MICROSTRUCTURE AND MORPHOLOGY OF SURFACE OXIDE-FILMS ON TI-6AL-4V

The microstructure of anodic oxide films grown on Ti-6A1-4V in H2S04 was investigated by SEM, TEM, STEM, EDX, and AES, as a complement to a recent surface spectroscopic investigation of the same oxides by XPS, AES, and SIMS. The anodic oxide films are heterogeneous and the texture reflects the duplex microstructure (α and β phases) of the underlying metal. Porous oxide regions are observed with different appearances on a-phase and mixed-phase regions. The oxide films are essentially amorphous in the investigated thickness range 60–300 nm (in contrast to as-grown anodic films on pure Ti), but crystallize to the anatase structure upon annealing. Considerable lateral variation of the V content in the oxide is observed, reflecting the corresponding variation in the underlying metal. The results are compared with a previous, similar investigation of anodic oxides on pure Ti. © 1990, Materials Research Society. All rights reserved.