Posts

Ti-6Al-4V, AMS 4928 AMS 4965

Ti-6Al-4V: AMS 4928 vs AMS 4965

/in /by

Introduction

Ti-6Al-4V is a titanium alloy commonly used in aerospace, medical, and high performance applications for its excellent strength-to-weight ratio, corrosion resistance, and high temperature stability. When comparing AMS 4928 and AMS 4965, the two specifications cover different forms of Ti-6Al-4V and differ in processing and intended applications.

Product form: AMS 4928 vs AMS 4965

AMS 4928 Ti-6Al-4V, UNS R56400 Form

This specification covers a titanium alloy in the form of bars, wire, forgings, flash welded rings, drawn shapes up through 6.000 inches (152.40 mm) inclusive in diameter or least distance between parallel sides and stock of any size for forging or flash welded rings.

AMS 4965 Ti-6Al-4V, UNS R56400 Form

This specification covers a titanium alloy in the form of bars, wire, forgings, and flash welded rings 4.000 inches (101.60 mm) and under in nominal diameter or least distance between parallel sides and of stock for forging and flash welded rings.

Chemical composition: AMS 4928 vs AMS 4965

AMS 4928 Ti-6Al-4V, UNS R56400 Chemical Composition

Element Min. Max.
Aluminum 5.50 6.75
Vanadium 3.50 4.50
Iron — 0.30
Oxygen — 0.20
Carbon — 0.08
Nitrogen — 0.05 (500 ppm)
Hydrogen (3.1.1) — 0.0125 (125 ppm)
Yttrium (3.1.2) — 0.005 (50 ppm)
Other Elements, each (3.1.2) — 0.10
Other Elements, total (3.1.2) — 0.40
Titanium Remainder —

AMS 4965 Ti-6Al-4V, UNS R56400 Chemical Composition

Element Min. Max.
Aluminum 5.50 6.75
Vanadium 3.50 4.50
Iron — 0.30
Oxygen — 0.20
Carbon — 0.08
Nitrogen — 0.05 (500 ppm)
Hydrogen (3.1.1) — 0.0125 (125 ppm)
Yttrium (3.1.2) — 0.005 (50 ppm)
Other elements, each (3.1.2) — 0.10
Other elements, total (3.1.2) — 0.40
Titanium Remainder

Mechanical properties: AMS 4928 vs AMS 4965

AMS 4928 Ti-6Al-4V, UNS R56400 Mechanical Properties

Nominal Diameter or Least Distance Between Parallel Sides (mm) Tensile Strength (MPa) Yield Strength at 0.2% Offset (MPa) Elongation in 50.8 mm or 4D % Long. Elongation in 50.8 mm or 4D % L.T. Elongation in 50.8 mm or 4D % S.T. Reduction of Area % Long. Reduction of Area % L.T. Reduction of Area % S.T. (2)
Up to 50.80, incl (1) 931 862 10 10 — XXV 20 20
Over 50.80  to 101.60, incl 896 827 10 10 10 XXV 20 15
Over 101.60 to 152.40, incl. (3) 896 827 10 10 8 20 20 15
Note: Long. = longitudinal LT = long horizontal ST = short horizontal
1. Tensile strength of 130 ksi (896 MPa) minimum and yield strength of 120 ksi (827 MPa) minimum are permitted for wire or rod for fastener applications and for flash welded rings made from extrusions up to 2.000 inches (50.80 mm), inclusive, in distance between parallel sides.
2. Short-transverse reduction of area is waived for flash welded rings made from extrusions.
3. See 8.3.

