Strengthening Mechanism of TiB₂-5%TaB₂-1%CoB and TiB₂-5%W₂B₅-1%CoB Materials

Abstract

TiB₂-5%TaB₂-CoB and TiB₂-5%W₂B₅-1%CoB materials have higher transverse rupture strength, hardness and density than those of TiB₂-1%CoB materials. The strengthening mechanism of both types materials, TiB₂-5%TaB₂-1%CoB and TiB₂-5%W₂B₅-1%CoB, has been discussed. The higher transverse rupture strength of the both materials has been caused mainly by suppressing grain growth of TiB₂ with the solid solution between TiB₂ and TaB₂, or between TiB₂ and W₂B₅, and caused secondarily by the lattice strain of TiB₂, and reduction of residual pores.