Mechanical Alloying Synthesis of AB3 Zirconium Substituted Intermetallic

Abstract

Several ternary RareEarth-Magnesium-Nickel intermetallics (RE-Mg-Ni) emerged in last decade for their specific hydrogen storage capability. Nickel is now considered among strategic metals with recurrent rising price, Magnesium although its good gravimetric facility suffers from frequent oxidation or irreversible poisoning. Zirconium alloys are recognized for their improved anti-corrosion properties with enhanced wear resistance for high temperature machinability in industrial applications or energy research purposes. We proposed in this paper double substitution possibility replacing Magnesium and reducing Nickel charge. We developed new generation of quaternary Zirconium-AB3 intermetallic LaZr2Ni5Al4 using mechanical alloying method. Two binary raw materials are involved in this alloying reaction, the first is LaNi5 and the second is ZrAl2 (Laves phase C14) and both precursors are achieved quasi-quantitively using high frequency induction melting. The final target AB3 compound crystallizes in Trigonal system with space group R-3m (166) and following experimental conditions (Fritsch P7, Ω = 450 rpm) an acceptable synthesis yield (>80%) is obtained starting from 20 hours mechanical alloying. Rietveld refinement is performed to have real matrix parameters and AB3 powder surface is analyzed using Scanning Electron Microscopy.

Keywords

• intermetallic compounds
• mechanical alloying
• metals and alloys
• Rietveld refinement
• Zirconium