The effects of alloy production method on microstructure and hence fatigue crack growth rate and fracture mechanism have been examined for a variety of fine-grained/high dispersoid Al-Li-Mg-Zr and Al-Li-Cu-Mg-Zr alloys. Microstructures have been assessed by scanning and transmission electron microcopy, together with electron back scattered diffraction pattern assessment. In these fine-grained/h...

The effect of microstructural refinement and intercritical annealing on the mechanical properties and work-hardening response of a low carbon St12 steel was studied. It was revealed that intercritical annealing of the ferritic-pearlitic sheet results in the formation of a coarse-grained DP microstructure with discrete martensite islands normally formed in place of pearlitic colonies, which resu...

Ultra-fine grained (UFG) structure (~0.6 µm) was produced in the stir zone (SZ) of 6061-T6 aluminum alloy joints using friction stir processing (FSP) cooled by liquid nitrogen (N2). A new experimental set-up was used to simultaneously quench the lower and upper surfaces of the samples during the processing. In addition, FSPed joints, using a steel backing plate, were produced at room temperatur...

In this research an ultra-fine grained composite structure consisting of an intermetallic matrix together with dispersed nano-sized Al2O3 obtained via mechanical activation of TiO2 and Al in a high energy ball mill and sintering of consolidated samples. Phase composition and morphology of the milled and sintered samples were evaluated by XRD and SEM techniques Thermal behavior of the powder sa...

The high strength Al-Zn-Mg alloy is widely used for structure components in critical aerospace applications. Small additions of scandium (Sc) often refine cast microstructure and mechanical properties by forming metastable Al3Sc dispersoids. The main role of the Al3Sc dispersoid is to prevent recrystallization during hot deformation and solution treatment. A new technique to apply for surface m...

We developed a multiscale approach to explore the effective thermal conductivity of polycrystalline graphene sheets. By performing equilibrium molecular dynamics (EMD) simulations, the grain size effect on the thermal conductivity of ultra-fine grained polycrystalline graphene sheets is investigated. Our results reveal that the ultra-fine grained graphene structures have thermal conductivity on...