High temperature x ray diffraction determination of the body-centered-cubic–face-centered-cubic transformation temperature in (Fe70Ni30)88Zr7B4Cu1 nanocomposites

Abstract

In situ high-temperature x ray diffraction and magnetization measurements were performed on a melt-spun (Fe70Ni30)88Zr7B4Cu1 amorphous alloy to follow its structural evolution. At 728 K, a bcc-FeNi phase was observed as the primary crystallization product followed by transformation to an fcc phase ∼773 K. During cooling to room temperature, the fcc-to-bcc transformation was not observed, and the metastable fcc-NiFe phase was retained at room temperature.

Nanostructure and compositional segregation of soft magnetic FeNi‐based nanocomposites with multiple nanocrystalline phases

“…In Fig. 2(b), two individual BCC and FCC nanocrystalline grains are found to be contact with a Kurdjumov-Sachs orientation relationship with the BCC in a [1][2][3][4][5][6][7][8][9][10][11] zone axis and the FCC in a [110] zone axis orientation [21]. Cube-on-cube orientation relationships have also been observed.…”

“…Newer alloy systems are being explored that have substantially modified compositions with a significant content of other ferromagnetic transition metal elements such that other close-packed nanocrystalline phases (e.g., FCC, HCP) become similar or lower in free energy as compared with BCC-derivative phases. These alloys are based upon (i) high Co-containing alloys in which nanoscale BCC, FCC, and HCP (as well as highly faulted close-packed) grains can be found in varying proportions and (ii) FeNi alloys for which nanoscale FCC grains become a significant or dominant crystalline phase after optimized annealing treatments [3,4,5,6,7,8,9]. These alloy systems are attractive for numerous applications, as they exhibit unique mechanical and magnetic properties which make them highly scalable from a manufacturing perspective and exceptionally tunable in terms of magnetic properties through the application of field and mechanical strain during thermal annealing [4,8,10,11,12,13].…”

“…In the case of FeNi-based alloy systems, interesting observations have also been reported in the literature regarding the interplay between BCC and FCC based nanocrystals forming during primary crystallization processes. A detailed high-temperature X-ray diffraction study of an (Fe 70 Ni 30 ) 88 Zr 7 B 4 Cu 1 alloy demonstrated initial nucleation of BCC nanocrystals during the early stages of crystallization followed by the formation of FCC nanocrystals at higher annealing temperatures [5], with retention of FCC metastable nanocrystals upon cooling to room temperature. In a detailed study of the (Fe 1-x Ni x ) 80 Nb 4 Si 2 B 14 alloy system with varying Fe and Ni content, the x=0.3 composition was found to lie approximately at the transition between predominantly FCC as compared with BCC nanocrystals with BCC phase dominating in the more Fe-rich compositions as would be expected [3,4].…”

Nanostructure and compositional segregation of soft magnetic FeNi-based nanocomposites with multiple nanocrystalline phases

“…In Fig. 2(b), two individual BCC and FCC nanocrystalline grains are found to be contact with a Kurdjumov-Sachs orientation relationship with the BCC in a [1][2][3][4][5][6][7][8][9][10][11] zone axis and the FCC in a [110] zone axis orientation [21]. Cube-on-cube orientation relationships have also been observed.…”

“…Newer alloy systems are being explored that have substantially modified compositions with a significant content of other ferromagnetic transition metal elements such that other close-packed nanocrystalline phases (e.g., FCC, HCP) become similar or lower in free energy as compared with BCC-derivative phases. These alloys are based upon (i) high Co-containing alloys in which nanoscale BCC, FCC, and HCP (as well as highly faulted close-packed) grains can be found in varying proportions and (ii) FeNi alloys for which nanoscale FCC grains become a significant or dominant crystalline phase after optimized annealing treatments [3,4,5,6,7,8,9]. These alloy systems are attractive for numerous applications, as they exhibit unique mechanical and magnetic properties which make them highly scalable from a manufacturing perspective and exceptionally tunable in terms of magnetic properties through the application of field and mechanical strain during thermal annealing [4,8,10,11,12,13].…”