MECHANICAL ALLOYING IN THE FE-AL SYSTEM

The mechanical alloying technique has been applied to alloy synthesis from Fe-Al powder mixtures containing 10, 20, 30, 40 and 50 at.% Al. A n evolution of the powder morphology from flaky in the first stage to spherical in the final stage has been observed. The particle size has been estimated as 50 and 5 mum in the first and final stages of millin g respectively. For all alloys studied a disordered b.c.c. solid solut ion has been formed by ball milling. A grain size of several nanometre s and a maximum r.m.s. strain level up to 1% have been observed. The c hange in lattice parameter has been calculated to be up to 2.4%.