Fatigue and Fracture Behavior of Titanium Extrusions

Extrusion is a near-net shaping process which reduces the buy-to-fly ratio, material consumption and also saves valuable spindle time during machining a finished part.  Titanium alloy plate is processed by hot rolling, and while increasing the buy-to-fly ratio, it is preferred by many machining centers due to its versatility, since part dimensions can be readily changed, and due to the ability to nest multiple different parts in a single plate. Mechanical properties of Ti-6Al-4V extrusions in various conditions are presented and compared against standard and ELI grade-Ti-6Al-4V plate material.  Second tier properties such as fracture toughness, fatigue and fatigue crack growth rate are compared, and show the excellent combinations of these properties that can be obtained in both product forms to meet customer specific application requirements.  The dependence of these properties on microstructure will also be discussed.