Titanium Grade 5 (Ti-6Al-4V) delivers an exceptional strength-to-weight ratio for lightweight structures. Inconel 718 dominates where extreme temperature and corrosion resistance are non-negotiable. Here is the comparison every aerospace and engine designer needs.
1. Chemical Composition Comparison (%)
| Element | Titanium Gr5 (Ti-6Al-4V) | Inconel 718 (UNS N07718) |
|---|---|---|
| Titanium (Ti) | Balance | — |
| Aluminum (Al) | 5.5 – 6.75 | 0.20 – 0.80 |
| Vanadium (V) | 3.5 – 4.5 | — |
| Nickel (Ni) | — | 50.0 – 55.0 |
| Chromium (Cr) | — | 17.0 – 21.0 |
| Iron (Fe) | ≤0.40 | Balance |
| Nb+Ta | — | 4.75 – 5.50 |
2. Mechanical Properties (Typical, Annealed / Aged)
| Property | Titanium Gr5 | Inconel 718 |
|---|---|---|
| Tensile Strength (MPa) | ≥895 | ≥1240 |
| Yield Strength 0.2% (MPa) | ≥828 | ≥1034 |
| Elongation (%) | ≥10 | ≥12 |
| Density (g/cm³) | 4.43 | 8.19 |
| Max Service Temp | ~400°C | ~700°C |
3. Key Technical Differences
- Weight: Grade 5 is less than half the density of 718 — a massive advantage for rotating and airborne parts.
- Temperature: 718 retains strength to 700°C; Grade 5 is limited to ~400°C.
- Corrosion: Both are excellent; Grade 5 is superb in seawater, 718 in high-temp oxidation and acids.
- Cost: Grade 5 is generally less expensive than 718 despite titanium's reputation.
5. Key Application Areas
Titanium Grade 5 (Ti-6Al-4V) application areas
- Aircraft airframe and engine compressor components
- Marine and seawater structural parts
- Medical implants and surgical devices
- Sporting goods and high-performance automotive components
Inconel 718 application areas
- Turbine discs, blades, and hot-section engine parts
- Rocket engine and propulsion components
- Oil & gas downhole tools and high-strength fasteners
- High-temperature aerospace and industrial hardware
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Frequently asked questions
Why use titanium instead of Inconel?
For weight savings — Grade 5 components can be less than half the weight of 718 for the same strength.
Can Grade 5 replace 718 in jet engines?
Only in lower-temperature sections (compressor, airframe); turbine hot sections require 718 or higher superalloys.
Which is easier to machine?
Both are difficult; Grade 5 is gummy, 718 work-hardens aggressively.
Is Grade 5 weldable?
Yes with proper inert gas shielding; 718 requires careful post-weld heat treatment.
Which has better seawater corrosion resistance?
Both are excellent; Grade 5 is slightly better in pure seawater, 718 better in hot acidic chloride.
Does Hangbo supply both?
Yes, in bar, sheet, plate, forgings, and precision-machined aerospace components.