Study of Ordering and Properties in Fe-Ga Alloys With 18 and 21 at. pct Ga

摘要

Dynamical mechanical and positron annihilation spectroscopies were applied to study the structure of two Fe-Ga alloys with 18 and 21 at. pct Ga after quenching and subsequent annealing. It was found that the alloy with 18 pct Ga has much better damping capacity (Psi approximate to 30 pct) than the alloy with 21 pct Ga (Psi approximate to 5 pct). The reason for that is the ordering of the Ga atoms in Fe-21Ga alloy. Ordering processes in both alloys are studied at heating by differential scanning calorimetry, dilatometry, and internal friction or by step-by-step annealing using positron annihilation spectroscopy and hardness tests. Experimental results are explained by sequence of ordering transitions: A2 -> D0(3) -> L1(2). (C) The Minerals, Metals & Materials Society and ASM International 2015