Study of Alpha-Sigma Phase Transformation in Mechanically Alloyed Fe-Cr-Sn Alloys

Abstract

The solubility of tin is significantly extended by mechanical alloying in near equiatomic Fe-Cr alloys. The influences of Sn concentration and of grain size on the kinetics of formation of the s-phase have been studied using different techniques. The s-phase formation is much faster for as-milled alloys than it is for conventional alloys. The s-phase formation rate decreases with the increase of Sn concentration in alloys with nanometer-sized grains as it does in coarse-grained alloys. The mechanisms which are responsible for the slowing-down of the a-s transformation are different in both kinds of alloys.

Metallography of Sputter-Deposited SS304+Al Coatings

“…In steels, it is generally observed at relatively high temperatures and usually forms after prolonged heat treatments together with a higher content of r-forming elements like Cr, V, Nb, and Mo [33]. Precipitation of the r phase typically requires hundreds of hours and high temperatures between 500 and 800°C [34][35][36]; its formation was observed to occur faster during friction stir welding [37] and also during mechanical alloying [38].…”

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.…”

Suppression of σ-phase in nanocrystalline CoCrFeMnNiV high entropy alloy by unsolicited contamination during mechanical alloying and spark plasma sintering

“…MA being a non-equilibrium process, it is also important to briefly discuss the kinetic factors affecting the precipitation of σ-phase. The evolution of σ-phase during non-equilibrium processing routes has been investigated previously for binary [27][28][29] and ternary alloys [30]. MA, in general, provides both favourable scenario as well as kinetic constraints for the precipitation of σ-phase.…”