Mass spectrometric study of the laser‐evaporated TaC–ZrC mixed carbide up to 4550 K

Abstract The vapor composition of the TaC–ZrC mixed carbide system was examined in the vicinity of its melting domain. Single‐phase TaC–ZrC carbide samples of different compositions (with a mole fraction of TaC from 50 to 95 %) were prepared and their laser‐induced vaporization was analyzed using time‐of‐flight mass spectrometry. The measurements of relative partial pressures of the main vapor species of TaC–ZrC carbide were taken in the temperature range from 4200 to 4550 K. It was established that in vapor, the atomic ratios of Zr/Ta and C/(Zr+Ta) depended only on the composition of the carbide itself, but were independent of temperature. Moreover measured C/(Zr+Ta) atomic ratio was close to 1.3 in a wide composition range except the situation when the fraction of TaC in the carbide is more than 95 %.