AlCrN/TiSiN/AlCrTiSiON多层复合刀具涂层耐热及切削性能研究OA

To address the critical challenge of high cutting temperature and the consequent susceptibility of tools to oxidative wear when applying the AlCrN/TiSiN coating in high-speed dry cutting operations,this study proposes a"multilayer composite+pre-oxidation"strategy.Specifically,an AlCrN/TiSiN coating is deposited by arc ion plating,followed by a controlled pre-oxidation treatment.This process induces the in-situ formation of a stable,dense,and protective thin oxide layer on the coating surface,resulting in an AlCrN/TiSiN/AlCrTiSiON multilayer composite architecture.This functional oxide barrier serves a dual purpose:it impedes the inward diffusion of harmful elements such as oxygen into the underlying coating,while simultaneously reducing the conduction of cutting heat to the tool substrate.Consequently,this design significantly enhances the coating's high-temperature oxidation resistance and thermal stability,thereby bolstering its resistance to both oxidative and diffusion wear mechanisms.This ultimately leads to a substantial improvement in the tool's service life and machining efficiency. To systematically verify the inhibitory effect of the pre-oxidation treatment on the oxygen diffusion behavior and to elucidate the underlying high-temperature oxidation failure mechanisms,a comprehensive evaluation is conducted.This evaluation integrates static high-temperature oxidation experiments,dynamic high-temperature friction and wear tests,and actual cutting experiments to assess the high-temperature oxidation behavior,tribological behavior,and cutting performance of the AlCrN/TiSiN/AlCrTiSiON coating.The experimental results demonstrate that the pre-oxidation treatment successfully generates a dense oxide protective layer on the coating surface.Crucially,following high-temperature oxidation experiments conducted across a range of temperatures,no new oxide phases are detected within the coating,indicating excellent phase stability.An analysis of the mechanical properties reveals that with increasing oxidation temperature,both the hardness and elastic modulus of the coating initially increase and then decrease.The coating achieves its peak hardness value of 49.64 GPa after oxidation at 600℃. In high-temperature friction tests,the intensity of oxide diffraction peaks within the coating progressively increases with rising test temperature,indicating the formation of lubricious oxide phases that contribute to improved tribological performance.The minimum wear rate of the coating,measured at 2.28×10-10 mm3/(N·mm),is observed at friction temperature of 700℃.Furthermore,the minimum friction coefficient of 0.63 is obtained at 800℃.The effectiveness of this coating strategy is further validated through dry milling tests on hardened 45 steel.The results show that the tool life of the AlCrN/TiSiN/AlCrTiSiON multilayer composite coated milling cutter is 3.46 times longer than that of the conventional AlCrN/TiSiN coated cutter.After 120 minutes of continuous milling,the cutting temperature of the AlCrN/TiSiN/AlCrTiSiON multilayer composite coated cutter is measured to be 68℃lower than that of the AlCrN/TiSiN coated cutter. In conclusion,the fabrication of a pre-oxidized protective layer on the surface of a nanoscale multilayer coating significantly enhances its structural stability under high-temperature oxidizing environments,thereby effectively prolonging the service life of coated cutting tools.