Surface Corrosion of Ti-16Si-4B Powder Alloy Implanted With Nitrogen by Plasma-Based Technique

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Titanium materials with a new ternary phase, Ti(6)Si(2)B, can be manufactured by high-energy ball milling and further sintering of titanium, silicon, and boron powders. In this paper, hot pressing was chosen to compact the granules and then prevent high porosity and grain coarsening during sintering. Subsequently, the surface of the Ti-16Si-4B (at.%) alloy was modified by nitrogen ion implantation using a plasma immersion technique. The marine corrosion behavior of this powder alloy was studied in this paper. Scanning electron microscopy and X-ray diffraction analyses were performed on the powders and alloys in order to observe phase compositions and morphologies. The morphology of sample surfaces was also observed by utilizing an atomic force microscope. The concentration profile of the detected elements has been investigated using Auger electron spectroscopy depth profiling. The results show that a shallow nitrogen-rich layer was obtained after implantation treatment. Potentiodynamic analyses showed that, with the nitrogen insertion, there is a significant reduction of the anodic current in almost the whole potential spam explored, meaning that the corrosion rate decreases when ion implantation is performed.