Effect of Ti on Microstructural Evolution of Re containing Single Crystal Superallys

AbstractThe influence of titanium on the microstructural evolution of the rhenium containing second generation single crystal superalloys has been investigated by changing titanium content only. The results showed that with the increase of titanium, the percentage of γ/γ’ eutectic increased, initial melting temperature lowered, and the size of γ’ phase of the alloys after full heat treatment increased. Three-dimensional atom probe (3DAP) analyses showed that the addition of titanium increased the rhenium distribution ratio in γ and γ’ phase as well as the misfit of γ and γ’ phase, and hence to promote the γ’ phase rafting and growing up. The experimental results also showed that the amount of TCP (μ) phase precipitates increased gradually with the increase of the content of titanium during prolonged aging at 1093°C