Mössbauer spectrometry of near equiatomic Fe–Cr alloys: Influence of preparation method

Long ball-milling of bcc-FeCr at different injected powers: Amorphization and partial crystallization

“…The calculated field is 17.5 T for the starting alloy and 20.0 T from the composition of alloys milled for 500 h and longer. As milling decreases the field by about ∼ 2 T [5], the expected field of ∼ 18 T agrees with experiment. Figure 2 shows the paramagnetic area fraction A P (t), as obtained from Mössbauer spectra, as a function of milling time for the alpha phase for both series.…”

“…For series 2 (A ∼ 2.0 to 2.5), the composition of the alpha phase is Fe 57.1 Cr 42.9 at% and Fe 58.0 Cr 42.0 at%, after 960 h and 2430 h of milling, respectively. These compositions were estimated from the hyperfine magnetic field values [4,5] and are close to those obtained from microprobe analysis of some samples. The iron content increases due to contamination by the milling tools, but the oxygen, despite its increase, remains small even after 1500 h hours of milling.…”

Mechanically induced phase transformations of the sigma phase of nanograined and of coarse-grained near-equiatomic FeCr alloys

“…Similarly, the mean hyperfine magnetic fields of coarse-grained bcc Fe 0.51 Cr 0.49 are essentially identical ( B = 16 T) when the alloy is filed (d = 250 nm) or when it is ball-milled (d = 25 nm) despite domain sizes d which differ by an order of magnitude [42].…”

Debye temperature of nanocrystalline Fe–Cr alloys obtained by mechanical alloying

“…The total milling time was 16h at maximum, but it was interrupted every hour for 15 min. The total milling time was not the same for all samples in order to obtain samples with different crystallite sizes, but the time was always been sufficient to form an alloy, as known from our previous studies in mechanosynthesis of Fe-Cr alloys [22][23][24][25]. The chemical composition analysis of the samples was performed by electron probe microanalysis (EPMA) with a Camebax SX 50 system -see Table 1.…”

“…Results depicting the Debye temperature obtained with the Mӧssbauer spectroscopy (MS) on a series of nanometer-sized Fe 100-x Cr x alloys (0  x  84), hereafter called n-Fe 100-x Cr x , obtained by mechanical alloying (MA) are reported in this paper. Although n-FeCr alloys prepared by MA were often studied by MS e. g. [13][14][15][16][17][18][19][20][21][22], there is not, to our best knowledge, such study on the Debye temperature known in the available literature.…”