Development of New High Strength Alloy: Titanium 5Al-5V-5Mo-3Cr

The history of a new titanium forging alloy, Ti 5-5-5-3, developed by Boeing and VSMPO will be presented. The development  started with an initial evaluation of the existing Russian alloy VT22 and led to the evolution of VT22-1 which was later re-named to  Ti 5553.   The steps required from the initial concept to actual implementation into a commercial airplane will be discussed. The two heat treated conditions, STA-180 and BASCA-160 will be contrasted and some of the applications of Ti 5553 used on the Boeing 787 will be highlighted.