Project B1: Hydrogenated Ti powder pre-forms
•	Project Chief Investigators: Matthew Barnett (Project Leader)
•	Senior Researchers/Research Associates: Monash: Rimma Lapovok, Dacian Tomus; Deakin: Pinaki Bhattacharjee
•	Research Students: Deakin: Alireza Ghaderi
•	Research Assistants Visiting Scholars, Hons Students etc: Deakin: Umashankar Gunasheker
Assessment of densification of powder compacts with varying levels of H addition has been performed. Densification was performed using rolling and Equal Channel Angular Extrusion at temperatures between room temperature and 500°C. Hydrogen levels were altered by hydrogenation, de-hydrogenation and by powder blending.
In general, no marked improvement in densification was observed with the addition of hydrogen (Figure B1). However, encouragingly high levels of densification have been achieved in the temperature range examined and across the H levels investigated. In particular, successful compaction of TiH2 was obtained using ECAE at 300°C. These high levels of densification show promise for a process in which the deformation process is performed at temperatures below which significant oxygen uptake occurs.
The samples produced so far show considerable brittleness. In the case of ECAE, this is due to the fact that a subsequent annealing step has not yet been performed. In the case of rolling, there appears to be some oxygen uptake during the heat treatments that reduces the ductility. Nonetheless, cold rolling was able to be performed on an as-hot rolled sample so long as the small edge cracks were ground away each pass.
Figure B1 - Porosity / density values obtained using (a) rolling and (b) ECAE to compact Ti powders with varying levels of TiH2 and/or H.
Infrastructure acquired during the course of this project includes a vacuum furnace constructed in-house to allow rapid heating and cooling to simulate annealing on a continuous sheet line, and various dies for test equipment.
Activity plan for 2008
Future work will focus on studying the impact low temperature compaction and hydrogen addition have on the properties of the final component. The influence of H on deformation forces will also be assessed. In parallel work outside of the Australian Partnership in Light Metals Research, the influence of H on the deformation mechanisms and crystallographic texture of CP Ti will be determined.