| Pulsed bias arc ion plating, developed in the past ten years, is a newly promising film-deposition technique. Compared to conventional arc ion plating, it has more advantages such as low deposition temperature, low residual stress, fine grain size and droplet particles cleaning. It is thus suitable for deposition of high-quality multilayer films. By using this technique, Ti/TiN, TiN/TiC and TiNbN multilayer films have been deposited and their structures and properties have been investigated, and verified the possibility of deposition of multilayer films by using pulsed bias are ion plating. A solid and molecule experience electron theory and improved TFD method have been applied to calculate the valence electronic structures of Ti, TiN, TiC and NbN, and the interface electric structures of Ti/TiN, TiN/TiC and TiN/NbN in order to explain the multilayer hardening effect. Based on some developed models on hardening effects, a hardening model suitable for this processing is put forward in this present thesis to study the superhard effect of films deposited by this technique.First, the results show that a multilayer modulated structure is observed in Ti/TiN multilayer films by SEM, which verifies the possibility of deposition of multilayer films by pulsed bias arc ion plating. In order to understand and optimize the processing of pulsed bias arc ion plating for Ti/TiN multilayer film, under the condition of the same other parameters, an orthogonal design method has been applied to investigate the effect of the pulsed bias related parameters on microhardness, film/substrate adhesion and gliding wear-resistance properties. The results show that pulsed bias magnitude is the major factor for microhardness, overweighing frequency and duty ratio, in which pulsed bias magnitude correlates in a significant manner with deposition ion energy. Microhardness of Ti/TiN multilayer films increases with increasing pulsed bias magnitude, and the maxium microhardness value of 29.5GPa is obtained under U_p= -900V. This correlates with improvement of microstructure by pulsed ion bombardment. The orthogonal results also show that pulsed bias magnitude is the major factor for film/substrate adhesion and the wear-resistance properties of the multilayer films.The obtained optimized processing based on above-mentioned results has also been applied to synthesize Ti/TiN mutilayer films with different modulation period and period ratio.The results show that the properties of the multilayer films correlate in a significant manner with modulatin period and period ratio. When the modulation period equals to 46nm, microhardness of the multilayer film reaches to 43.6GPa, and its adhesion manifests very high values (higher than 70N).In order to analyze the effect of multilayer alternating with different shear modulus on hardness of the films, TiN/TiC multilayer films have been synthesized using a similar processing. It is found that obvious multilayer modulated structure is observed, and their interface thickness is about 20nm to 30nm. But their microhardness is not obviously enhanced compared with that of TiN and TiC films. Their frictional coefficients (0.2) are much fewer than those of Ti/TiN multilayer films, so that their wear-resistance properties have been improved. Furthermore, film/substrate adhesion values of TiN/TiC multilayer films are much higher than that of TiC film.In order to understand the effect of ion energy of deposition on structure of the films, taking advantage of much higher magnitude values under pulsed biases compared to that under direct current biases, TiNbN films have been synthesized. By changing the pulsed bias magnitude, phase compositions of TiNbN ternary hard films have been effectively controlled. With increasing pulsed bias magnitude, the content of hcp-M2N phase is obviously increased, and orientation plane is changed from (111) plane under low bias magnitude(-300V) to (220) plane under high bias magnitude(-900V). Under higher pulsed bias magnitude, fine grain size has been obtained. Based on them, by alternating pulsed bias magnitude with high value and low value, the TiNbN structure multilayer films have been deposited, of which the highest microhardness value reaches to 37.3GPa. The adhesion values of film/substrate of the multilayer films are slightly increased than those of TiNbN films, but the wear-resistance properties of TiNbN films are not improved than those of TiN film.We then analyze valence electron structure and interface electron structure of bulk material. Then we relate their electron structures and their mechnical properties. It is found that the resistance value of TiN, TiC and NbN shearing along {111} plane denotes their toughness. And the interface electron density could denote interface stress, the configuration value the interface stability. The interface stress of TiN/NbN is lower than that of TiN/TiC, but the interface stability of the former is higher that the latter. From the experimental results, we can see that low adhesion value of TiC film is consistant with its low calculated value of toughness. The adhesion values of the TiN/TiC multilayer films are increased in comparison to that of TiC film. Furthermore, high adhesion values of TiNbN multilayer films are obtained partly due to their low interface stressed from the calculated results.Finally, based on some developed hardening mechanism models, the hardness enhancedment effect is analyzed for the multilayer films under low bias magnitude, which lies in fine grain size and multilayer interface effects restricting dislocations to move smoothly. In this case, superhard effect is not obtained. A superhard effect is observed in multilayer films under high bias magnitude by pulsed bias arc ion plating. We then put forward a hardening model suitable for this present processing, and our model denotes that the superhard effect arises from alternating stress field, that is to say, a gradient modulated structure produced in the films resulted from high pulsed bias magnitude.
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