Cutting performance of two-layered cutting tool tips with thin M20 and K10 sintered carbide plates compared to homogeneous tips

Two-layered cutting tool tips with thin sintered carbide plates on the rake faces are introduced as a means to significantly reduce tungsten consumption in cutting tools as a response to the sharp and manifold rise of global tungsten raw material prices. The objective of this study is investigation of factors leading to premature failure of the two-layered cutting tool tips as compared to homogeneous sintered carbide tips. Cutting tests were performed and the effects of coolant, thin sintered carbide plate material type and its thickness on stress state and fracture are discussed. It was established that the absence of coolant, as well as, higher Young's modulus and less thickness of the thin sintered carbide plate results in higher stresses on the tip's rake face, leading to its premature failure.