Structure of Nanocrystalline Fe_(1-x)Ni_x Alloys by Mechanical Alloying

Nanocrystalline Fe_(1-x)Ni_x(30%≤x≤50%) alloys are prepared by mechanical alloying from pure Fe and Ni powders.The phase transformation and grain sizes of the mechanical-alloyed powders are studied by X-ray diffraction(XRD).It is found from the XRD patterns that the mixed powders have been fully alloyed after milling for 3hrs and the average grain sizes are all lower than 20nm after 10hrs' milling.During ball milling,the average size of grain D in the Fe_(1-x)Ni_x alloys follows exponential relationship.All the samples contain both b.c.c.(Fe,Ni) and f.c.c.(Fe,Ni) solid solution in the early stage of milling,but the b.c.c.phase will transform to f.c.c.phase completely after sufficient milling time.And the time it takes for b.c.c.phase to transform to f.c.c.phase completely decreases with the increasing of Ni content.