Titanium Ti-6Al-4V: The Workhorse of Aerospace Titanium

Ti-6Al-4V (Grade 5, UNS R56400, GB TC4) is the most used titanium alloy, making up about half of all titanium tonnage. Its alpha-beta microstructure delivers an outstanding strength-to-weight ratio (about 950 MPa / 4.43 g/cm3), corrosion resistance and service temperature to about 400 C. Boyer (1996) reviewed why titanium dominates airframe and engine applications despite its cost, and Luetjering (1998) showed how processing - forging, beta annealing, solution treat and age - controls the alpha lath size and therefore strength and fatigue.

Composition is tightly specified: 5.5-6.75 Al, 3.5-4.5 V, balance Ti, with strict Fe/O/N limits. Two microstructures are common: mill-annealed (moderate strength, good toughness) and solution-treated-and-aged STA (higher strength). Williams, Baggerly and Paton (2002) linked the deformation behaviour to this microstructure, explaining the alloy's good high-cycle-fatigue resistance.

For buyers, Ti-6Al-4V is the default for aerospace, medical implants (ASTM F136 ELI grade) and marine hardware. JLHSteel supplies Grade 2/5/23 plate, bar, forgings and fasteners with EN 10204 / ASTM B265 certificates and can source other titanium grades (Gr2, Gr7, Gr9, Gr23) on request.

References
1. Boyer, R.R. (1996). An overview on the use of titanium in the aerospace industry. Materials Science and Engineering A213(1-2): 103-114. https://doi.org/10.1016/0921-5093(96)00099-X
2. Luetjering, G. (1998). Influence of processing on microstructure and mechanical properties of alpha-beta titanium alloys. Materials Science and Engineering A243(1-2): 32-45. https://doi.org/10.1016/S0921-5093(97)00853-8
3. Williams, J.C., Baggerly, R.G., Paton, N.E. (2002). Deformation behavior of Ti-6Al-4V. Metallurgical and Materials Transactions A 33: 837-850. https://doi.org/10.1007/s11661-002-0145-1