| The multi-component hard film,because of its ability to improve the tools' cutting performance effectively and to improve the high-temperature oxidation performance of the tool and die,was widely concerned.The multi-component film has a series of strengthen mechanism such as grain refinement,solid-solution strengthening and multicomponent strengthening,so it has higher hardness.Different compositions such as Ti, Cr,Al,can improve its various aspects of performance including hardness,friction, high-temperature performance and so on,which could make the multi-component film's apply more extensively.As one of the most important branches in film's application,no matter the theory than the application about the multi-component film were all developed.The films deposited by Arc ion plating process are characterized by high density and high bond force between substrate and films.CrAlTiN film was deposited by cathodic vacuum arc ion plating technology in this paper.Several technological parameters impacting the major mechanical properties of composite thin films were explored,and the high temperature oxidation performance of the CrAlTiN film and the comparison between TiAlN,CrN and TiN were investigated.The composition, structure and performance of films were investigated by XRD,SEM,EDS,Microhardness tester,Nano-indenter and scratching tester.Key findings were as follows:(1)The preparation of CrAlTiN film through arc ion plating method:the investigations focused on ion bombardment before plating and the technology for the deposition of interlayer;the effects of negative biased potential,deposition temperature and chamber pressure on the binding force between substrate and film,hardness and film thickness.The experiment indicated that the optimized parameters were as follows: heating temperature 420℃,biased potential 200V,chamber pressure 1.5 Pa,rotational speed 4r/min and inlet flow of N2 650scom.This film was silver-gray,and owned 3000Hv hardness and 65N of the binding force.(2)The study on high temperature oxidation performance of arc ion plating CrAlTiN film:the high temperature oxidation resistance for CrAlTiN film using mass gain method was studied by comparison with that of TiAlN,CrN and TiN films;and the surface and cross-sectional morphology before and after the oxidation and the variations in resultant phase,structure and basic properties were also investigated in this paper.The results were as follows:the temperature oxidation resistance for CrAlTiN films,determined by the ratio of Cr/Al/Ti,were higher than that for CrN and far higher than that for TiN film.Cr0.56Al0.28Ti0.16N excelled good toughness and good high temperature oxidation resistance when the temperature was higher than 850℃due to the formation of Cr2O3,preventing from the oxidation.While Cr0.11Al0.45Ti0.44N films displayed worse high temperature oxidation resistance due to the formation of TiO2 and Al2O3.Elemental transfer was observed during oxidation process.The migration of Fe in substrate and Al,Ti in the film to the interlayer of Cr-CrN were occurred,which produced insignificant influence on the binding force between film and substrate.Also the decreases of nano-indention hardness and Young's modulus were found after oxidation. |
PDF Full Text Request