Coefficient of friction and wear resistance of zirconia–MWCNTs composites

• Published in: Ceramics international 2015-01, Vol.41 (1), p.459-468
• Main Authors: Melk, Latifa, Roa Rovira, Joan Josep, Antti, Marta-Lena, Anglada, Marc
• Format: Article
• Language: English
• Subjects: B. Nanocomposites; C. Wear resistance; Carbon nanotubes; Coefficient of friction; D. Zirconia; Engineering Materials; Friction; Materialteknik; Nanocomposites; Nanostructure; Reciprocating; Spark plasma sintering; Tetragonal zirconia polycrystals; Wear resistance; Yttria stabilized zirconia; Zirconium dioxide
• ISSN: 0272-8842; 1873-3956; 1873-3956
• DOI: 10.1016/j.ceramint.2014.08.092

Composites of 3mol% yttria-doped tetragonal zirconia (3Y-TZP) reinforced with multiwalled carbon nanotubes (MWCNT) up to 2wt% content have been produced using spark plasma sintering (SPS). The theoretical densities of the studied composites were found to be between 99.4% and 97.4%. The addition of MWCNT content resulted in reduction of 3Y-TZP grain size from 174 to 148nm. The effect of MWCNT on the friction coefficient (COF) was studied by performing nano- and macro-scratches using diamond Berkovich and Rockwell indenters, respectively. Moreover, the COF and the wear rate were also investigated in reciprocating sliding against a zirconia ball under a load of 5N. The results showed that the COF decreased upon the increase in MWCNT content. However, in macro-scratch testing, there was a critical load over which brittle fracture sets in and its value decreases as the MWCNT content increases. The wear resistance was found to be decreasing very slightly for less than 1wt% MWCNT, while it increases strongly for the addition of 2wt% MWCNT under the conditions studied. The results were discussed in terms of material properties, scanning electron microscopy observations of the wear track and nanoindentation tests.