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Here, we present a preselected small set of ordered structures (PSSOS) method, a first principles-based high fidelity (HF), high throughput (HT) approach, for fast screening of the large composition space of high entropy alloys (HEAs) to select the most energetically stable, single-phase HEAs. Taking quinary AlCoCrFeNi HEA as an example system, we performed PSSOS calculations on the formation energies and mass densities of 8801 compositions in both FCC and BCC lattices and selected five most stable FCC and BCC HEAs for detailed analysis. The calculation results from the PSSOS approach were compared with existing experimental and first-principles data, and the good agreement was achieved. We also compared the PSSOS with the special quasi-random structures (SQS) method, and found that with a comparable accuracy, the PSSOS significantly outperforms the SQS in efficiency, making it ideal for HF, HT calculations of HEAs. [ABSTRACT FROM AUTHOR]

Tantalum (Ta) metal is receiving increasing interest as biomaterial for load-bearing orthopedic applications and the synthetic properties of Ta can be tailored by altering its grain structures. This study evaluates the capability of sliding friction treatment (SFT) technique to modulate the comprehensive performances of pure Ta. Specifically, novel nanocrystalline (NC) surface with extremely small grains (average grain size of ≤20 nm) was fabricated on conventional coarse-grained (CG) Ta by SFT. It shows that NC surface possessed higher surface hydrophilicity and enhanced corrosion resistance than CG surface. Additionally, the NC surface adsorbed a notably higher percentage of protein as compared to CG surface. The in vitro results indicated that in the initial culture stages (up to 24 h), the NC surface exhibited considerably enhanced osteoblast adherence and spreading, consistent with demonstrated superior hydrophilicity on NC surface. Furthermore, within the 14 days culture period, NC Ta surface exhibited a remarkable enhancement in osteoblast cell proliferation, maturation and mineralization as compared to CG surface. Ultimately, the improved osteoblast functions together with the good mechanical and anti-corrosion properties render the SFT-processed Ta a promising alternative for the load-bearing bone implant applications. [ABSTRACT FROM AUTHOR]