International Topical Meeting on Nuclear Research Applications and Utilization of Accelerators

4-8 May 2009, Vienna

Measurement of surface wear using the thin layer activation (TLA) technique

R. W. Smith^1,2, F. Ditrói¹, E. Corniani^2,1, Th. Wopelka², and M. Jech²

¹Cyclotron Application Department, Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen, Hungary
²Austrian Center of Competence for Tribology (AC2T research), Wiener Neustadt, Austria

Corresponding Author: r.smith@atomki.hu

There are many instances when it is important to be able to measure the wear of surfaces. One particular case of interest is the study of the wear of piston rings and cylinder liners in motor car engines to enable prediction of their lifetime and to test the wear resistance of new materials, coatings and lubricants. At ATOMKI (Debrecen, Hungary) and AC2T Research (Wiener Neustadt, Austria) the thin layer activation (TLA) technique is being used to measure the on-line wear of piston rings and cylinder liners. The procedure, effectively using a radionuclide tracer, involves two main steps. Firstly the surface of interest is activated using a charged particle beam e.g. H, D, ³He or ⁴He produced by the cyclotron at ATOMKI. The piston ring and cylinder liner piece, with the activated area located at the contact point, are then mounted in a tribometer at AC2T Research. The tribometer simulates the running of an engine while a flow of lubricant passes through the contact zone. The lubricant goes to a reservoir which is located inside a NaI(Tl) gamma-ray well detector and is then pumped back to the contact zone. As wear takes place activated particles are detached from the surface of interest and taken away by the lubricant. The number of gamma rays detected in the lubricant indicates how much wear has taken place and if recorded as a function of time enables determination of the wear rate. This whole procedure and set-up (activation and measurement) is known as the nano-wear Volume Coherence Technology (nVCT) method. It will be discussed along with technical factors to be considered (including the different nuclear reactions used to study different elements) and its limitations. Other known and potential applications will also be described.

Full text paper