Stable, Ductile and Strong Ultrafine HT-9 Steels via Large Strain Machining

El-Atwani O., Kim H., Gigax J. G., Harvey C., Aytuna B., Efe M., ...Daha Fazla

NANOMATERIALS, cilt.11, sa.10, 2021 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 11 Sayı: 10
  • Basım Tarihi: 2021
  • Doi Numarası: 10.3390/nano11102538
  • Dergi Adı: NANOMATERIALS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Communication Abstracts, INSPEC, Metadex, Directory of Open Access Journals, Civil Engineering Abstracts
  • Anahtar Kelimeler: nanocrystalline, large strain machining, microtensile, nanoindentation, HT-9 steel, BULK NANOSTRUCTURED MATERIALS, MECHANICAL-PROPERTIES, STRUCTURAL-MATERIALS, GRAIN-SIZE, IRRADIATION RESISTANCE, MATERIALS CHALLENGES, RADIATION TOLERANCE, MICROSTRUCTURE, NANOCRYSTALLINE, DEFORMATION
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

Beyond the current commercial materials, refining the grain size is among the proposed strategies to manufacture resilient materials for industrial applications demanding high resistance to severe environments. Here, large strain machining (LSM) was used to manufacture nanostructured HT-9 steel with enhanced thermal stability, mechanical properties, and ductility. Nanocrystalline HT-9 steels with different aspect rations are achieved. In-situ transmission electron microscopy annealing experiments demonstrated that the nanocrystalline grains have excellent thermal stability up to 700 & DEG;C with no additional elemental segregation on the grain boundaries other than the initial carbides, attributing the thermal stability of the LSM materials to the low dislocation densities and strains in the final microstructure. Nano-indentation and micro-tensile testing performed on the LSM material pre- and post-annealing demonstrated the possibility of tuning the material's strength and ductility. The results expound on the possibility of manufacturing controlled nanocrystalline materials via a scalable and cost-effective method, albeit with additional fundamental understanding of the resultant morphology dependence on the LSM conditions.