Synthesis and Characterization of a Novel Mg-Zn-Zr-Cu Alloy by Powder Metallurgy Technique

The present study attempts to fabricate a novel quaternary Mg-Zn-Zr-Cu alloy for high strength applications in automotive industry. The nominal composition of the alloy was made as Mg - 3.0 wt.% Zn - 0.7 wt.% Zr – 1 wt.% Cu. Powder Metallurgy technique (PM) was adopted where the sintering of the compacted specimens was carried out at 450oC and subsequently hot extruded. Hot extruded samples after stress relieving were then subjected to different characterization studies. The results indicated some notable improvement in metallurgical and mechanical properties of Mg-3.0Zn-0.7Zr-1.0Cu alloy in comparison with Pure Mg. A fair distribution of grains was evident from the microstructural examination. This along with restricted localized matrix deformation enhanced the micro hardness of Mg-3.0Zn-0.7Zr-1.0Cu alloy. Mg-3.0Zn-0.7Zr-1.0Cu alloy sintered at 450oC exhibited low porosity, superior micro hardness value (78 HV), tensile yield strength (170 MPa), ultimate tensile strength (244 MPa) and good tensile elongation (7.8%). Thus, it can be inferred that Mg alloys with superior properties can be successfully developed using powder metallurgy process followed by hot extrusion.