Effect of HNT on the Microstructure, Thermal and Mechanical Properties of Al/FACS-HNT Composites Produced by GPI

Abstract

To develop an optimised manufacturing method of fly ash-reinforced metal matrix composites, the preliminary tests were performed on the cenospheres selected from fly ash (FACS) with halloysite nanotubes (HNTs) addition. The preform made out of FACS with and without the addition of HNT (with 5 and 10 wt.%) has been infiltrated by the pure aluminium (Al) via adapted gas pressure infiltration process. This paper reveals the influence of HNT addition on the microstructure (analysis was done by computed tomography and scanning electron microscopy combined with energy-dispersive x-ray spectroscopy), thermal properties (thermal expansion coefficient, thermal conductivity and specific heat) and the mechanical properties (hardness and compression test) of manufactured composites. The analysis of structure-property relationships for Al/FACS-HNT composites produced shows that the addition of 5 wt.% of HNT to FACS preform contributes to receiving of the best mechanical and structural properties of investigated composites.