Production of aluminium foams reinforced with silicon carbide and carbon nanotubes prepared by powder metallurgy method

Abstract

In this study, aluminium foams reinforced with silicon carbide and carbon nanotubes were produced by powder metallurgy method. The master alloy aluminium powder (AlSi12) was used as the matrix material, titanium hydride (TiH2) powder was used as a foaming agent and silicon carbide (SiC) particles and carbon nanotubes (CNTs) were used as reinforcing elements. Therefore, 1% of TiH2 by weight and different proportions of SiCx/CNTy (x: 0%, 2%, 4%, 6%, y: 0%, 0.2%, 0.5%, 0.8%, 1%) were added into the master alloy AlSi12 powder and mixed. The mixed powders were further pressed at a pressing pressure of 600 MPa and a temperature of 430 °C. The pressed samples were subjected to the extrusion process at 430 °C, and samples having diameters of 11.76 mm were produced. The foamable precursor materials that were obtained in this manner were subjected to the foaming process at a temperature of 750 °C. The experimental results exhibited that the relative density values of more than 94% were obtained from the foamable precursor materials. It was determined that the CNT and SiC particles significantly affected the elastic–plastic deformation behaviour of the precursor materials. Further, increasing tendencies have been observed in the case of Young's modulus and averege stress in composite foams depending on an increase in the number of CNT and SiC particle.