Creep Behavior of High Temperature Titanium Alloys at Low Stress-High Temperature Regime

摘要

The application of titanium alloys at elevated temperature ranges from compressor disks/blades in aircraft jet engines to automotive exhaust systems. Near alpha titanium alloys such as Ti-6242S and TIMET AL834 (Ti-834) are the most notable titanium alloys for jet engine parts, where creep property at higher stress levels is one of the critical properties. One of disadvantages of near alpha titanium alloys is their poor formability that limits the applications where extensive cold forming and fabrication are required. Besides jet engines applications,there are certain applications that do not require higher stress but higher service temperatures are required. Notable applications include heat shields of aircrafts,sheets for thermal protection systems or jet engine exhaust and exhaust pipes/mufflers of automobiles. In this paper creep properties of two titanium alloys Ti-6242S and TIMET AL21S (Ti-21S),at elevated temperatures beyond 538°C were studied. Factors that control creep at low stress-high temperature regime are discussed.