Metastable and quasiperiodic phases in rapidly quenched Fe–B–Si–Nb(Cu) alloys

Abstract

The formation of metastable phases as a result of devitrification of amorphous iron‐based alloys, in particular at the initial stages of the process, was investigated. Compositions with 4–14 at% B, 3–10 at% Nb, 13–15 at% Si, 0–1 at% Cu were studied by means of transmission electron microscopy, X‐ray diffraction, and differential thermal analysis. The following metastable phases were observed: bcc phase with α‐Mn‐type structure; quasiperiodic structure with cubic symmetry; hexagonal phase (rhombohedral distortion of α‐Mn structure); and Laves C14 phase. Some of these phases are also observed in “Finemet” alloys with 1% Cu: cubic quasiperiodic phase and α‐Mn‐type phase after laser annealing of amorphous phase, and the hexagonal phase at the late stages of crystallization. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Crystallization process and glass stability of anFe48Cr15Mo14C15Hirata1, Hirotsu2, Amiya3 et al. 2008Phys. Rev. B521260View full textAdd to dashboardCite

“…It is likely that the LPSs are similar to the ␣-Mn-like ͑␣-Mn is a prototype of -FeCrMo͒ quasiperiodic structure already found in the Fe-B-Si-Nb alloy. 19 In addition, the Qi͑Q͒ profile at 893 K, where perfect -FeCrMo was hardly found, can be explained by using the -FeCrMo structure. Here, it should be noted that the -FeCrMo structure includes atomic coordination polyhedra with coordination numbers of 12, 13, and 16.…”

Formation, Time–Temperature–Transformation curves and magnetic properties of FeCoNbSiBP metallic glasses

“…Master alloys with nominal composition (atomic percent) Fe 52 Co 23 Microstructure analysis has been carried out using a Leica Stereoscan 420 Scanning Electron Microscope (SEM) and phase composition was checked by Energy Dispersive X-ray Spectroscopy (EDS). XRD patterns were collected using Co Ka and Cu Ka radiation to examine the structure of the master alloys, of the as-quenched and annealed ribbons.…”

“…4d). The H phase has hexagonal structure and has been reported as rhombohedral distortion of the a-Mn type cubic structure [23]. It has already been found during the early stages of crystallization of Fe-Si-B-Nb alloys with more than $8 at.% B and low content of Nb (0.5/4 at.%) [24].…”

Quasicrystal-like structure and its crystalline approximant in an Fe48Cr15Mo14C15B6Tm2 bulk metallic glass

“…In previous works, the ␣-Mn type structure was frequently found in Fe-based metallic glasses [17][18][19][20][21][22]. Before the formation of -FeCrMo, moreover, -FeCrMo-like structures similar to quasicrystals were also observed as nanograins with a size of about 5 nm [23].…”