Nanocrystalline titania films codoped with aluminum and boron were prepared by cathodic vacuum arc deposition.In the process,titanium alloy target was used under an O_(2) /Ar atmosphere,and sensitization of films were carried out by natural dye-sensitized complex in anhydrous ethanol.The structure,surface morphology and UV-vis spectra of titania films codoped were measured by X-ray diffraction analysis,scanning electron microscopy and ultraviolet-visible spectrometer.The as-deposited films are found to be amorphous.The films annealed were examined to be of anatase structure with orientation along the(101)planes,the average crystal size is in the range between 41 and 45 nm.SEM results show that there are some pores in the codoped titania films,the optical properties of the dye-sensitized films were also measured which reveals that the spectral responses of films shift to the visible region.Under simulated sunlight illumination,the overall energy conversion efficiency of dye-sensitized nanocrystalline solar cell is 0.9%.
TiAlCrN coatings were deposited by means of vacuum cathodic arc ion plating technique on TC 11 （Ti-6.5Al-3.5Mo-1.5Zr-0.3Si） titanium alloy substrates. The composition, phase structure, mechanical performance, and oxidation-resistance of the nivide coatings were investi- gated by scanning electron microscopy （SEM）, atomic force microscope （AFM）, X-ray diffraction （XRD）, auger electron spectroscopy （AES）, and X-ray photoelectron microscopy （XPS）. A new process for preparing protective coatings of the titanium alloy is successfully ac- quired. The experimental results indicate that the added element chromium in the TiAlN coatings make a contribution to form the （220） pre- ferred direction. The phases of the coatings are composed of （Ti,Al）N and （Ti,Cr）N. After 700~C and 800~C oxidation, AES analysis shows that the diffusion distribution of the TiAlCrN coatings emerges a step shape. From the outside to the inner, the concentrations of O, Al, and Cr reduce, but those of Ti and N increase. The Al-rich oxide is formed on the surface of the coatings, and the mixed structure of Ti-rich and Cr-rich oxides is formed in the internal layer. The oxidation resistance of the TiAlCrN coatings is excellent at the range of 700 to 800~C. Adhesion wear is the dominant mechanical characteristic for the titanium alloy at room temperature, and the protective coatings with high hardness can improve the mechanical properties of the titanium alloy. The wear resistance of the TC 11 alloy is considerably improved by the TiAlCrN coatings.
