Ti-xHf(x=10%,20%,30% and 40%,mass fraction) alloys were prepared by arc melting,and the microstructure was controlled for 24 h at 1 000 ℃ in argon atmosphere.The formation of nanotube was conducted by anodizing on Ti-Hf alloys in 1.0 mol/L H3PO4 electrolytes with small amounts of NaF at room temperature.And then TiN coatings were coated by DC-sputtering on the anodized surface.Microstructures and nanotube morphology of the alloys were examined by field emission scanning electron microscopy(FE-SEM) and X-ray diffractometry(XRD).The corrosion properties of the specimens were examined through potentiodynamic test(potential range from -1 500 to 2 000 mV) in 0.9 % NaCl solution by potentiostat.The microstructure shows the acicular phase and α' phase with Hf content.The amorphous oxide surface is transformed to crystalline anatase phase.TiN coated nanotube surface has a good corrosion resistance.
展开▼
