Effect of Cu on microstructure evolution and mechanical properties of Fe-Nb dissimilar welds

Publication date: 1 January 2019Source: Materials Letters, Volume 234Author(s): Qiaoling Chu, Min Zhang, Jihong Li, Fuxue Yan, Cheng YanAbstractIn this paper, we report a thorough study of phase formation in Fe-Nb weld metals using a combination of microscopy and composition analysis. The correlation of microstructure and mechanical properties was established by nanoindentation. A simplified scenario of weld formation was proposed. Nb weld metal was dominated by the coarse Laves phase (Fe2Nb) with high hardness (∼20.4 GPa). With the addition of Cu, sound weld metal was obtained with alternative distribution of α-Fe, Cu phases and fine eutectic phases (α-Fe + Fe2Nb). These transformation products with lower hardness (α-Fe + Fe2Nb ∼ 11.6 GPa) improved the overall mechanical properties of the weld metal.Graphical abstract
Source: Materials Letters - Category: Materials Science Source Type: research