Interface in carbon nanotube reinforced aluminum silicon composites: Thermodynamic analysis and experimental verification

Abstract

Interface in carbon nanotubes (CNTs) reinforced aluminium–silicon composites are studied via thermodynamic and kinetic analysis. A pseudo-phase diagram has been generated based on the thermodynamic calculations to predict the type of carbide (Al 4C 3 or SiC) that would form at the matrix–CNT interface as a function of matrix composition and processing temperature. The pseudo-phase diagram is useful in high temperature processes like thermal spray forming. Critical thickness values for carbide nucleation suggest the formation of Al 4C 3 with Al–11.6 wt.% Si alloy and SiC with Al–23 wt.% Si alloy. Thermodynamic calculations show that the amount of Al 4C 3 increases with an increase in the CNT content. The computed results perfectly agree with the results obtained by XRD, SEM of fracture surface and high-resolution transmission electron microscopy (HRTEM) observations on Al–11.6 wt.% Si and Al–23 wt.% Si alloy reinforced with CNT.