Unique cyclic deformation behavior of a heavily alloyed Al–Si piston alloy at different temperatures

The cyclic deformation behavior of a near-eutectic Al–Si piston alloy with a variety of alloying elements is investigated. Due to the distinctive microstructure, the alloy exhibited various cyclic deformation characteristics at different temperatures. Unique double-stage cyclic hardening occurred at room temperature, while the first hardening was mainly caused by the interaction between the dislocations and the finely dispersive precipitates, and the dislocation/dislocation interaction resulted in the second hardening. At elevated temperatures (200 °C and 350 °C), the alloy mainly presented cyclic softening because of the fact that the thermally activated dislocations could bypass or shear the obstructive precipitates.