One such system that has been studied intensively is the platinum‐aluminium (Pt/Al) thin‐film couple due to its multiple applications. It is a well known fact that platinum‐based alloys are being developed for high‐temperature applications due to its good resistance to corrosion and oxidation. In the pursuit of increasing the efficiency of modern gas turbines, the working temperatures of various parts of the engine are being pushed higher. This increase in working temperature created new oxidation challenges. To overcome these high‐temperature oxidation problems, various surface coatings and coating techniques have been developed and studied. Pt/Al alloys based on the Pt3/Al compound have the potential of high‐strength alloys with superior corrosion and oxidation resistance at ultrahigh temperatures. Diffusion studies are being undertaken to assess the mobility of the different elements within a Pt/Rh/Al alloy, and to assess the stability of the microstructure over long periods of time at high annealing temperatures. In this study, a chemical potential, Monte Carlo model, is developed and employed to predict the microstructure of a Pt/Rh/Al thin‐film system at an annealing temperature of 550 °C. The predicted results are compared to experimentally measured auger electron spectroscopy (AES) elemental maps and SEM images. A good correlation between the theoretical model and the experimentally measured results were found. Copyright © 2010 John Wiley & Sons, Ltd.