Effect of carbon on the mechanical properties and structure of titanium alloys

Conclusions

• 1. The addition of carbon to titanium alloys leads to an increase of the ultimate strength and decrease of the impact toughness at 20°, with no change in the ductility. The largest increase in strength (14–18 kg/mm²) results from the addition of 0.05% C.

• 2. After holding for 100 h at 600° the ductility of the alloys with as much as 0.15% C is the same as in the original condition.

• 3. The addition of 0.05% C raises the ultimate strength of Ti 6.5Al 3Zr 2Mo by 7–10 kg/mm² at 600°. The strength of the alloy without Mo decreases or remains the same when carbon is added.

• 4. The addition of 0.05–0.15% C to Ti 6.5Al 3Zr 2Mo leads to an increase of the long-term strength at 500 and 600°. The long-term strength of the alloy without Mo remains unchanged when carbon is added.

• 5. The addition of 0.05% C also reduces the grain size of α phase and raises the α+β→β transformation temperature.