Shaolou Wei (魏紹樓)

Binary Ti-Al together with ternary Ti-Al-V alloy systems form the basis of numerous high-performance titanium alloys in aerospace industry and chemical engineering. Even though the subsequent plastic deformation and heat treatment are the crucial procedures to produce advanced Ti-based alloys, it is equally essential to control their initial solidification process for optimizing desirable microstructures.

The objectives of this project are to systematically investigate the liquid state undercoolability and primary dentritic growth mechanisms by both electromagnetic levitation and drop tube techniques. Theoretical calculations and numerical simulation were employed to understand the dominant parameters of rapid solidification. The microstructural evolution mechanisms with respect to cooling rates as well as undercoolings were also studied.

Seeking high-performance structural materials with low density, high specific strength and superior oxidation resistance in the temperature range of 873-1073 K since the 1980s, due to the rapid development in the fields of aeronautics and astronautics. Among the numerous technique to improve the performance of titanium-based alloys at elevated temperatures, introducing ceramic-based reinforcements is often regarded as the most optimal approach due to its low cost and convenience in fabrication.

In the present work, the microstructural features and high-temperature oxidation resistance of hybrid (TiC+TiB) networks reinforced Ti-6Al-4V composites were investigated after fabricated with reaction hot pressing technique. With the combination of theoretical calculations and experiments the high-temperature cyclic and isothermic oxidation behavior and mechanisms were systematically study. Phenomenological and analytical models were also addressed for the oxide scale growth process.