Study On Performances Of Films Modification For Three Kinds Of Key Aviation Materials By AIP

Along with the increasingly worldwide intensity of uncertain factors, the national defense draws more and more countries’ attention in the world. It is worth emphasizing that aviation plays an increasingly important role in national defense. However, one of the main factors which limit the development of the national aviation industry is aviation material. This paper attempts to design the different methods for the three kinds of aviation material surface modification according to respectively applicative conditions in order to achieve the performance requirements.First, the author deposits a series of TiN/CrN multilayer films on TC4titanium alloy by arc ion plating (AIP). The surface morphology, thickness, phase structure, hardness, adhesion strength and friction coefficient of films are evaluated. The experimental results show the films with a total thickness of480nm comprise periodic TiN-film layers and CrN-film layers, and the periodic is60nm. The film surface property is closely related to and remarkably improved by the value of bias voltage. The micro-hardness of TiN/CrN multilayer films increases with increasing pulsed bias magnitude, and the maximum microhardness value of24.7GPa is obtained under Up=-500V. Comparing with the titanium substrate, the friction coefficient greatly decreases from0.35(titanium substrate) to0.14-0.17, the results also show that pulsed bias magnitude is the major factor for wear-resistance properties of the multilayer films. The films are tightly adhering to substrates, and the adhesion strength is60N-80N. Treating with TiN/CrN multilayer films by AIP, the coated TC4titanium could meet the demand of wear-resisting property under the condition of sand and dust friction.Secondly, according to the same applicative condition, the surface of38CrMoAl steel and300M steel of aviaiion materials are treated in the same way. Four different series films of TiN、ZrN-Cu、ZrN-Cr and ZrN-AIN are deposited at two kinds of the substrates, and the structure and properties of films are evaluated. The results show that the microhardness of ZrN-Cu films is the higher than the other films, respectively29.99GPa and27.77GPa, which are12times and5times higher than the microhardness of two substrates (2.53GPa,5.32GPa). Also. the film/substrate adhesion and water contact angle of ZrN-Cu films are superior to the others. The friction coefficient of ZrN-Cu films at300M steel substrate is the lowest. thus the wear-resistance properties are remarkably improved. In conclusion, comparing with the other three films, all performances of the ZrN-Cu films reach the level of the demand of the applicative environment.Finally, based on excellent performance of ZrN-Cu films, the Cu content of ZrN-Cu films is adjusted, and the relevant performances are evaluated. The results show that the Cu content plays an important role in the performances of ZrN-Cu films.