Mechanochemical study of a novel Magnesium alloy with trace addition of Gd, Nd, Ce, and La rare-earth and Sr elements.

This article focuses on the development and evaluation of Mg-Zn-Ca-Mn magnesium alloys micro-alloyed with trace amounts of rare-earth (RE) elements—Gadolinium (Gd), Neodymium (Nd), Cerium (Ce), Lanthanum (La)—and the alkaline element Strontium (Sr). The study analyzes the microstructure, mechanical properties, and corrosion behavior of these extruded alloys using microscopy, X-ray diffraction, tensile testing, immersion, and electrochemical methods. Results show that Gd- and Nd-containing alloys exhibit the highest yield and ultimate tensile strengths, while the Sr-containing alloy has the greatest elongation. Corrosion resistance is superior in Gd-, Nd-, and Sr-containing alloys, primarily due to their lower fraction of secondary phases, which act as micro-galvanic cells; Ce- and La-containing alloys demonstrate higher corrosion rates linked to greater secondary phase fractions. The findings indicate that the fraction of secondary phases is the dominant factor influencing corrosion rates, and the Mg-4Zn-0.7Ca-0.5Mn alloys with Gd or Nd additions offer the best balance of mechanical strength and corrosion resistance.