Effects of multilayer structure on impacting fatigue resistance and high-speed dry cutting performance against Ti-6Al-4V of AlTiN/AlTiBN multilayer coatings

AlTiN/AlTiBN multilayer coatings with various numbers of bilayers were constructed to evaluate their high-frequency cyclic impact resistances and high-speed dry cutting performances. The multilayer coatings showed improvement in adhesion, micro-hardness as well as resistance to impacting fatigue and thermal decomposition. High-speed dry cutting (80 and 100 m/min without cutting fluid) experiments manifested the enhanced resistance to crack generation, delamination and rapid failure of coated tools by construction of multilayer structure, and the C5 coated tool presented better cutting lifetime of ~2800 m (80 m/min) and ~1200 m (100 m/min) ascribed to the best adhesive strength of 96 N (Lc2), the highest hot-hardness (3375 HK0.025 at 1000 °C) as well as the best fatigue resistance.