ISSN: 1003-6326
CN: 43-1239/TG
CODEN: TNMCEW

Vol. 27    No. 6    June 2017

Processing, characterization, room temperature mechanical properties and fracture behavior of hot extruded multi-scale B4C reinforced 5083 aluminum alloy based composites
Ali ALIZADEH1, Alireza ABDOLLAHI1, Mohammad Javd RADFAR2
(1. Faculty of Materials & Manufacturing Processes, Malek Ashtar University of Technology, Tehran 15875-1774, Iran;
2. Faculty of Engineering, South Tehran Branch, Islamic Azad University, Tehran 158474-3311, Iran
)
Abstract: Microstructural characteristics and mechanical behavior of hot extruded Al5083/B4C nanocomposites were studied. Al5083 and Al5083/B4C powders were milled for 50 h under argon atmosphere in attrition mill with rotational speed of 400 r/min. For increasing the elongation, milled powders were mixed with 30% and 50% unmilled aluminum powder (mass fraction) with mean particle size of >100 μm and <100 μm and then consolidated by hot pressing and hot extrusion with 9:1 extrusion ratio. Hot extruded samples were studied by optical microscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), tensile and hardness tests. The results showed that mechanical milling process and presence of B4C particles increase the yield strength of Al5083 alloy from 130 to 566 MPa but strongly decrease elongation (from 11.3% to 0.49%). Adding <100 μm unmilled particles enhanced the ductility and reduced tensile strength and hardness, but using the >100 μm unmilled particles reduced the tensile strength and ductility at the same time. By increasing the content of unmilled particles failure mechanism changed from brittle to ductile.
Key words: Al5083 alloy; metal matrix composite; boron carbide; multi-scale composite; hot extrusion; mechanical milling
Superintended by The China Association for Science and Technology (CAST)
Sponsored by The Nonferrous Metals Society of China (NFSOC)
Managed by Central South University (CSU)