Microstructural and mechanical properties of in situ Na-modified Al–20%Mg2Si after extrusion process

This study is undertaken to evaluate the hot-extrusion on the microstructure and mechanical properties of in situ Na-modified Al–20 wt.%Mg2Si composite. Microstructural observations showed that hot-extrusion breaks up the dendrite of the primary Mg2Si in unmodified sample and its average particle size decreases. But hasn’t significant influence on primary Mg2Si in modified sample. Tensile tests demonstrate that the hot- extrusion process increases both ultimate tensile strength (UTS) and elongation values of Na-modified composite specimens from 152MPa and 2.2% to 182 MPa and 3.5%. A study of the fracture surfaces via SEM revealed shrinkage in cast composite however hot-extrusion process removes this defect.

Keywords:

Metal matrix composite , Microstructure , Tensile properties , Extrusion