The Effect of sintering temperature on microstructure and hardness of milled WC- ۲۰ wt.% equiatomic (Fe,Co) cemented carbides

In this study, WC–۲۰ wt.% equiatomic (Fe,Co) powder mixture was milled in a planetary ball mill. The effects of different milling time (۱۵ min, ۵h, ۱۰h, and ۲۵ h) and sintering temperatures on the microstructure and mechanical properties of this equi-Fe substituted cermet were investigated. The structural evolution and the crystallite size changes of the powders during milling were monitored by X-ray diffraction (XRD). Microstructure developments of the samples were examined using scanning electron microscope (SEM). The results showed that the crystalline size of WC and internal strain were ۲۲ nm and about ۱.۱ % after ۲۵ hours of milling, respectively. The hardness and the relative density of the WC-۲۰wt.% (Fe,Co) composites consolidated by conventional sintering at different temperatures, ranging from ۱۱۵۰ to ۱۴۵۰ ˚C in hundreds, were investigated. The optimized sintering temperature was measured at ۱۳۵۰°C. At a constant sintering temperature, ۱۳۵۰°C, the highest relative density of ۹۸.۲% and hardness of ۱۲۸۱ (HV۳۰) were obtained for the milling time of ۲۵h.

کلیدواژه ها:

Cemented carbides ، Microstructure ، mechanical properties ، Sintering temperature