Wear test for bulk metal forming using a radionuclide technique

Various parameters influence tool life, such as the tool material and the workpiece material, the lubricant, the tool pressure, the initial surface roughness, the relative velocity between the tool and the workpiece and the temperature. Usually investigations of tool wear require great experimental effort. Therefore a new testing procedure was sought which permits the wear to be identified from a small number of workpieces. There are two methods using radioisotopes which in principle satisfy these conditions: neutron activation analysis and tool surface activation. Experiments showed, however, that commercial steels do not satisfy the demands concerning material purity which is a precondition of neutron activation analysis. The use of surface activation offers a suitable technique for wear measurements which may be carried out continuously during a test. It is important that the position of maximum wear is exactly known and that the wear particles are carried away from the place of origin without further interaction with the tribosystem. (orig.)