The application of energetic ion beams in the study of wear and porosity

Abstract

The use of the thin layer activation technique in measuring surface loss of materials due to wear and corrosion with particular reference to iron and steels is described. The active layer is usually between 30 μm and 300 μm thick and the sensitivity of the method is about 0.5 μm. However the potential exists for active layers as small as a few micrometres and as large as about 30 mm to be produced and monitored during the wear process. The distribution of activity with depth resulting from the irradiation of such common industrial materials as iron, copper, aluminium and carbon by various charged particle beams is considered. The technique described is applicable to these materials and composites containing them, e.g. ceramics and plastics, and to many other elements including silicon and hence glasses, enamels and abrasives. Charged particle beams have also been used to measure pore size and porosity in sinters, corroded steels, graphite and other porous industrial materials. This technique may be of potential value in the determination of pore size in bearing surfaces which contain impregnated lubricants.