Dr. Yufeng ZHENG, invited by Prof. Yunzhi Wang will give a lecture on June 25th, 2013, Beijing Time. You are welcome to attend if you are interested in materials characterization and phase transformations in Ti-alloys.

Speaker：Yufeng Zheng

Topic：Super Refined Alpha Phase Nucleation in Beta Titanium Alloys

Time：10:30am, June 25th, 2013, Beijing Time

Place：Room 210 of MSE Department Building

Abstract：

Due to the combination of high strength, great deep-hardenability and excellent corrosion resistance, Ti-5Al-5Mo-5V-3Cr (Ti-5553) becomes a promising beta titanium alloy for the application in aerospace components. Understanding phase transformations in Ti-5553 is integral to manipulating its structural/property interrelationships. For the work to be presented, the microstructure evolution in Ti-5553 during continuous heating at a rate of 5°C/min and 100°C/min were characterized using scanning electron microscopy, transmission electron microscopy and 3D atom probe. Super refined alpha precipitates could be formed homogeneously within the beta phase matrix during the slow, continuous heating, while refined alpha plates were formed during fast continuous heating. The role of metastable omega particles as heterogeneous nucleation sites during the following alpha precipitation has been identified. The structural, morphological, crystallographic and compositional characteristics of the alpha lath during the initial stages of precipitation will be discussed in detail.