Steel vs Ti-6Al-4V
Steel and Ti-6Al-4V are genuine alternatives to one another — a choice somebody actually makes — and differ on 3 measured properties, density most clearly.
Steel vs Ti-6Al-4V
Steel
Iron with a controlled, small proportion of carbon — the most-used engineered material in the world.
Ti-6Al-4V
One alloy is over half of all titanium used — the aerospace workhorse, and the metal a hip replacement is made of.
| Property | Steel | Ti-6Al-4V |
|---|---|---|
| Density | 7.75–8.05 g/cm³ higher | 4.42–4.45 g/cm³ |
| Electrical conductivity Only one of the two has a figure we can stand behind, so there is nothing to compare. | 6.99 MS/m | Not known |
| Melting point | 1370–1510 °C | 1604–1660 °C higher |
| Tensile strength | 400–2000 MPa higher | 900–1170 MPa |
| Thermal conductivity Only one of the two has a figure we can stand behind, so there is nothing to compare. | 15–54 W/(m·K) | Not known |
| Young's modulus Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | 110–114 GPa |
Choosing between them
Ti-6Al-4V is recorded as a substitute for Steel — lighter, more corrosion-resistant.
What it gives up: Several times the price, half the stiffness, and it machines and welds badly enough that fabrication cost dominates the material cost.
In this application, on the evidence cited above.