Thermo-Mechanical Processing of Large 6Al-4V ELI Titanium Sections From Ingot

Forging and subsequent heat treatment of alpha/beta Titanium Alloys play a critical role in producing the properties as required in Aerospace material specifications. The resulting microstructural effects as seen in as forged and heat treated microstructures will directly influence the mechanical strength and fracture properties of bulk product. Specifically, increasing fracture toughness of solution treated and annealed Ti 6Al-4V ELI is critical as the Aerospace industry increases the quantities of titanium used in airframes.  AMS-4931 6Al-4V ELI Titanium used for in marine and aerospace applications requiring fracture toughness capabilities.  Section sizes of 15.25” round and 12” X 18” requiring full mechanical properties, exceeding the 6” maximum of AMS-4931.  Billet stock to produce these sizes is not available from mills, so ingot stock and/or beta processed billet has to be used as starting stock. Through specialized thermo-mechanical processing fracture toughness properties exceeding 90 Ksi square root inch is achieved, while maintaining required tensile properties.  Careful control of chemistry is required to meet these properties.