The Effect of Laves Phase (Fe,Al)(2)Zr on the High-Temperature Strength of Carbon-Alloyed Fe3Al Aluminide

摘要

The effects of carbon on the phase structure and on the yield stress sigma(0.2) in the temperature range from 873 K to 1073 K (600 degrees C to 800 degrees C) of the Fe3Al type aluminides alloyed by Zr are analyzed. Four alloys with Zr and C in ranging from 1.0 to 5.0 at. pct of additives were used. The appearing of either Laves phase (Fe,Al)(2)Zr and/or carbides depend on the difference in concentrations, c(Zr) - c(C). This parameter (c(Zr) - c(C)) has been selected instead of the concentration ratio c(Zr)/c(C) used in previous works since it exhibits a significantly better correlation with the Laves phase concentration which influences the high-temperature yield stress, sigma(0.2), of the tested alloys. The presence of Laves phase or eutectic (matrix-Laves phase), respectively, enhances the value of the yield stress sigma(0.2). The amount of Laves phase is decreased by the presence of C due to the affinity of carbon to Zr. (C) The Minerals, Metals & Materials Society and ASM International 2015