Enhanced Thermal Stability and Mechanical Properties of Ultrafine-Grained Aluminum Alloy
The paper reports on microstructure, strength and fatigue of ultrafine-grained (UFG) samples of the Al-Cu-Mg-Si aluminum alloy processed by high pressure torsion (HPT) at various temperatures. Application of the HPT treatment led to strong grain refinement, as well as to a raise of the mean-root square strains and dynamic precipitation. In case of optimal HPT treatment the UFG samples have demonstrated the enhanced thermal stability, an increase in ultimate tensile strength in 2.5 times and enhancement in fatigue endurance limit by 20 % in comparison with coarse-grained alloy subjected to standard treatment. It is shown that the regime of the HPT treatment governs the volume fraction of precipitates and segregations, thereby affecting a grain size and thermal stability of ultrafine-grained structure.
Jing Tao Wang, Roberto B. Figueiredo and Terence G. Langdon
R. K. Islamgaliev et al., "Enhanced Thermal Stability and Mechanical Properties of Ultrafine-Grained Aluminum Alloy", Materials Science Forum, Vols. 667-669, pp. 331-336, 2011