Published online by Cambridge University Press: 31 January 2011
No abrupt reaction was observed during mechanical alloying (MA) of Ru and Al powder mixtures with an eutectic composition (Ru70Al30). As-milled powders constitute mainly a Ru(Al) solid solution and/or mixture (matrix), and a very small quantity of RuAl. The complete reaction between Ru and Al during MA was speculated to be hampered by excess Ru in Ru70Al30. No exothermic heat release was detected in differential scanning calorimetry for as-milled powders. Precipitation of RuAl from as-milled Ru(Al) matrix was observed after annealing at various temperatures. The phase fraction of Ru and RuAl reaches an approximately equilibrium value after annealing at 1173 K.