Sd. Kaloshkin et al., Phase transformations in Fe-Ni system at mechanical alloying and consequent annealing of elemental powder mixtures, PHYSICA B, 299(3-4), 2001, pp. 236-241
Fe100-x Ni-x alloys (10 <x < 90at%) were prepared by mechanical alloying (M
A) of elemental powders in a high-energy planetary ball mill and studied by
X-ray diffractometry and Mossbauer spectroscopy. It is shown that the conc
entration ranges of single-phase solid solutions of MA samples extend signi
ficantly as compared with those obtained by conventional techniques. In our
case, the BCC phase exists in the range from 0 to 20 at% Ni and FCC phase
from 30 to 100at% Ni. Block sire was 10-15nm. Consequent annealing of MA sa
mples resulted in further extension of FCC single-phase concentration range
to the relatively low Ni content (20at%). This was caused by considerable
retardation of austenite-martensite transformation in MA alloys. The FCC al
loys with 20-28 at% Ni were found to be non-ferromagnetic at room temperatu
re: only the paramagnetic component was observed in the corresponding Mossb
auer spectra. However, the treatments of low-nickel austenite alloys like c
ooling in liquid nitrogen or mechanical deformation provoked austenite-mart
ensite transformation and led to the rise of ferromagnetic prpoerties. (C)
2001 Elsevier Science B.V. All rights reserved.