The ω-phase formation in titanium upon deformation under pressure

Reobservations on ordering, precipitation and polymorphic phase transformation phenomena during annealing of a severely cold rolled magnetic Fe-Co-10V alloy

“…According to extensive SEM study (not all images shown here), these precipitates could be observed after 10 min soaking at 550 °C. Previous studies [11][12][13]15,21] on ternary Fe-Co-V system have argued that the crystal structure of these precipitates is L1 2 (ordered FCC) except for the work of Saito [54] on binary Co-V system, who reported that these particles are of HCP crystal structure and have the exact stoichiometric composition of the Co 3 V compound. Owing to the nanometric size scale of those precipitates overlapping the diffraction patterns of the precipitates and the surrounding matrix, we employed a deep etching technique dissolving the ferrite (actually low vanadium content phases) to patently determine the crystal structure of these precipitates.…”

“…Anyway, despite the significant effect of these precipitates on magnetic properties of Fe-Co-V based alloys due to their paramagnetic nature [1,[11][12][13][14][15]21,53], the precipitation phenomenon has not attracted much attention yet. Therefore, we investigated microstructural and morphological features of the precipitates as well as temperature intervals for the precipitation using various techniques.…”

“…Furthermore, the composition of the precipitates, determined in the etched region of the samples, was found to be constant (Co,Fe) 3 V while annealed at temperatures of 600 and 650 ºC (Table 2), whereas the composition of the austenite changed. In a number of studies [11][12][13]15,21], the ordered L1 2 austenite has been considered as precipitated particles, and this is an obvious reason for some discrepancies concerning the morphological features of these precipitates (Table 8).…”

“…Existence of blocky Co 3 V precipitates has been reported by Hasani et al [20] in an Fe-Co-7.15V alloy while no precipitation phenomenon was observed in the study of Zakharov et al [18] for a similar alloy. Zel'dovich et al [15,21] have reported two kinds of morphology for precipitates in an Fe-52.9Co-10.6V, namely rod-shaped and broad plates (equiaxed), formed inside and on boundaries of martensite laths respectively. For an Fe-Co-2V alloy, Ashby et al [3] proposed that an iron-substituted Co 3 V compound, (Co,Fe) 3 V with L1 2 (ordered FCC) structure, grows as rods along the 〈 〉 direction of ferrite matrix in the temperature range of 477-627 °C.…”

Stability of B2 phase in Ti–Ni–Fe alloys against MeV electron-irradiation-induced solid-state amorphization and martensite transformation

“…It should be noted that of the compounds in the six systems cited, only TiNi undergoes both SSA and martensite transformation. TiNi undergoes SSA when subjected to various treatments such as electron irradiation [3,4], neutron irradiation [26], ion irradiation [27], compression [28], cold rolling [29e31], shot peening [32,33], and high-pressure torsion [34,35]. TiNi undergoes martensite transformation from the B2 to a monoclinic distorted B19 structure [36].…”