脉冲偏压占空比对TiAlCrN多元复合薄膜微观结构和性能的影响规律OA

To systematically investigate the effect of the pulsed bias duty cycle,the work aims to deposit TiAlCrN multi-component composite films on the M2 high-speed steel via arc ion plating.The microstructure was characterized by scanning electron microscopy(SEM).Phase identification and texture analysis were performed through X-ray diffraction(XRD).Elemental composition was quantified by energy dispersive spectroscopy(EDS).Microhardness was measured with a Vickers microhardness tester.Adhesion was evaluated via scratch tests on a multifunctional surface properties tester.Tribological performance was assessed with a pin-on-disk testing machine and electrochemical behavior was examined through potentiodynamic polarization tests.Increasing the pulsed bias duty cycle enhanced the ion bombardment intensity over a given period,which reduced the macroparticles.As the pulsed bias duty cycle increased from 10%to 50%,the amount of macroparticles decreased from 547 to 312 due to the stronger repulsive force from the substrate bias.This amount reduction of macroparticles contributed to a lower coefficient of friction and better surface quality.At the pulsed bias duty cycle below 20%,the TiAlCrN multi-component composite films displayed a preferred orientation along the(200)plane.While the pulsed bias duty cycle increased more than 30%,the ion flux density increased and the pull up time of ion flux prolonged,which accelerated TiAlCrN multi-component composite film deposition and led to the internal stress rise.Meanwhile,the strain energy minimization dominated the TiAlCrN multi-component composite film growth and the preferred orientation transited from(200)to(111).At a pulsed bias duty cycle of 10%,the Al content reached a maximum of 21.37at.%,the average grain size and hardness of TiAlCrN multi-component composite films reached the maximum values of 6.17 nm and 2 381HV,respectively.This was attributed to the synergistic effects of solid solution strengthening and the reverse Hall-Petch effect.When the grain size decreased to a critical value,the hardness trend was consistent with the reverse Hall-Petch effect.The relatively coarser grain size corresponded to the maximum hardness.The reduction of strain energy enabled the TiAlCrN multi-component composite film to achieve optimal adhesion 74 N.At a pulsed bias duty cycle of 20%,during sliding friction test process,minimal film delamination limited the wear debris generation,which decreased the average coefficient of friction to 0.84.With the pulsed bias duty cycle increasing to 40%,the Cr element content of TiAlCrN multi-component composite films reached the highest value of 22.37at.%,which promoted the grain refinement and the average grain size reached to the smallest 2.86 nm.This dense microstructure effectively impeded the penetration of corrosive medium.The TiAlCrN multi-component composite film had superior corrosion resistance and the corrosion potential reached to-0.39 V(vs.SCE).With the pulsed bias duty cycle increasing to 50%,the time-dependent enhancement of ion attraction promoted film growth and increased thickness,but the excessive ion bombardment raised internal stress and severely degraded the adhesion to 28 N.Meanwhile,the adhesion reduction of the TiAlCrN multi-component composite film induced the film delamination and accelerated debris generation during the friction process and the coefficient of friction reached to the maximum 0.91.Compared with the uncoated M2 high-speed steel substrate,the TiAlCrN multi-component composite films demonstrated significantly enhanced hardness,superior corrosion resistance and improved tribological performance.These research results provide experimental evidence and key deposition process for optimizing arc ion plating processes.These findings demonstrate the considerable potential of TiAlCrN films for enhancing the performance and durability of cutting tools and molds in advanced manufacturing applications.