A comparison between ultrafine WC-Co and fine WC-VC-Co alloys

During the last few years WC-VC-Co alloys have been developed starting from V8C7, WC and Co powders. After sintering, the alloys are composed of WC, (W,V)C and Co and, at a mean carbide grain size of 1-2 mu m, which can be defined as 'fine', they exhibit a hardness which is equal or superior to that of the hardest WC-Co alloys of equal cobalt content [1]. The hardest WC-Co alloys which are in production at present have mean grain size of approximately 0.4 mu m and are usually referred to as 'ultrafine' [2]. This paper compares the hardness as well as other properties of ultrafine WC-Co and fine WC-VC-Co alloys.