A novel Bi-processing technique for metal matrix nanocomposites

Abstract

The main problem of reinforcing metal matrix with nanoreinforcements is how can each single nanoreinforcement be well dispersed or/and aligned in a specific location and direction without any agglomeration or randomness. This study presents a novel solid-state Bi-processing technique for forming homogenous metal matrix nanocomposites (MMNCs). In this paper, carbon nanotubes (CNTs) of three weight concentrations were dispersed in precursor carbon polymer solution (PCPS). CNTs/PCPS dispersions were electrospun under optimum electrospinning conditions, and the collected hybrid CNT/precursor carbon nanofibril (CNF) hybrid fabrics were thermally stabilized under a static pressure in two steps to activate its high surface energy aiming to build strong and flexible CNT/CNF hybrid fabrics of 60-MPa strength. The flexible hybrid CNT/CNF fabrics were then placed in fine grooves that were machined in pure aluminum metal substrate. Then, friction stir process (FSP) was applied to produce aligned and well-dispersed CNT/CNF hybrid fabrics in aluminum matrix. Morphological characterization by using scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM) were conducted. Also, tensile and micro-hardness properties were evaluated in detail. The results proved the possibility of producing MMNCs by using Bi-processing technique (electrospinning and FSP) for the first time in literature.