Ti-6Al-4V VS. Ti-6.5Al-1Mo-1V-2Zr Titanium Alloys

Ti-6Al-4V and Ti-6.5Al-1Mo-1V-2Zr are two representative titanium alloys. The former is the most widely used general-purpose α+β titanium alloy, while the latter is a near-α titanium alloy designed for high-temperature applications. With different chemical compositions, they have distinct performance characteristics, excelling in comprehensive properties and high-temperature performance respectively, and are widely used in aerospace, high-end manufacturing, medical and other fields.

 

 

1. Ti-6Al-4V (TC4)

Ti-6Al-4V accounts for over 50% of global titanium alloy production and is known as the "universal titanium alloy".

 

Core advantages:

With excellent strength, plasticity and toughness,it is suitable for most conventional working conditions.

With a density of only 4.43g/cm³, it can achieve remarkable lightweight effect.

It has highly compatible with forging, welding, 3D printing and other processes.

It is widely used in medical implants and marine applications.

Mature supply chain and controllable cost, offering higher cost performance than special high-temperature titanium alloys.

 

2. Ti-6.5Al-1Mo-1V-2Zr (TA15)

This is a near-α titanium alloy with an increased aluminum content of 6.5%, and additions of molybdenum, zirconium and other elements. High-temperature strengthening is realized through multi-element alloying.

 

Core advantages:

With a long-term service temperature of 500℃ and instantaneous temperature resistance of 800℃, it has significantly higher high-temperature strength than Ti-6Al-4V.

With stable microstructure at high temperatures, it is suitable for high-temperature load-bearing components such as aero-engines.

With high joint strength and low cracking tendency, it is applicable to large integral welded structures.

It is capable of withstanding complex high-temperature corrosion conditions.

Room-temperature strength close to Ti-6Al-4V, with good plasticity and formability, balancing high-temperature performance and processability.

 

 

1. Comparison of Mechanical Properties

Performance Index	Ti-6Al-4V	Ti-6.5Al-1Mo-1V-2Zr
Tensile Strength	895-1180MPa	950-1100MPa
Yield Strength	825-895MPa	850-920MPa
Elongation	10%-15%	8%-12%
Tensile Strength at 500℃	≈450MPa	≥600MPa
Long-term service temperature	≤400℃	≤500℃
Creep resistance	Average	Excellent
Fatigue performance	Excellent, suitable for cyclic loads	Excellent, better high-temperature fatigue resistance

 

2. Comparison of Physical and Chemical Properties

Similar for both alloys, with equivalent lightweight effects.

 

Ti-6Al-4V is easy to realize microstructure coarsening and strength reduction above 400℃; Ti-6.5Al-1Mo-1V-2Zr has stable microstructure and minimal performance degradation at 500℃.

 

Similar room-temperature corrosion resistance; Ti-6.5Al-1Mo-1V-2Zr has better high-temperature oxidation resistance.

Ti-6Al-4V has good weldability, with joint strength about 90% of the base metal; Ti-6.5Al-1Mo-1V-2Zr has better weldability, more suitable for large thick-plate complex structures with lower cracking tendency.

 

3. Comparison of Process Performance

Ti-6Al-4V has good plasticity and easy forming, with excellent overall performance in hot and cold working, forging, rolling, etc.; Ti-6.5Al-1Mo-1V-2Zr has slightly lower plasticity but still meets conventional processing requirements.

 

Ti-6Al-4V has a wide heat treatment range, and solution aging can significantly improve strength; Ti-6.5Al-1Mo-1V-2Zr mainly adopts annealing, with small adjustable strength range, focusing on high-temperature stability.

 

Ti-6Al-4V has mature additive manufacturing technology, compatible with various processes and stable performance; 3D printing technology of Ti-6.5Al-1Mo-1V-2Zr is still under improvement with limited application scenarios.

 

 

1. Ti-6Al-4V

Used for fuselage frames, beams, joints, landing gears, spacecraft tanks, balancing lightweight and strength with controllable cost.

Used for artificial joints, bone plates, dental implants, orthopedic instruments, relying on good biocompatibility and corrosion resistance.

Used for deep-sea equipment, seawater desalination equipment, anti-corrosion pipes and valves, suitable for room-temperature high-pressure corrosion environments.

 

Used for racing parts, lightweight bodies, 3C structural components, with outstanding comprehensive performance and cost performance.

Not suitable for working conditions above 400℃ and long-term high-temperature load-bearing.

 

2. Ti-6.5Al-1Mo-1V-2Zr

Used for high-pressure compressor blades, discs and turbine discs, adapting to 500℃ high-temperature, high-speed and high-load environments.

Used for central wing boxes, high-temperature skins and welded load-bearing parts, relying on high-temperature strength and excellent weldability.

Used for heat-resistant load-bearing components of missiles and rocket engines, meeting instantaneous high-temperature and long-term thermal stability requirements.

 

Used for high-temperature and high-pressure reactors, nuclear power and oil and gas exploitation components, adapting to complex high-temperature corrosion environments.

 

Lower cost performance than Ti-6Al-4V in scenarios requiring room-temperature superplastic forming, high plasticity and low-cost mass production.

 

 

Ti-6Al-4V is an all-round material with balanced comprehensive properties, mature process and controllable cost, suitable for scenarios below 400℃, and widely used in medical, aerospace, marine, automotive and other fields.

 

Ti-6.5Al-1Mo-1V-2Zr is a special high-temperature material, with outstanding strength, thermal stability, creep resistance and weldability at 500℃, suitable for 400-500℃ high-temperature components such as aero-engines.

 

Choose Ti-6Al-4V for room-temperature general use and cost performance; choose the latter for high-temperature service and high stability. The two

alloys complement each other to form the core application system of titanium alloys. Ruihang is specilized in R&D, production and sales with more than 13 years in Ti-6Al-4V titanium products. For more details, please feel free to contact us by email: Sam.Rui@bjrh-titanium.com.