Milling Characteristics of BCC, FCC and HCP Metals

Abstract

Nanoparticles have a wide range of applications like biological sensors, optoelectronic devices, catalysis and nanofluids.Bulk synthesis of nanoparticles by a feasible and economically viable technique is therefore a major research area.Here,in the present research work metals having FCC crystal structure nickel (Ni), BCC crystal structure Iron(Fe)and HCP crystal structure Zinc(Zn) have been milled in a high-energy planetary ball mill and their milling characteristics have been investigated. Mechanical milling (MM) of pure elemental Ni, Fe and Zn powders was carried out in hardened chrome steel medium. Milling was carried out for a period of 20 h using toluene as a process control agent (PCA). As-milled powder samples were taken out at an interval of 5 h of milling. The as-milled powders were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) high resolution transmission electron microscopy (HRTEM), differential scanning cal orimetry and thermogravimetric analysis (DCS/TGA) and particle size analyzer.The variation in crystallite size,lattice strain and lattice parameter of Nickel, Iron and Zinc and with milling time was determined from the XRD spectra of the various as-milled powder samples of Ni, Fe and Zinc.It has been foundthat element Ni, Fe and Zn could be reduced to nanometric dimension within 5 h of milling. From both the XRD and HRTEManalysis of the 20 h milled Ni, Fe and Zn
powdersit could be confirmed that the crystallite size of Ni (20 nm), Fe(24) and Zn (96).