Mechanical and thermal properties of spark plasma sintered Alumina-MWCNTs nanocomposites prepared via improvised colloidal route

Abstract

This paper concentrates on the fabrication of Al2O3-MWCNTs composites by spark plasma sintering at temperature of 1400 °C by varying the percentage of MWCNTs and alumina through colloidal route. The effect of incorporating MWCNTs into Al2O3 were examined for physical, mechanical, and thermal properties and characterised using techniques like scanning electron microscopy, X-ray diffraction and elemental analysis. The characterized composites corresponded towards the phases of α-Al2O3 and carbon which were further confirmed through SEM and EDS. Densification behaviour of the nanocomposites revealed reduction in relative density with increase in MWCNTs content. Mechanical properties like Vickers hardness, fracture toughness and flexural strength of composites were analysed along with its thermal and wear behaviour under varying load and sliding distance. Composites with MWCNTs incorporation led to enhanced mechanical properties with 1 wt% reinforced Al2O3 demonstrating superior hardness (17.26 ± 0.4 GPa), fracture toughness (KIC = 5.6 ± 0.3 MPa m1/2) and flexural strength (515 ± 33 MPa) compared to the monolithic Al2O3.