Effect of sintering temperature on a single-wall carbon nanotube-toughened alumina-based nanocomposite

Spark plasma sintering is used to produce single-walled carbon nanotube-toughened Al2O3-based composites that exhibit excellent toughness (6.9–9.7 MPa m1/2), being at least two times higher than that of single phase alumina. Raman spectroscopy indicates that carbon nanotube cannot be retained at high sintering temperature. A high compressive stress (2.0 GPa) in the alumina matrix is also responsible for the improvement in toughness. The controversy in the literature over the effective toughening of alumina by carbon nanotube is discussed.