Titanium and Titanium Alloys: Strength – to – Weight Ratio & ASTM Grades
Core Advantage
Titanium and its alloys boast a high strength – to – weight ratio — superior to other metals. Unalloyed titanium matches some steels in strength but weighs nearly half as much, making it ideal for weight – sensitive applications (aerospace, automotive, etc.).
ASTM Grade Specifications
The table below outlines key mechanical properties (UTS, YS, Young’s Modulus) and alloy details for titanium grades, aligned with industry standards:
| ASTM Grade | Alloy Composition | Min. UTS (MPa) | Min. YS (MPa) | Young’s Modulus (GPa) | UNS No. | Sour Service Approved* |
| 1 | Unalloyed Ti | 240 | 170 | 103 | R50250 | – |
| 2 | Unalloyed Ti | 345 | 275 | 103 | R50400 | Yes |
| 3 | Unalloyed Ti | 450 | 380 | 103 | R50550 | – |
| 4 | Unalloyed Ti | 550 | 480 | 105 | R50700 | – |
| 5 | Ti – 6Al – 4V | 895 | 825 | 114 | R56400 | – |
| 6 | Ti – 5Al – 2.5Sn | 825 | 795 | 110 | R54250 | – |
| 7 | Ti – 0.15Pd | 345 | 275 | 103 | R52400 | – |
| 9 | Ti – 3Al – 2.5V | 620 | 485 | 107 | R56320 | – |
| 10 | Ti – 11.5Mo – 6Zr – 4.5Sn | 690 | 620 | 103 | R58030 | – |
| 11 | Ti – 0.15Pd | 240 | 170 | 103 | R52250 | – |
| 12 | Ti – 0.3Mo – 0.8Ni | 485 | 345 | 103 | R53400 | Yes |
| 13 | Ti – 0.5Ni – 0.05Ru | 280 | 170 | 103 | R53413 | – |
| 14 | Ti – 0.5Ni – 0.05Ru | 410 | 280 | 103 | R53414 | – |
| 15 | Ti – 0.5Ni – 0.05Ru | 480 | 380 | 103 | R53415 | – |
| 16 | Ti – 0.05Pd | 345 | 275 | 103 | R52402 | – |
| 17 | Ti – 0.05Pd | 240 | 170 | 103 | R52252 | – |
| 18 | Ti – 3Al – 2.5V – 0.05Pd | 620 | 480 | 105 | R56322 | – |
| 19 | Ti – 3Al – 8V – 6Cr – 4Zr – 4Mo (Beta C) | 795 | 760 | 93 – 96 | R58640 | Yes |
| aged | 1170 | 1105 | 102 | – | – | |
| 20 | Ti – 3Al – 8V – 6Cr – 4Zr – 4Mo – 0.05Pd | 795 | 760 | 93 – 96 | R58645 | – |
| aged | 1530 | 1879 | 165 | – | – | |
| 21 | Ti – 15Mo – 2.7Nb – 3Al – 0.25Si (TIMETAL 21S) | 790 | 760 | 103 | R58210 | – |
| aged | 1170 | 1100 | 103 | – | – | |
| 23 | Ti – 6Al – 4V ELI | 825 | 760 | 114 | R56407 | – |
| 24 | Ti – 6Al – 4V – 0.05Pd | 900 | 830 | 113 | R56405 | – |
| 25 | Ti – 6Al – 4V – 0.5Ni – 0.05Pd | 900 | 830 | 113 | R56403 | Yes |
| 26 | Ti – 0.1Ru (Grade 2 interstitials) | 345 | 275 | 103 | R52404 | – |
| 27 | Ti – 0.1Ru (Grade 1 interstitials) | 240 | 170 | 103 | R52254 | – |
| 28 | Ti – 3Al – 2.5V – 0.1Ru | 620 | 485 | 107 | R56323 | Yes |
| 29 | Ti – 6Al – 4V – 0.1Ru | 825 | 760 | 114 | R56404 | Yes |
Key Applications by Grade
- Grade 2 (Unalloyed Ti): Sour service – approved; used in oil/gas pipelines, chemical processing (corrosion resistance).
- Grade 5 (Ti – 6Al – 4V): High strength – to – weight; aerospace (aircraft frames, engine parts), medical implants.
- Grade 12 (Ti – 0.3Mo – 0.8Ni): Sour service – approved; offshore oil/gas equipment (resists H₂S corrosion).
Material Properties Overview
- Strength: Ranges from 240 MPa (Grade 1) to 1530 MPa (aged Grade 20), suiting low – to – high – stress environments.
- Corrosion Resistance: Alloys with Pd/Ru (e.g., Grade 7, 25) excel in harsh chemical environments.
- Weight Advantage: Density ~4.5 g/cm³ (vs. steel ~7.8 g/cm³), critical for lightweight designs.