Synthesis of nano-RuAl by mechanical alloying

Single phase RuAl has been synthesised directly by an abrupt reaction durin g mechanical alloying (MA). The structural evolution during MA and subseque nt thermal stability of as- milled powders have been analysed by thermal an alysis (DSC) and isothermal annealing. The results indicate that there are two stages of alloying and reaction between Ru and Al in MA before single p hase RuAl is obtained under the present milling conditions, and that the as -milled single phase RuAl undergoes reordering, strain relaxation and grain growth at high temperatures. The grain size of 20-40 nm after annealing at 1073 K for 0.5 h shows a strong stability of the nano-grained RuAl. (C) 20 01 Elsevier Science Ltd. All rights reserved.