AMS 4965 Ti-6Al-4V, UNS R56400 Mechanical Properties

Nominal Diameter or Distance Between Parallel Sides Tensile Strength Yield Strength
at 0.2% Offset		 Elongation (1)
in 50.8 mm
or 4D, L		 Elongation (1)
in 50.8 mm
or 4D, T		 Reduction
of Area, L
mm MPa MPa (%) (%) (%)
Up to 12.70, incl. 1138 1069 10 — 20
Over 12.70 to 25.40, incl. 1103 1034 10 — 20
Over 25.40 to 38.10, incl. 1069 1000 10 — 20
Over 38.10 to 50.80, incl. 1034 965 10 — 20
Over 50.80 to 76.20, incl. 965 896 10 8 20
Over 76.20 to 101.60, incl. 896 827 8 6 20
NOTE: For forgings, the elongation in all dimensions shall not be less than 8% (L) and 6% (T).
Nominal Thickness Nominal Width Tensile Strength Yield Strength
at 0.2% Offset		 Elongation in 50.8 mm or 4D, L Elongation in 50.8 mm or 4D, T Reduction
of Area, L
mm mm MPa MPa (%) (%) (%)
Up to 12.70, incl. Over 12.70  to 203.20, incl. 1103 1034 10 10 25
Over 12.70 to 25.40, incl. Over 25.40 to 101.60, incl. 1069 1000 10 10 20
Over 12.70 to 25.40, incl. Over 101.60 to 203.20, incl. 1034 965 10 10 20
Over 25.40 to 38.10, incl. Over 25.40 to 101.60, incl. 1034 965 10 10 20
Over 25.40 to 38.10, incl. Over 101.60 to 203.20, incl. 1000 931 10 10 20
Over 38.10 to 50.80, incl. Over 50.80 to 101.60, incl. 1000 931 10 10 20
Over 38.10 to 50.80, incl. Over 101.60 to 203.20, incl. 965 896 10 10 20
Over 50.80 to 76.20, incl. Over 76.20 to 203.20, incl. 965 862 10 8 20
Over 76.20 to 101.60, incl. Over 101.60 to 203.20, incl. 896 827 8 6 20

Melting Practices

AMS 4928 Ti-6Al-4V, UNS R56400 Melting Practice

Alloy shall be multiple melted. The first melt shall be made by vacuum consumable electrode, nonconsumable electrode, electron beam cold hearth, or plasma arc cold hearth melting practice. The subsequent melt or melts shall be made under vacuum using vacuum arc remelting (VAR) practice. Alloy additions are not permitted in the final melt cycle.
The atmosphere for nonconsumable electrode melting shall be vacuum or shall be argon and/or helium at an absolute pressure not higher than 1000 mm of mercury.
The electrode tip for nonconsumable electrode melting shall be water-cooled copper.

AMS 4965 Ti-6Al-4V, UNS R56400 Melting Practice

Alloy shall be multiple melted; melting cycle(s) prior to final melting cycle shall be made using consumable electrode, nonconsumable electrode, electron beam, or plasma arc melting practices. The final melting cycle shall be made under vacuum using consumable electrode practice with no alloy additions permitted.
The atmosphere for nonconsumable electrode melting shall be vacuum or shall be argon and/or helium at an absolute pressure not higher than 1000 mm of mercury.
The electrode tip for nonconsumable electrode melting shall be water-cooled copper.

Heat treatment

AMS 4928 Ti-6Al-4V, UNS R56400 Heat Treatment

Bars, wire, forgings, drawn shapes and flash welded rings shall be heat treated as follows; pyrometry shall be in accordance with AMS2750.
1. Solution Heat Treatment
Except as specified in 3.4.3 when solution heat treatment is used, heat to a temperature within the range 50 to 150 °F (28 to 83 °C) degrees below the beta transus, hold at the selected temperature within ±25 °F (±14 °C) for a time commensurate with section thickness and the heating equipment and procedure used, and cool at a rate equivalent to an air cool or faster.
2. Annealing
Except as specified in 3.4.3, heat to a temperature within the range 1300 to 1450 °F (704 to 788 °C), hold at the selected temperature within ±25 °F (±14 °C) for not less than 1 hour, and cool as required.
3. Continuous Heat Treating
Wire 0.125 inch (3.18 mm) and under in diameter may be continuously heat treated provided that process parameters (e.g., furnace temperature set points, heat input, travel rate, etc.) for continuous heat treating lines shall be established by the material producer and validated by testing of product to requirements of 3.5.

