Observatorio de I+D+i UPM

Memorias de investigación
Communications at congresses:
Influence of the notch root radius on the fracture toughness of brittle metals: nanostructure tungsten alloy, a case study
Year:2015
Research Areas
  • Physics chemical and mathematical,
  • Engineering
Information
Abstract
Tungsten materials and alloys are considered as candidate materials for next generation nuclear fusion reactors. Unfortunately, its use for structural applications is compromised due to its inherent brittleness. In order to improve this crucial feature, it is necessary to accurately measure its fracture toughness, independent of geometrical parameters and the method used to introduce the induced crack. This is the objective of this work, where the notch tip radius influence on the fracture toughness of a brittle nanostructured tungsten alloy is analysed in depth. Three point bending tests (TPB) were performed at room temperature on four types of notch geometries in which the notch root radius was gradually reduced. Notches were introduced via four different methods: classical diamond disk, diamond wire, razor blade and ultra-short pulsed laser. Single edge notched beam (SENB) specimens overestimate fracture toughness values and introduce some deformation on the notch root grains. Razor blade (SEVNB), however, gives very good results with low dispersion, but is only suitable for coarse grain materials since size effect appears when the grain size decreases. In a case of nanostructured materials as in this case, notch root radius is still too big (several times the grain size), requiring a new method to be implemented. This was solved by producing very sharp single edge laser-notched beam (SELNB) specimens, 5-20 nm root radius, by ultra-short pulsed laser ablation. This method was previously used on ceramics but no evidence of its use was found on metals.
International
Si
Congress
EUROMAT 2015, European Congress and Exhibition on Advanced Materials and Processes
960
Place
Warsaw, Poland
Reviewers
Si
ISBN/ISSN
0000-0000
Start Date
20/09/2015
End Date
24/09/2015
From page
1
To page
1
Proceedings of EUROMAT 2015
Participants
  • Autor: Teresa Palacios Garcia (UPM)
  • Autor: Jose Ignacio Pastor Caño (UPM)
Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Materiales Estructurales Avanzados y Nanomateriales
  • Centro o Instituto I+D+i: CENTRO INVEST. MATERIALES ESTRUCTURALES (CIME)
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