1. Introduction
Titanium alloys are widely valued for their high specific strength, corrosion resistance, and excellent biocompatibility. Based on their microstructure, they are classified into three major categories: α titanium alloys, α+β titanium alloys, and β titanium alloys. Among them, β titanium alloys are particularly favored for high-end applications due to their outstanding mechanical properties and excellent formability.
This article provides an in-depth overview of beta titanium alloys, focusing on TB5 and TB6 alloys, and compares them with other titanium alloy types.
2. Overview of β Titanium Alloys
2.1 Definition
Beta titanium alloys are titanium alloys in which the microstructure is primarily composed of β-phase (body-centered cubic, BCC) at room temperature. They are stabilized by the addition of elements such as vanadium (V), chromium (Cr), molybdenum (Mo), and iron (Fe).
2.2 Key Features
- High strength: Post-heat treatment tensile strengths can exceed 1000 MPa.
- Good ductility and formability: Excellent for complex hot and cold forming processes.
- Outstanding corrosion resistance: Perform well in marine and aggressive environments.
- Good weldability: Suitable for various welding methods such as TIG and EBW.
- Heat treatability: Mechanical properties can be tailored by solution treatment and aging.
3. TB5 Titanium Alloy (Ti-15V-3Cr-3Sn-3Al)
3.1 Overview
TB5 is a stable β titanium alloy with high strength, moderate density, excellent formability, and good weldability, internationally corresponding to Ti-15V-3Cr-3Sn-3Al.
3.2 Chemical Composition (wt.%)
| Element | Range |
|---|---|
| V | 14.0–16.0 |
| Cr | 2.5–3.5 |
| Sn | 2.5–3.5 |
| Al | 2.5–3.5 |
| O | ≤0.13 |
| N | ≤0.05 |
| C | ≤0.08 |
| H | ≤0.015 |
| Fe | ≤0.25 |
| Ti | Balance |
3.3 Physical and Mechanical Properties
| Property | Value |
|---|---|
| Density | 4.65 g/cm³ |
| Melting Point | 1620°C |
| Elastic Modulus | 105 GPa |
| Ultimate Tensile Strength | ≥ 1030 MPa |
| Yield Strength | ≥ 965 MPa |
| Elongation | ≥ 10% |
| Reduction of Area | ≥ 25% |
3.4 Applications
- Aerospace load-bearing components (wing spars, frames)
- Lightweight automotive structures
- High-end sports equipment (premium bicycles)
- Marine and offshore structures
4. TB6 Titanium Alloy (Ti-10V-2Fe-3Al)
4.1 Overview
TB6 is another widely used β titanium alloy, corresponding to Ti-10V-2Fe-3Al internationally, noted for its higher strength, lower density, and excellent fracture toughness.
4.2 Chemical Composition (wt.%)
| Element | Range |
|---|---|
| V | 9.0–11.0 |
| Fe | 1.5–2.5 |
| Al | 2.5–3.5 |
| O | ≤0.13 |
| N | ≤0.05 |
| C | ≤0.08 |
| H | ≤0.015 |
| Ti | Balance |
4.3 Physical and Mechanical Properties
| Property | Value |
|---|---|
| Density | 4.62 g/cm³ |
| Melting Point | 1620°C |
| Elastic Modulus | 105 GPa |
| Ultimate Tensile Strength | ≥ 1200 MPa |
| Yield Strength | ≥ 1100 MPa |
| Elongation | ≥ 10% |
| Reduction of Area | ≥ 25% |
4.4 Applications
- Aircraft landing gear structures
- Aerospace fasteners
- Lightweight racing car frames
- Missile and defense components
5. Comparison with α and α+β Titanium Alloys
| Aspect | α Titanium Alloys | α+β Titanium Alloys | β Titanium Alloys (TB5/TB6) |
|---|---|---|---|
| Structure | HCP (α-phase) | HCP + BCC | BCC (β-phase) |
| Strength | Moderate | High | Very High |
| Ductility | Excellent | Good | Excellent |
| Heat Treatability | Non-heat treatable | Heat treatable | Highly heat treatable |
| Formability | Poor | Good | Excellent |
| Weldability | Good | Good | Excellent |
| Typical Alloys | TA1, TA2 | TC4 (Ti-6Al-4V) | TB5, TB6, Ti-15V-3Cr-3Sn-3Al, Ti-10V-2Fe-3Al |
6. Conclusion
Beta titanium alloys play a vital role in modern high-end manufacturing due to their excellent combination of strength, ductility, corrosion resistance, and processability.
TB5 titanium alloy and TB6 titanium alloy each excel in specific areas, meeting the stringent demands of aerospace, automotive, medical, and defense industries.
Shaanxi NiTiCu Metal Co., Ltd. provides high-quality TB5, TB6, and other β titanium alloys, offering customized specifications and precision processing services. We welcome inquiries and cooperation from clients worldwide.
