SIMS analysis of the wear of boron nitride tools for the machining of compacted graphite iron and grey cast iron

Cubic boron nitride (cBN) is a common material for tools or the machining o f cast irons at high cutting speed. During the machining of compacted graph ite iron (CGI) in continuous culling the wear of the cBN tools was found to be significantly higher compared to the machining of grey cast iron. This is possibly a result of a heating of the tool surface during the cutting of CGI. One possible reason for the wear is diffusion of some elements from t he cutting tool into the CGI or from the CGI into the cutting tool. SIMS me asurements were carried out which prove the existence of such diffusion pro cesses. A static model experiment has been performed by heating cBN tools t o 700 degrees C while in contact with CGI or cast iron (CI). SIMS depth pro files of the cBN tools and of CGI/CI show that there is a diffusion of seve ral elements in both directions (B, W and Ti from the cBN tools into the CG I or CI, Fe and Si from the CGI or CI samples into the cBN) up to a depth o f 20 mu m.