Materials scientists developed innovative design strategy for fabricating advanced titanium alloys

A research team led by material scientists of CityU has recently developed an innovative design strategy for fabricating advanced titanium alloys by 3D printing. Creatively combining different alloys using additive manufacturing methods has great potential to produce novel materials with interesting microstructures and excellent properties.

In this work, the team innovatively uses laser powder bed fusion to combine small amounts of 316L stainless steel into Ti64 titanium alloy by controlling the laser power and its scanning speed. This process creates an alloy with a distinctive lava-like microstructure with a high metastability and non-uniform composition, allowing the alloy to be very strong, ductile, and in light weight. This groundbreaking in situ design strategy should also be useful for improving mechanical properties in many other alloy systems for various structural applications.

The research was led by Prof. LIU Chain-Tsuan and Dr. YANG Tao of CityU’s Department of Materials Science and Engineering, and Prof. WANG Yunzhi from the Ohio State University. Dr. Zhang Tianlong, (Postdoc, CityU) conducted the main experiments while Dr. KONG Haojie and Dr. LUAN Juanhua (Postdocs, CityU) performed the mechanical testing and 3D-APT, respectively. President KUO Way was also a key contributor of this work.

Their findings were recently published in the latest issue of the highly prestigious scientific journal, Science, titled “In situ design of advanced titanium alloy with concentration modulations by additive manufacturing”. Dr. Yan and Prof. Liu had published an article in Science (T. Yang, et al. "Ultrahigh-strength and ductile superlattice alloys with nanoscale disordered interfaces." Science 369.6502 (2020): 427-432.) back in July 2020 and they made it once again in just over a year’s time.