Abstract:The microstructures of ultrafine WC powders were studied by means of TEM and XRD. The results show that there exist highly densified stacking faults, dislocation networks and mosaicstructures in the ultrafine WC powders, and that the microstress in the crystallines is high. The mosaic structures' sizes determind by XRD obey the same changing law as the powder sizes determined by TEM observations,but the former ones are smaller than the latter ones. which is related with the stucking faults and mosaic structures in the powders.

Key words: tungsten carbide ultrafine powder micro-structures cemented carbide