Ti-6Al-4V (Grade 5) — Complete Material Properties
Comprehensive material properties data for Ti-6Al-4V (Grade 5) titanium alloy. Mechanical, thermal, physical properties with industry standard references for CNC machining.
| Property | Value | Unit | Notes |
|---|---|---|---|
| Density | 4.43 | g/cm³ | ~60% of steel density |
| Tensile Strength (Ultimate) | 950 | MPa | Minimum per ASTM B348 |
| Tensile Strength (Yield, 0.2% offset) | 880 | MPa | Minimum per ASTM B348 |
| Elongation at Break | 14 | % | In 4D, minimum |
| Hardness | 36 | HRC | Typical, annealed condition |
| Modulus of Elasticity | 114 | GPa | ~54% of steel |
| Thermal Conductivity | 6.7 | W/m·K | Low — causes heat accumulation during machining |
| Specific Heat Capacity | 560 | J/kg·K | At 20°C |
| Electrical Resistivity | 1.7 | µΩ·m | At 20°C |
| Melting Point | 1660 | °C | Solidus temperature |
| Maximum Service Temperature | 400 | °C | Long-term structural use |
| Thermal Expansion Coefficient | 9.0 | µm/m·K | 20-100°C range |
Quick Answer
Ti-6Al-4V (Grade 5) has a density of 4.43 g/cm³, ultimate tensile strength of 950 MPa (minimum), yield strength of 880 MPa, and modulus of 114 GPa. Its low thermal conductivity (6.7 W/m·K) is the primary factor affecting machinability.
Material Properties Table
| Property | Value | Unit | Notes |
|---|---|---|---|
| Density | 4.43 | g/cm³ | ~60% of steel |
| Ultimate Tensile Strength | 950 | MPa | Min per ASTM B348 |
| Yield Strength (0.2%) | 880 | MPa | Min per ASTM B348 |
| Elongation | 14 | % | Min in 4D |
| Hardness | 36 | HRC | Annealed, typical |
| Modulus of Elasticity | 114 | GPa | ~54% of steel |
| Thermal Conductivity | 6.7 | W/m·K | Accumulates heat in cutting zone |
| Specific Heat | 560 | J/kg·K | At 20°C |
| Electrical Resistivity | 1.7 | µΩ·m | At 20°C |
| Melting Point | 1660 | °C | Solidus |
| Max Service Temp | 400 | °C | Long-term structural |
| CTE | 9.0 | µm/m·K | 20-100°C |
Benchmark Comparison
| Property | Ti-6Al-4V | Al 6061-T6 | AISI 4140 Steel |
|---|---|---|---|
| Density (g/cm³) | 4.43 | 2.70 | 7.85 |
| Strength-to-Weight Ratio | High | Moderate | Moderate |
| Thermal Conductivity (W/m·K) | 6.7 | 167 | 42.6 |
| Max Service Temp (°C) | 400 | 180 | 540 |
| Corrosion Resistance | Excellent | Good | Poor (needs coating) |
Engineering Notes
- Heat Management: Use high-pressure coolant (70-100 bar) to manage heat in the cutting zone
- Tool Material: Carbide tools with AlTiN or TiAlN coatings are recommended
- Work Hardening: Ti-6Al-4V work-hardens rapidly — maintain consistent feed rates
- Springback: The low modulus (114 GPa) causes more springback than steel — account for this in fixture and tool design
Relevant Standards
- ASTM B265 — Sheet, strip, and plate
- ASTM B348 — Bars and billets
- ASTM F136 — Medical implant grade (ELI)
- AMS 4928 — Bar, rod, and forging stock
- ISO 5832-3 — Implants for surgery
FAQ
What is the fatigue strength of Ti-6Al-4V? Approximately 500-600 MPa at 10⁷ cycles (smooth, unnotched specimens).
Does Ti-6Al-4V require special handling for medical implants? Yes. For medical implants, specify Grade 23 (Ti-6Al-4V ELI) per ASTM F136, which has tighter interstitial element controls for improved fracture toughness.
Engineering Interpretation
The numerical values above are authoritative material data from ASTM B265/B348 and ASM Handbook Volume 2. Engineering interpretation (titanium.blog): the combination of low thermal conductivity (6.7 W/m-K) and a high strength-to-weight ratio makes Ti-6Al-4V the default aerospace and medical alloy, but the same low conductivity concentrates heat in the cutting zone, so rigid setups, sharp carbide tooling and high-pressure coolant are the practical levers for productive machining.
Evidence Basis
Based on published material-property data from ASTM B265 / ASTM B348 and ASM Materials Handbook Volume 2.