Abstract
This paper describes the low cycle fatigue behavior and mean stress effect of Ti-6Al-4V alloy that is commonly used in aerospace and other industries due to their excellent specific strength, heat resistance, etc. Strain controlled fatigue tests for 10^3〜10^4 cycles, low cycle fatigue region, and load controlled tests for longer than 10^4 cycles have been carried out. Cyclic stress-strain response based on hysteresis loop peaks at 10 cycles and half life indicated cyclic softening. Minimum stress relaxation was affected by compressive yield stress. Comparing the S-N data obtained strain controlled fatigue tests and load controlled tests, the effect on mean stress was investigated. This mean stress effect can be estimated by using Walker stress.
