| This alpha-beta alloy is the workhorse alloy of the titanium industry. The alloy is fully heat treatable in section sizes up to 15mm and is used up to approximately 400°C (750°F). Since it is the most commonly used alloy – over 70% of all alloy grades melted are a sub-grade of Ti6Al4V, its uses span many aerospace airframe and engine component uses and also major non-aerospace applications in the marine, offshore and power generation industries in particular. The addition of 0.05% palladium, (grade 24), 0.1% ruthenium (grade 29) and 0.05% palladium and 0.5% nickel (grade 25) significantly increase corrosion resistance in reducing acid, chloride and sour environments, raising the threshold temperature for attack to well over 200°C (392°F). Ti6Al4V ELI (Grade 23) The essential difference between Ti6Al4V ELI (grade 23) and Ti6Al4V (grade 5) is the reduction of oxygen content to 0.13% (maximum) in grade 23. This confers improved ductility and fracture toughness, with some reduction in strength. Grade 23 has been widely used in fracture critical airframe structures and for offshore tubulars. Mechanical properties for fracture critical applications can be enhanced through processing and heat treatment. Grade 29 also having lowered level of oxygen will deliver similar levels of mechanical properties to grade 23 according to processing. Composition Table 1. The composition of Ti6Al4V Grade 5. | | | C | <0.08% | | Fe | <0.25% | | N2 | <0.05% | | O2 | <0.2% | | Al | 5.5-6.76% | | V | 3.5-4.5% | | H2(sheet) | <0.015% | | H2(bar) | <0.0125% | | H2(billet) | <0.01% | | Ti | Balance | |