Influence of sintering temperature on the interfacial behavior of Ti3Al(Si)C2 ceramic and Ti6Al4V alloy

Abstract

AbstractMAX phases possess a combination of ceramic and metallic characteristics, exhibiting good mechanical properties, high thermal conductivity, high thermal stability, and corrosion resistance. To apply MAX phases containing Ti and Al in the casting process of titanium alloy to improve the alloy properties, the interfacial behaviors between pre‐sintered Ti3Al(Si)C2 substrates and molten Ti6Al4V alloy were investigated. The results indicated that Ti3Al(Si)C2 substrates, pre‐sintered at 1100°C, exhibited better resistance to the penetration of alloy than those at 1300 and 1500°C. The reason was that the pre‐sintering temperature was a dynamics factor affecting the reaction of the Ti3Al(Si)C2 substrates in a graphite bed to generate titanium carbide. When the pre‐sintering temperature was 1100°C, the reaction was weak and a small amount of carbon was introduced into the pre‐sintered Ti3Al(Si)C2 substrates, which led to a low concentration gradient of Ti between the alloy and the substrates. The low concentration gradient slowed the diffusion speed of the alloy toward the substrates. Besides, remarkable V/Si lines were detected between the alloy and Ti3Al(Si)C2 substrates for all tested samples. The interface reaction between pre‐sintered Ti3Al(Si)C2 samples and Ti6Al4V alloy was mainly controlled by the diffusion of V because of its inherent segregation effect. The penetration depths of V into substrates were 0.643, 1.135, and 1.324 mm corresponding to Ti3Al(Si)C2 samples pre‐sintered at 1100, 1300, and 1500°C, respectively. That was attributed to the reaction product (Ti, V)5Si3 playing a positive role in diffusion barrier behavior.