Selective laser melted CrMnFeCoNi+3 wt% Y2O3 high-entropy alloy matrix nanocomposite: Fabrication, microstructure and nanoindentation properties

초록

A Y2O3-reinforced equiatomic CrMnFeCoNi high-entropy alloy (HEA) matrix nanocomposite was fabricated by high-energy attrition milling and selective laser melting (SLM) additive manufacturing. The SLM-built HEA nanocomposite possessed heterogeneous grain structures and substructures decorated with a dislocation network and exhibited a high number density of nano-sized Y2O3. The SLM-built HEA + Y2O3 nanocomposite exhibited higher nanohardness (similar to 9.22 GPa) than other equiatomic CrMnFeCoNi HEAs produced by casting (similar to 4.13 GPa) and SLM (similar to 6.95 GPa). This suggested that the dispersion hardening by the Y2O3 nanoparticles enabled superior mechanical properties. This study, therefore, demonstrated that Y2O3 reinforcement can effectively improve the mechanical properties of SLM-built CrMnFeCoNi HEA matrix nanocomposites.

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