Effect of Vibrations on Lifetime of Ni Base Single Crystals Subjected to Tensile Stress
The lifetime of superalloy single crystals CMSX-4 and CM186LC subjected to tensile mean stress with vibrations at high temperatures has been experimentally studied. Both beneficial and detrimental effect of cyclic stress component has been observed. An increase of lifetime due to superposition of cyclic component on the mean stress is explained by reduction of creep rate due to vibrations. The onset of decrease of lifetime with increasing stress amplitude is observed when the fatigue damage due to initiation and propagation of fatigue crack overbalances the beneficial influence of high frequency cycling.
L. Kunz et al., "Effect of Vibrations on Lifetime of Ni Base Single Crystals Subjected to Tensile Stress", Materials Science Forum, Vols. 567-568, pp. 293-296, 2008