Study on Damping and Mechanical Properties of Ultrafine-grained Pure Magnesium

Author of the article:YANG Jing 1,2 , FAN Jianfeng 1,2 , REN Rui 1,2

Author's Workplace：1. Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China; 2. School of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China

Key Words： pure magnesium; mobile dislocation density; grain boundary; mechanical properties; damping

Abstract：Pure magnesium samples with grain sizes of 15 μm, 11 μm, 560 nm and 98 nm were prepared by high-energy
ball milling. The balance between damping and mechanical properties was analyzed from the aspects of movable
dislocation density, grain size and grain boundary absorption dislocation. The results show that the tensile strength and yield
strength increase gradually with the grain size decreasing from micron to nanometer, and the yield strength and tensile
strength of the sample with 98 nm grain size reach 135 MPa and 274 MPa, respectively. The damping curves of all samples
conform to G-L theory and belong to dislocation damping, which increases first and then decreases with the decrease of
grain size. The strain amplitude damping performance of the sample with grain size of 560 nm is the best.