Understanding and quantification of grain growth mechanism in ZrO2‑carbon nanotube composites

Publication date: 5 November 2017
Source:Materials & Design, Volume 133
Author(s): Ben Milsom, Harshit Porwal, Giuseppe Viola, Zhipeng Gao, Micheal J. Reece
The high temperature grain growth behaviour of Y2O3 partially stabilised ZrO2 and ZrO2-CNT (0.5 and 2vol%) composites was investigated in a series of isothermal experiments carried out between 1500 and 1800°C. The grain growth activation energy was found to be 417±20kJmol⁻¹ for the ZrO2, which increased with the addition of CNTs to 509±41 and 497±17 kJ mol⁻¹ for the 0.5 and 2vol% composites respectively. A sintering exponent of 2 was observed for the ZrO2, corresponding to normal grain growth, whilst the nanocomposites showed a CNT drag dominated sintering mechanism, with exponents of 2.7 and 3.2 for the 0.5 and 2vol% composites respectively. This work confirms and quantifies the direct influence of CNTs on the grain growth mechanism and activation energy of ZrO2-CNT composites.

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