An analysis of modern creep lifing methodologies in the titanium alloy Ti6-4

Traditional creep lifing techniques based on power law equations have shown themselves to be extremely limited, particularly in the prediction of long term data based only on short term experiments. More recently, alternative approaches such as the Wilshire equations and hyperbolic tangent methods have been proposed which offer a new insight into the field, with the Wilshire equations in particular showing promise in predicting long term behaviour based on short term results. The aerospace industry however has different requirements to the power generation industry where the Wilshire equations have been thoroughly tested. The current work seeks to investigate the ability of these methods to extrapolate across temperatures and in the case of the Wilshire equations offer a capability to accurately describe the time to specific strains during creep deformation.