Development of a high-damping composite: Mg2Si/Mg

A new material has been processed and characterized, It is a lightweight and high-damping composite formed by unidirectional Mg2Si fibres embedded in a pure magnesium matrix. This composite has been produced by unidirectional solidification of a Mg-Si near eutectic alloy (2 wt% Si), Mechanical strength was measured through tensile tests and the damping capacity was deduced from mechanical spectroscopy measurements in a low-frequency torsion pendulum. These composites have a tensile strength comparable with industrial magnesium cast alloys such as AZ63 and a damping capacity which is 10 to 100 times higher. The mechanical properties and damping capacity are interpreted as functions of sample microstructure with emphasis on the effects of matrix and fibre orientation on the dislocation mobility.