Growth behavior of WC grains with two different sizes in the same liquid matrix has been studied in the WC-36％Ni3Al (volume fraction) system.Traditional powder metallurgy technology was used to manufacture the WC-36％Ni3Al composites and WC-36％Co composites.SEM imaging was performed on etched sections using a scanning electron microscope with an X-ray energy dispersive spectroscopy system.The chemical compositions of binder phase were characterized by energy dispersive spectroscopy.The high-magnification WC morphology was measured using transmission electron microscopy.The samples were sintered under a carbon saturated condition.The present investigation shows that surfaces of coarse WC grains and fine WC grains are strongly micro-faceted and stepped.The growth behavior of fine WC grain is affected by lower solubility of W in Ni3Al matrix and the abnormal growth of WC grains is suppressed.With the increase of sintering time,the average size of the coarse WC grains increases continuously and very large oriented plate-like triangular prismatic WC grains appear,which is attributed to the difference in energy between the two families of prismatic planes.
NETL
NSTL
万方数据
维普
