Tensile and high cycle fatigue test of Al-3% Ti thin films

This paper presents the results of tensile and high cycle fatigue tests with stress ratio R = 0.1 for an Al-3% Ti thin film of 1 μm thickness in atmospheric air at room temperature. Specimens with three different widths (50, 100, and 150 μm) were fabricated to study the width effects of each sample. Test results show that tensile and fatigue properties for the Al-3% Ti thin film with different widths are very close, and, thus, width effects were found to be minimal. The elastic moduli ranged from 80 to 82 GPa, and the tensile strengths ranged from 369 to 379 MPa. Fatigue strength coefficients of the specimens with 50, 100, and 150 μm width were 193, 181, and 164 MPa, respectively. In addition, fatigue strength exponents of the specimens with 50, 100, and 150 μm width were -0.023, -0.020, and -0.013, respectively. When present test results are compared with typical properties of bulk aluminium, the Al-3% Ti thin film is found to have longer life at the same stress, but it is more sensitive to the stress level.