Titanium alloys have revolutionized numerous industries with their exceptional strength-to-weight ratio and outstanding corrosion resistance. Among the various titanium grades available, Grade 3 and Grade 4 titanium stand out as commercially pure titanium options that offer unique advantages for specific applications. This comprehensive guide will explore everything you need to know about Grade 3 and Grade 4 titanium, helping you make informed decisions for your projects.
Understanding Commercially Pure Titanium Grades
Commercially pure (CP) titanium is categorized into four grades (1-4), with each grade offering different mechanical properties and corrosion resistance levels. While Grade 1 and Grade 2 titanium are more commonly used due to their excellent formability and moderate strength, Grade 3 and Grade 4 titanium provide enhanced strength characteristics that make them ideal for more demanding applications.
Chemical Composition of Grade 3 and Grade 4 Titanium
The primary difference between these grades lies in their chemical composition, particularly the oxygen content, which directly influences their mechanical properties:
Grade 3 Titanium (Ti Grade 3 / UNS R50550):
- Titanium (Ti): Balance (minimum 99.0%)
- Oxygen (O): 0.30% maximum
- Nitrogen (N): 0.05% maximum
- Carbon ©: 0.08% maximum
- Hydrogen (H): 0.015% maximum
- Iron (Fe): 0.30% maximum
- Residual elements: Each 0.10% maximum, total 0.40% maximum
Grade 4 Titanium (Ti Grade 4 / UNS R50700):
- Titanium (Ti): Balance (minimum 99.0%)
- Oxygen (O): 0.40% maximum
- Nitrogen (N): 0.05% maximum
- Carbon ©: 0.08% maximum
- Hydrogen (H): 0.015% maximum
- Iron (Fe): 0.50% maximum
- Residual elements: Each 0.10% maximum, total 0.40% maximum
The higher oxygen content in Grade 4 titanium contributes to its increased strength compared to Grade 3, while both maintain excellent corrosion resistance due to their high titanium purity.
Mechanical Properties Comparison
The chemical composition differences translate to distinct mechanical properties:
Grade 3 Titanium:
- Minimum Tensile Strength: 75,000 psi (517 MPa)
- Minimum Yield Strength: 65,000 psi (448 MPa)
- Minimum Elongation: 18%
Grade 4 Titanium:
- Minimum Tensile Strength: 90,000 psi (620 MPa)
- Minimum Yield Strength: 80,000 psi (551 MPa)
- Minimum Elongation: 15%
Grade 4 titanium offers approximately 20% higher tensile and yield strength compared to Grade 3, making it the strongest of the commercially pure titanium grades. However, this increased strength comes with slightly reduced ductility, as evidenced by the lower elongation percentage.
Applications of Grade 3 Titanium
Grade 3 titanium strikes a balance between strength and formability, making it suitable for:
- Aerospace components requiring moderate strength
- Chemical processing equipment
- Heat exchangers
- Marine hardware
- Medical implants and devices
- Architecture and building components
- Automotive parts
Its excellent corrosion resistance combined with moderate strength makes Grade 3 titanium an excellent choice for applications where Grade 2 titanium may lack sufficient strength, but the higher strength of Grade 4 is not necessary.
Applications of Grade 4 Titanium
As the strongest commercially pure titanium grade, Grade 4 is preferred for applications demanding maximum strength and excellent corrosion resistance:
- Aerospace structural components
- High-performance marine applications
- Chemical processing vessels and piping
- Cryogenic vessels
- Medical implants requiring high strength
- Industrial equipment exposed to corrosive environments
- Sports equipment
- Oil and gas industry components
Grade 4 titanium’s superior strength makes it particularly valuable in applications where weight savings are critical, such as aerospace and high-performance automotive applications.
Conclusion
Grade 3 and Grade 4 titanium represent the higher end of commercially pure titanium grades, offering an excellent balance of strength, corrosion resistance, and formability. While Grade 4 provides the highest strength among CP titanium grades, Grade 3 offers better formability and may be more suitable for certain applications.
At Daxun Alloy, we provide premium Grade 3 and Grade 4 titanium products that meet the most stringent industry standards. Our team of experts is ready to help you select the optimal titanium grade for your application, ensuring superior performance and value.
For more information about our titanium products or to discuss your specific requirements, contact our knowledgeable team today. Let Daxun Alloy be your trusted partner for high-quality titanium solutions.
