Ti-6Al-4V (Grade 5): The Workhorse Titanium Alloy vs Aluminum 7075-T6: Aerospace-Strength Al-Zn-Mg-Cu Alloy — Aircraft Structures & High-Stress Parts
Side-by-side engineering comparison of Ti-6Al-4V (Grade 5): The Workhorse Titanium Alloy (ASTM B265/B348 / AMS 4911) and Aluminum 7075-T6: Aerospace-Strength Al-Zn-Mg-Cu Alloy — Aircraft Structures & High-Stress Parts (ASTM B209 / AMS 4045 / AMS-QQ-A-250/12). Compare mechanical properties, chemical composition, density, yield strength, international equivalents, and typical applications to select the right material for your project.
Quick Verdict
Choose Ti-6Al-4V when the application demands high strength at elevated temperature (up to 350°C), corrosion immunity, or biocompatibility — aerospace engines, medical implants, and marine components. Choose 7075-T6 when maximum strength at minimum weight is needed at ambient temperature and cost is a primary concern — aircraft structures, sporting goods, and military equipment.
Maximum strength at elevated temperature (up to 350°c)
Lower cost and weight for ambient-temperature applications
Quick Comparison
| Property | Ti-6Al-4V (Grade 5): The | Aluminum 7075-T6: Aerospa |
|---|---|---|
| Standard | ASTM B265/B348 / AMS 4911 | ASTM B209 / AMS 4045 / AMS-QQ-A-250/12 |
| Category | Titanium Alloy | Aluminum Alloy |
| Density | 4.43 g/cm³ | 2.81 g/cm³ |
| Yield Strength | 880 MPa (128 ksi) annealed | 503 MPa (73 ksi) typical for plate ≤25 mm |
| Tensile Strength | 950 MPa (138 ksi) annealed | 572 MPa (83 ksi) typical for plate ≤25 mm |
| Key Applications | <a href="https://ykwiki.com/materials/ti-6al-4v/">Ti-6Al-4V</a> (Grade 5) accounts for over 50% of global titanium usage... | 7075-T6 is the highest-strength conventional aluminum alloy, with a specific strength (strength-to-weight ratio) compara... |
International Equivalents
| Ti-6Al-4V (Grade 5): Equivalents | Aluminum 7075-T6: Ae Equivalents |
|---|---|
| EN 3.7165 | EN AW-7075 |
| BT6 | DIN AlZnMgCu1.5 |
| JIS TAP6400 | JIS A7075P |
| TC4 | GB 7A04 |
| ISO Ti-6Al-4V | Duralumin 7075 |
How to Choose
| Choose Ti-6Al-4V (Grade 5): The when... | Ti-6Al-4V delivers 880 MPa at 4.43 g/cm³ with 350°C service capability—standard for aerospace engines and biomedical implants. |
| Choose Aluminum 7075-T6: Aerospa when... | 7075-T6 provides 503 MPa at 2.81 g/cm³ for ambient-temp aerospace structures. |
Decision Checklist: Which Is Right for You?
| Criterion | Ti-6Al-4V (Grade 5): | Aluminum 7075-T6: Ae |
|---|---|---|
| Maximum Strength At Elevated Temperature (Up To 350°C) | ✓ | |
| Lower Cost And Weight For Ambient-Temperature Applications | ✓ | |
| Higher yield strength | ✓ | |
| Lower density / lighter | ✓ | |
| Temperature — Ti-6Al-4V serves to 350°C; 7075-T6 loses strength above ... | ✓ | |
| Cost — Ti-6Al-4V costs 10-20× more than 7075-T6 per kg, and titanium f... | ✓ | |
| Corrosion — Ti-6Al-4V is virtually immune to corrosion in most environ... | ✓ |
Selection Guide
Choose Ti-6Al-4V when the application demands high strength at elevated temperature (up to 350°C), corrosion immunity, or biocompatibility — aerospace engines, medical implants, and marine components. Choose 7075-T6 when maximum strength at minimum weight is needed at ambient temperature and cost is a primary concern — aircraft structures, sporting goods, and military equipment.
