Below is a comparison of the chemical composition and mechanical properties of TC4 (Ti-6Al-4V), TC4-ELI, Ti-6Al-4V ELI, and GR5 (often equivalent to TC4).
It should be noted that GR5 is the grade in the ASTM standard and has the same composition as TC4 (Ti-6Al-4V), while the ELI version is an Extra Low Interstitial variant with stricter impurity control.
Notes:
TC4 and Ti-6Al-4V are different names for the same alloy (TC4 is a Chinese brand, GR5 is an American ASTM standard, and Ti-6Al-4V is an internationally accepted name), and TC4-ELI is its extra low interstitial element (ELI, Extra Low Interstitial) version, which is mainly used in fields with higher requirements for low temperature toughness or high fracture toughness.
1. Comparison of chemical composition (weight percentage %)
|
Element |
TC4 (Ti-6Al-4V) / GR5 |
TC4-ELI / Ti-6Al-4V ELI |
|
Al |
5.5 - 6.75 |
5.5 - 6.5 |
|
V |
3.5 - 4.5 |
3.5 - 4.5 |
|
Fe (max) |
0.30 |
0.25 |
|
O (max) |
0.20 |
0.13 |
|
C (max) |
0.08 |
0.08 |
|
N (max) |
0.05 |
0.03 |
|
H (max) |
0.015 |
0.0125 |
|
Others |
residual Ti |
residual Ti |
Key Differences:
ELI versions have lower levels of interstitial elements (O, N, H), which improves the toughness and low temperature properties of the material.
2. Mechanical properties comparison
Typical mechanical properties at room temperature (annealed state)
|
propertites |
TC4 (Ti-6Al-4V) / GR5 |
TC4-ELI / Ti-6Al-4V ELI |
|
Tensile strength (MPa) |
≥ 895 |
≥ 828 |
|
Yield strength (MPa) |
≥ 825 |
≥ 759 |
|
Elongation (%) |
≥ 10 |
≥ 15 |
|
Reduction of area (%) |
≥ 25 |
≥ 30 |
|
Modulus of elasticity (GPa) (%) |
~110 |
~110 |
Other properties
Fatigue performance: ELI version has longer fatigue life due to fewer impurities.
Low temperature performance: ELI version has better toughness and crack resistance at low temperatures (such as -196°C).
High temperature performance: TC4 conventional version can be used at 300-400°C for a short period of time, ELI version has slightly lower high temperature performance (due to lower strength).
3. Application scenario comparison
TC4 (GR5):
Aerospace structural parts, engine parts, ship parts, medical devices (such as artificial joints), etc., suitable for medium and high strength demand scenarios.
TC4-ELI (Ti-6Al-4V ELI):
Aerospace cryogenic parts (such as liquid hydrogen storage tanks), biomedical implants (requiring higher toughness), deep-sea equipment, etc.
4. Standard Specifications
TC4: Corresponds to China GB/T 3620.1, US ASTM B348 (GR5).
TC4-ELI: Corresponds to ASTM F136 (medical), AMS 4907 (aviation).
Summary
The ELI version reduces the interstitial element content, sacrificing a small amount of strength in exchange for higher toughness and low temperature performance.
Conventional TC4 is more suitable for general high strength requirements, while ELI is suitable for areas with strict requirements on purity and toughness.
TC4 (GR5) has balanced comprehensive performance and low cost, and is suitable for most conventional industrial scenarios.
When choosing, you need to decide whether to use the ELI version based on actual needs (such as low temperature and crack growth resistance).
If more specific standard data (such as ASTM or GB standard number) is required, further explanation can be provided.
If more specific standard data (such as different heat treatment states) is required, further explanation can be provided.
