Microstructure and mechanical properties of the Mg–Zn–Cu/SiC p composite in the as-cast and as-extruded conditions

• Published in: Journal of materials research 2019-11, Vol.34 (21), p.3707-3716
• Main Authors: Nafari, Afshin, Malekan, Mehdi, Lotfpour, Mehrab
• Format: Article
• Language: English
• ISSN: 0884-2914; 2044-5326
• DOI: 10.1557/jmr.2019.246

Effects of adding different amounts of SiC p on the microstructure and mechanical properties of the as-cast and as-extruded Mg–7% Zn–1.5% Cu (ZC71) alloys were studied. The as-cast ZC71 alloy consisted of α-Mg phase that encircled with the MgZnCu and Mg(Zn,Cu) 2 intermetallics. Hot extrusion has led to a grain-refined structure with distributed intermetallics along the extrusion direction. Adding SiC p decreased the grain size values for the as-extruded composites. The Vickers hardness values increased with SiC p addition for both conditions. The ultimate tensile strength and tensile elongation (El%) values reached the optimum level with 5 wt% SiC p addition. More SiC p additions led to more agglomerations and decrement in strength and elongation. The yield tensile strength also increased with SiC additions. Adding 5 wt% SiC p changed the brittle fracture to the more quasi-cleavage. Hot extrusion altered the fracture mode to more ductile for all composites.