Standards
Ti-6Al-4V（GR5）, commonly known as 6Al-4V(GR5) Titanium, is an alpha-beta titanium alloy that stands out due to its combination of high strength, lightweight properties, and excellent corrosion resistance. two widely used standards are AMS 4928 and AMS 4911. Both cover the same alloy composition but are intended for different forms and applications, primarily in aerospace and industrial sectors. This article will explore the key differences between these two standards, helping you understand which one is better suited for your specific needs.
What is AMS 4928?
AMS 4928 is a specification that covers Ti-6Al-4V bars, forgings, and flash welded rings. This standard is specifically designed for aerospace applications, requiring materials that deliver high strength, durability, and excellent corrosion resistance. AMS 4928 titanium bars are widely used in critical components such as jet engines, airframes, and military hardware.
Key Features of AMS 4928:
- Material: Ti-6Al-4V (Grade 5)
- Product Forms: Bars, forgings, flash welded rings
- Applications: Jet engines, aircraft structural components, military hardware, and high-stress aerospace applications.
What is AMS 4911?
AMS 4911 also covers Ti-6Al-4V (Grade 5) titanium, but focuses on sheets, plates, and strips. This specification is utilized for products that require high strength and corrosion resistance, specifically in forms that allow for different manufacturing processes. AMS 4911 is commonly used in applications like aircraft skin panels and structural components.
Key Features of AMS 4911:
- Material: Ti-6Al-4V (Grade 5)
- Product Forms: Sheets, plates, strips
- Applications: Aircraft panels, structural components, and parts fabricated from titanium sheet or plate.
Chemical Composition: AMS 4928 vs. AMS 4911
Both AMS 4928 and AMS 4911 share the same chemical composition for Ti-6Al-4V alloy, consisting of 90% titanium, 6% aluminum, and 4% vanadium. They also have strict limits on impurities.
| Element | AMS 4928 | AMS 4911 |
| Aluminum (Al) | 5.50 – 6.75% | 5.50 – 6.75% |
| Vanadium (V) | 3.50 – 4.50% | 3.50 – 4.50% |
| Oxygen (O) | ≤ 0.20% | ≤ 0.20% |
| Nitrogen (N) | ≤ 0.05% | ≤ 0.05% |
| Carbon (C) | ≤ 0.08% | ≤ 0.08% |
| Hydrogen (H) | ≤ 0.0125% | ≤ 0.0125% |
| Iron (Fe) | ≤ 0.40% | ≤ 0.40% |
| Titanium (Ti) | Balance | Balance |
Mechanical Properties: AMS 4928 vs. AMS 4911
The mechanical properties for both standards are similar, but may vary slightly due to the different processing methods. Both are designed for high-stress applications requiring strong, lightweight materials.
| Property | AMS 4928 | AMS 4911 |
| Tensile Strength | 130 – 135 ksi | 130 – 135 ksi |
| Yield Strength | 119 – 125 ksi | 120 – 125 ksi |
| Elongation | 8 – 10% | ≥ 10% |
| Reduction of Area | 15 – 25% | ≥ 25% |
Key Differences Between AMS 4928 and AMS 4911
·Product Forms:
·AMS 4928 covers bars, forgings, and rings.
AMS 4911 is specific to sheets, plates, and strips.
·Applications:
AMS 4928 is used for rotating components and high-stress structural parts.
AMS 4911 is ideal for aircraft skins and wing components.
·Fabrication Processes:
AMS 4928 often involves forging, enhancing mechanical properties.
AMS 4911 products are produced through rolling or forming, suitable for machining or welding.
Cost:
AMS 4911 products may be more cost-effective for large-scale projects due to easier manufacturing and handling of sheet material.
Which Standard Should You Choose?
For projects involving rotating parts or high-stress applications, such as jet engines or landing gear, AMS 4928 is the preferred choice due to its superior strength from the forging process.
Conversely, if your project focuses on aircraft panels or parts requiring fabrication from sheets or plates, AMS 4911 is likely the better option, allowing for easier machining and shaping.
Conclusion: AMS 4928 vs. AMS 4911
Both AMS 4928 and AMS 4911 are essential standards for Ti-6Al-4V (Grade 5) titanium alloy, commonly used in aerospace for their strength, durability, and corrosion resistance. Understanding the differences between these specifications is crucial for selecting the right material for your aerospace projects.