Regularities of the contact interaction of double carbides (Ti1 –nMenIV, V)C with the Ni–Mo melt

Resumo

Regularities of dissolution, phase formation, and structure formation during the interaction of double carbides (Ti_1–nMe_n^{IV, V})C with the Ni–25%Mo melt (t = 1450°C, τ = 1 h, vacuum 10^–1 Pa) are investigated for the first time by electron probe microanalysis and scanning electron microscopy. The role of each alloying metal in the composition and microstructure formation of studied compositions is revealed. It is established that Group IV alloying metals (Zr and Hf) almost do not enter the composition of the forming K-phase (carbide Ti_1–nMo_nC_x); therefore, its composition is independent of their concentration in double carbide. In contrast with zirconium and hafnium, Group V alloying metals (V and Nb) actively participate in the formation of the K-phase; however, the dependences of the composition of the K-phase and metallic matrix on the vanadium and niobium content are the opposite in this case. An interpretation of the causes of these distinctions is proposed.