Sintering and Characterizations of WC-20wt.% (Fe,Co) Nano-Structured Powders Developed by Ball-Milling

Subject Areas : Composite materials

Minoo Karbasi ¹ , Maryam Karbasi ² , Ali Saidi ³ , Mohammad Hossein fathi ⁴

1 - Department of Materials Engineering, Isfahan University of Technology, Isfahan, 8415683111 IRAN
2 - Instructor Department of Materials Engineering, Isfahan University of Technology, Isfahan, 8415683111 IRAN
3 - Professor Department of Materials Engineering, Isfahan University of Technology, Isfahan, 8415683111 IRAN
4 - Professor Department of Materials Engineering, Isfahan University of Technology, Isfahan, 8415683111 IRAN

Received: 2014-04-23 Accepted : 2014-08-30 Published : 2014-08-01

Keywords: Microstructure, WC-based cemented carbides, Ball milling, Hardness, Sintering,

Abstract :

The aim of the present work is to study the effects of the nanostructured WC-20 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 30 nm) in the binder matrix was formed after 25 h milling. The hardness and the relative density of the WC-20wt. % (Fe,Co) composites consolidated by conventional sintering at 1350˚C were investigated. In sintered samples after 25 h milling, tungsten carbide grains have a uniform distribution with a lower grain size. Densification and hardness improved after 25 h milling and reached optimum levels for the 25 h milled powders with equal ratio of iron to cobalt.