Ti-6Al-4V Titanium Alloy

Grade 5, also known as Ti6Al4V, Ti-6Al-4V or Ti 6-4, is the most commonly used alloy. It has a chemical composition of 6% aluminum, 4% vanadium, 0.25% (maximum) iron, 0.2% (maximum) oxygen, and the remainder titanium. It is significantly stronger than commercially pure titanium while having the same stiffness and thermal properties (excluding thermal conductivity, which is about 60% lower in Grade 5 Ti than in CP Ti). Among its many advantages, it is heat treatable. This grade is an excellent combination of strength, corrosion resistance, weld and fabricability.

This alpha-beta alloy is the workhorse alloy of the titanium industry. The alloy is fully heat treatable in section sizes up to 15mm and is used up to approximately 400°C (750°F). Since it is the most commonly used alloy – over 70% of all alloy grades melted are a sub-grade of Ti6Al4V, its uses span many aerospace airframe and engine component uses and also major non-aerospace applications in the marine, offshore and power generation industries in particular.

Chemical Range for 6AL-4V

Element           Minimum          Maximum

 Carbon                --                       0.08

 Nitrogen             --                       0.05

 Hydrogen           --                       0.015

 Iron                      --                       0.25

 Oxygen               --                       0.2

 Aluminum          5.5                      6.75

 Vanadium          3.5                      4.5

 Titanium             --                  Balance

Typical Mechanical Properties for 6AL-4V:

Form                             Tensile Strength, min         Yield Strength, min          Elongation in 4D, min

Strip, Sheet and Plate

(ASTM B265)                            130 ksi                                 120 ksi                                   10%

Bar and Rod

(ASTM B348)                            130 ksi                                 120 ksi                                   10%

Typical Physical Data for 6AL-4V:

Density                                              0.160 lb / cu. in.

Electrical Resistivity                        1.71 µohms-m

Thermal Conductivity                    6.6-6.8 W/mK

Modulus of Elasticity                      16.5 psi x 10⁶

Melting Point                                    3200 °F

Specific Heat                                    0.135 btu/pound/°F

Modulus of Elasticity                      16.5 psi x 10⁶

Applications: Blades, discs, rings, airframes, fasteners, components, vessels, cases, hubs, forgings. Biomedical implants.

Generally, Ti-6Al-4V is used in applications up to 400 degrees Celsius. It has a density of roughly 4420 kg/m³, Young’s modulus of 115 GPa, and tensile strength of 1000 MPa. By comparison, annealed type 316 stainless steel has a density of 8000 kg/m³, modulus of 193 GPa, and tensile strength of only 570 MPa. And tempered 6061 aluminum alloy has 2700 kg/m³, 69 GPa, and 310 MPa, respectively.