Research Paper - Mechanical Behavior - : Study of Dynamic Torsional Characteristics of Al - Li Alloys
이창길Chang Gil Lee, 김기종Ki Jong Kim, 조경목Kyung Mox Cho, 이성학Sung Hak Lee
Abstract
The objective of this study is to investigate dynamic torsional characteristics of Al-Li alloys using torsional Kolsky bar. The materials used were a 2090 and an 8090 Al-Li alloy. Dynamic (γ∼1200/sec) torsional tests were conducted at room temperature and low temperature (-196℃), and the deformed regions and the fracture surfaces of the tested specimens were examined. A number of planar slip bands were formed predominantly in the heavily deformed region in the case of the room temperature dynamic testing, but the amount of planar slip bands tended to decrease with decreasing test temperature. This indicated that the overall deformation mode of both Al-Li alloys changed from the planar slip to the homogeneous deformation with decreasing temperature, resulting in the improvement of the cryogenic properties under dynamic torsional loading.