Metallurgical Investigation of Cracking in a Beta21S Titanium Alloy Exhaust Nozzle

An aircraft engine exhaust nozzle was investigated after cracking was found along an attachment flange. The investigation focused on the flange material, in particular the condition of the bolt holes, as well as the available attachment bolts. This paper presents the results of this investigation, as well as further root cause investigation into several possible causes that were identified.