Formation of (W,V)C_x layers at the WC/Co interfaces in the VC-doped WC-Co cemented carbide

摘要

WC-Co hard metals are practically important materials widely used for cutting tools, mining tools, and many other wear parts. The hard metals are generally fabricated by liquid-phase sintering above the eutectic temperature of a ternary system of W, C, and Co [1 ]. After sintered, they show the composite structure of hard WC grains bound with Co-based phase [2]. In the hard metals, decreasing the WC grain size is one of the effective ways to improve their mechanical properties [3]. In the purpose of decreasing the grain size, other carbides are often added as grain growth inhibitors [4]. Especially, VC remarkably inhibits the WC grain growth during liquid-phase sintering [5]. To reveal the grain growth inhibition mechanism, there are many reports which observed the micro structures in other carbides doped hard metals [6-10].