Ti-6Al-4V titanium alloy

Known as grade 5, and about half of all titanium produced is this one alloy. At 900-1100 MPa it matches a quenched and tempered alloy steel at 56% of the weight, which is the trade every aerospace part is making. Its thermal conductivity of 6.7 W/(m·K) is a seventh of steel's, so machining heat has nowhere to go but the cutting edge — this is why titanium is expensive to machine and why the advice is always slow speed, heavy feed and flood coolant.

Properties

Density

4,430 kg/m³ — 4.43 g/cm³

Melting range

1604–1660 °C

Tensile strength

900–1100 MPa

Young's modulus

114 GPa

Thermal conductivity

6.7 W/(m·K)

Thermal expansion

8.6 µm/(m·K)

Floats in water

No

Magnetic

No

What it is used for

• Jet engine fan blades and compressor discs
• Airframe fasteners and landing gear parts
• Hip stems and spinal implants
• Motorsport connecting rods and valves

How it compares

Does it rust?

Ti-6Al-4V titanium alloy does not rust — rust is iron oxide specifically — but it does corrode, forming its own oxide or salts over time.

Is it magnetic?

Ti-6Al-4V titanium alloy is not ferromagnetic. Most metals are not.