Effects of Severe Plastic Deformation on Grain Refinements and Fatigue Performance of the Metastable Beta-Titanium Alloy TIMETAL LCB

摘要

The effect of severe plastic deformation by rotary swaging on microstructure and resulting tensile properties as well as fatigue performance of TIMETAL LCB will be presented. Swaging to various degrees of deformation was performed at an elevated temperature of T=660°C. Part of the swaged material was annealed at T=760°C to result in a fully recrystallized microstructure with about 20% primary alpha particles. This material was tested with or without an additional final heat treatment at 540°Cfor 8 hours. Compared to the asreceived condition,swaging alone already resulted in marked increases in yield stress and tensile ductility. Aging of the recrystallization annealed material resulted in increases in Young's modulus,yield stress and tensile strength while tensile ductility showed a significant drop. Best fatigue performance in combination with a low Young's modulus was observed in the swaged conditions without any further heat treatments.