The analysis of cyclic properties of Ti-6Al-4V titanium alloy at room and liquid nitrogen temperature

This paper presents the analysis of Ti-6Al-4V titanium alloy test results. Fatigue tests were carried out at room temperature and at the temperature of liquid nitrogen using single sample method. The values of plastic strain, cyclic modulus, cyclic yield stress and fatigue fracture surface were analyzed. The results of the tests were compared to the results from the monotonic tensile test. The presented analysis allowed to determine the value of the total strain at which there is a significant change in the material properties of the tested alloy. Two intervals are distinguished on the basis of this value, which are characterized by the range of low strain and the range of high strain. Different material properties were used in these intervals for analytical description of the cyclic material properties. The analytical description was based on the modification of the Ramberg-Osgood model.