In a significant development for the construction and energy sectors, researchers have uncovered crucial insights into the behavior of titanium when doped with titanium dioxide (TiO2) using powder metallurgy (PM) techniques. The study, led by Serhii Lavrys from the Karpenko Physico-Mechanical Institute of the NAS of Ukraine, explores how varying concentrations of TiO2 affect the microstructure and corrosion resistance of titanium, particularly in harsh chemical environments.
Titanium is renowned for its exceptional strength-to-weight ratio and corrosion resistance, making it a valuable material in industries ranging from aerospace to energy. However, the cost of traditional alloying elements like vanadium and molybdenum can be prohibitive. Lavrys and his team investigated the potential of using oxygen, a much more cost-effective element, to enhance titanium’s properties through powder metallurgy.
The researchers prepared three different blends of titanium powder mixed with varying concentrations of TiO2 (0, 0.2 wt.%, and 0.4 wt.%). These blends were then processed using conventional PM techniques, involving uniaxial pressing followed by vacuum sintering. The results revealed that increasing the TiO2 content in the powder mixture led to higher residual porosity in the final titanium specimens.
“An increase in the content of TiO2 powder in the raw powder mixture enhanced the residual porosity in titanium specimens,” Lavrys explained. This porosity, combined with the dissolved oxygen atoms, caused a change in the lattice constant of the titanium, which in turn increased its microhardness and residual microstrain.
However, the study also found that these microstructural changes came at a cost. Electrochemical impedance spectroscopy, polarization tests, and immersion tests in a 10 wt.% solution of hydrochloric acid showed that oxygen doping decreased the corrosion resistance of the titanium specimens. The enhanced residual microstrain and porosity due to the introduction of TiO2 were identified as the primary factors worsening the material’s corrosion performance.
The findings, published in the journal ‘Corrosion Communications’ (translated from Ukrainian as ‘Corrosion Communications’), have significant implications for the energy sector, where titanium is often used in environments exposed to corrosive chemicals. While the use of TiO2 doping offers a cost-effective alternative to traditional alloying methods, the trade-off in corrosion resistance is a critical consideration.
“This research highlights the delicate balance between cost, strength, and corrosion resistance in material science,” Lavrys noted. “Understanding these trade-offs is essential for developing more efficient and economical materials for demanding applications.”
The study suggests that future developments in the field may focus on optimizing the concentration of TiO2 and other doping elements to achieve a balance between enhanced mechanical properties and corrosion resistance. This could lead to the creation of new titanium alloys that are not only stronger and more cost-effective but also better suited for harsh chemical environments.
As the energy sector continues to push the boundaries of material performance, the insights from this research could pave the way for innovative solutions that meet the dual challenges of cost and durability. The work of Lavrys and his team serves as a reminder that the path to material innovation is often a complex interplay of scientific discovery and practical application.