Nanoindentation and fracture toughness of nanostructured zirconia/multi-walled carbon nanotube compositesShow others and affiliations
2015 (English)In: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956, Vol. 41, no 2, p. 2453-2461Article in journal (Refereed) Published
Abstract [en]
Multi-walled carbon nanotubes (MWCNTs)/3 mol% yttria-doped tetragonal zirconia (3Y-TZP) composites were produced using spark plasma sintering (SPS) with MWCNT content ranging within 0-2 wt%. In the present paper, it was shown that the addition of MWCNTs results in a refinement of the composites microstructure. Moreover, nanoindentation tests were performed in order to monitor the change in elastic modulus and hardness with MWCNT content and it was found that both properties decrease with the addition of MWCNT content. A novel method was used to measure the true fracture toughness of the composites by producing a shallow surface sharp notch machined by ultra-short pulsed laser ablation on the surface of beam specimens. The true fracture toughness obtained on this laser machined single edge V-notch beam (SEVNB) specimens tested in four point bending was compared to the indentation fracture toughness measured using a Vickers indenter. It was found that the indentation fracture toughness increases with increasing MWCNT content, while the true fracture toughness determined with SEVNB was practically independent of the composition. Finally, it was concluded that the increase in the resistance to indentation cracking of the composites with respect to 3Y-TZP matrix cannot be associated to higher true fracture toughness. The results were discussed in terms of transformation toughening, damage induced in front of the notch tip, microstructure of the composites, and fracture toughness of 3Y-TZP.
Place, publisher, year, edition, pages
2015. Vol. 41, no 2, p. 2453-2461
National Category
Other Materials Engineering
Research subject
Engineering Materials
Identifiers
URN: urn:nbn:se:ltu:diva-7562DOI: 10.1016/j.ceramint.2014.10.060ISI: 000348961400067Scopus ID: 2-s2.0-84919427557Local ID: 5f26f0e1-51b9-4553-ab72-ea559a3acbc8OAI: oai:DiVA.org:ltu-7562DiVA, id: diva2:980452
Note
Validerad; 2015; Nivå 2; 20141021 (andbra)
2016-09-292016-09-292023-09-14Bibliographically approved