An in-situ transmission electron microscopy study on room temperature ductility of TiAl alloys with fully lamellar microstructure

作者：Kim Seong Woong^*; Na Young Sang; Yeom Jong Taek; Kim Seung Eon; Choi Yoon Suk

来源：Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 2014, 589: 140-145.

DOI：10.1016/j.msea.2013.09.080

• TiAl
• As-cast alloy
• Ductility
• Microstructure
• In-situ TEM

An in-situ transmission electron microscopy study was conducted at room temperature in order to understand an underlying mechanism on room temperature ductility of TiAl alloys. From in-situ straining transmission electron microscopy experiments, it was revealed that the crack path is different between the TiAl alloys with/without room temperature ductility. The crack in TiAl alloys having room temperature ductility interacted with lamellae by forming bridging ligaments between the two alpha 2 lamellae and the gamma lamellae. In contrast, the cracks in TiAl alloys without room temperature ductility propagated along grain (colony) boundaries showing brittle intergranular fracture. Finally, we proposed the important microstructural factors to have room temperature ductility of TiAl alloys.

• 出版日期2014-1-1