Microstructural features and tensile properties of a nanostructured Al6063-Al2O3 nanocomposite |
Paper ID : 1498-UFGNSM-FULL |
Authors: |
Abstract: |
A nanostructured Al6063 matrix nanocomposite were produced by reactive mechanical alloying (RMA) of Al alloy powder in a Ar-5vol% O2 atmosphere followed by hot powder extrusion. Microstructural features were evaluated by electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) methods. Microstructural studies revealed the formation of approximately 1 vol.% amorphous Al2O3 nanoparticles (~40-100 nm) during RMA process that were uniformly distributed throughout the Al alloy. Furthermore, Al matrix showed a duplex grain structure consisted from ultrafine grains (100-400 nm) and nanocrystalline grains (<100 nm). Tensile yield and ultimate strength of Al6063-Al2O3 nanocomposite were improved 175 and 126%, respectively, compared to coarse-grained Al6063 alloy. The strengthening mechanisms are discussed based on the dislocation-based models. It is shown that alumina nanoparticles play a significant role on the strengthening of Al6063-Al2O3 nanocomposite. The fracture surfaces of the nanocomposite material exhibited a combination of dimple and cleavage fracture modes. |
Keywords: |
Al6063; Al2O3; Nanocomposite; Mechanical alloying; EBSD; Strengthening mechanism |
Status : Paper Accepted (Oral Presentation) |