Study on thermal stability of CrTiAlN coating for dry drilling

The present paper is emphasized on the effect of thermal stability of the coating for dry drilling. The comparison of CrTiAlN and TiN coated drills as well as bare drill indicates that besides appreciable hardness, thermal stability is a crucial factor. The microstructure and mechanical properties after annealing at different temperatures were investigated. The results show that when the hardness is similar, the high oxidation resistance of the coating with good thermal stability at elevated temperature (in morphology, microstructure or phase) will exhibit good performance for dry cutting. The higher the hardness of the work piece, the more pronounced effect of the thermal stability of the coating layer.