Effect of carbide formation at CNT/Al matrix interface on the mechanical properties of Al/CNT composite

In the current study, the effect of aluminum carbide (Al4C3) on the mechanical properties of Al/CNT was investigated. Al nanocomposites reinforced with carbon nanotubes were produced through a several-stage process. At first, carbon nanotubes (CNTs) were crushed by using mechanical milling for 20 hours to prepare carbon source for the synthesis of carbide. Thereafter, crushed-CNTs were added to the raw-CNT and mixed by milling for 1 hour to decorate the surface of raw CNTs with crushed ones. Finally, the resultant powder was mixed with Al, cold pressed and sintered to produce composite sample. Spark plasma sintering was chosen as an alternative sintering process. Metallographic studies confirmed uniform distribution of CNTs in the aluminum matrix. Moreover, carbide formation was confirmed by X-ray diffraction (XRD) analysis. Results of micro-hardness and wear tests showed an improvement in mechanical properties of the produced nanocomposites in comparison with the reference sample (pure Al). The improvement was attributed to the Al4C3 carbide formation.