METROLOGY CONDITIONS FOR THIN-LAYER ACTIVATION IN WEAR AND CORROSION STUDIES

Thin Layer Activation (TLA) is an ion beam technique. This method cons ists of an accelerated ion bombardment of the surface of interest of a machine part subjected to wear. Radioactive tracers are created by nu clear reactions in a well defined volume of material. Loss of material owing to wear, corrosion or abrasion phenomena is characterized by mo nitoring the resulting changes in radioactivity. For the industrial ap plication of this method, special attention has been paid during irrad iation to the range of activated thickness, yields and activation homo geneity and to on-line radioactivity measurements. There are two basic methods for measuring the material loss by TLA technique. One of them is based on remanant radioactivity measurements using a previously ob tained calibration curve. The second is based on measuring the increas ing radioactivity in the lubricant due to suspended wear particles. In this paper, we have chosen to present some calibration curves for bot h proton and deuteron irradiation of Fe, Cr, Cu, Ti and Ni samples. Th ickness ranges are indicated and intrinsic error checking and calculat ional procedures are also presented. The article ends with a review of some typical experiments involving running-in programme optimization and lubricants certifying procedures.