Enhanced elevated-temperature mechanical properties of Al-Mn-Mg containing TiC nano-particles by pre-strain and concurrent precipitation

The influence of pre-strain on the tension and creep behavior of Al-Mn-Mg containing nano-sized TiC particles at elevated temperatures was investigated. Introduction of TiC nano-particles and the application of pre-strain significantly increase the strength at the ambient temperature and at 473 K, even though the strengthening effect diminishes at 573 K due to the more activated dislocation climb. Small pre-strain (von Mises strain of 0.2) could increase the yield strength at 573 K from 72 MPa to 96 MPa. Larger pre-strain promotes the precipitation during hot deformation at 573 K, and concurrent precipitation suppresses work softening by the pinning effect, leading to a significantly enhanced ductility and creep rupture life.