Cumulative effect of strength enhancer—Lanthanum and ductility enhancer—Cerium on mechanical response of magnesium

Abstract

In the present work, the cumulative effect of strength enhancer Lanthanum (La) and ductility enhancer Cerium (Ce) on the mechanical response of pure Mg was investigated. A ternary Mg-4La-0.4Ce alloy was developed using a disintegrated melt deposition method followed by hot extrusion. The mechanical characterization revealed that the ternary alloy exhibited superior hardness and tensile and compressive strengths when compared to Mg and Mg-0.4Ce binary alloy, thereby validating the role of La as a strength enhancer. Furthermore, the ductility of the chosen alloy was also enhanced as compared to Mg and other La rich Mg alloys, indicating that the ductility enhancement is primarily due to Ce. The microstructural characterization revealed that the cumulative addition of La and Ce refined the grain size and led to the formation of a large volume of secondary phases which affected the mechanical properties. The effect of fine grains and the presence of secondary phases on the deformation behavior of the alloy were conclusively ascertained with the aid of deformation and fracture studies. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.