In cutting-edge fields such as aerospace, medical implants, and high-end chemicals, titanium materials have become an irreplaceable choice due to their outstanding strength-to-weight ratio and corrosion resistance. However, within the titanium family, industrial pure titanium TA1 (Gr1) and titanium alloy TC4 (Ti-6Al-4V, Gr5) exhibit strikingly different performances in terms of chemical composition, physical properties, and practical applications.
From the compositional differences under ASTM standards (TA1 (Gr1) with a purity of up to 99.5% versus TC4 (Gr5) with 6% aluminum and 4% vanadium alloying), to the significant disparity in mechanical properties (TC4 (Gr5) with a tensile strength exceeding 900 MPa, three times that of TA1 (Gr1)), and the division of application scenarios (TA1 (Gr1) dominating chemical pipelines while TC4 (Gr5) ruling the roost in aircraft engines) - this "performance showdown" in the titanium materials domain reflects the deep alignment between material science and engineering demands.
This article will, based on standards such as ASTM B265/F1472, systematically analyze the essential differences between these two key titanium materials from microstructure to macro application, helping you precisely match material selection with project requirements.
1.
|
Element |
TA1(Gr1) |
TC4(Gr5) |
|
Ti |
≥ 99.5% |
Balance |
|
Al |
- |
5.5-6.75% |
|
V |
- |
3.5-4.5% |
|
Fe(max) |
0.20% |
0.40% |
|
O(max) |
0.18% |
0.20% |
|
C(max) |
0.08% |
0.08% |
|
N(max) |
0.03% |
0.05% |
|
H(max) |
0.015% |
0.015% |
TA1(Gr1)(Industrial Pure Titanium)
Main Components: Titanium (Ti) content ≥ 99.5%, with trace impurities (such as iron, carbon, oxygen, nitrogen, etc.).
No other alloying elements, close to pure titanium.
TC4(Gr5)(Ti-6Al-4V)
Main Components: Titanium (Ti) as the base, with 6% aluminum (Al) and 4% vanadium (V) added.
It is an α+β dual-phase titanium alloy, with improved performance through alloying.
2.
|
Property |
TA1(Gr1) |
TC4(Gr5) |
|
Density(g/cm³) |
4.51 |
4.43 |
|
Melting Point(°C) |
About1668 |
About1600-1650 |
|
Thermal Conductivity( W/m· K) |
17 |
6.7 |
|
Electrical Resistivity(μΩ·m) |
0.42 |
1.7 (due to alloying elements) |
|
Coefficient of Thermal Expansion(10⁻⁶/°C) |
8.6 |
8.9 |
Difference:TC4(Gr5)has lower thermal conductivity and higher electrical resistivity due to alloying, suitable for high-temperature structural components but with poorer heat dissipation.
3.
|
Property |
TA1(Gr1) |
TC4(Gr5) |
|
Tensile Strength(MPa) |
240-550 |
895-930(min) |
|
Yield Strength(MPa) |
170-485 |
825(min)_ |
|
Elongation(%) |
24(min)_ |
10(min)_ |
|
Hardness(HV) |
Lower (about 120 HV) |
Higher (about 330 HV) |
|
Elastic Modulus(GPa) |
102 |
110-114 |
Difference: TC4(Gr5) has a strength 2-3 times that of TA1(Gr1), but with lower plasticity (lower elongation).
TC4(Gr5) has better fatigue strength and creep resistance (suitable for dynamic loads).
4.Corrosion Resistance
Common Points: Both pass ASTM B861/B862 corrosion tests and perform well in seawater and chloride environments.
Differences:
TA1(Gr1): Slightly better in reducing acids (such as hydrochloric acid) than TC4(Gr5) (due to no risk of Al/V segregation).
TC4(Gr5): May form a protective film due to Al element in high-temperature oxidation environments, but has slightly higher stress corrosion sensitivity.
5.
|
Process |
TA1(Gr1) |
TC4(Gr5) |
|
Cold Working |
Excellent (ASTM B381 allows deep drawing) |
Requires annealing (otherwise prone to cracking) |
|
Hot Working |
Not required |
Requires above β phase transition temperature (~955°C) |
|
Weldability |
Excellent (TIG/laser welding, ASTM B862) |
Good (requires protective gas to prevent oxidation) |
|
Machinability |
Tendency to stick to the blade |
Worse (requires special tools) |
6.
|
Field |
TA1(Gr1) |
TC4(Gr5) |
|
Aerospace |
Non-load-bearing components (such as tubes) |
Engine blades, landing gear (AMS 4928/4930) |
|
Chemical Industry |
Heat exchangers, reactors (ASTM SB338) |
High-pressure valves, pump bodies |
|
Medical |
Bone plates, screws (ASTM F67) |
Artificial joints, dental implants (ASTM F136) |
|
Marine |
Seawater pipes (ASTM SB338) |
Submarine pressure hulls (MIL-DTL-46077) |
|
Civil |
Construction decoration, golf club heads |
Racing connecting rods, high-end bicycle frames |
7. Cost
TA1(Gr1): Lower price (due to the absence of expensive alloying elements).
TC4(Gr5): Higher cost (contains aluminum and vanadium, and has a complex processing procedure).
The two complement each other, covering the demands from basic industries to cutting-edge technologies in all scenarios.
