Characterization of microstructures and age hardening of Fe1
2xAlxVx alloys

P.A. FERREIRÓS; P.R. ALONSO; P.H. GARGANO; P.B. BOZZANO; H.E. TROIANI; A. BARUJ; G.H. RUBIOLO

INTERMETALLICS

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2014 p. 65 - 78

0966-9795

The Fe-rich corner of the FeeAleV system has shown phase separation into disordered A2 and orderedL21 phases. In a former work we model this ordering reaction by using ab-initio thermodynamics. Theapproach is now employed to suggest the Fe1
2xAlxVx alloys in order to reduce the Al content byincreasing the addition of vanadium looking for a better ductility of the solid solution which can beafterwards strengthened by coherent L21 precipitates. Four alloys with compositions in the range0.08 < X < 0.15 were studied. The phase transition temperatures and microstructures of the alloys werecharacterized by differential scanning calorimetry (DSC) and transmission electron microscopy (TEM),respectively. The region (A2 þ L21) occurs for 0.10 < X < 0.15 up to maximum temperature of 720 C,higher temperatures causes the appearance of (A2 þ B2), B2 and (B2 þ L21) regions. The microstructurein the (A2 þ L21) region consists of nanosized precipitates of L21 phase in A2 matrix which morphologyevolutes with temperature and ageing time. The hardness values, measured at room temperature, for thealloys with X < 0.125 and ageing temperature between 650 and 700 C are comparable to those obtainedwith other FeeAl based alloys.