Electron beam melting of (FeCoNi)86Al7Ti7 high-entropy alloy

The development of traditional alloy materials has reached the bottleneck due to the constructive interaction between strength and plasticity. Hence, novel alloy systems like (FeCoNi)86Al7Ti7 high-entropy alloys (HEAs) were fabricated using selective electron beam melting (SEBM). The (FeCoNi)86Al7Ti7 HEA dominantly consisted of ordered L12 and disordered fcc matrix phases. The bottom surface (SEBM-bottom)) of the (FeCoNi)86Al7Ti7 HEA blocks presents an equiaxed microstructure; however, coarse columnar grains across layers were observed along the building direction (SEBM-side). Island-like precipitates (ILPs) are distributed evenly within the equiaxed grain. The boundaries of columnar grains and high-density multicomponent cubic nanoparticles (MCCNPs) are dispersed uniformly in the matrix. A strong < 100 > // building direction (BD) fiber texture can be observed. The (FeCoNi)86Al7Ti7 HEA exhibits superior strengths of 2048 MPa and up to 12% ductility at ambient temperature. However, the SEBM (FeCoNi)86Al7Ti7 HEA exhibits anisotropy in its mechanical properties.

Automated summary

Novel alloy systems, such as (FeCoNi)86Al7Ti7 high-entropy alloys, were fabricated using selective electron beam melting. These alloys exhibit ordered L12 and disordered fcc matrix phases. The equiaxed microstructure is observed on the bottom surface, while coarse columnar grains are observed along the building direction. Island-like precipitates and high-density multicomponent cubic nanoparticles are uniformly distributed in the matrix. The (FeCoNi)86Al7Ti7 HEA demonstrates superior strength and ductility, but also exhibits anisotropy in its mechanical properties.