Towards homogeneous distribution of coarse grain in a tri-modal Al-based composites utilizing localized grain growth

Abstract

Two types of nanostructured powders with different thermal stability were synthesized by cryomilling. The homogeneous distribution of coarse grain in a tri-modal Al-based composites was obtained via localized grain growth during consolidation. Representative SEM images and high-angle annular dark/bright field STEM images displayed the distribution of UFG/CG in the Nano-B4C free zone. The yield strength of the tri-modal composite could reach up to 817 ± 32 MPa with an acceptable strain of ~9.3%. Multiple “vein-like” structure caused by deformation during the compressive testing was detected on the fracture surface.