AMS 4965 Ti-6Al-4V, UNS R56400 Heat Treatment

Bars, wire, forgings, and flash welded rings shall be solution heat treated by heating in a suitable atmosphere to 1750 °F ± 25 (954 °C ± 14), holding at heat for 1 to 2 hours, and quenching in agitated water, and aged by heating to a temperature within the range 900 to 1150 °F (482 to 621 °C), holding at the selected temperature within ±15 °F (±8 °C) for 4 to 8 hours, and cooling in air. Pyrometry shall be in accordance with AMS 2750.

Applications

AMS 4928 Ti-6Al-4V, UNS R56400 Application

These products have been used typically for parts requiring moderate strength with a maximum service temperature in the 750 to 900 °F (399 to 510 °C) range depending on time at temperature where the product is to be used in the annealed condition, but usage is not limited to such applications.

AMS 4965 Ti-6Al-4V, UNS R56400 Application

These products have been used typically for parts which are machined after solution heat treatment and aging and are suitable for parts requiring high strength-to-weight ratios up to moderately elevated temperatures, but usage is not limited to such applications.

Titanium Grade 5

Titanium Grade 5 (Ti-6Al-4V): The Versatile Titanium Alloy

/in /by

Introduction

Titanium Grade 5 (Ti-6Al-4V) is one of the most widely used titanium alloys in aerospace, oil and gas, marine engineering, and chemical processing industries. Known for its remarkable balance of strength, corrosion resistance, and lightweight properties, it has become the go-to material in applications that demand durability under extreme conditions. This blog will explore the fundamental properties, benefits, applications, and considerations of Ti-6Al-4V, providing clear guidance for engineers, procurement teams, and professionals seeking to understand this exceptional material.

Overview of Titanium Grade 5 (Ti-6Al-4V)

Titanium Grade 5, or Ti-6Al-4V, is an alpha-beta titanium alloy comprising 6% aluminum and 4% vanadium. It is the most commonly used titanium alloy, accounting for over 50% of total titanium use worldwide. Its versatility and superior properties make it ideal for high-performance applications where strength, weight, and corrosion resistance are paramount.

Essential Properties:

  • Density: 4.43 g/cm³
  • Tensile Strength: 895 – 930 MPa (annealed), up to 1100 MPa (heat-treated)
  • Yield Strength: 830 MPa
  • Melting Point: 1660°C
  • Elastic Modulus: 114 GPa
  • Corrosion Resistance: Excellent in most environments, including marine, chemical, and aerospace conditions

These properties make Ti-6Al-4V suitable for critical applications where traditional materials fail under stress, temperature, or corrosion.

Why Choose Titanium Grade 5?

Titanium Grade 5 is often selected due to its unique combination of properties that deliver tangible benefits:

1. High Strength-to-Weight Ratio

One of Ti-6Al-4V’s primary advantages is its impressive strength relative to its weight. With a density significantly lower than steel or nickel alloys but comparable strength, it is ideal for industries such as aerospace and automotive, where weight reduction is a key driver of performance and fuel efficiency.

2. Exceptional Corrosion Resistance

Titanium is inherently corrosion resistant, but adding aluminum and vanadium further enhances this property. Ti-6Al-4V performs exceptionally well in environments exposed to saltwater, chlorides, and harsh chemicals, making it a preferred material in marine engineering, offshore oil and gas, and chemical processing plants.

3. High-Temperature Resistance

Ti-6Al-4V retains its mechanical properties at elevated temperatures up to 400°C, which is critical for applications in aerospace engines, turbines, and components subjected to high thermal stresses.

4. Biocompatibility

This alloy is biocompatible and safe for use in medical applications such as implants and prosthetics. Its ability to withstand bodily fluids without corroding and its low weight makes it an ideal choice in the medical field.

Applications of Titanium Grade 5

Titanium Grade 5 is a workhorse alloy used across many industries. Below are some of its most significant applications in critical fields:

1. Aerospace

Titanium Grade 5 plays a vital role in the aerospace industry due to its strength, weight savings, and resistance to temperature and fatigue. Aircraft components, such as airframes, landing gear, engine parts, and fasteners, rely heavily on Ti-6Al-4V to reduce weight while maintaining strength. Its high fatigue strength is also suitable for critical parts like fan blades and compressor disks.

