文摘
Ta-doping promotes the formation of (Zr,Ta)B2 solid solution during sintering. (Zr,Ta)B2 in the matrix oxidizes into ZrO2 encasing TaB2 nano-sized grains. TaB2, Ta and Ta2O5 are found within the oxidized ceramic. TaB2, in the presence of ZrB2, has excellent stability to oxygen attack up to 1600 °C. Ta-suboxides and Ta2O5 crystals are the detrimental factors above 1650 °C.