Internal friction peaks associated with the precipitation in AZ91 magnesium alloy

Grain boundary relaxation in fine-grained magnesium solid solutions

“…It is recognized that the existence of grain boundaries will affect the damping capacity (internal friction) and elastic constant at high temperatures and at low frequencies (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20), because grain boundaries can behave in a viscous manner under such conditions [5][6][7][8]. Viscous flow at grain boundaries converts mechanical energy into thermal energy as a result of grain boundary relaxation or grain boundary internal friction through GBS and, thus, increases the damping capacity of the materials.…”

Discontinuous and continuous precipitation in magnesium–aluminium type alloys

“…The microstructure of as-cast Mg-Al alloys is generally characterized by: a solid solution of aluminium in magnesium (an ␣-Mg phase with a hexagonal close-packed structure) and an ␣ + ␥ eutectic (fully or partially divorced depending on its solidification rate) [5][6][7][8][9][10]. The ␥-phase (called also ␤-phase [11][12][13][14][15]) is an intermetallic compound with a stoichiometric composition of Mg 17 Al 12 (at 43.95 wt.% Al) and an ␣-Mn type cubic unit cell.…”

Effects of composition and microstructure on behaviors of electrical resistivity during continuous heating above room temperature in Mg-based alloys

“…The further heating above 250 • C starts to dissolve strain-induced ␥-phase Mg 17 Al 12 which is reflected in an increase of ER up to 350 • C (curve 1, Fig. 7a) [18]. The DSC experiments have revealed the endothermic peak which begins about 225 • C and finishes around 375 • C (Fig.…”