Synthesis of onion-like carbon-reinforced AlCuFe quasicrystals by high-energy ball milling

Abstract

High-energy ball milling of a hexagonal carbon and AlCuFe pure quasicrystal (QC) powder mixture was performed to prepare a nanocomposite material. The structure and morphology of as-milled powders were investigated using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). XRD results revealed that, with increasing milling time, the peaks of the quasicrystalline phase become broader, whereas the peaks of the hexagonal carbon phase gradually disappeared, indicating the nanostructured nature of the sample. The Raman spectra observations revealed the presence of nanocrystalline carbon particles used as reinforcements in the composite. TEM results confirm that the high-energy ball milling method led to the formation of a nano-quasicrystalline material with highly deformed onion-like carbon (OLC) particles in a relatively short period of milling time. In the SEM analysis, it was found that the powder particles are refined during the milling process. However, it was observed by TEM that the particle size of the QC is clearly larger than the OLC particles, indicating the ability to obtain good dispersion and homogeneity of the reinforcement. The OLC particles have diameters ranging from 4 to 12 nm, and the number of graphite layers varies from 8 to 22. High-resolution TEM images show that the as-prepared OLC shows an intershell spacing around 0.33 nm, which corresponds to the (002) crystallographic planes of hexagonal graphite. The obtained OLC can be used as reinforcement in the QC matrix to get a product with high hardness and wear resistance.