2. Oil and Gas

In the oil and gas sector, Titanium Grade 5 is essential in harsh offshore environments, where resistance to saltwater corrosion and chemical attack is paramount. This alloy is commonly used for downhole tubing, wellhead components, and subsea equipment where strength, corrosion resistance, and weight are needed.

3. Marine Engineering

Marine applications, particularly in submarines, ships, and offshore platforms, benefit from the corrosion-resistant properties of Ti-6Al-4V. The material can withstand constant exposure to seawater without degradation, making it suitable for hulls, propeller shafts, and other critical marine components that require long-term reliability and resistance to corrosion fatigue.

4. Chemical Processing

Titanium Grade 5’s resistance to chemical corrosion and ability to operate in high-temperature environments make it a prime choice for chemical processing equipment such as heat exchangers, reaction vessels, and piping systems. In industries with chlorides, strong acids, and other corrosive substances, Ti-6Al-4V’s durability ensures extended service life and low maintenance costs.

5. Medical

Due to its biocompatibility and ability to integrate with human tissue, Titanium Grade 5 is used extensively in medical devices, especially orthopedic implants such as bone screws, joint replacements, and dental implants. Its strength and resistance to body fluids ensure long-term performance, reducing the likelihood of rejection or degradation.

Solutions and Considerations for Users

Understanding how to leverage Titanium Grade 5’s capabilities effectively is crucial for users working in high-performance industries. Below are some key considerations and solutions for everyday challenges:

1. Machinability and Fabrication

While Ti-6Al-4V offers excellent properties, its machinability can be challenging compared to steel or aluminum. Its low thermal conductivity leads to heat build-up during machining, which can result in tool wear. To address this, it’s essential to use the right cutting tools, coolants, and techniques to minimize heat and ensure precise machining.

Solution: Select proper tooling and adopt high-speed machining practices. For best results, consider CNC machining with carbide or coated tools.

2. Cost-Effectiveness

Titanium, including Grade 5, is more expensive than other metals like steel or aluminum. Balancing performance needs with cost is essential for budget-conscious applications.

Solution: Evaluate if the superior properties of Ti-6Al-4V justify the cost. For applications where corrosion resistance, weight reduction, or high-temperature performance are non-negotiable, the long-term benefits typically outweigh the initial expense.

3. Surface Treatments and Coatings

Although Ti-6Al-4V is naturally corrosion-resistant, specific environments may require additional surface treatments or coatings to enhance wear or improve resistance to particular chemical media.

Solution: Surface treatments such as anodizing, nitriding, or applying protective coatings can provide additional benefits, especially in aggressive chemical or high-friction environments.

Future Prospects and Advancements

The future of Titanium Grade 5 lies in continuous development and innovation. New fabrication techniques, such as additive manufacturing (3D printing), are expanding the possibilities of using Ti-6Al-4V in complex shapes and designs. As industries seek lighter, more robust, and more durable materials, the demand for Titanium Grade 5 is expected to grow, particularly in the aerospace, automotive, and medical sectors.

Moreover, the drive toward more sustainable materials and processes positions Titanium Grade 5 as a key player due to its recyclability and long service life, reducing the need for frequent replacements in demanding environments.

Conclusion

Titanium Grade 5 (Ti-6Al-4V) remains the alloy of choice for industries requiring an optimal combination of strength, corrosion resistance, and lightweight properties. Its versatility in aerospace, oil and gas, marine engineering, and chemical processing makes it indispensable in environments where reliability and performance are critical. By understanding the alloy’s properties, applications, and considerations, professionals can make informed decisions to harness the full potential of Ti-6Al-4V, ensuring long-term success and efficiency in their operations.

Whether designing cutting-edge aerospace components, ensuring the longevity of offshore oil equipment, or developing medical implants, Titanium Grade 5 delivers unparalleled performance in the most demanding situations.