Nanocrystalline bcc solid solutions of Al-Fe-V system prepared by mechanical alloying

Solid state reactions in Al50Fe50, Al50Fe45V5 and Al50Fe25V25 powder mixtur es by mechanical alloying (MA) and following annealing were studied. MA war performedin the high energy planetary ball mill in an argon atmosphere. X- ray diffraction (XRD) and Mossbauer spectroscopy (MS) methods were used. If was established that the partially ordered solid solution of B2 type has b een formed in the Al50Fe50 alloy and the BCC (A2) phase has been formed in the V containing alloys According to MS one can conclude that the short ran ge order of B2 type in the mechanically alloyed Al50Fe45V5 and Al50Fe25V25 alloys was presented too. MA phases were characterised by a crystallite siz e of 10 nm. Annealing at 750 degrees C for 2h of mechanically alloyed Al50F e50 and Al50Fe45V5 resulted in the formation of completely ordered B2 phase s. After annealing of the Al50Fe25V25 alloy the A2 structure transformed in two phases - with B2 and D8(a) structure. (C) 1999 Acta Metallurgica Inc.