Crack propagation characteristic and toughness of functionally graded WC–Co cemented carbide

The propagation characteristic of cracks produced at the corners of Vickers indent and the toughness change in functionally graded WC–Co cemented carbide with dual phase structure were investigated. It is shown that cracks tend to propagate both around and across WC crystal grain and in the presence of η phase across η(W3Co3C) phase with high resistance. The changes of toughness with the microstructure and an integrated strengthening effect, as well as high toughness characteristic of the alloy are revealed.