Key Decision Factors
- Temperature — Ti-6Al-4V serves to 350°C; 7075-T6 loses strength above 150°C and is limited to ~80°C continuous service
- Cost — Ti-6Al-4V costs 10-20× more than 7075-T6 per kg, and titanium fabrication (machining, welding) costs 3-5× more
- Corrosion — Ti-6Al-4V is virtually immune to corrosion in most environments; 7075-T6 requires protective coating
- Density — 7075 is 37% lighter than Ti-6Al-4V (2.81 vs 4.43 g/cm³), but Ti-6Al-4V provides higher specific strength at temperature
When to Use Each
Use Ti-6Al-4V (Grade 5): for:
Ti-6Al-4V's biocompatibility, osseointegration capability, and corrosion immunity in body fluids make it the standard for orthopedic and dental implants per ASTM F136.
Ti-6Al-4V retains strength at 300-350°C where aluminum alloys lose all useful properties. Used for compressor blades, discs, and casings in jet engines.
Titanium's self-healing TiO₂ passive film provides immunity to seawater corrosion, chloride pitting, and most chemical environments — no stainless steel can match it.
Use Aluminum 7075-T6: Ae for:
7075-T6 provides 503 MPa yield at 2.81 g/cm³ — nearly the same specific strength as Ti-6Al-4V at 4.43 g/cm³, at 10-20× lower cost for ambient-temperature structures.
7075-T6's combination of high strength, light weight, and moderate cost makes it the performance benchmark for aluminum bicycle frames and components.
7075-T6 is standard for AR-15 upper and lower receivers where high strength, light weight, and cost-effectiveness are required at ambient temperature.
Frequently Asked Questions
What is the main difference between Ti-6Al-4V (Grade 5): The Workh and Aluminum 7075-T6: Aerospace-St?
Ti-6Al-4V (Grade 5): The Workhorse Titanium Alloy (ASTM B265/B348 / AMS 4911) provides 880 MPa (128 ksi) annealed yield strength at 4.43 g/cm³ density, while Aluminum 7075-T6: Aerospace-Strength Al-Zn-Mg-Cu Alloy — Aircraft Structures & High-Stress Parts (ASTM B209 / AMS 4045 / AMS-QQ-A-250/12) delivers 503 MPa (73 ksi) typical for plate ≤25 mm at 2.81 g/cm³. The choice depends on whether your application prioritizes maximum strength at elevated temperature (up to 350°C) or lower cost and weight for ambient-temperature applications.
Can Ti-6Al-4V (Grade 5): The Workh be substituted for Aluminum 7075-T6: Aerospace-St?
Direct substitution is generally not recommended as these materials belong to different categories (Titanium Alloy vs Aluminum Alloy) with fundamentally different properties. Consult a materials engineer for application-specific guidance.
Is titanium stronger than aluminum?
By absolute strength, yes — Ti-6Al-4V has 880 MPa yield vs 503 MPa for 7075-T6. By specific strength (strength-to-weight), they are closer: Ti-6Al-4V is 880/4.43 = 199 MPa/(g/cm³); 7075-T6 is 503/2.81 = 179 MPa/(g/cm³). At ambient temperature, the difference is only 11%. At elevated temperature, titanium's advantage grows dramatically as aluminum loses strength.
Why is titanium so expensive?
The Kroll process for titanium extraction is energy-intensive and batch-based — it requires magnesium reduction of TiCl₄ at 800°C under argon atmosphere. Additionally, titanium's reactivity with oxygen and nitrogen requires vacuum or inert-atmosphere melting (VAR or EBM), and its poor machinability (low thermal conductivity, work hardening) increases fabrication costs 3-5× over aluminum.
Can Ti-6Al-4V be welded?
Yes, but only with proper shielding. Titanium reacts with oxygen and nitrogen at welding temperatures, causing embrittlement. TIG welding requires argon shielding on both front and back of the joint, with trailing shields for cooling metal. Electron beam welding (in vacuum) produces the highest quality titanium welds. Never weld titanium without inert gas protection.
Is Ti-6Al-4V magnetic?
No. Ti-6Al-4V is paramagnetic — essentially non-magnetic. This makes it suitable for MRI-compatible medical devices and sensitive instrumentation where magnetic interference must be avoided. Both Ti-6Al-4V and 7075-T6 are non-magnetic, but 7075-T6 is not biocompatible.
Why is Ti-6Al-4V called 'Grade 5' titanium?
The ASTM grading system for titanium assigns Grade 1-4 to commercially pure titanium (increasing strength) and Grade 5 to Ti-6Al-4V (the most common alloyed grade). Grade 5 accounts for approximately 50% of all titanium usage worldwide. It is called Ti-6Al-4V because it contains 6% aluminum and 4% vanadium as alloying elements.