Influence of the high temperature impact resistance of cutting tool coatings on their cutting performance

Metal cutting is a highly dynamic process, where the loading condition of tool coating is very complex. Excellent static mechanical properties of tool coatings are not enough to meet the dynamic cutting environment, including impact load, cyclic load and so on. The high-frequency and high-temperature cycle impact test device based on ultrasonic vibration was developed in this study. The device performed the high-frequency impact on coating samples through high-frequency reciprocating motion of ultrasonic horn, whose impact frequency could reach 20 kHz. In addition, a high-temperature module was added to perform high-frequency fatigue test at high temperature. Cutting experiments of titanium alloy and impact tests with different temperatures and loads were carried out for the bilayer TiSiN/TiAlN coating. The results of cutting experiments and impact tests were compared and analyzed. The relationship between impact test and cutting experiment was proposed to characterize and evaluate the cutting performance of coated cutting tool by using the high-temperature impact tests.