Sintering and Characterizations of WC-۲۰wt.% (Fe,Co) Nano-Structured Powders Developed by Ball-Milling

The aim of the present work is to study the effects of the nanostructured WC-۲۰ wt. % (Fe,Co) with different ratios of iron to cobalt on the microstructure and hardness of sintered samples. Furthermore, a sample with a cobalt binder under the same condition was produced for the comparison purposes. The nanocomposite development, after different milling times, has been monitored by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). A homogenous distribution of nanostructured WC (crystallite size less than ۳۰ nm) in the binder matrix was formed after ۲۵ h milling. The hardness and the relative density of the WC-۲۰wt. % (Fe,Co) composites consolidated by conventional sintering at ۱۳۵۰˚C were investigated. In sintered samples after ۲۵ h milling, tungsten carbide grains have a uniform distribution with a lower grain size. Densification and hardness improved after ۲۵ h milling and reached optimum levels for the ۲۵ h milled powders with equal ratio of iron to cobalt.

کلیدواژه ها:

WC-based cemented carbides ، Ball milling ، Microstructure ، Hardness ، Sintering